Abstract

Introduction: An extremely high prevalence of gastric cancer (GC) was observed in Xianyou County, the Southeastern of China, yet it remains unclear how interaction of environmental factors affects the GC risk in this area.
Methods: A population-based case-control study was conducted during March 2013 and January 2017 in Xianyou County. All newly diagnosed patients with GC were compared with healthy controls matched (1:1) by sex, age (± 3 years) and place of residence.
Results: A total of 622 cases of GC and 622 matched healthy controls were included. Participants who consumed pickled vegetables and had a preference for hard solid food had the highest risk of GC (adjusted OR=12.42, 95% CI: 7.56-20.41) compared to individuals who did not have such food patterns. Increased GC risk was also observed among those who consumed pickled vegetables but not drink tea (adjusted OR=6.88, 95% CI: 3.74-12.66), compared to those drinking tea but did not consume pickled vegetables. Furthermore, participants who did not consume tea but were exposed to pesticides during farm work also had 2.50 times (95% CI: 1.30-4.80) higher risk of GC risk compared to those had tea consumption but were not exposed to pesticides. No statistically significant interactions were observed for pesticide exposure, smoking, beef or pork consumption, fruit consumption, chronic atrophic gastritis and family history of any cancer in relation to GC.
Conclusion: Strong synergistic effects in raising the risk of GC were seen between pickled vegetables consumption and hard solid food preference, as well as between pickled vegetables consumption and not drinking tea.

Keywords: Combined effect; Oncology; Stomach cancer