Aspirin use in relation to long-term survival after gastrectomy for gastric adenocarcinoma.

Background: Low-dose aspirin use may reduce cancer incidence and mortality, but its influence on gastric adenocarcinoma survival is unclear. This study aimed to assess whether aspirin use improves long-term survival following gastrectomy for gastric adenocarcinoma.

Methods: This population-based cohort study included almost all patients who underwent gastrectomy for gastric adenocarcinoma in Sweden from 2006 to 2015, with follow-up throughout 2020. Preoperative exposure to a daily low-dose (75-160 mg) aspirin for 1 (main exposure), 2 and 3 years and for 1 year after gastrectomy was examined in relation to 5-year all-cause mortality (primary outcome) and disease-specific mortality. Multivariable Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI), adjusted for age, sex, education, calendar year, comorbidity, statin use, tumour location, tumour stage, neoadjuvant chemotherapy, surgeon volume of gastrectomy and surgical radicality.

Results: Among 2025 patients, 545 (26.9%) used aspirin at the date of gastrectomy. Aspirin use within 1 year before surgery did not decrease the adjusted risk of 5-year all-cause mortality (HR = 0.98, 95% CI 0.85-1.13) or disease-specific mortality (HR = 1.00, 95% CI 0.86-1.17). Preoperative aspirin use for 2 years (HR = 0.98, 95% CI 0.84-1.15) or 3 years (HR = 0.94, 95% CI 0.79-1.12) did not decrease the risk of 5-year all-cause mortality. Patients remaining on aspirin during the first year after gastrectomy had a similar 5-year all-cause mortality as non-users of aspirin (HR = 1.01, 95% CI 0.82-1.25).

Conclusions: Low-dose aspirin use might not improve long-term survival after gastrectomy for gastric adenocarcinoma and may thus not be a target for adjuvant therapy in this group of patients.