Methods: Forty-five smokers patients with moderate COPD and affected by non-small cell lung cancer stage T1-3N0M0 were progressively enrolled. They underwent successful smoking cessation program with varenicline or NRT (nicotine replacement therapy), at the time stereotactic body radiotherapy (SBRT) was undertaken. It is a cohort not randomized study Twenty smokers’ patients without quitting affected by early stage lung cancer were recruited for comparison. The baseline characteristics of the two groups were comparable. Adenocarcinoma was the prevalent histo-type in both groups. Follow up of six months was completed. Patients performed the Fagestrom dependence nicotine test (FTND), spirometer with plethymography technique with detection of postbronchodilator forced expiratory one second volume (FEV1) obtained by salbutamol 400 μg, 6 minute walking test, hemogasanalysis, and carbon monoxide exhaled test at baseline and after 6 months. Endpoints: to detect differences in lung function decline after SBRT, between the two groups Outcomes Self-reported smoking cessation confirmed by measurement of exhaled CO. Comparison of FEV1 and forced vital capacity (FVC) level after SBRT between groups

Results: After radiotherapy, a minimal decline in lung function in the study group (quitters patients) compared with patients who not quit. Specifically FEV 1 was reduced by only 4 mm differently from the control group that reduced by 160 ml. FVC was also reduced less than control group (8 ml vs 250 ml). The Forced Expiratory Flow (FEF) 25-75 dropped down more in control group by 11%. 6-minute walking test(WT) was also reduced more in control group in terms of walking distance. PaO2 didn’t change significantly in the study group in comparison with control and dyspnea test modified Medical Research Council (mMRC) changed only in control group.

Conclusions: Smoking cessation is confirmed as an effective therapeutic presidium leading a good clinical response to stereotactic body radiation and good tolerance in COPD and lung cancer patients. SBRT along with smoking cessation should be considered for patients with lung cancer stage I-II, who are no fit for surgery.