Helicobacter pylori infection, atrophic gastritis, and pancreatic cancer risk

Abstract

Background:To investigate the associations of Helicobacter pylori (Hp) infection and atrophic gastritis (AG) with pancreatic cancer risk.Methods:A literature search in PubMed was performed up to July 2017. Only prospective cohort and nested case–control studies enrolling cancer-free participants were eligible. Incident pancreatic cancer cases were ascertained during the follow-up. The risks of pancreatic cancer were compared between persons infected and noninfected with Hp, or between those with and without AG status at baseline. Odds ratios (ORs) or hazard ratios were combined. Subgroup and sensitivity analyses were performed, and publication bias was estimated.Results:Three cohort studies and 6 nested case–control studies, including 65,155 observations, were analyzed. The meta-analyses did not confirm the association between pancreatic cancer risk and Hp infection (OR = 1.09, 95% confidence interval [CI] = 0.81–1.47) or AG status (OR = 1.18, 95% CI = 0.80–1.72). However, particular subpopulations potentially had increased risks of pancreatic cancer. Cytotoxin-associated gene A (CagA)-negative strains of Hp might be a causative factor of pancreatic cancer (OR = 1.30, 95% CI = 1.05–1.62), but a sensitivity analysis by leave-one-out method did not fully warrant it (OR = 1.20, 95% CI = 0.93–1.56). In 1 nested case–control study, AG at stomach corpus in Hp-negative subpopulation might have increased risk of pancreatic cancer, but with a poor test power = 0.56. Publication biases were nonsignificant in the present meta-analysis.Conclusion:Based on current prospective epidemiologic studies, the linkage of pancreatic cancer to Hp infection or AG status was not warranted on the whole. Nevertheless, prospective studies only focusing on those specific subpopulations are further required to obtain better power.

Association betweenH. pyloriinfection and health Outcomes: an umbrella review of systematic reviews and meta-analyses

“…Overall, 3036 articles that met our search criteria were first identified from the seven databases. Sixty articles9–18 27–76 of observational studies were finally selected, covering 88 unique outcomes (figure 1). Fifty-four meta-analyses10–17 28–34 38–40 42–44 47–50 54–60 64–70 72–75 were reanalysed because they did not present all of the results of estimates (i.e.…”

“…Among the 1239 individual studies, 274 (22%) were cross-sectional studies, 748 (60%) were case–control studies, 124 (10%) were cohort studies and 93 (8%) were mentioned as observational studies. Furthermore, 1 meta-analysis62 did not present the number of participants, and 12 meta-analyses27 35 36 41 45 49 51 53 54 61–63 72 did not present the number of cases. Among the meta-analyses that indicated the number of cases or participants, the median number of cases was 1032 (28–96 753) and the median number of participants was 3826 (222–377 976).…”

Helicobacter Pylori infection of the gallbladder and the risk of chronic cholecystitis and cholelithiasis: A systematic review and meta‐analysis

“…Samples were also obtained during ERCP, PTCD, and EPT. Considering that some studies has reported the potential association between H. pylori infection and pancreatic cancer risk, whether the unknown infectious role of H. pylori in biliary tract of pancreatic cancer patients might influence the comparison between the case and control groups needs further observation. Secondly, in addition to H. pylori , there also have been other Helicobacter species in cholelithiasis and chronic cholecystitis patients with high presence detected in several studies.…”

The Interplay between Immunity and Microbiota at Intestinal Immunological Niche: The Case of Cancer

“…As well, Hp may enhance the activator of signal transducer and activator of transcription3 (STAT3) implicated in carcinogenesis through its capacity to promote cellular proliferation and, conversely, inhibit apoptosis [115,116]. Despite this supportive evidence, a recent meta-analysis, based on prospective epidemiologic studies, has not documented a strong association between Hp infection and pancreatic cancer [117].…”