Rectosigmoid findings are not associated with proximal colon cancer: Analysis of 6196 consecutive cases undergoing total colonoscopy

Table 1 Characteristics of all included patients (n = 6196).

Variable	Value (%)
Gender
Male	3999 (64.5)
Female	2197 (35.5)
Age (yr)
-49	1166 (18.8)
50-59	1618 (26.1)
60-69	1860 (30.0)
70-	1552 (25.0)
mean±SD	60.1 (13.3)
Indications for colonoscopy
Asymptomatic	575 (9.3)
Positive for fecal occult blood	2500 (40.3)
Symptomatic	3121 (50.4)
Bleeding	922
Lower abdominal pain	861
Altered bowel habit	634
Anemia	261
Elevated CEA	212
Other reasons	231

Table 2 Findings in rectosigmoid and proximal colon of all patients (n = 6196).

Findings	Rectosigmoid colon	Proximal colon
	Number of patients (%)	Number of patients (%)
No neoplasm	4245 (68.5)	3991 (64.4)
Histology of most advanced lesion
Diminutive adenoma1	598 (9.7)	968 (15.6)
Small adenoma2	500 (8.2)	561 (9.1)
Advanced adenoma3	673 (10.9)	519 (8.3)
Cancer	180 (2.9)	157 (2.5)
No. of lesions
One	1329 (21.4)	1173 (18.9)
Two or more	622 (10.0)	1032 (16.7)

¹Tubular adenoma (5 mm or less in diameter)

²Tubular adenoma (6-9 mm in diameter)

³Tubular adenoma (10 mm or more in diameter), villous histology, or severe dysplasia.

Table 3 Prevalence of proximal advanced adenoma and cancer.

Rectosigmoid findings	Number of pts	Proximal findings
		Advanced adenoma			Cancer
		Number of pts	(%)	(95% CI)	Number of pts	(%)	(95% CI)
No neoplasm	4245	264	(6.2)	(5.5-6.9)	116	(2.7)	(2.2-3.2)
Histology of most advanced neoplasm
Diminutive adenoma	598	41	(6.9)	(4.8-8.9)	11	(1.8)	(0.8-2.9)
Small adenoma	500	60	(12.0)	(9.2-14.8)	14	(2.8)	(1.4-4.2)
Advanced adenoma	673	122	(18.1)	(15.2-21.0)	15	(2.2)	(1.1-3.3)
Cancer	180	32	(17.8)	(12.2-23.4)	1	(0.6)	(0.0-1.6)
No. of neoplasms
One	1329	150	(11.3)	(9.6-13.0)	27	(2.0)	(1.3-2.8)
Two or more	622	105	(16.9)	(13.9-19.8)	14	(2.3)	(1.1-3.4)

Table 4 Risk of proximal advanced adenoma and cancer according to gender, age, and rectosigmoid findings (multivariate analysis).

Variables	No. of pts	Advanced adenoma
		Advanced adenoma			Cancer
		Odds ratio	(95%CI)	P	Odds ratio	(95%CI)	P
Gender
Female	2197	1	(Referent)		1	(Referent)
Male	3999	2.1	(1.7-2.6)	<0.0001	0.9	(0.6-1.3)	0.5287
Age (yr)
-49	1166	1	(Referent)		1	(Referent)
50-59	1618	2.5	(1.7-3.6)	<0.0001	10.0	(2.4-42.4)	0.0018
60-69	1860	3.1	(2.12-4.5)	<0.0001	13.8	(3.3-57.2)	0.0003
70-	1552	3.5	(2.4-5.1)	<0.0001	35.6	(8.7-145.2)	<0.0001
Findings of rectosigmoid colon
No neoplasm	4245	1	(Referent)		1	(Referent)
Diminutive adenoma	598	0.9	(0.6-1.3)	0.4995	0.7	(0.3-1.2)	0.1881
Small adenoma	500	1.6	(1.2-2.2)	0.0019	1.0	(0.6-1.8)	0.9731
Advanced adenoma	673	2.5	(2.0-3.2)	<0.0001	0.8	(0.5-1.4)	0.4577
Cancer	180	2.6	(1.7-3.8)	<0.0001	0.2	(0.0-1.2)	0.0726