Lung Cancer in Never-Smoker Subjects: Epidemiological, Clinical and Survival Patterns based on Gender

Abstract

Introduction: Tobacco smoke is the predominant risk factor for the development of lung cancer (LC ). However, a recent increase of LC in never-smokers is prominent in some countries. Objective: Our aim was to verify epidemiological and survival  characteristics in never-smoker LC patients. Method: A historical cohort of never-smoker subjects with LC diagnosed from 2000 to 2009. Overall survival was compared using Log-rank test, and Cox regression analysis was used to identify independent prognostic factors. Results: A total of 254 never-smoker LC patients were studied (median age: 65.5 years; 66.5% women). The most common histological type was adenocarcinoma (65.7% in women and 60.0% in men), being that the majority of the patients had advanced staging (III-IV) (79.6% in women and 92.8% in men). According to treatment, 9.9% of the patients were treated with surgery (13.1% in women and 3.6% in men). The overall 1-year, 3-year and 5-year survival rates were, respectively: 37.2%, 14.2%, and 9.5%. The median overall survival was 8.3 months. Women had a better survival than men (9.6 vs. 6.9 months; p=0.023). Non-surgical treatment (p<0.001), performance status 2-4 (p=0.038), and stage III-IV (p<0.001) were associated with a poorer overall survival. Conclusions: We found a higher occurrence of adenocarcinoma, of advanced staging, and of non-surgical treatment. Women had a better survival than men. Due to a low overall survival, these  data underscores the importance of early diagnosis of LC in never-smoker patients.