Endoscopic surveillance of gastric cancers after Helicobacter pylori eradication

Table 1 Incidence of metachronous cancer after successful Helicobacter pylori eradication

Ref.	Country	Subject	Study design	Follow-up(yr)	Synchronous rate	Metachronous	Incidence(%)	Effect, OR (95%CI)
Uemura et al[15], 1997	Japan	65/67	NR	4	6 (9%)	> 0 yr	0.0/9.0	Effective, P = 0.011
Fukase et al[16], 2008	Japan	272/272	RCT	3	ND	> 0 yr	3.3/8.8	Effective, 0.35 (0.16-0.78) P = 0.009
Maehata et al[17], 2012	Japan	177/91	Retrospective	3 (1.1-11.1)	ND	> 1 yr	8.5/14.3	Non-effective, 1.71 (0.72-4.03)
Kato et al[18], 2013	Japan	263/105	Retrospective	2.2 (2-5)	110 (9%)	> 1 yr	9.1/5.7	Non-effective
Choi et al[19], 2013	South Korea	439/441	RCT	3 (2.0-4.5)	ND	> 0 yr	2.3/3.9	Non-effective, P = 0.15
Seo et al[20], 2013	South Korea	61/13	Retrospective	2.3	ND	> 1 yr	9.8/23.1	Non-effective, 0.36 (0.08-1.70) P = 0.189
Chon et al[21], 2013	South Korea	85/44	Retrospective	2.2 (1.4-2.5)	ND	> 1 yr	4.7/11.4	Effective, HR = 0.143, P = 0.008
Bae et al[22], 2014	South Korea	485/182	Retrospective	5 (2-11.4)	ND	> 6 mo	7.0/13.2	Effective, HR = 1.9, P = 0.01
Kwon et al[23], 2014	South Korea	214/69	Retrospective	3.4 (3-5)	ND	> 1 yr	4.7/14.5	Effective, 2.3 (1.1-4.7) P = 0.021
Kim et al[24], 2014	South Korea	49/107	Retrospective	4.3 (1-11.3)	5 (3%)	> 1 yr	4.1/15.0	Effective, P = 0.006
Jung et al[25], 2015	South Korea	506/169	Retrospective	3.3	15%	> 1 yr	4.2/5.9	Non-effective, HR = 0.67, P = 0.29

Number of subjects with/without eradication. NR: Non-randomized; RCT: Randomized controlled trial; Follow-up: Median (range); ND: Not described; Metachronous: Metachronous cancer classified as a second lesion within 1 year (> 0 year) or after 1 year (> 1 year); Incidence: Percentage of metachronous lesions with/without eradication including failure; OR: Odds ratio; CI: Confidence interval; HR: Hazard ratio.

Table 2 Incidence of multiple gastric cancers after endoscopic resection of primary early gastric cancer n (%)

Ref.	Country	Subject	Follow-up (yr)	Synchronous cancers	Metachronous cancers
Arima et al[30], 1999	Japan	76	7	5 (6.6)	6 (7.9)
Nasu et al[31], 2005	Japan	143	13.1 (median 4.8)	16 (11.2)	20 (14.0)
Nakajima et al[32], 2006	Japan	633	13.9 (mean 4.4)	58 (9.2)	53 (8.2)
Kobayashi et al[33], 2010	Japan	234	19.6 (median 5.0)	45 (19.2)	30 (12.8)
Han et al[34], 2011	South Korea	176	4	7 (4.0)	9 (5.1)
Kato et al[18], 2013	Japan	1258	6 (mean 2.2)	110 (8.7)	65 (5.2)
Kim et al[35], 2013	South Korea	602	ND	12 (2.0)	ND
Boda et al[36], 2014	Japan	357	9.5 (median 4.4)	50 (14.0)	39 (10.9)
Kosaka et al[37], 2014	Japan	438	9.8	45 (10.2)	34 (7.8)

Number of subjects without eradication. ND: Not described; Synchronous cancers: Second gastric cancers discovered within 1 yr after the initial endoscopic resection; Metachronous cancers: Second gastric cancers discovered 1 yr or later from the initial endoscopic resection.