Gender difference as a prognostic factor in patients undergoing resection of non-small cell lung cancer

Purpose. We studied the effects of gender difference on the incidence of lung cancer and its mortality rate, which is a subject of much discussion. Methods. We examined gender difference in the clinical features of 491 men and 222 women who underwent resection of primary non-small cell lung cancer (NSCLC) between 1994 and 2004. Results. The histological types of cancer were adenocarcinoma in 249 (51%) of the men and 182 (82%) of the women, and squamous cell carcinoma in 182 (37%) of the men and 27 (12%) of the women. The incidence of adenocarcinoma was significantly higher in the women. The proportion of stage IA disease was significantly higher in the women than in the men (45% vs 29%, respectively). The 5-year overall survival rates were 50% in the men and 63% in the women. In a multivariate analysis, gender difference was an independent prognostic factor; however, when death as a result of unrelated disease was excluded, there was no significant difference in prognosis. Conclusion. Although the higher incidences of adenocarcinoma and stage IA cancer contributed to the good results of surgery in women, the low incidence of death attributed to diseases other than lung cancer was a major reason for their better prognosis.