Helicobacter pylori positively associated with colorectal cancer and advanced, but not low-risk, adenomas: A retrospective study in China

Table 1 Helicobacter pylori infection status in different sexes and ages, n (%)/mean ± SD

	H. pylori negative	H. pylori positive	H. pylori positive rate (%)	Test statistic	P value
Total	4334	1652	27.60
Sex				5.601	0.020
Male	1957 (45.15)	802 (48.55)	29.07
Female	2377 (54.85)	850 (51.45)	26.34
Average age		52.3 ± 10.8	51.1 ± 10.5	3.920	< 0.001
Different ages				17.220	< 0.001
< 40	579 (13.36)	242 (14.65)	29.48
40-60	2726 (62.90)	1100 (66.59)	28.75
> 60	1029 (23.74)	310 (18.76)	23.15

Sex and different ages were analyzed using the χ² statistical test as categorical variables; Average age was analyzed using the independent-samples t-test as continuous variables. H. pylori: Helicobacter pylori.

Table 2 Distribution of different types of colorectal polyps and colorectal cancer in different sexes and ages, n (%)/mean ± SD

	Normal	NAPs	LRAs	AAs	CRC	P value
Total	3707	689	1149	367	74
Sex						< 0.05
Male	1511 (40.76)	362 (52.54)	616 (53.61)	230 (62.67)	40 (54.05)
Female	2196 (59.24)	327 (47.46)	533 (46.39)	137 (37.33)	34 (45.95)
Average age	49.9 ± 10.9	53.3 ± 9.50	55.2 ± 9.14	57.9 ± 9.23	62.3 ± 10.4	< 0.001
Different ages						< 0.001
< 40	689 (18.6)	57 (8.27)	56 (4.87)	17 (4.63)	2 (2.70)
40-60	2378 (64.1)	472 (68.5)	750 (65.3)	201 (54.8)	25 (33.8)
> 60	640 (17.3)	160 (23.2)	343 (29.9)	149 (40.6)	4 7(63.5)

For the sex distribution: Normal group (χ² = 126.56, P < 0.0001); non-adenomatous polyps’ group (χ² = 0.889, P = 0.346); low-risk adenomas group (χ² = 6.00, P = 0.014); AAs group (χ² = 23.57, P < 0.0001); colorectal cancer group (χ² = 0.338, P = 0.561). The P < 0.05 indicated a statistically significant difference in sex distribution only within the Normal, low-risk adenomas, and advanced adenomas groups. For the different ages distribution: < 40 (χ² = 245.6, P < 0.00001); 40-60 (χ² = 38.6, P < 0.0001); > 60 (χ² = 292.4, P < 0.00001). NAPs: Non-adenomatous polyps; LRAs: Low-risk adenomas; AAs: Advanced adenomas; CRC: Colorectal cancer.

Table 3 The association between Helicobacter pylori and the proportion of different types of colorectal polyps and colorectal cancer, n (%)

	H. pylori negative	H. pylori positive	P value
Total	4334	1652
Normal	2719 (62.73)	988 (59.81)	0.037
NAPs	503 (11.61)	186 (11.26)	0.707
LRAs	819 (18.90)	330 (19.98)	0.344
AAs	243 (5.61)	124 (7.51)	0.006
CRC	50 (1.15)	24 (1.45)	0.349

The showed a single variable association. NAPs: Non-adenomatous polyps; LRAs: Low-risk adenomas; AAs: Advanced adenomas; CRC: Colorectal cancer; H. pylori: Helicobacter pylori.

Table 4 Odds ratios value of Helicobacter pylori infection in different types of colorectal polyps and colorectal cancer from multivariable logistic regression, n (%)

	H. pylori negative	H. pylori positive	Odds ratio	95%CI	P value
Normal	2719 (73.35)	988 (26.65)	1
NAPs	503 (73.00)	186 (27.00)	1.03	0.86-1.24	0.72
LRAs	819 (71.28)	330 (28.72)	1.15	0.99-1.34	0.06
AAs	243 (66.21)	124 (33.79)	1.53	1.20-1.93	< 0.001
CRC	50 (67.57)	24 (32.43)	1.65	0.98-2.71	0.051

The showed multivariable associations. Sex and age were included in the model as covariates. Helicobacter pylori negative was the reference exposure (odds ratio = 1.00), and that “normal” colonoscopy findings were the reference outcome category. NAPs: Non-adenomatous polyps; LRAs: Low-risk adenomas; AAs: Advanced adenomas; CRC: Colorectal cancer; H. pylori: Helicobacter pylori; CI: Confidence interval.

Table 5 The association between Helicobacter pylori infection levels and the proportion of different types of colorectal polyps and colorectal cancer, n (%)

	H. pylori +	H. pylori ++	H. pylori +++	P value
Total	1034	557	61
Colonoscopy results
Normal	612 (59.19)	342 (61.40)	34 (55.74)	0.556
NAPs	121 (11.70)	60 (10.77)	5 (8.20)	0.635
LRAs	209 (20.21)	107 (19.21)	14 (22.95)	0.749
AAs	79 (7.64)	39 (7.00)	6 (9.84)	0.702
CRC	13 (1.26)	9 (1.62)	2 (3.28)	0.406

Percentages were calculated within each Helicobacter pylori infection level. The histological grading criteria was shown in Figure 2. NAPs: Non-adenomatous polyps; LRAs: Low-risk adenomas; AAs: Advanced adenomas; CRC: Colorectal cancer; H. pylori: Helicobacter pylori.

Table 6 The association between Helicobacter pylori and the site, number of colorectal advanced adenomas, n (%)

	H. pylori negative	H. pylori positive	P value
Total	243	124
Site			0.811
Distal	102 (41.98)	54 (43.55)
Proximal	50 (20.58)	22 (17.74)
Multiple	91 (37.45)	48 (38.71)
Number			0.260
Single	101 (41.56)	44 (35.48)
Multiple	142 (58.44)	80 (64.52)

Site and number of advanced adenomas were analyzed using the χ² test. The distal end refers to the left colon and rectum; the proximal end refers to the right colon and multiple polyps refer to both proximal and distal. These categories are mutually exclusive. H. pylori: Helicobacter pylori.

Table 7 The association between Helicobacter pylori and the site of colorectal cancer, n (%)

	H. pylori negative	H. pylori positive	P value
Total	50	24
Site			0.026
Distal	34 (68.00)	22 (91.67)
Proximal	16 (32.00)	2 (8.3)

P value (0.026) was obtained using Fisher’s exact probability method. Percentages were calculated within each Helicobacter pylori group. H. pylori: Helicobacter pylori.