OUP accepted manuscript

The incidence of postoperative complications is relatively high in smokers. Although 4-week smoking cessation before surgery is generally recommended, it has not been sufficiently studied in lung cancer surgery. This study investigated whether smoking cessation for a short period of time significantly reduced complications after lung cancer surgery.This was a retrospective, observational study that investigated the relationship between the smoking cessation period and the incidence of complications in lung cancer surgery. Patients who underwent curative-intent surgery for lung cancer at our institution between January 2014 and December 2017 were included. The smokers were classified into the following 4 categories of smoking cessation period before surgery: current (<4 weeks), recent (4 weeks to 12 months), distant (12 months to 5 years) and ex-smokers (>5 years).A total of 911 patients were included in this study. The incidence of pulmonary complications was 5 times higher in the smoker group than in the never smoker group (12.9% vs 2.5%, P < 0.001). On multivariable analysis in both models, the odds ratio for complications was significantly higher in distant smokers than in recent smokers and never smokers. Across all models, low lung function significantly predicted the development of postoperative complications.The evidence-based smoking cessation duration that reduces the incidence of complications after thoracic surgery remains unclear. The incidence of postoperative complications was more strongly affected by low pulmonary function than by the duration of preoperative smoking cessation. For patients with marginal indications for surgery, postponing surgery to accommodate a smoking cessation period seemed unnecessary.