Helicobacter pylori infection and esophageal cancer risk: An updated meta-analysis

Table 1 Characteristics of literatures included in the meta-analysis

Ref.	Study area	Year	Study type	HP Dm	Hp+definition1	ESCC				EAC				Matched/adjusted3	Control
						Case		Control		Case		Control
						Hp+	CagA+	Hp+	CagA+	Hp+	CagA+	Hp+	CagA+
Murphy et al[7]	Finnish	2012	Pop	S	HpSe+	64/82	35/82	63/82	36/82	-	-	-	-	Yes/yes	Matched with age, smoking and Alcohol consumption, and date of blood draw to controls, all of cases and controls were male smokers
Khoshbaten et al[9]	Iran	2011	Pop	S	HpSe+	58/100	28/100	83/100	36/100	-	-	-	-	Yes/no	Sex-matched and age-matched health individuals, any clinical evidence of gastrointestinal symptoms were excluded
Venerito et al[8]	Germany	2011	Clin	S, H, U	His+, HpSe+, CagA+ or U+	53/75	42/75	53/75	40/75	-	-	-	-	Yes/no	Sex and age-matched individuals with upper GI symptoms but no malignancy of the upper GI tract
Whiteman et al[11]	Australia	2010	Pop	S	HpSe+	54/208	-	302/1316	-	35/260	-	302/1316	-	Yes/yes	Randomly selected from the same areas, matched to each stratum of age and state
Cook et al[10]	Finnish	2010	Pop	S	HpSe+	64/78	35/78	71/91	42/91	-	-	-	-	Yes/yes	Matched to case for age, years of smoking, cigarettes per day, or body mass index
Wu et al[5]	Taiwan	2009	Pop	S	HpSe+	112/317	91/317	563/1103	268/700	-	-	-	-	No/yes	One part of control is matched by gender and age, but another part wasn't matched
Hu et al[6]	Taiwan	2009	Pop	S	HpSe+	66/180	-	102/194	-	-	-	-	-	Yes/yes	Healthy and cancer-free individuals, matched to age, sex and ethnicity
Früh et al[12]	Canada	2008	Clin	S	CagA + or VacA+	-	-	-	-	36/100	29/100	43/101	30/101	Yes/yes	Healthy GRERD-free, non-blood-related family member and friends of other cancer/surgical patients
Derakhshan et al[24]	Iran	2008	Clin	S	HpSe+	-	-	-	-	9/19	-	28/38	-	Yes/yes	Dyspeptic patients with no peptic ulcer or tumor in their endoscopy
Anderson et al[25]	Ireland	2008	Pop	S	HpSe+	-	-	-	-	55/123	57/123	157/253	150/253	Yes/yes	Randomly selected population-based controls, frequency matched to EAC cases for age and sex
Löfdahl et al[23]	Sweden	2008	Pop	S	HpSe+ or CagA+	-	-	-	-	130/230	-	304/499	-	Yes/no	Random selected from the population register, frequency matched for age and sex
Anandasabapathy et al[26]	United States	2007	Clin	H	His+	-	-	-	-	4/25	-	10/30	-	No/no	Barrett’s patients with no dysplasia
Iijima et al[27]	Japan	2007	Clin	S, H, U	HpSe+, His+ or U+	60/73	-	56/73	-	-	-	-	-	Yes/yes	Endoscoped patients with no localized lesion, matched to cases for age and sex
Kamangar et al[14]	China	2007	Pop	S	HpSe+	231/335	178/335	662/992	552/992	-	-	-	-	No/yes	Randomly selected from the entire baseline participants in the stdy cohort
Simán et al[13]	Sweden	2007	Pop	S	HpSe+	15/37	24/37	68/129	82/129	4/12	6/12	24/47	32/47	Yes/yes	Randomly selected from the study cohorted, matched with age, sex, and date enrollment
Wang et al[28]	China	2006	Pop	S	HpSe+	?/107	-	?/107	-	-	-	-	-	Yes/yes	Neighborhood controls, randomly selected, and matched to cases for age and gender
Wu et al[15]	Taiwan	2005	Pop	S	HpSe+	28/127	-	74/171	-	-	-	-	-	No/yes	Randomly selected from the same community
de Martel et al[29]	United States	2005	Pop	S	HpSe+	-	-	-	-	19/51	9/18	74/150	44/71	Yes/yes	Randomly selected from the study cohorted, matched with age, sex, and date enrollment race, and study site
Ye et al[16]	Sweden	2004	Pop	S	HpSe+	32/85	63/85	198/499	293/499	18/97	42/97	198/499	293/499	Yes/yes	Randomly selected population-based controls, frequency matched to EAC cases for age and sex
2Wang et al[30]	China	2003	Pop	S	HpSe+	33/63	-	145/310	-	-	-	-	-	Yes/no	Healthy subjects with no difference in age and gender
Wu et al[22]	United States	2003	Pop	S	HpSe+	-	-	-	-	49/80	18/80	230/356	106/356	Yes/yes	Matched to cases for age, sex, neighborhood of residence, and race
El Omar et al[21]	United States	2003	Pop	S	HpSe+	31/53	7/26	84/210	46/224	35/108	5/68	84/210	46/224	Yes/no	Matched to cases for age, sex, and study center
Weston et al[20]	United States	2000	Clin	H	His+	-	-	-	-	3/20	-	96/217	-	No/no	Patients with GERD symptoms but no Barrett’s esophagus
Vieth et al[19]	Germany	2000	Clin	H	His+	-	-	-	-	66/138	-	468/712	-	No/no	Patients with non-ulcer dyspepsia and no endoscopic signs of GERD
Peek et al[18]	United States	1999	Clin	S, H	HpSe+ or His+	-	-	-	-	11/30	3/30	20/48	25/48	No/no	Patients endoscoped for reasons other Than GERD or Barrett’s
Oberg et al[31]	United States	1999	Clin	H	His+	-	-	-	-	5/37	-	32/229	-	No/no	Patients with foregut symptoms and benign diseases
Talley et al[17]	United States	1991	Clin	S	HpSe+	20/41	-	96/252	-	-	-	-	-	No/no	Asymptomatic volunteers and patients with benign esophageal, lung, or culoskeletal disorders

¹Helicobacter pylori (H. pylori) positivity definition;

²Because the article showed that there was no difference in age and gender between cases and health controls, this study was analyzed as a matched population study;

³Individual-matching of controls to cases for age and gender/reporting adjusted ORs for the association between H. pylori and cancer. Clin: Clinical based; Pop: Population based; NR: Not reported; Hp Dm: Hpdetection method; S: Serology; H: Histology; U: Rapid urease test; His⁺: Positive histological examination of tissue samples; HpSe⁺: Sero-positivity for antibodies to whole-cell; VacA⁺: Sero-positivity for antibodies to VacA; CagA⁺: Sero-positivity for antibodies to cytotoxin-associated gene-A; U⁺: Positive rapid urease test; GERD: Gastroesophageal reflux disease; ESCC: Esophageal squamous cell carcinoma; EAC: Esophageal adenocarcinoma; GI: Gastrointestinal.