Does Helicobacter pylori eradication therapy for peptic ulcer prevent gastric cancer?

Table 1 Baseline characteristics of 4133 patients

	Eradication group (n = 3781)	Non-eradication group (n = 352)
Male/Female	2715/1066	249/103	P = 0.671
Male (%)	71.80	70.70
Mean age	52.4 ± 12.7	58.1 ± 12.6	P < 0.0012
Min-max	13.2-85.9	22.2-91.9
Age (yr)			P < 0.0011
< 60	2732 (72.3)	186 (52.8)
60-70	701 (18.5)	102 (29.0)
> 70	348 (9.2)	64 (18.2)
Location of ulcer			P = 0.411
GU	2048 (54.2)	195 (55.4)
GDU	418 (11.1)	45 (12.8)
DU	1265 (33.5)	110 (31.3)
Unknown	50 (1.3)	2 (0.6)
Salt consumption			P < 0.0011
Restricted	1377 (36.4)	173 (49.1)
No interest in salt consumption	729 (19.3)	29 (8.2)
Not restricted	1185 (31.3)	105 (29.8)
Unknown	490 (13.0)	45 (12.8)
Smoking history			P < 0.0011
Non-smokers	1174 (31.0)	120 (34.1)
Past smokers	565 (14.9)	48 (13.6)
Current smokers	1931 (51.1)	159 (45.2)
Unknown	111 (2.9)	25 (7.1)
Mean duration of follow-up (yr)	5.6 ± 1.1	5.2 ± 1.8	P < 0.0012
Min-max	0.09-7.96	0.11-8.41

¹χ² test;

²t test. Eradication group: patients who received Helicobacter pylori eradication therapy with or without successful eradication. Non-eradication group: Patients who received conventional antacid therapy. GU: Gastric ulcer; GDU: Gastroduodenal ulcer; DU: Duodenal ulcer.

Table 2 Distribution of cases of gastric cancer

Sex	Male	Female			Total
Eradication group	38	9			47	P = 0.3281
Non-eradication group	9	0			9
Type of peptic ulcer	GU/GDU	DU
Eradication group	43	4			47	P = 0.2441
Non-eradication group	7	2			9
Histological type of cancer	Intestinal	Diffuse	Unknown
Eradication group	35	10	2		47	P = 0.3042
Non-eradication group	5	4	0		9
Location of cancer	L	M	U	Unknown
Eradication group	21	18	6	2	47	P = 0.7592
Non-eradication group	3	5	1	0	9
Stage	Early	Advanced	Unknown
Eradication group	34	11	2		47	P = 0.1982
Non-eradication group	9	0	0		9
Treatment	Endoscopy (EMR/ESD)	Surgery	Chemotherapy
Eradication group	12	31	2		47	P = 0.7632
Non-eradication group	2	7	0		9

¹Fisher’s direct test;

²Student’s t test or χ² test. ESD: Endoscopic submucosal dissection; L: Lower third of the stomach; M: Middle third of the stomach; U: Upper third of the stomach.

Table 3 Results of poisson regression analysis

	IRR
	Univariate	95% CI	P	Multivariate	95% CI	P
Eradication group	0.45	0.22-0.92	0.03	0.61	0.29-1.27	0.18
Non-eradication group	1.00			1.00
Sex
Male	1.00		0.05	1.00		0.03
Female	0.49	0.24-1.00		0.39	0.17-0.88
Age (yr)	1.09	1.05-1.12	< 0.01
< 60	1.00			1.00
60-70	3.22	1.74-5.95	< 0.01	2.59	1.37-4.91	< 0.01
> 70	5.18	2.69-10.0	< 0.01	4.23	2.09-8.53	< 0.01
Location of ulcer	0.69	0.40-1.19	0.18
Stomach/Stomach + duodenum	1.00			1.00
Duodenum	0.28	0.13-0.63	< 0.01	0.37	0.16-0.83	0.02
Unknown	1.16	0.16-8.43	0.88	1.69	0.23-12.48	0.61
Salt consumption	0.94	0.84-1.06	0.27
Restricted	1.00			1.00
No interest in salt consumption	0.43	0.16-1.11	0.08	0.65	0.25-1.73	0.39
Not restricted	0.78	0.43-1.41	0.41	1.03	0.56-1.90	0.93
Unknown	0.58	0.24-1.39	0.22	0.58	0.22-1.60	0.29
Smoking history	1.04	0.89-1.22	0.63
Non-smokers	1.00			1.00
Past smokers	1.56	0.74-3.29	0.25	0.97	0.43-2.20	0.95
Current smokers	0.94	0.50-1.76	0.85	0.78	0.38-1.61	0.50
Unknown	1.71	0.50-5.88	0.39	1.65	0.41-6.65	0.48

IRR: Incidence rate ratio.

Table 4 IRRs of gastric cancer by follow-up period and location of ulcer

	Eradication group			Non-eradication group			IRR		IRR (sex- and age-adjusted)
	per 1000 person-years	n	Incidence	per 1000 person-years	n	Incidence		95% CI		95% CI
Overall	21.2	47	2.22	1.82	9	4.93	0.45	0.22-0.92	0.58	0.28-1.19
Follow-up period (yr)
< 1	3.77	17	4.51	0.34	2	5.81	0.78	0.18-3.33	1.16	0.27-5.00
1-3	7.48	20	2.67	0.64	4	6.27	0.43	0.15-1.25	0.50	0.17-1.49
> 3	9.92	10	1.01	0.84	3	3.56	0.28	0.08-1.03	0.34	0.09-1.28
Gastric/Gastric + duodenal ulcers	13.8	41	2.97	1.21	7	5.76	0.52	0.23-1.15	0.62	0.27-1.39
Duodenal ulcers	7.12	5	0.70	0.60	2	3.35	0.21	0.04-1.08	0.31	0.06-1.61