Elderly women with non-small-cell lung cancer have significantly better cancer-specific, overall and relative survival rates than men, regardless of the type of treatment, according to the results of a new study. Elderly women with non-small-cell lung cancer have significantly better cancer-specific, overall and relative survival rates than men, regardless of the type of treatment, according to the results of a study published in the May 1st issue of the Journal of Clinical Oncology.

It has not been clear if "this results from better response to treatment, different tumor biology, or a longer life expectancy," co-authors Dr. Juan P. Wisnivesky and Dr. Ethan A. Halm, from Mount Sinai School of Medicine, New York, write.

Using data from the Surveillance, Epidemiology and End Results registry and Medicare records, the team identified 18,967 elderly patients with stage I or II non-small-cell lung cancer, diagnosed between 1991 and 1999. The subjects were grouped into three categories based on the treatment they received: surgery, radiation or chemotherapy but no surgery, and no treatment.

Compared with men, women in all treatment groups had better lung cancer-specific, overall, and relative survival (p < 0.0001). Results of stratified and multivariate analyses demonstrated that survival remained better among women than men after controlling for confounders. Potential sex differences in smoking did not explain the association between sex and survival according to results of sensitivity analyses.

"The reasons for this survival advantage have not been identified," the authors note. "Hormonal influences may play a role in lung cancer progression given that studies have confirmed the presence of estrogen receptors in malignant lung tissue and hormones have also been linked to the pathogenesis of lung cancer," they continue. Additionally, the survival benefit seen among women may be associated with genetic and metabolic factors.