Female and male differences in the survival of patients undergoing resection for lung cancer.

Objective: In recent years much attention has been focused on the rapidly increasing incidence of primary lung cancer in women. The aim of this study was to determine gender differences in patients treated surgically for lung cancer.

Methods: We performed a retrospective review of patients who had lung resection for primary lung cancer from January 1994 to December 1998.

Results: There were 530 men and 42 women. Women were younger than men (55.6 +/- 10 versus 57 +/- 9.9). The difference was not statistically significant (p = 0.9). The mean cigarette consumption was greater in men than in women (p < 0.001). We observed a higher operative morbidity and mortality rate in men compared to women (p < 0.05). Men had more squamous cell carcinoma (61.7%). In female patients, squamous cell cancer and adenocarcinoma were found with almost the same incidence (35.7% versus 33.3%). There was a significant difference in the distribution of cell types (p < 0.001). Pathologic stages for women were; I = 38.2%, II = 21.4%, IIIa = 21.4%, IIIb = 9.5%, IV = 9.5% and for men; I = 40.4%, II = 26.6%, IIIa = 24%, IIIb = 6%, IV = 3%. There was no significant difference in the stage distribution between genders (p = 0.2). Median survival for female and male patients were 38 +/- 9.2 and 35 +/- 3.2 months. Female patients' survival was longer than male patients but the difference was not statistically significant (p > 0.05).

Conclusions: This study emphasizes sex differences in cigarette consumption, operative mortality and the distribution of cell types of patients with primary lung cancer. These initial results should strongly encourage additional studies in different countries on the interaction between sex and lung cancer characteristics to improve clarity.