The effectiveness of smoking cessation interventions after cancer diagnosis: A systematic review and meta-analysis

Objectives: patients with cancer who smoke have more side effects during and after treatment, and a lower survival rate than patients with cancer who quit smoking. Supporting patients with cancer to quit smoking should be standard care. The aim of this systematic review was to determine the most effective smoking cessation method for patients diagnosed with cancer. Methods: PubMed, Embase, Web of Science and Google Scholar were systematically searched. Included were randomized controlled trials and observational studies published after January 2000 with any smoking cessation intervention in patients with any type of cancer. Result of these studies were evaluated in a meta-analysis. Results: A total of 18,780 papers were retrieved. After duplicate removal and exclusion based on title and abstract, 72 publications were left. After full text screening, 19 (randomized) controlled trials and 20 observational studies were included. The overall methodological quality of the included studies, rated by GRADE criteria, was very low. Two out of 21 combined intervention trials showed a statistical significant effect. Meta-analysis of 18 RCTs and 3 observational studies showed a significant benefit of combined modality interventions (OR 1.67, 95% C.I.: 1.24-2.26, p = 0.0008) and behavioural interventions (OR 1.33, 95% C.I.: 1.02 - 1.74, p = 0.03), but not for single modality pharmacological interventions (OR 1.11; 95% C.I.: 0.69-1.78, p = 0.66). Conclusion: A combination of pharmacological and behavioural interventions may be the most effective intervention for smoking cessation in patients with cancer.