The objectives of this study were to determine the frequency with which deeper levels reveal a lesion in polyp biopsies where no polyp was found on initial sections and to identify features that predict such occult (histologically unapparent) lesions. All initially negative biopsy specimens were accumulated over an 18-month period. Following standard sections, three to ten levels were cut, 50 μm apart. The presence of any lesion, the level at which it was found, the location, number and size of fragments, number of levels obtained, presence of any lymphoid aggregate, endoscopic size and appearance, and bowel preparation quality were recorded. There were 214 specimens, mean patient age 61.4 years (range 27-86 years). Deeper levels revealed a lesion in 52/214 (24.3 %) cases; 76.9 % were tubular adenomas (TA), 21.2 % were hyperplastic polyps, and one was a leiomyoma. All TAs were negative for high-grade dysplasia and malignancy. The mean level at which TAs were found was 1.85 (range 1-9). Male sex (p = 0.021) and right-sided location (p = 0.0075) were statistically significant predictors of an occult TA. As the presence of an adenoma affects screening, pathologists should consider "pursuing" polyps when initial sections reveal no lesion, after ascertaining the incidence of occult lesions in their own practice.

Serrated lesions are an important contributor to colorectal cancer (CRC), notably in the proximal colon. Findings in the distal colorectum are markers of advanced proximal adenomatous neoplasia. However, it is not known whether they affect the odds of advanced proximal serrated lesions.

We performed a retrospective cross-sectional study of data from 1910 patients (59.3 ± 8.0 years, 53.8% female) who underwent an average-risk screening colonoscopy from August 2005 through April 2012 at Indiana University Hospital and an associated ambulatory surgery center. Colonoscopies were performed by an endoscopist with high rates of detection of adenomas and serrated polyps. Tissue samples of all serrated polyps (hyperplastic, sessile serrated adenoma/polyp [SSA/P], or traditional serrated adenoma) proximal to the sigmoid colon and serrated polyps >5 mm in the rectum or sigmoid colon were reviewed by a gastrointestinal pathologist and reclassified on the basis of World Health Organization criteria. Advanced serrated lesion (ASL) was defined as SSA/P with cytologic dysplasia, SSA/P ≥10 mm, or traditional serrated adenoma. Advanced conventional adenomatous neoplasia (ACN) was defined as tubular adenoma ≥10 mm, villous histology, high-grade dysplasia, or cancer. The prevalence of proximal ASL and ACN was calculated on the basis of distal colorectal findings. Multivariable logistic regression analysis was performed to determine the age-adjusted and sex-adjusted odds of advanced proximal adenomatous and serrated lesions. Secondary analyses were performed to examine the effect of variable ASL definitions.

Fifty-two patients (2.7%) had proximal ASL, and 99 (5.2%) had proximal ACN. Of the 52 patients with proximal ASL, 27 (52%) had no distal polyps. Of the 99 patients with proximal ACN, 40 (40%) had no distal polyps. Age and type of distal adenomas were significantly associated with proximal ACN. There were no significant associations between distal polyp type and proximal ASL. In secondary analyses, distal SSA/Ps (P = .008) but not distal hyperplastic polyps or conventional adenomas were associated with any proximal SSA/P.

The findings at flexible sigmoidoscopy that traditionally serve as indications for colonoscopy (conventional adenomas) are likely to be ineffective for detection of proximal ASL. This finding, plus the observation that most patients with proximal ASL have no distal polyps, favors screening colonoscopy over sigmoidoscopy, especially in the elderly. The observation that non-advanced distal SSA/Ps are associated with any proximal SSA/P warrants further study.

Flexible sigmoidoscopy (FS) and colonoscopy are two commonly used screening tools for colorectal cancer (CRC), and FS mainly detects distal lesions. Colonoscopy resource is limited, yet there is no definite evidence on when flexible sigmoidoscopy is suitable as a screening alternative. This study evaluated the optimal cut-off score from a validated risk stratification system which best predicts proximal advanced neoplasia (PAN) by comparing the sensitivity, specificity and relative risk of PAN according to various cut-off scores. 5819 asymptomatic subjects aged between 50 and 70years (average age 57.7years, standard deviation (SD) 4.9) received colonoscopy between 2008 and 2014 in Hong Kong. Their prevalence of PAN was evaluated according to a prediction tool for colorectal neoplasia based on age, gender, smoking status, family history of CRC, body mass index (BMI) and diabetes (ranging from 0 to 6). One binary logistic regression model was performed with PAN as the outcome variable and the risk score as the variable tested for association. In multivariate regression analysis, risk score ⩾3 was associated with significantly higher risk of PAN (3.4-9.1%; AOR=3.18-8.09, p<0.001) when compared with those scoring 0. Risk scores 0-2 were associated with either insignificant or lower risks of PAN compared to the overall risk. Applying FS for screening those who scored 0-2 and colonoscopy for those who scored ⩾3 led to a very small proportion of PAN being missed (1.60%), whilst maintaining a high level of specificity (81.9%). Clinicians may use this scoring system to inform subjects and facilitate their choice between colonoscopy and FS.

The aim of the study was to evaluate the impact of sex, age, family history and distal findings on the risk of proximal advanced neoplasia (cancer or advanced adenoma) in the large bowel.

Records for 10 111 asymptomatic participants of the Colonoscopy Screening Program (CSP), recruited from the Warsaw region between 2000 and 2004, were analyzed. A multivariate logistic regression model was used to estimate the impact of sex, age, family history and most advanced distal lesions on the occurrence of proximal advanced neoplasia. To enhance comparability of the study two definitions of the proximal colon were applied - either the splenic flexure (1(st)) or the bend between the descending and sigmoid colon (2(nd) definition) represented the boundary.

One hundred and thirty-three (1(st)) and 167 patients (2(nd) definition) were found to have at least one advanced neoplastic lesion in the proximal part, respectively. Eleven and 14 patients were found to have carcinoma, while in 130 and 163 patients at least one proximal advanced adenoma appeared. Men were at twice as high risk of having advanced neoplasia in the proximal colon than women (OR = 1.94, 95% CI: 1.31-2.87, p = 0.001 or OR = 1.69, 95% CI: 1.20-2.40, p = 0.003, respectively). The presence of distal advanced neoplastic lesions was associated with 3.5 times higher risk of proximal advanced neoplasia (OR = 3.58, 95% CI: 2.00-6.43, p < 0.0001 or OR = 3.41, 95% CI: 1.95-5.96, p < 0.0001), respectively.

The results may confirm some limitation of flexible sigmoidoscopy in the screening settings in comparison with colonoscopy, at least in men and people with distal advanced neoplasia.

Quantifying the risk of advanced proximal colorectal neoplasia might allow tailoring of colorectal cancer screening, with colonoscopy for those at high risk and less invasive screening for very low-risk persons.

We analyzed findings from 10,124 consecutive adults aged≥50 years who underwent screening colonoscopy to the cecum. We quantified the risk of advanced neoplasia (tubular adenoma≥1 cm, a polyp with villous histology or high-grade dysplasia, or adenocarcinoma) both proximally (cecum to splenic flexure) and distally (descending colon to anus). The prevalence of advanced proximal neoplasia was quantified by age, gender, and distal findings.

The mean (standard deviation) age was 57.5 (6.0) years; 44% were women; 7835 (77%) had no neoplasia, and 1856 (18%) had 1 or more nonadvanced adenomas. Overall, 433 subjects (4.3%) had advanced neoplasia (267 distally, 196 proximally, 30 both), 33 (0.33%) of which were adenocarcinoma (18 distal, 15 proximal). The risk of advanced proximal neoplasia increased with age decade (1.13%, 2.00%, and 5.26%, respectively; P=.001) and was higher in men (relative risk [RR], 1.91; confidence interval [CI], 1.32-2.77). In women aged less than 70 years, the risk was 1.1% overall (vs 2.2% in men; RR, 1.98; CI, 1.42-2.76) and 0.86% in those with no distal neoplasia (vs 1.54% in men; RR, 1.81; CI, 1.20-2.74).

Risk of advanced proximal neoplasia is a function of age and gender. Women aged less than 60 to 70 years have a very low risk, particularly those with no distal adenoma. Sigmoidoscopy with or without occult blood testing may be sufficient and even preferable for screening these subgroups.

Previous studies examining the effect of fellow participation on adenoma detection rate in colonoscopy have yielded conflicting results, and factors such as adenoma size and location have not been rigorously evaluated.

To examine whether fellow participation during screening, surveillance, or diagnostic colonoscopy affects overall, size-specific, or location-specific adenoma or polyp detection rate.

This was a retrospective study of 2430 colonoscopies performed in our ambulatory surgical center between September 2006 and December 2007, comparing adenoma and polyp detection rates of colonoscopies performed by fellows with supervising staff endoscopists (n = 318) with colonoscopies performed by staff endoscopists without fellow participation (n = 2112). Study participants included patients who underwent screening, surveillance, or diagnostic colonoscopies in our GI suite. Logistic regression analysis was used to evaluate the association of fellow participation with adenoma and polyp detection.

There was evidence of a higher rate of small (<5 mm) adenoma detection in colonoscopies with a fellow present (25% vs 17%, P = .001). This remained significant after multiple-testing adjustment (P ≤ .003 considered significant). Findings were similar, although not significant for small polyps (36% vs 29%, P = .007). There was a trend toward increased adenoma detection in colonoscopies with a fellow present compared with those without (30% vs 26%, P = .11). Multivariable adjustment for potentially confounding variables did not alter these associations.

The study had a retrospective design, and information regarding bowel preparation was not available for 37% of patients.

Fellow involvement was associated with increased detection rates of small adenomas, providing evidence that the presence of a fellow during colonoscopy plays a role in enhancing the effectiveness of the examination.

Adenoma detection rates might be improved through use of high-definition colonoscopy, which can detect subtle mucosal changes. We investigated whether the use of high-definition white-light (HDWL) colonoscopy resulted in a higher rate of adenoma detection than standard-definition white-light (SDWL) colonoscopy in a clinical practice setting.

This retrospective study included 2430 patients who underwent colonoscopies from September 2006 to December 2007; 1226 received SDWL colonoscopy and 1204 received HDWL colonoscopy. We analyzed data from consecutive screening, surveillance, and diagnostic colonoscopies, comparing adenoma and overall polyp detection between procedures. Potentially confounding variables were controlled using multivariable logistic regression analysis.

The adenoma detection rate was higher among patients who underwent HDWL compared with SDWL colonoscopies (28.8% vs 24.3%; P = .012), as was the polyp detection rate (42.2% vs 37.8%; P = .026). These findings remained after adjustments for potentially confounding variables (P = .018 and .022, respectively).

In a general clinical practice setting, HDWL colonoscopy resulted in a higher adenoma detection rate compared with SDWL colonoscopy. The use of SDWL colonoscopy could reduce the number of missed adenomas and the subsequent risk for colorectal cancer.

Colorectal cancer is the second leading cause of cancer-related death. Prevention of colorectal cancer should be achievable by screening programs in asymptomatic patients.

To assess the colonoscopic findings in asymptomatic people submitted to screening.

A prospective study was undertaken on 153 consecutive asymptomatic people submitted to colonoscopy. Sex, age, previous diseases and familial cases of cancer, as well as tobacco and alcohol ingestion were assessed. Patients with rectal macro- or microscopic bleeding and colorectal diseases were excluded. Bowel preparation, polyps, angioectasias, diverticular disease, inflammation and neoplasm were also verified. Polyps were classified according to their size, number and location.

Mean age was 52.5 +/- 11.7 years. Family history for colorectal cancer occurred in 79.8% of individuals. Colonoscopic alterations were detected in 99 individuals: polyps in 64.3%, diverticular disease in 27.9%, inflammatory mucosal alterations in 9.7%, melanosi coli in 2.6% and angioectasias in 7.8%. There were an increasing incidence of polyps in patients older than 50 year. Multivariate logistic regression showed age and sex as predictive factors for polyps (OR = 1.43; 1.19 <OR <2.67).

There is a significant incidence of colonoscopic alterations in asymptomatic people submitted to colonoscopy for colorectal cancer screening.

The capacity for colonoscopy is limited and a method to prioritize patients for diagnostic colonoscopy is needed in health care centers. A retrospective cross-sectional cohort study was carried out in county and community endoscopy centers, which included 1,065 county and 279 community patients aged > or = 40 years undergoing diagnostic colonoscopy. We constructed a risk profile for proximal advanced neoplasms on diagnostic colonoscopy at the county center based on the size of the regression coefficients for independent risk factors from logistic regression. An advanced neoplasm was defined as one of size > or = 1 cm or containing villous histology, high-grade dysplasia, or cancer. In our county colonoscopy population (n = 929 after exclusions), the stepwise logistic regression analysis identified age > or = 60 years (adjusted odds ratio [AOR]: 2.60; 95% confidence interval [CI]:1.14, 6.14), iron deficiency anemia (AOR: 4.74; 95% CI: 2.07, 11.34), and an advanced neoplasm in the recto-sigmoid (AOR: 6.01; 95% CI: 2.02, 16.00) as the statistically significant predictors of an advanced proximal neoplasm. In the county population, the prevalence rates of an advanced proximal neoplasm and proximal high-grade dysplasia/cancer in the low-risk group were 0.71% (95% CI: 0.15, 2.05) and 0.24% (95% CI: 0.01, 1.31), respectively. Avoiding colonoscopy in this group would increase the capacity for colonoscopy by 46% in the higher risk groups. In a disparate community population (n = 237 after exclusions), this scoring system had a goodness-of-fit test showing high concordance (P = 0.51). This clinical profile stratified the risk for an advanced neoplasm proximal to the sigmoid in patients undergoing diagnostic colonoscopy. It identified a large subset of low-risk patients.

To determine the yield of colonoscopy in a predominantly Asian American gastroenterology practice in California from 8/2003 to 2/2005.

A total 2,723 subjects were included: 87% were Asian and 13% were non-Asian. Advanced neoplasia prevalence was 12% in Asian men and 9% in non-Asian men (P = 0.21), and 8% and 7% in women (P = 0.62). Similar results were found in asymptomatic patients (13% and 13%, P = 0.99, for men; 8% and 6%, P = 0.46, for women). Factors associated with presence of advanced neoplasia were total number of polyps and presence of right-sided lesions. Asian men were more likely to have neoplasia overall compared with non-Asian men with odds ratio (OR) of 2.14 (1.23-3.72); however, there were no significant differences in the prevalences of advanced neoplasia in the two groups.

Colorectal neoplasia is as prevalent in Asian Americans and preventive guidelines for colorectal cancer should also be advocated for this ethnic group.

Colorectal neoplasm is rapidly increasing in Asia, but a guideline for screening is not available.

To evaluate the characteristics of colorectal neoplasm in asymptomatic Asian subjects.

Prospective cohort study.

Multinational multicenters, including both primary and referral centers in Asia.

A total of 860 consecutive asymptomatic adults undergoing screening colonoscopy in 11 Asian cities from July 2004 to December 2004. Patients under 16 years old; those patients with a colorectal resection history, colonoscopies, or barium enema within 5 years; symptoms suggestive of colorectal diseases; and those who had undergone surveillance colonoscopy were excluded.

The incidence and distribution of colorectal neoplasm and advanced neoplasm.

The mean age (+/-SD) was 54.4+/-11.6 years; 471 were men (54.8%). The prevalence of colorectal neoplasm and advanced neoplasm was 18.5% and 4.5%, respectively. Male sex, advancing age, and a family history of colorectal cancer were risk factors for advanced neoplasm. Of the 168 patients with colorectal neoplasm, 76 had distal neoplasm only (45.2%), 66 had proximal neoplasm only (39.3%), and 26 had both proximal and distal neoplasms (15.5%). Although the presence of distal advanced neoplasm was a significant risk factor for proximal advanced neoplasm, 14 of the 758 subjects without distal neoplasm had proximal advanced neoplasm (1.8%).

The small number of enrolled subjects, especially from certain ethnic groups.

The overall prevalence of advanced colorectal neoplasm in asymptomatic Asians is comparable with the West. Male sex, advancing age, and a family history of colorectal cancer were associated with a higher risk of advanced neoplasm.

To assess the clinical relevance of dark-lumen MR colonography (MRC) for the detection of colorectal lesions using conventional colonoscopy (CC) and histopathologic examinations as reference standard.

A total of 72 patients underwent MRC and CC. MRC was performed using a contrast-enhanced high spatial resolution T1 weighted 3D volumetric interpolated breathhold examination (VIBE)-sequence. All removed colorectal lesions were evaluated by an experienced pathologist.

CC confirmed 65 polyps less than 5 mm in diameter. Non of those lesions could be detected using MRC. Just two (4%) of the 49 removed lesions smaller than 5 mm showed signs of dysplasia. Additionally, CC confirmed 25 polyps between 6-15 mm in diameter (MRC 22). All those 25 lesions were removed in CC. Only four (16%) of those polyps showed signs of dysplasia and malignancy (11, 13, 13 and 15 mm).

Dark-lumen MRC failed to detect all polyps smaller than 5 mm in diameter which are generally not clinically relevant at the moment of their detection and thus can be kept under surveillance. However, MRC as a non-invasive imaging modality is a promising alternative to CC in the detection of clinically relevant polyps larger than 5 mm in diameter.

Colorectal cancer is one of the leading causes of cancer death in the United States and Europe. Recently, the incidence of colorectal cancer has been increasing remarkably in Korea. To reduce the high incidence, screening of colorectal cancer in asymptomatic individuals has been advocated. Sigmoidoscopy is simpler, faster, and better tolerable than total colonoscopy, but the scope cannot reach the proximal colon segment and, therefore, may miss proximal colon cancer. In the present study, we intended to investigate the prevalence of proximal adenoma and cancer according to the findings in rectosigmoid colon and to find their risk factors. Data were collected retrospectively from 1541 consecutive patients who underwent total colonoscopy at the Department of Gastroenterology, Hanyang University, between October 2003 and December 2004. Neoplasms were classified as diminutive adenoma (< or =5 mm), small adenoma (6-9 mm), advanced adenoma (> or =10 mm, with villous component or high-grade dysplasia), and cancer. The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal (from cecum to descending colon) colon. The prevalence of advanced proximal adenoma was associated with severe rectosigmoid findings. On the other hand, the prevalence of proximal colon cancer did not show such a tendency. Among the 131 patients with proximal advanced adenoma, 66% had no neoplasm in the rectosigmoid colon. Moreover, among the 27 patients with proximal cancer, 52% had no neoplasm in the rectosigmoid colon. Multivariate logistic regression analysis revealed that age, gender, and advanced rectosigmoid adenoma were the risk factors of advanced proximal adenoma, but nothing was associated with the risk for proximal colon cancer. Advanced rectosigmoid adenoma may be the predictor of advanced proximal adenoma, especially in old males. However, nothing is related to the risk for proximal colon cancer. Therefore, colonoscopy may be more adequate for colorectal cancer screening than sigmoidoscopy in the Korean population.

Adenomas of the rectosigmoid colon are considered markers of risk for advanced adenomas of the proximal colon. However, studies report a wide variation in risk. This study was designed to determine the risk for advanced adenomas in the proximal colon in patients from a large, homogeneous population with an advanced or nonadvanced adenoma of the distal colon. We designed a prospective study of 7157 patients who were evaluated for neoplasia by flexible sigmoidoscopy and, when adenomas were found, by colonoscopy. Adenomas were considered advanced if they were > or =10 mm in size or had villous or dysplastic features. Ninety-seven patients had an advanced adenoma of the distal colon (Group A) and were compared with 183 patients who had a nonadvanced adenoma (Group B). Seven patients (7.2%) in Group A had an advanced adenoma of the proximal colon, compared with four patients (2.2%) in Group B (P < 0.05, relative risk = 3.3). When patients with adenomas of the distal colon >5 mm (Group C) were compared to patients with adenomas < or =5 mm (Group D), the prevalence of advanced adenomas of the proximal colon remained at 7% (10/143) for Group C but fell to 0.73% (1/137) for Group D (P = 0.011, relative risk = 9.6). By expanding the criteria for risk from adenomas of the distal colon to include all adenomas >5 mm, the relative risk for advanced adenoma of the proximal colon was increased threefold.

Flexible sigmoidoscopy is advised as a screening test for colorectal cancer for persons with a family history of late-onset colorectal cancer. The expected outcome for this approach is not well established. We designed a large, prospective study of an unselected population to assess the impact of a family history of one first-degree relative with colorectal cancer on the prevalence of advanced adenomas at screening flexible sigmoidoscopy. We evaluated 8121 patients referred for flexible sigmoidoscopy between 1997 and 1999 and 3147 patients met the inclusion criteria. The 3147 patients were divided into 210 with a family history of colorectal cancer and 2937 without a family history and analyzed for differences in the prevalence of advanced adenomas. Of the 210 with a family history, 3 had an advanced adenoma of the rectosigmoid colon (1.4%) Of the 2937 without a family history, 52 had an advanced adenoma of the rectosigmoid colon (1.8%), including 2 cancers. These differences were not significant. In conclusion, a family history of colorectal cancer had no impact on the prevalence of advanced adenomas in asymptomatic patients at screening flexible sigmoidoscopy. The prevalence rates for advanced adenomas and carcinomas of the rectosigmoid colon were low.

This article presents inter- and intraobserver agreement for estimates of polyp diameter using CT colonography, including the effects of different visualization displays and prior experience.

Four observers, three of whom had prior experience with CT colonography, estimated the maximum diameter of 48 polyps using three different visualization displays: 2D colonography window, 2D abdominal window, and 3D surface rendering. Each re-measured a subset of 10 polyps. Polyps measured 2 to 12 mm according to a colonoscopic reference. Inter- and intraobserver agreement and agreement with the reference measurement were determined using the Bland-Altman method, paired Student's t testing, analysis of variance, and analysis of covariance (ANCOVA), and by calculating the components of variance.

CT measurements overestimated polyp diameter, a phenomenon found least using the 2D abdominal display. Generally, 95% limits of agreement encompassed different size categories for individual polyps: the widest spanned 14.6 mm (-4.6 mm to 10.0 mm) for an experienced observer using the 3D display. When using the 2D abdominal display, no significant difference was found between estimates and the reference value for the other two experienced observers (p = 0.83 and 0.23). All the observers' measurements were significantly different from the reference when using the 3D display (p < 0.001). The novice was significantly different from the experienced observers in some analyses. Inter- and intraobserver agreement were poorest for the 3D display.

Measurement of polyp diameter from CT colonography is subject to variation contingent on the observer's experience and the viewing display used. Although 3D visualization display is commonly used for polyp detection, it should not be used for measurement.

Although the association between distal neoplasia on sigmoidoscopy and proximal colonic pathology on follow-up colonoscopy has been well-described, it is not known if these findings are consistent across ethnic groups. The aim of this study was to evaluate ethnic variations in the prevalence of proximal neoplasia on follow-up colonoscopy after a neoplastic lesion is found on sigmoidoscopy.

Consecutive asymptomatic patients at average-risk for colorectal cancer who were referred for screening flexible sigmoidoscopy were prospectively enrolled. Colonoscopy was recommended for all patients with a polyp on flexible sigmoidoscopy, regardless of size. Advanced neoplasms were defined as adenomas > or = 10 mm in diameter or any adenoma, regardless of size, with villous histology, high-grade dysplasia, or cancer.

Among the 2,207 patients who had sigmoidoscopy, 970 were Caucasian, 765 were African American, 395 were Hispanic, and 77 were Asian. The prevalence of neoplasia in the distal colon was 12.6% in Caucasians, 11.2% in African Americans, 15.9% in Hispanics, and 24.7% in Asians (p = 0.002). Of the 290 patients with neoplastic lesions on sigmoidoscopy, follow-up colonoscopy identified neoplasms in the proximal colon in 63.9% of Caucasians, 59.3% of African Americans, 66.7% of Hispanics, and 26.3% of Asians (p = 0.01). Advanced neoplasms in the proximal colon were highest in African Americans (34.9%) and lowest in Asians (10.5%).

In our study population, Asians demonstrated a higher prevalence of distal colonic neoplasia and a lower prevalence of proximal colonic neoplasia compared to non-Asians. Future studies should explore ethnic variation in colonic neoplasia prevalence and location since ethnic variation could lead to tailored colorectal cancer screening strategies.

Among the risk factors for colorectal cancer (CRC) is a family history of colorectal cancer. Reliable evidence is needed regarding the clinical characteristics of cancer in patients with this history to determine if a change in the diagnostic approach is needed.

This study set out to determine specific clinical outcomes in patients with CRC with a family history of one first-degree relative with sporadic colorectal cancer compared to control patients with colorectal cancer but without the family history.

We designed a case-control study of colorectal cancer registry data between 1988 and 1999. Patients with a family history of one first-degree relative with colorectal cancer were compared to those without the history with regard to four characteristics: age at cancer diagnosis, anatomic location of the cancer, presence of distal adenomas with proximal cancer, and stage of disease at diagnosis.

Nine hundred and twenty-one patients met the inclusion criteria. Family history was positive in 124 patients. The demography of the populations was similar, except for mean age, which was 65 yr for men with a family history and proximal cancer compared to 70 yr for their counterparts without the family history (p = 0.03). The anatomic location of the cancer, presence of distal benign neoplasia when the cancer was proximal, and disease stage at diagnosis were not different between the groups.

Men with a family history of sporadic colorectal cancer and proximal colon cancer were younger than men without the family history and proximal colon cancer. The overall results do not indicate that a change in the diagnostic approach is needed.

This study evaluates the potential ability of a specific panel of DNA mutations to identify right-sided colorectal carcinomas (CRCs) that would be missed by a flexible sigmoidoscopy (FS) screening program. This panel could then be applied to stool DNA analysis for noninvasive proximal CRC detection. A series of resected right-sided CRCs from 101 patients who had no left-sided advanced colonic neoplasms distal to the splenic flexure were analyzed. Tumor DNA was isolated from microdissected tumor sections. Deletions in the BAT-26 locus, a marker of microsatellite instability, and mutations at 19 loci spread among the p53, K-ras, and Apc genes were detected following PCR amplification. Mutations were identified in 83% of successfully amplified samples and were variably present in each of the target sites: p53 (42%), Apc (37%), K-ras (28%), and BAT-26 (24%). Mutations were identified across all Dukes stages (CIS/A 6/8 [75%], B 41/51[80%], C 30/32 (94%), and D 6/9 [67%]). Our data suggest that this 20-marker mutation panel may be associated with more than 80% of cancers undetectable by FS. The adjunctive use of stool DNA mutation analysis using this marker panel in FS CRC screening programs may significantly increase the detection of proximal CRC.

For colorectal cancer screening, the predictive value of distal findings in the ascertainment of proximal lesions is not fully established. The aims of this study were to assess distal findings as predictors of advanced proximal neoplasia and to compare the predictive value of endoscopy alone vs. combined endoscopic and histopathologic data.

Primary colonoscopy screening was performed in 2210 consecutive, average-risk adults. Age, gender, endoscopic (size, number of polyps), and histopathologic distal findings were used as potential predictors of advanced proximal neoplasms (i.e., any adenoma > or =1 cm in size, and/or with villous histology, and/or with severe dysplasia or invasive cancer). Polyps were defined as distal if located in the descending colon, the sigmoid colon, or the rectum. Those in other locations were designated proximal.

Neoplastic lesions, including 11 invasive cancers, were found in 617 (27.9%) patients. Advanced proximal neoplasms without any distal adenoma were present in 1.3% of patients. Of the advanced proximal lesions, 39% were not associated with any distal polyp. Older age, male gender, and distal adenoma were independent predictors of advanced proximal neoplasms. The predictive ability of a model with endoscopic data alone did not improve after inclusion of histopathologic data. In multivariate logistic regression analysis, the predictive ability of models that use age, gender, and any combination of distal findings was relatively low. The proportion of advanced proximal neoplasms identified if any distal polyp was an indication for colonoscopy was only 62%.

A strategy in which colonoscopy is performed solely in patients with distal colonic findings is not effective screening for the detection of advanced proximal neoplasms in an average-risk population.

Distal colonic adenomas found on flexible sigmoidoscopy are associated with proximal neoplasias, thus requiring a complete colonoscopic examination, but data regarding the association of distal mixed polyps with proximal neoplasia are lacking. We conducted this study to elucidate the significance of distal mixed colonic polyps in predicting proximal neoplasia.

We retrospectively analyzed data from patients who underwent a flexible sigmoidoscopic examination for colorectal cancer screening and a follow-up colonoscopic examination because of distal colonic polyps. Distal index polyps were classified by a pathologist as early tubular adenoma (ETA), serrated, or true mixed categories. Index polyps also were immunostained with a monoclonal antibody, Adnab-9, a marker for the colorectal adenoma carcinoma sequence.

In 636 patients with distal index polyps, 6% were malignant, 55% were adenomas, 13% were ETAs, 6% were serrated, 4% were true mixed, and 17% were hyperplastic. Compared with distal hyperplastic index polyps, distal malignant polyps (P = 0.0006) and adenomas (P = 0.001) were associated with a significantly increased number of synchronous proximal neoplasia, but the small distal mixed, serrated, or ETA did not predict the increased incidence of proximal neoplasia. Large distal polyps of each category were significantly associated with an increased number of synchronous proximal neoplasias. In support of these findings, immunostaining of distal polyps with Adnab-9 showed predictability for proximal neoplasia only in the adenoma category (P < 0.05).

Small ETAs, serrated, or mixed polyps found on flexible sigmoidoscopic examination do not increase the probability of synchronous proximal neoplasia.

Adenomatous polyps are a precursor of colorectal cancer and a frequent finding on screening flexible sigmoidoscopy (FS). Performance of colonoscopy when a diminutive (<6mm) adenoma is found on FS has been the subject of considerable debate.

We retrospectively reviewed the data from our colorectal cancer screening program for patients with adenoma(s) found on FS. Patients were divided into three groups based on FS findings: (1) an adenoma <6mm in size, (2) multiple non-advanced adenomas or an adenoma 6-10mm in size, or (3) advanced adenoma defined as an adenoma >10mm or with villous histology or high-grade dysplasia or cancer. A comparison of the proximal findings was then made.

5291 FS reports were reviewed with 606 (12%) patients having at least one adenoma. Colonoscopy reports were available in 550 patients. Of the 258 patients with a diminutive distal adenoma, 69 (27%) had a proximal adenoma and 13 (5%) had an advanced proximal adenoma on colonoscopy. Of the 164 patients with an adenoma 6-10mm or multiple non-advanced adenomas, 59 (36%) had a proximal adenoma and 13 (8%) had an advanced proximal adenoma. Of the 128 patients with a distal advanced adenoma, 58 (45%) had a proximal adenoma and 15 (12%) had an advanced proximal adenoma. The increase in proximal adenomas across the three groups was significant (P=0.001), and there was a trend for increased prevalence of advanced adenomas (P=0.061).

The prevalence of proximal adenomas increased significantly with more advanced lesions found distally at FS, and there was a trend towards a higher prevalence of advanced proximal adenomas. Based on current guidelines, flexible sigmoidoscopy is a screening option that can be used to identify average-risk patients at increased risk of proximal neoplasia.

The use of colonoscopy as a primary screening test for colorectal cancer (CRC) in average risk adults is a subject of controversy. Our primary objective was to build a predictive model based on a few simple variables that could be used as a guide for identifying average risk adults more suitable for examination with colonoscopy as a primary screening test.

The prevalence of advanced adenomas was assessed by primary screening colonoscopy in 2210 consecutive adults at least 40 yr old, without known risk factors for CRC. Age, gender, and clinical and biochemical data were compared among people without adenomas, those with non-advanced adenomas, and those with any advanced neoplasm. A combined score to assess the risk of advanced adenomas was built with the variables selected by multiple logistic regression analysis.

Neoplastic lesions were found in 617 subjects (27.9%), including 259 with at least one neoplasm that was 10 mm or larger, villous, or with moderate-to-severe dysplasia, and 11 with invasive cancers. Advanced lesions were more frequent among men, older people, and those with a higher body mass index (BMI). These three variables were independent predictors of advanced adenomas in multivariate analysis. A score combining age, sex, and BMI was developed as a guide for identifying individuals more suitable for screening colonoscopy.

Age, gender, and BMI can be used to build a simple score to select those average risk adults who might be candidates for primary screening colonoscopy.

Screening for colorectal cancer clearly reduces colorectal cancer mortality, yet many eligible adults remain unscreened. Several screening tests are available, and various professional organizations have differing recommendations on which screening test to use. Clinicians are challenged to ensure that eligible patients undergo colorectal cancer screening and to guide patients in choosing what tests to receive.

To critically assess the evidence for use of the available colorectal cancer screening tests, including fecal occult blood tests, sigmoidoscopy, colonoscopy, double-contrast barium enema, and newer tests, such as virtual colonoscopy and stool-based molecular screening.

All relevant English-language articles were identified using PubMed (January 1966-August 2002), published meta-analyses, reference lists of key articles, and expert consultation.

Studies that evaluated colorectal cancer screening in healthy individuals and assessed clinical outcomes were included. Evidence from randomized controlled trials was considered to be of highest quality, followed by observational evidence. Diagnostic accuracy studies were evaluated when randomized controlled trials and observational studies were not available or did not provide adequate evidence. Studies were excluded if they did not evaluate colorectal screening tests and if they did not evaluate average-risk individuals.

Randomized controlled trials have shown that fecal occult blood testing can reduce colorectal cancer incidence and mortality. Case-control studies have shown that sigmoidoscopy is associated with a reduction in mortality, and observational studies suggest colonoscopy is effective as well. Combining fecal occult blood testing and sigmoidoscopy may decrease mortality and can increase diagnostic yield.

The recommendation that all men and women aged 50 years or older undergo screening for colorectal cancer is supported by a large body of direct and indirect evidence. At present, the available evidence does not currently support choosing one test over another.

The relationship between distal and proximal colonic findings is uncertain. Thus, there is no consensus on which findings on screening flexible sigmoidoscopy should trigger colonoscopy.

We analyzed data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to assess the relationship between distal and proximal colonic findings.

A total of 8802 subjects had an abnormal baseline sigmoidoscopy and colonoscopy follow-up. Subjects with <10-mm single or multiple tubular adenomas had similar risks for advanced proximal neoplasia as subjects with hyperplastic polyps or other benign lesions (3%-5%). Subjects with large (>or=10 mm), villous, or severely dysplastic distal adenomas had similarly elevated risks for advanced proximal neoplasia (11%-12%). Multivariate logistic modeling showed a significantly increased risk for advanced proximal neoplasia associated with the presence of a large tubular (odds ratio [OR], 2.6; 95% confidence interval [CI], 2.0-3.4) or villous distal adenoma (OR, 2.7; 95% CI, 2.1-3.5) but not with the presence of one (OR, 1.05; 95% CI, 0.8-1.3) or multiple (OR, 0.8; 95% CI, 0.5-1.2) <10-mm tubular distal adenomas.

Among subjects with a polypoid lesion on screening flexible sigmoidoscopy, those with small tubular distal adenomas are at similar risk for advanced proximal neoplasia as those without distal adenomas. Subjects with a large, villous, or dysplastic distal adenoma are at increased risk. A strategy that encourages individuals with small tubular adenomas on sigmoidoscopy to undergo follow-up colonoscopy and excludes those with nonadenomatous lesions is of questionable validity, because both groups are at similar risk for advanced proximal neoplasia.

The current literature is unclear about the association between distal hyperplastic polyps and synchronous neoplasia (adenomatous polyps and cancer) in the proximal colon.

To estimate the prevalence of proximal neoplasia associated with distal hyperplastic polyps.

Database searches (medline and embase from 1966 to 2001) and manual search of the bibliographies of included and excluded studies, case reports, editorials, review articles, and textbooks of Gastroenterology.

Studies describing the prevalence of proximal neoplasia in persons with distal hyperplastic polyps.

Demographics, clinical variables, study design, and prevalence of proximal neoplasia associated with various distal colorectal findings.

Of 18 included studies, 12 involved asymptomatic individuals in which the pooled absolute risk of any proximal neoplasia associated with distal hyperplastic polyps was 25% (95% confidence interval [95% CI], 21% to 29%). In 4 studies where colonoscopy was performed irrespective of distal findings, the absolute risk was 21% (95% CI, 14% to 28%). The relative risk of finding any proximal neoplasia in persons with distal hyperplastic polyps was 1.3 (95% CI, 0.9 to 1.8) compared to those with no distal polyps. Among 6 studies of patients with symptoms or risk factors for neoplasia, the absolute risk of proximal neoplasia was 35% (95% CI, 32% to 39%) in persons with distal hyperplastic polyps. In 2 studies of screening colonoscopy, advanced proximal neoplasia (cancer, or a polyp with villous histology or severe dysplasia, or a tubular adenoma >/=1 cm) was present in 4% to 5% of persons with distal hyperplastic polyps, which was 1.5 to 2.6 times greater than in those with no distal polyps.

In asymptomatic persons, a distal hyperplastic polyp is associated with a 21% to 25% risk for any proximal neoplasia and a 4% to 5% risk of advanced proximal neoplasia, and may justify examination of the proximal colon. Further study is needed to determine the risk of advanced proximal neoplasia associated with size and number of distal hyperplastic polyps.

In cost-effectiveness analyses of cancer prevention, the ratio of cost and medical effectiveness serves as the primary measure for comparing various strategies, effectiveness being measured in terms of (quality adjusted) life-years gained through medical intervention. Such analyses are reliable in comparing different medical management strategies and revealing the most important factors to influence their cost-effectiveness ratios, but less helpful in judging the general merit of a given medical strategy. Models of medical decision making are used to simulate the natural history of colorectal cancer and test how it becomes affected by various means of screening and prevention. The analyses suggest that, compared with no prevention, a single colonoscopy at age 65 is the most cost-effective means of cancer prevention in the general population, followed by screening colonoscopy every ten years or screening colonoscopy every ten years plus chemoprevention with daily aspirin. Other means of prevention, involving annual fecal occult blood testing or flexible sigmoidoscopy every 5-10 years, are dominated by cheaper and more effective strategies. Economic and decision models do not obviate the primacy of clinical data gathered through controlled clinical trials, since they cannot account for all factors that may eventually determine the cost-effectiveness of actual screening and cancer prevention.

An ex vivo magnetic resonance (MR) colonographic system with a bovine colon with polyps of predetermined dimensions was developed for evaluation and optimization of different combinations of imaging sequences and intraluminal contrast agents. Findings were then applied during in vivo testing in human subjects. The results show that optimized contrast and lesion conspicuity and minimized motion artifacts can be obtained with true fast imaging with steady-state precession combined with water as an intraluminal contrast agent.

OBJECTIVE: To reduce mortality associated with colorectal cancer, an increased interest has focused in recent years on screening of colorectal cancer. No studies of colorectal cancer screening in Finland has been reported. A pilot study of screening sigmoidoscopy was started in 1994 and the results are presented in this paper.SUBJECTS AND METHODS: Between March 1994 and May 2000 all 1224 persons aged 60 years from four communities (population 15 400) were invited to screening sigmoidoscopy; 896 (73%) took part in this study. The screening procedure was flexible sigmoidoscopy to 60 centimetres. All the patients who had adenomas or cancers, were invited to have a double contrast barium enema (DCBE) or colonoscopy to investigate the proximal colon. To study the experience of persons undergoing screening sigmoidoscopy, a questionnaire was sent to 81 consecutive persons after the examination. Sixty persons (74%) returned the filled-in questionnaire.RESULTS: Hyperplastic polyps were found in 136 people (15.2% of the whole material). Hyperplastic polyps were more common in males than females (19.3% and 11.4%, respectively, P=0.0015). People with hyperplastic polyps had the same rate of neoplasia as people without. Neoplastic lesions were found in 65 people. Adenomas were found in 62 patients (6.9%). Twenty-five people (2.8%) had at least one advanced adenoma (>10 mm or villous component). The rate of advanced adenomas in males was 4.9% and in females 0.9% (P=0.0006). Three patients (0.3%) were found to have colorectal cancer. Of 43 diabetic patients, 7 (16.3%) had adenomas whereas 6.5% of the non-diabetic persons had adenomas (P=0.03). The proximal colon was investigated in 34 patients by DCBE and/or colonoscopy and the rate of proximal adenomas in patients with neoplastic findings in screening sigmoidoscopy was 5/34 (14.7%). Concerning the experience of screening sigmoidoscopy, 56 persons (93%) found bowel preparation easy and 4 unpleasant, 55 (92%) experienced either no or mild discomfort during the endoscopy whereas 5 found the examination painful; 59 people (98%) said that they would participate again in screening sigmoidoscopy.CONCLUSIONS: In this study of screening sigmoidosopy, the first published in Finland, adenoma rate was 6.9%, advanced adenoma rate was 2.8% and cancer rate was 0.3%. Males had more hyperplastic polyps and advanced adenomas than females. Diabetic people had more adenomas than non-diabetics. Experiences of the people screened were positive and nearly all said that they would participate again in screening sigmoidoscopy.

In deciding how to interpret the significance and management of small distal adenomatous polyps found on FS, one must first decide on the goal of a screening program. If the goal is maximal reduction of CRC risk, regardless of cost, there is little argument that screening colonoscopy is the most effective approach. Unfortunately cost and cost-effectiveness are important considerations when administering a screening program with a fixed budget. Although comparing the cost-effectiveness of different strategies is beyond the scope of this article, rigorous comparisons by other authors have suggested that a sigmoidoscopy-based approach is more cost-effective than a colonoscopy-based approach. The most cost-effective approach may change, however, if the frequency of screening and surveillance can be reduced without significantly impacting effectiveness. Other authors using assumptions including low compliance rates for regular FOBT or FS have determined that colonoscopy every 10 years is the most cost-effective approach. Multiple studies support the recommendation that villous polyps regardless of size and adenomatous polyps greater than 1 cm found on FS are important markers for the presence of advanced polyps and cancer in the proximal colon. These patients should undergo colonoscopy. If one assumes that a sigmoidoscopy-based approach is reasonable, and accepts that such an approach always misses a small number of proximal lesions, how should one manage patients with a small adenomatous polyp on FS? In aggregate, the studies discussed previously suggest that patients with no distal polyps, distal hyperplastic polyps, or a single small distal tubular adenoma have a similar and low risk of advanced proximal adenomas of the colon. There are some studies, however, that do not support this. With the exception of the study by Read et al, these studies included patients at elevated risk of CRC because of a family history, or inclusion of patients with positive FOBT (or not tested). The study by Read et al also included patients with distal villous adenomas in their low-risk group. Because a sigmoidoscopy-based strategy typically excludes patients at elevated risk, these results may not be applicable to low-risk patients undergoing sigmoidoscopy. Given these caveats, what can one conclude about the predictive value of a small tubular adenoma found on FS? These studies suggest that the risk of proximal advanced polyps is similar or slightly increased in patients with a distal adenoma than those with a negative FS. The risk of finding an advanced adenoma seems to be 0% to 4% regardless of the findings of no polyps, hyperplastic polyps, or small tubular adenomatous polyps on FS in low-risk patients. A small portion of patients with hyperplastic polyps found on FS have advanced proximal adenomas. If a hyperplastic polyp on FS is not an indication for colonoscopy and the risk of proximal advanced adenomas is similar in patients with only a small distal adenoma, it is inconsistent to recommend colonoscopy for a small distal tubular adenoma and not a hyperplastic polyp. Based on the studies of asymptomatic patients with no family history and negative FOBT, the authors believe it is reasonable to defer colonoscopy if no polyp, a hyperplastic, or a small tubular adenoma is found at sigmoidoscopy in low-risk patients. If the patient or physician is unwilling to accept a small (0% to 4%) chance of missing an advanced proximal lesion, then a sigmoidoscopy-based approach (regardless of the threshold to go on to colonoscopy) is not appropriate. Screening FS remains an effective examination to screen for CRC in asymptomatic patients. There is no question that colonoscopy clearly detects more lesions than FS. It remains to be seen if the increase in costs and risks justifies the improved detection rate of colonic polyps. Given manpower issues that face us today, and examining the question from a population perspective, reserving colonoscopy for only those patients with an advanced distal polyp on FS gives the biggest yield.

To analyse results of a screening program for colorectal cancer using flexible sigmoidoscopy.

Survey of results of screening program and follow-up colonoscopies and identification of missed cases from State cancer registry data.

Asymptomatic, average-risk people aged 55-64 years who were either mailed invitations after random selection from the electoral roll or volunteered after hearing about the program.

Fremantle Hospital, Western Australia (a public teaching hospital), July 1995 to November 1999 (first 4.5 years of the screening program).

Participation rates; lesions detected; stage of colorectal cancers diagnosed at the hospital before and after the screening program began (1989-1995 versus 1996-1999); and diagnoses of colorectal cancer in previously screened individuals (from State cancer registry data).

6446 people were mailed invitations, and 1483 were screened (23% participation rate). Another 1122 people volunteered, giving 2605 people screened overall. Flexible sigmoidoscopy showed adenomatous polyps in 352 people (14%), and colonoscopy was recommended in 399 (15%) on the basis of clinically suspicious lesions. Colonoscopy was performed in 302 (76% participation rate). Screening and follow-up colonoscopy detected 14 colorectal cancers (10 invasive, with eight of these Dukes stage A). One participant was diagnosed with colorectal cancer 12 months after sigmoidoscopy gave normal results. Incidence of colorectal cancer was 119 per 100000 per year, and prevalence was 0.5%. Before the screening program, 12% of cancers diagnosed at our hospital were Dukes stage A, compared with 28% after (P<0.001).

Flexible sigmoidoscopy screening is an acceptable strategy in asymptomatic, average-risk people which detects colorectal cancer and adenomatous polyps. Screening has been associated with a trend to earlier presentation of cancer in our institution.

The role of colonoscopy in screening for colorectal cancer is uncertain. At 13 Veterans Affairs Medical Centers, we performed colonoscopy to determine the prevalence and location of advanced colonic neoplasms and the risk of advanced proximal neoplasia in asymptomatic patients (age range, 50 to 75 years) with or without distal neoplasia. Advanced colonic neoplasia was defined as an adenoma that was 10 mm or more in diameter, a villous adenoma, an adenoma with high-grade dysplasia, or invasive cancer. In patients with more than one neoplastic lesion, classification was based on the most advanced lesion.

Of 17,732 patients screened for enrollment, 3196 were enrolled; 3121 of the enrolled patients (97.7 percent) underwent complete examination of the colon. The mean age of the patients was 62.9 years, and 96.8 percent were men. Colonoscopic examination showed one or more neoplastic lesions in 37.5 percent of the patients, an adenoma with a diameter of at least 10 mm or a villous adenoma in 7.9 percent, an adenoma with high-grade dysplasia in 1.6 percent, and invasive cancer in 1.0 percent. Of the 1765 patients with no polyps in the portion of the colon that was distal to the splenic flexure, 48 (2.7 percent) had advanced proximal neoplasms. Patients with large adenomas (> or = 10 mm) or small adenomas (< 10 mm) in the distal colon were more likely to have advanced proximal neoplasia than were patients with no distal adenomas (odds ratios, 3.4 [95 percent confidence interval, 1.8 to 6.5] and 2.6 (95 percent confidence interval, 1.7 to 4.1], respectively). However, 52 percent of the 128 patients with advanced proximal neoplasia had no distal adenomas.

Colonoscopic screening can detect advanced colonic neoplasms in asymptomatic adults. Many of these neoplasms would not be detected with sigmoidoscopy.

The clinical significance of a distal colorectal polyp is uncertain. We determined the risk of advanced proximal neoplasia, defined as a polyp with villous features, a polyp with high-grade dysplasia, or cancer, among persons with distal hyperplastic or neoplastic polyps as compared with the risk among persons with no distal polyps. We analyzed data from 1994 consecutive asymptomatic adults (age, 50 years or older) who underwent colonoscopic screening for the first time between September 1995 and December 1998 as part of a program sponsored by an employer. The location and histologic features of all polyps were recorded. Colonoscopy to the level of the cecum was completed in 97.0 percent of the patients.

Sixty-one patients (3.1 percent) had advanced lesions in the distal colon, including 5 with cancer, and 50 (2.5 percent) had advanced proximal lesions, including 7 with cancer. Twenty-three patients with advanced proximal neoplasms (46 percent) had no distal polyps. The prevalence of advanced proximal neoplasia among patients with no distal polyps was 1.5 percent (23 cases among 1564 persons; 95 percent confidence interval, 0.9 to 2.1 percent). Among patients with distal hyperplastic polyps, those with distal tubular adenomas, and those with advanced distal polyps, the prevalence of advanced proximal neoplasia was 4.0 percent (8 cases among 201 patients), 7.1 percent (12 cases among 168 patients), and 11.5 percent (7 cases among 61 patients), respectively. The relative risk of advanced proximal neoplasia, adjusted for age and sex, was 2.6 for patients with distal hyperplastic polyps, 4.0 for those with distal tubular adenomas, and 6.7 for those with advanced distal polyps, as compared with patients who had no distal polyps. Older age and male sex were associated with an increased risk of advanced proximal neoplasia (relative risk, 1.3 for every five years of age and 3.3 for male sex).

Asymptomatic persons 50 years of age or older who have polyps in the distal colon are more likely to have advanced proximal neoplasia than are persons without distal polyps. However, if colonoscopic screening is performed only in persons with distal polyps, about half the cases of advanced proximal neoplasia will not be detected.

The characteristics of adenomas found during sigmoidoscopy have been suggested to predict synchronous adenomas in the proximal colon. Our aim was to examine whether the presence and characteristics of distal colonic lesions are associated with the presence and characteristics of lesions in the proximal colon. We performed a university hospital based case-control study with 3,268 consecutive subjects who received colonoscopy between January 1992 and December 1995. Subjects who had a history of colonic polyps, inflammatory bowel disease, intestinal resection, or had a contraindication against biopsies were excluded. Number size, and histologic characteristics of polyps in the distal and proximal colon were recorded. Advanced lesions were defined as neoplastic lesions with 1 or more of the following features: 1) > or = 1 cm diameter, and/or 2) villous histology, and/or 3) severe dysplasia or carcinoma, and/or 4) > or = 3 lesions. We found that 439 patients had neoplastic lesions in the distal colon only (61.3% with advanced lesions), 198 patients had lesions in the proximal colon only (55.1% advanced), and 197 had lesions in both the distal colon (74.6% advanced) and the proximal colon (55.8% advanced). Distal lesions were significantly more often advanced in patients with synchronous proximal lesions compared with patients with lesions in the distal colon only (odds ratio: 1.9; 95% confidence interval [CI]: 1.3-2.8; p < 0.001). The odds ratios for finding any neoplastic lesion in the proximal colon and an advanced proximal lesion, respectively, were 3.7 (2.6-5.3) (p < 0.001) and 2.2 (1.3-3.7) (p < 0.01) when a nonadvanced lesion was found in the distal colon, and 6.8 (5.3-8.7) (p < 0.001) and 6.7 (4.9-9.0) (p < 0.001) when an advanced lesion was found in the distal colon. Logistic regression analysis revealed number of distal polyps and villous histology as independent predictors of advanced lesions in the proximal colon; size and severe dysplasia were not independent predictors. In conclusion, characteristics of neoplastic lesions in the distal colon predict the presence and characteristics of lesions in the proximal colon.

The District of Columbia General Hospital has a flexible sigmoidoscopy (FS) colorectal cancer screening program. We noted that this program was underused. The aim of this study was to determine whether education could improve use of a flexible sigmoidoscopy screening program in an inner city population.

Patients undergoing screening FS 5 months before our educational initiative were compared to patients undergoing screening FS 5 months after implementation. A 1-month period was allowed for implementation. Procedure logs and GI charts were reviewed.

A total of 121 patients underwent FS screening during our study period. Of the patients, 97% were African-American; 58% were female; and the average age was 61 yr. A total of 50 patients underwent FS in the pre-education group, and 71 patients underwent FS after implementation of our educational initiative.

Education resulted in a 42% increase in FS screening in this inner city, predominantly African-American population. Larger scale educational initiatives should be conducted to determine whether these benefits can persist and can be improved upon.

Colorectal cancer is an important problem in the United States, with over 130,000 new cases and 55,000 deaths each year. There is now strong evidence that screening for colorectal cancer with fecal occult blood testing can decrease mortality, and additional evidence that removing benign adenomas can decrease cancer incidence. Evidence-based screening guidelines depend on colorectal cancer risk. Individuals at higher risk because of a personal or family history deserve more intensive screening than asymptomatic individuals over age 50.