Abstract
BACKGROUND: Studies have suggested that medication with statins improves survival in patients with gastric cancer, but methodological issues have limited the interpretability and prohibited conclusive results. We aimed to provide valid evidence as to whether statin use improves survival of gastric adenocarcinoma. METHODS: This nationwide and population-based cohort study included virtually all patients who underwent curatively intended surgery (gastrectomy) for gastric adenocarcinoma in Sweden between 2006 and 2015 with follow-up throughout 2019 for disease-specific mortality and 2020 for all-cause mortality. Data came from medical records and national healthcare registries. The exposure was statin use during the year prior to gastrectomy which was compared to no such use during the same period. The outcomes were 5-year disease-specific mortality (main) and 5-year all-cause mortality (secondary). Multivariable Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI), adjusted for age, sex, education, calendar year, comorbidity, low-dose aspirin use, tumour sublocation, pathological tumour stage, neoadjuvant chemotherapy, annual surgeon volume, and surgical radicality. RESULTS: Among 1515 participating patients, the mean age was 69 years and 58.4% were men. Statin use, identified in 399 (26.3%) patients, was not associated with any statistically significantly decreased 5-year disease-specific mortality (HR 0.99, 95% CI 0.82-1.21) or 5-year all-cause mortality (HR 0.94, 95% CI 0.79-1.12). No risk reductions were found across subgroups of age, sex, aspirin user status, or tumour stage, or in patients with long-term preoperative of postoperative use of statins, all with point estimates close to 1. CONCLUSIONS: Perioperative use of statins does not seem to improve the 5-year survival in patients who undergo gastrectomy with curative intent for gastric adenocarcinoma in Sweden.