Preoperative Cumulative Smoking Dose on Lung Cancer Surgery in a Japanese Nationwide Database

Background: Smoking is a known risk factor for postoperative mortality and morbidity. However, the significance of cumulative smoking dose in preoperative risk assessment has not been established. We examined the influence of preoperative cumulative smoking dose on surgical outcomes after lobectomy for primary lung cancer. Methods: A total of 80,989 patients with primary lung cancer undergoing lobectomy from 2014 to 2016 were enrolled. Preoperative cumulative smoking dose was categorized by pack-years (PY): nonsmokers, PY = 0; light smokers, 0 < PY < 10; moderate smokers, 10 ≤ PY < 30; and heavy smokers, 30 ≤ PY. The risk of short-term outcomes was assessed according to PY by multivariable analysis adjusted for other covariates. Results: Postoperative 30-day mortality, as well as pulmonary, cardiovascular, and infectious complications, increased with preoperative PY. Multivariable analysis revealed that the odds ratios (ORs) for postoperative mortality compared with nonsmokers were 1.76 for light smokers (P = .044), 1.60 for moderate smokers (P = .026), and 1.73 for heavy smokers (P = .003). The ORs for pulmonary complications compared with nonsmokers were 1.20 for light smokers (P = .022), 1.40 for moderate smokers (P < .001), and 1.72 for heavy smokers (P < .001). Heavy smokers had a significantly increased risk of postoperative cardiovascular (OR, 1.26; P = .002) and infectious (OR, 1.39; P = .007) complications compared with nonsmokers. Conclusions: The risk of mortality and morbidity after lung resection could be predicted according to preoperative cumulative smoking dose. These findings contribute to the development of strategies in perioperative management of lung resection patients.