To Örebro University

BACKGROUND: The current study aims to address the clinical equipoise regarding the association of ongoing statin therapy at time of surgery with long-term postoperative mortality rates after elective, curative, surgical resections of colon cancer by analyzing data from a large validated national register.

METHODS: All adults with stage I to III colon cancer who underwent elective surgery with curative intent between January 2007 and October 2016 were retrieved from the Swedish Colorectal Cancer Register, a prospectively collected national register. Patients were identified as having ongoing statin therapy if they filled a prescription within 12 months pre- and postoperatively. Study outcomes included 5-year all-cause and cancer-specific postoperative mortality. To reduce the impact of confounding from covariates owing to nonrandomization, the inverse probability of treatment weighting method was used. Subsequently, Cox proportional hazards models were fitted to the weighted cohorts.

RESULTS: In total, 19,118 patients underwent elective surgery for colon cancer in the specified period, of whom 31% (5,896) had ongoing statin therapy. Despite being older, having a higher preoperative risk, and having more comorbidities, patients with statin therapy had a higher postoperative survival. After inverse probability of treatment weighting, patients with statin therapy displayed a significantly lower mortality risk up to 5 years after surgery for both all-cause (hazard ratio 0.68, 95% confidence interval 0.63-0.74, P < .001) and cancer-specific mortality (hazard ratio 0.76, 95% confidence interval 0.66-0.89, P < .001).

CONCLUSION: The results of this study indicate that statin therapy is associated with a sustained reduction in all-cause and cancer-specific mortality up to 5 years after elective colon cancer surgery. The findings warrant validation in future prospective clinical trials.