Gender Differences in Long-Term Survival after Surgery for Non-Small Cell Lung Cancer

Background This retrospective study examined gender differences in non-small cell lung cancer (NSCLC) by analyzing surgical cases at a single institution. Patients and Methods In this study, 735 NSCLC patients who underwent surgery from 1995 to 2010 were included. Clinical and pathological characteristics were retrieved by reviewing charts retrospectively, and variables between genders were compared. Results There were 489 males and 246 females in the study. The percentage of screening-detected lung cancers (83.7%), never smokers (82.9%), adenocarcinoma histology (90.7%), and pathological stage IA (42.7%) was higher in females than that in males (71.2, 8.2, 51.3, and 23.1%, respectively). Female patients had fewer cases of coronary artery disease (2.8%) and fewer pneumonectomy cases (2.0%) than the male patients (7.4 and 5.3%, respectively). The median follow-up period after surgery was 5.9 years. The overall survival rates at 5 years were 57.3% for males and 76.2% for females (p < 0.001, log-rank test). Based on univariate analysis, we report that histology, smoking history, and pathological stage were significant prognostic factors in addition to gender. Based on multivariate analysis, pathological stage III/IV (hazard ratio, 3.60; 95% confidence interval [CI], 2.84-4.54) and female gender (hazard ratio, 0.55; 95% CI, 0.37-0.82) were significant prognostic factors. Subgroup analysis demonstrated that female gender and adenocarcinoma histology were significant positive prognostic factors only in pathological stages I and II (n = 557). Conclusion Female gender as well as pathological stage was favorable prognostic factors. The survival advantage observed in female NSCLC patients was limited to those with cancer at stages I and II.