Association Between Helicobacter Pylori Infection And Outcome In Advanced Gastric Cancer Patients Treated With S-1 Adjuvant Chemotherapy.

4043Background: The beneficial and deleterious effects of Helicobacter pylori (H. pylori) infection remain to be fully elucidated. A clear understanding of the infectious mechanism is crucial since the potential effect may result in a survival benefit for life-threatening diseases. To understand the potential beneficial effect in advanced gastric cancer, we analyzed survival for patients treated with surgery-only or adjuvant chemotherapy on the basis of H. pylori infection status. Methods: A cohort of 491 patients who underwent R0 resection for locally-advanced gastric cancer between 2000 and 2009 at 12 institutions in northern Japan from the Northern Japan Gastric Cancer Consortium was included. H. pylori infection status was assessed from paraffin-embedded formalin-fixed samples. Overall survival (OS) and disease-free survival (DFS) in surgery-only (Surgery) and adjuvant chemotherapy (S-1) groups were analyzed. A propensity score matching was employed to correct for confounding factors by indication. To...