Gastric cancer research in Mexico: A public health priority

Table 3 Studies of Helicobacter pylori in pathologies associated with the development of gastric cancer and gastric cancer in a Mexican population

Ref.	Year	Institute of adscription of corresponding author-city	Main finding	Quantity and type of groups studied
[39]	2013	ISSSTECuliacan, Sinaloa	Association between alcohol consumption and H. pylori infection.No relationship between H. pylori and smoking and coffee consumption	269 H. pylori positive 269 H. pylori negative
[46]	2013	IMSSMexico City	Association between H. pylori and p53 expression and between p53 and intestinal metaplasia	104 patients with no evidence of acute or clinically significant gastric pathology
[41]	2013	INSPCuernavaca, Morelos	IgG2 response to CagA could be used as a novel serological marker to identify patients with H. pylori-associated gastric cancer	46 intestinal metaplasia41 gastric cancer50 controls
[47]	2013	INSPCuernavaca, Morelos	No association between CagA and gastric cancer	67 gastric cancer 368 non atrophic gastritis124 preneoplastic lesion
[48]	2012	UNAMMexico City	Correlation of antibody subclass titers with Th1/Th2 markers may aid pathology characterization and diagnosis	14 gastric cancer5 peptic ulcer13 bleeding peptic ulcer12 dyspepsia
[49]	2012	IMSSMexico City	Failure to express cag19 and cag24 in vivo in precancerous lesions might serve as a biomarker of the risk of development of gastric cancer	11 gastric cancer10 non atrophic gastritis10 duodenal ulcer
[40]	2011	INSPCuernavaca, Morelos	Vac-A neutralizing antibodies might serve as a biomarker of the risk of development of gastric cancer and duodenal ulcer	90 intestinal metaplasia60 gastric cancer52 duodenal ulcer145 non atrophic gastritis
[43]	2009	UNAMTlalnepantla, Estado de Mexico	Patients with chronic gastritis had a high incidence of infection by H. pylori; 44% of the H. pylori strains may be considered as highly virulent since they possessed two or three of the virulence markers analyzed: vacA s1 cagA babA2	238 chronic gastritis
[50]	2009	IMSSMexico City	30 genes are significantly associated with non-atrophic gastritis, duodenal ulcer, or gastric cancer and may serve as risk biomarkers	10 non atrophic gastritis10 duodenal ulcer9 gastric cancer
[51]	2008	UNAMMexico City	H. pylori is uniformly distributed across the stomach in dyspepsia and has preference for fundus and corpus in gastric cancer.H. pylori genotype diversity across the systematic whole-organ and tumor is remarkable.There is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori	16 gastric cancer14 dyspepsia
[38]	2008	INSPCuernavaca, Morelos	H. pylori infection and CagA are risk markers for intestinal metaplasia. In gastric cancer, prevalence of these risk markers decreases, probably reflecting the fact that infection reduces when advanced atrophy and metaplasia develops	368 non atrophic gastritis126 precancerous lesions65 gastric cancer59 duodenal ulcer
[52]	2004	UANLNuevo Leon, Nuevo Leon	Absence of the HLA-DQA1*0503 allele could be a host risk factor for the development of gastric cancer.Infection with H. pylori CagA+, VacA+ strains represents a significant risk in terms of the development of gastric cancer	22 gastric cancer H. pylori positive8 high grade dysplasia H. pylori positive77 matched controls H. pylori positive
[37]	2004	INSPCuernavaca, Morelos	There is no association between nitrite and ascorbic consumption or interactions of these nutrients with seropositivity to H. pylori CagA+.Seropositivity to H. pylori CagA+ strains may be an independent factor in diffuse gastric cancer	211 gastric cancer454 controls
[53]	2001	SU1California, United States	In regions with a high prevalence of chronic atrophic gastritis, serological screening with CagA alone is an effective test for identifying eligible subjects	178 H. pylori positive155 H. pylori CagA+
[45]	1997	INSPCuernavaca, Morelos	H. pylori infection present in 87.2% of cases and 82.5% of controls	109 gastric cancer 177 controls
[44]	1993	INCanMexico City	In a high-risk population, precursor lesions for adenocarcinoma are universally associated with H. pylori infection	245 symptomatic patients

¹In collaboration with INCan, UNAM Mexico City and the Colegio de la Frontera Sur, San Cristobal de las Casas, Chiapas. H. pylori: Helicobacter pylori; ISSSTE: Institute of Social Security and Services of State Employees/Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado; IMSS: Mexican Institute of Social Security/Instituto Mexicano del Seguro Social; INSP: National Institute of Public Health/Instituto Nacional de Salud Pública; EBV: Epstein-Barr virus; UNAM: National Autonomous University of Mexico/Universidad Nacional Autónoma de México; UANL: Autonomous University of Nuevo Leon/Universidad Autónoma de Nuevo León; SU: Stanford University; INCan: National Institute of Cancerology/Instituto Nacional de Cancerología.