Study finds notable gender differences in response to mesothelioma surgery
Women diagnosed with the most common type of pleural mesothelioma survive longer and are more likely to benefit from aggressive treatment than men, according to research conducted at Boston's Brigham and Women's Hospital.
The study reviewed 702 surgical cases — 145 women, 557 men — between July 1987 and December 2008. The researchers found that women who contract epithelioid mesothelioma survive longer after extrapleural pneumonectomy, a radical surgery that involves removing the diseased lung, the lining of the lung, a portion of the diaphragm and sometimes a portion of the pericardium, or lining around the heart.
Pleural mesothelioma is a deadly cancer of the lung lining. The disease is distinguished by the type of cancer cell involved. Epithelioid mesothelioma, which grows more slowly and is more likely to respond to treatment, represents about 70 percent of all cases. Sarcomatoid mesothelioma, the most dangerous form of the disease and the hardest to treat, is the rarest, accounting for less than 10 percent of cases. A third type, biphasic, contains both epithelioid and sarcomatoid cells and accounts for 10-20 percent of cases.
Mesothelioma is caused by asbestos exposure. Roughly 90 percent of the more than 3,000 cases diagnosed annually in the United States occur in men, who likely were exposed to asbestos on the job. Many women who contract the disease are exposed to asbestos second-hand, such as by washing the contaminated work clothes of a spouse or family member.
The Brigham and Women's researchers report no difference in survival among the 250 men and women with sarcomatoid or biphasic mesothelioma. They do, however, note that women are often diagnosed with the disease at a younger age, a factor that may explain their better response to treatment. In the great majority of mesothelioma cases, symptoms usually do not appear until 30-50 years after asbestos exposure, when the disease has reached an advanced stage.
The researchers concluded that, absent other health problems, women with the epithelial type of pleural mesothelioma may generally be better able to tolerate surgery than men.
The study concluded that “These findings support an aggressive approach to treating MPM, including extrapleural pneumonectomy, in individuals with favorable prognostic predictors, particularly women with epithelial histology and no other risk factors.”
The study appears in the September, 2010 issue of Annals of Thoracic Surgery.