Sex-associated differences in presentation and survival in patients with lung cancer.

A retrospective study of 478 men and 294 women with primary lung cancer was conducted to characterize sex-associated differences in their presentation and survival. At the time of diagnosis, women were younger than men (mean age, 57.4 +/- 10.4 v 60.2 +/- 9.9 years, respective; P = .0007). Men were more likely to be current or previous smokers (94% v 84%; P less than .005), and in patients with a positive smoking history, cigarette consumption was greater in men (52.2 v 40.2 pack years; P = .0001). The proportion of adenocarcinomas compared with squamous cancers was high in women (45% v 23%), while these cell types were equally represented in men. The majority of patients in both sex groups had regionally advanced or metastatic disease at diagnosis. Survival was related to age, stage at presentation and cell type. In addition, sex was found to be an independent prognostic factor for survival. Women with tumors of all cell types lived longer than their male counterparts (P less than .0001), and survival by stage in patients with nonsmall-cell cancers was greater for women than it was for men. These data demonstrate that important sex-associated differences exist in presentation and survival from lung cancer. Such differences should be considered when planning and analyzing clinical trials.