Effect of beta-blockers on survival of lung cancer patients: a systematic review and meta-analysis

The recent interest in beta-blockers as possible agents for drug repurposing in oncology arises from many pre-clinical and epidemiologic studies suggesting a possible clinically relevant antitumour effect. In lung cancer, given the contradictory results obtained, it is crucial to further study its effects. A systematic review of the literature was planned to evaluate a possible beneficial effect of beta-blocker on overall survival in lung cancer patients. Medline and Embase databases were searched from inception until 1 May 2018 to identify published studies that assessed the effect beta-blocker use on overall survival in lung cancer patients. Risk of bias was evaluated by Newcastle-Ottawa scale. Hazard ratios and 95% confidence intervals for overall survival were estimated using a random-effects model. Of 920 studies, seven (all retrospective and observational, six cohort and one case-control), including 7448 patients, met the inclusion criteria. Beta-blocker users with lung cancer had no increased overall survival compared to non-users (hazard ratio = 1.00; 95% confidence interval = 0.91-1.10; I-2= 45%). Similarly, beta-blocker users with non-small cell lung cancer had no increased overall survival compared to beta-blocker non-users (hazard ratio = 0.96; 95% confidence interval = 0.80-1.17; I-2= 56%). Our findings do not suggest an overall survival advantage in patients with lung cancer using beta-blocker therapy when compared to non-users. Further prospective cohort studies, designed to overcome the intrinsic limitations of retrospective observational studies are warranted to definitively clarify any possible beneficial effect of beta-blockers on lung cancer overall survival.