Women With Malignant Pleural Mesothelioma Have a Threefold Better Survival Rate Than Men

Background. Many studies have reported that women with malignant pleural mesothelioma (MPM) experience longer survival compared with men, whereas others have not. To date, no large population-based studies have evaluated MPM outcome and its determinants in female patients. Methods. All pathologically confirmed cases of MPM in the Surveillance, Epidemiology and End Results database from 1973 to 2009 were evaluated. Age, year of diagnosis, race, stage, cancer-directed surgery, radiation, and vital status were analyzed according to gender. Cox proportional hazard models were derived to assess the association between prognostic factors and survival. Results. There were 14,228 cases of MPM, of which 3,196 (22%) were women. Despite similar baseline characteristics for both genders, 5-year survival was 13.4% in women and 4.5% in men (p < 0.0001). The effect of female gender on survival persisted when stratified by age (dichotomized at 50 years), stage, or race, but differed depending on treatment. Even when adjusted for age, stage, race, and treatment, female MPM patients experienced longer survival than men (hazard ratio = 0.78; 95% confidence interval 0.75 to 0.82). Conclusions. This large data set confirms that although MPM is less common in women, they present with similar stage and are offered similar treatment options compared with men. Nevertheless, survival is far better in women compared with men, independent of confounders such as age, stage, and treatment. Differences in asbestos exposure, tumor biology, and the impact of circulating hormones on host response must be investigated to understand this survival advantage and improve prognosis for patients of both genders. (C) 2014 by The Society of Thoracic Surgeons