The effect of smoking status on survival following radiation therapy for non-small cell lung cancer

The dangers of cigarette smoking are numerous and well-known, including the causal relationship to lung cancer. This study investigates the effect that smoking status at initial consultation has on radiation therapy for non-small cell lung cancer (NSCLC). We identified 237 patients treated between 1991 and 2001 with definitive radiation or chemoradiation who had complete smoking histories. Median age was 73, with 56% males. Distribution by stage was as follows: I/II - 27%, IIIA - 27%, IIIB - 45%, recurrent - 1%. Two-year overall survival, stratified by stage of disease, was calculated from the time of initiation of treatment. Median follow-up time from the end of treatment was 13 months. Among those with stage I/II disease, current smokers had a 2-year survival rate of 41% and a median survival of 13.7 months while non-smokers had a 2-year survival of 56% and a median survival of 27.9 months (P=0.01). Patients with stage III disease did not show any significant differences in overall survival. There were no significant differences in cancer-specific survival in either stage. In conclusion, among NSCLC patients diagnosed with early stage disease, current smokers have a poorer prognosis for survival after radiation therapy.