A recent study, the largest ever about the effect of gender on the asbestos-related cancer, proved definitively what doctors have suspected for years: women have an advantage over men when it comes to living longer after a diagnosis.
“This is very exciting,” said Andrea Wolf, M.D. of the Division of Thoracic Surgery at Mount Sinai Medical Center in New York, an assistant professor who worked on the study. “It’s great news for women, yes, but the goal now is to take what we’ve learned and use it to benefit both men and women.”
Published in the Annals of Thoracic Surgery, the study did not examine why women survived longer, but it forwarded the theory that the protective effects of estrogen in a woman could be key to developing better therapies for both sexes.
“The obvious suspicion is that this is a hormonal phenomenon,” Wolf told Asbestos.com. “It tells me that next there should be some sort of trial looking into a hormonal modification in treating this disease.”
The study included 14,228 pathologically confirmed American mesothelioma cases in the national Surveillance, Epidemiology and End Results (SEER) data base, ranging from 1973 to 2009.
About 22 percent of the cases involved women patients. Despite similar baseline characteristics, the five-year survival for women was 13.4 percent compared to 4.5 percent for men. For women who were diagnosed before they turned 50 years old, the survival rate was 38.6 percent. For men under 50, the rate was 17.3 percent.
Although females had a survival advantage in all age groups, the difference between the two groups grew smaller as they grew older. And the difference was not as dramatic among those who did not have surgery. Some 32 percent of men survived at least one year without surgery or radiation. That compared to 35 percent of the women in the same category.
The stage of diagnosis and treatment options for men compared to women was similar in the study, but the percentage of women opting for surgery was higher.
The effect of gender on survival was consistent across all other categories, including age, race and stage of disease. It differed depending upon treatment received.
“The fact that even older women have better survival rates than men suggests that there may be more than just hormones involved,” Wolf said. “Younger women seem to do great, and it gives us good reason to be more aggressive in treating them.”
The SEER database is a program run by the National Cancer Institute and the most authoritative source on cancer incidence and survival in America. It includes cancer-based registries that cover approximately 28 percent of the United States populations.
This study included cases from Georgia, Connecticut, Michigan, Hawaii, Iowa, New Mexico, California, Washington, Utah, Alaska, Kentucky, Louisiana and New Jersey. Researchers worked at Mount Sinai Medical Center and the North Shore/Long Island Jewish Health System-Hofstra School of Medicine.
The low incidence of women with the disease is mostly related to occupational exposure to asbestos, the primary cause of mesothelioma. It is normally associated with blue-collar professions, which traditionally have a smaller percentage of women.
Although the use of asbestos dropped dramatically in America over the past three decades, it still might be many years before there is an equally-dramatic drop in mesothelioma rates. The latency period between exposure to asbestos and diagnosis of mesothelioma can range from 20 to 50 years.
“There could be many factors in why women seem to do better with this disease. It could be different types of exposure, for example. Historically, women were not working in the shipyards with all the asbestos, but they were cleaning the clothes of workers who did work there.
Wolf previously was involved in similar studies when she worked at Brigham and Women’s Hospital in Boston, but those studies carried a much smaller scale.
The small scale of those studies made it difficult to draw any strong conclusions from a single-center database. The findings of the more sweeping recent study confirmed what she already suspected.
“This study really supports some of the earlier findings,” Wolf said. “There is something very real here. This could lead to a whole different route in treating the disease.”