Helicobacter pylori and oesophageal and gastric cancers in a prospective study in China

Abstract

In a cohort of 29 584 residents of Linxian, China, followed from 1985 to 2001, we conducted a case -cohort study of the magnitude of the association of Helicobacter pylori seropositivity with cancer risk in a random sample of 300 oesophageal squamous cell carcinomas, 600 gastric cardia adenocarcinomas, all 363 diagnosed gastric non-cardia adenocarcinomas, and a random sample of the entire cohort (N ¼ 1050). Baseline serum was evaluated for IgG antibodies to whole-cell and CagA H. pylori antigens by enzymelinked immunosorbent assay. Risks of both gastric cardia and non-cardia cancers were increased in individuals exposed to H. pylori (Hazard ratios (HRs) and 95% confidence intervals ¼ 1.64; 1.26 -2.14, and 1.60; 1.15 -2.21, respectively), whereas risk of oesophageal squamous cell cancer was not affected (1.17; 0.88 -1.57). For both cardia and non-cardia cancers, HRs were higher in younger individuals. With longer time between serum collection to cancer diagnosis, associations became stronger for cardia cancers but weaker for non-cardia cancers. CagA positivity did not modify these associations. The associations between H. pylori exposure and gastric cardia and non-cardia adenocarcinoma development were equally strong, in contrast to Western countries, perhaps due to the absence of Barrett's oesophagus and oesophageal adenocarcinomas in Linxian, making all cardia tumours of gastric origin, rather than a mixture of gastric and oesophageal malignancies.

Association of smoking, alcohol and NSAIDs use with expression of cag A and cag T genes of Helicobacter pylori in salivary samples of asymptomatic subjects

“…Helicobacter pylori (H. pylori), termed as class I carcinogen by World Health Organization, is a worldwide menace with the ability to transform gastric lesions into a carcinogenic lymphoma [1][2][3] . It has been studied in depth by many workers proving its disease causing potential to be immense [4,5] .…”

Association between Helicobacter pylori seropositivity anddigestive tract cancers

“…The population-based casecontrol study in Huaian (case number 107) showed those with positive findings for H pylori antibody to be at 3-fold risk of developing esophageal SCC (AOR = 3.19, 95% CI: 1.11-9.15) [15] . But, in the case-cohort study including 335 ESCC patients in Linxian, no association was found between esophageal SCC risk and positive finding for antibodies to either H pylori (Hazard ratio = 1.17, 95% CI: 0.88-1.57) or CagA (Hazard ratio = 1.08, 95% CI: 0.80-1.47) [16] . In these two areas, the predominant risk factors for ESCC were diet and nutrition, instead of cigarette smoking and alcohol consumption mostly found in Western countries and Taiwan.…”

“…Siman et al [17] updated their nested case-control study and found neither H pylori (OR = 0.44, 95% CI: 0.15-1.2) nor CagA seropositivity (OR = 2.0, 95% CI: 0.24-infinity) was significantly associated with esophageal SCC risk (n = 37). Recently, two studies were conducted in two major endemic areas in ChinaHuaian City [15] and Linxian [16] . The population-based casecontrol study in Huaian (case number 107) showed those with positive findings for H pylori antibody to be at 3-fold risk of developing esophageal SCC (AOR = 3.19, 95% CI: 1.11-9.15) [15] .…”

“…In contrast, the relationship between H pylori infection and esophageal squamous cell carcinoma (SCC) is still inconclusive [8,[14][15][16][17] . Very few studies have examined the role of H pylori infection on colon and oral cancers.…”

Helicobacter pylori - Protective or Causative Agent in Oesophageal Cancer?

“…In a Chinese study [9] the authors did not find any association between H. pylori and oesophageal squamous cell carcinoma. H. pylori infection may cause gastric atrophy leading to atrophic gastritis which allows over growth of bacteria, Nitrosamines are produced by these bacteria leading to increase oesophageal cancer risk.…”