Objective s To investigate the effects of preoperative smoking and smoking cessation time on preoperative peripheral blood inflammatory indexes and postoperative hospitalization outcomes in male patients with lung cancer and surgery therapy.Methods We retrospectively enrolled 637 male patients who underwent curative-intent lung cancer resection between January 2014 and December 2016. Patients were classified as the current smokers, the never smokers, and the ex-smokers based on their smoking history, and the ex-smokers were allocated into five subgroups according to their smoking cessation times (CeT): CeT≤6 weeks, 6weeks<CeT≤1year, 1year<CeT≤5years, 5years<CeT≤10years, CeT>10years. The preoperative peripheral blood white blood cells (WBCs), albumin, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), intraoperative blood loss, 30-day mortality, in-hospital days, hospitalization costs, intensive care unit (ICU), admission days and placement time of closed thoracic drainage tube were compared among different groups.Results There were significant differences in WBC (F=5.275, P<0.001) and albumin (F=2.470, P<0.05) among patients of current smokers, ex-smokers with different smoking cessation time, and never-smokers. The blood WBC count in current smokers (7.7×10 ⁹/L) was significantly higher than that in ex-smokers (7.0×10 ⁹/L)and never-smokers (5.9×10 ⁹/L) (t=-2.145, P<0.05; t=-6.073, P<0.01, respectively). The level of peripheral blood albumin in current smokers (41.1 g/L) was lower than that in ex-smokers (42.1 g/L) and never-smokers (43.2 g/L) (t=2.323, P<0.05; t=3.995, P<0.01, respectively). The level of peripheral blood NLR in current smokers (3.7) was higher than that in ex-smokers (3.1) and never smokers (2.8) (t=-1.836, P<0.05; t=-2.889, P<0.01, respectively). There was no significant difference in WBC, albumin and NLR among five subgroups of different smoking cessation time. No significant difference was observed in intraoperative blood loss, 30-day mortality, hospitalization costs, hospital stay, ICU stay and placement time of closed thoracic drainage tube among groups either. Conclusion Smoking increases the preoperative inflammatory indexes in peripheral blood of lung cancer patients. Smoking cessation has beneficial effect on reducing levels of these inflammatory indexes, which may be not impacted by the time length of smoking cessation. Therefore, lung cancer patients should be encouraged to quit smoking at any time.

Key words: smoking, smoking cessation, lung cancer, surgical treatment, inflammatory factors, postoperative outcomes

Funding: Fund supported by the National Key R&D Program of China No(2018YFC2001800)