Background: Numerous studies have revealed that statins have antitumor effects in vivo and in vitro. However, few studies have explored the relationship between statin use and the mortality of gastric cancer (GC) patients after treatments. This study examines the relationship between statin use and the overall survival (OS) of GC patients after surgery and adjuvant chemotherapy, using data from the nationwide cohort database of Taiwan. Methods: All patients newly diagnosed with GC from 1999 to 2008 in Taiwan were identified from the Registry of Catastrophic Illness Patients Database. Through propensity score matching, statin users were matched to statin non-users at a 1:4 ratio. The relationship between statin use and the OS of patients with GC was estimated through Cox regression models. Results: The study cohort included 1835 patients with GC who had received therapies during the study period. The death numbers among statin users (defined as those who used more than 28 cumulative defined daily doses (cDDDs)) and statin non-users were 138 and 895, respectively. A dose–response association was noted between statin use and the OS of patients with GC after treatments. The adjusted hazard ratios were 0.62 (95% confidence intervals (CI), 0.50–0.78) and 0.34 (95% CI, 0.26–0.45) for statin users administered 28–167 cDDDs and >168 cDDDs, respectively, compared with no statin use (<28 cDDDs). Conclusions: This study highlights that statin use may dose-dependently improve the OS of patients with GC after surgery and adjuvant chemotherapy in Taiwan. Additional studies are required to confirm the efficacy and safety of statin use.

To determine whether exposure to antidepressants (ATDs) results in improved overall survival (OS) of patients with gastric cancer (GC) after surgery, we conducted a large cohort study and considered confounding factors that might affect the research outcomes. Patients who received a new diagnosis of GC and received surgery and chemotherapy between 1999 and 2008 were recruited and were classified into different groups based on the ATD level used. The association between the OS of patients with GC after surgery with different levels of ATD use, and the hazard ratio with comorbidities at different ATD use levels were compared. According to Kaplan–Meier method, the more of an ATD was taken, the longer the OS and a dose-dependent relationship was discovered in the OS curve; the adjusted HRs were 0.76 (95% confidence interval [CI] = 0.68–0.84) and 0.48 (95% CI = 0.41–0.57) for ATD users taking a cumulative defined daily dose (cDDD) of 28–167 and ≧168, respectively. Sensitivity analyzes were performed to investigate the effect of various comorbidities on OS with different degrees of ATD use and the results remained consistent among the varying models. Additionally, the effect of ATD use still exhibited a dose-dependent relationship in distinct stratifications for sex and age. The OS for patients with GC after surgery and chemotherapy improved with ATD use, and a dose-dependent relationship was discovered in this study. Further studies on the association between OS of GC and ATD use are required.