Survival differences by gender for resected non-small cell lung cancer: a retrospective analysis of 12,509 cases in a Japanese Lung Cancer Registry study.

INTRODUCTION: Women with non-small cell lung cancer (NSCLC) are more likely to have better survival than men. This study intended to assess gender differences in the survival of these patients in a large registry population.
METHODS: In 2005, the Japanese Joint Committee for Lung Cancer Registration performed a nationwide retrospective registry study regarding the prognosis and clinicopathologic profiles of patients who underwent resection for primary lung neoplasms in 1999. The registry data of 12,509 patients with NSCLC were analyzed in terms of gender differences in prognosis and clinicopathologic features.
RESULTS: There were 8353 (66.8%) men and 4156 (33.2%) women with a mean age at operation of 66.4 and 65.0 years, respectively (p < 0.001). Women had a higher incidence of adenocarcinoma (p < 0.001) and stage IA disease (p < 0.001) than men. The overall survival was significantly better in women than men. The 5-year survival rates (5-YSRs) for women and men were 75.6 and 57.9%, respectively (p = 0.0000). According to histology, the overall survival of women was significantly better than that of men for both adenocarcinoma (5-YSR, 77.7 versus 61.9%, p = 0.0000) and nonadenocarcinoma (5-YSR, 59.3 versus 53.1%, p = 0.035). In adenocarcinoma, women had a significantly better prognosis than men for pathologic stage I/II disease. However, in nonadenocarcinoma, there was no significant prognostic difference between the two genders in pathologic stage I/II disease.
CONCLUSIONS: Women with NSCLC, especially with an adenocarcinoma histology, had better survival than men. Women were more likely to have adenocarcinoma and stage IA disease, which might account for the better prognosis in women.