Effective smoking cessation interventions in people with cancer: A systematic review and meta-analysis of randomized controlled trials.

Abstract

Introduction: Continued smoking increases the risk of all-cause and cancer-specific mortality and adversely affects treatment outcomes. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the effectiveness of smoking cessation interventions in individuals diagnosed with cancer.

Methods: We conducted a systematic review across several databases, including PsychINFO, EMBASE (through OVID), PubMed (also through OVID), and CINAHL, of RCTs evaluating smoking intervention trials of adult cancer survivors regardless of cancer type, stage, or treatment received. The Cochrane Risk of Bias Tool 2 (ROB-2) evaluated the risk of bias. A meta-analysis was performed using fixed-effect models in R. The last database search was conducted in March 2025.

Results: The search yielded 984 publications. Twenty-three studies met the inclusion criteria. Smoking cessation interventions significantly enhanced cessation rates compared to control (risk ratio, RR=1.36; 95% CI: 1.22-1.51). Results did not show a difference between behavioral interventions alone versus control in the random-effects model (OR=1.08; 95% CI: 0.74-1.60). For studies using biochemical verification, the RR was stronger (RR=1.57; 95% CI: 1.32-1.87) than studies using self-report (RR=1.25; 95% CI: 1.09-1.42). In studies reporting higher success rates in the intervention group, there was a high number of contacts and follow-ups, averaging at least five times.

Conclusions: The present systematic review and meta-analysis provide robust evidence supporting the effectiveness of smoking cessation interventions in cancer patients, particularly when combining pharmacological and behavioral approaches. Cancer patients are capable of successfully quitting tobacco and should be encouraged by healthcare providers to initiate a smoking cessation effort that combines both approaches.