Fig. 1. Adjusted Kaplan-Meier plot for time to first recurrence by smoking status.
* Adjusted for age at diagnosis (<55, 56–65, 66–75, >75), stage of disease (II, III, IV), and treatment (immunotherapy, chemotherapy, radiation, combination, unknown). † Former smokers with ≥30 pack-years compared to never smokers. †† Current smokers with ≥40 pack-years compared to never smokers. ‡ Comparing all smoking levels (never, former with <30 pack-years, former with ≥30 pack-years, current with <40 pack-years, current with ≥40 pack-years).