New research reveals gender differences in mesothelioma cases
A clinical study of 238 cases of malignant mesothelioma suggests that the disease takes longer to develop in women than it does in men, and that people exposed to smaller amounts of asbestos often develop the disease later in life than those who had higher levels of exposure.
Delving into the case files of a private pulmonary and occupational medicine practice in
Houston, researchers from the Texas Occupational Medicine Institute examined data on 217 men and 21 women diagnosed with the disease between 1977 and 2009. While most mesothelioma research to date has focused on individual cases or small groups of patients, the Texas study is one of the few that has examined the clinical details of a large number of cases.
According to the findings, men were far more likely to have some direct asbestos exposure compared to women, who were more likely to have only non-occupational exposure. More than 87 percent of patients reported heavy or moderate exposure to asbestos, with more than 90 percent reporting that exposure had come on the job.
Some of the findings confirmed what physicians and scientists have long known about mesothelioma. The rare cancer is much more common in men than in women, reflecting higher rates of occupational asbestos exposure among men. Most people in the Texas study, more than 61 percent, reported having daily occupational exposure to asbestos; less than one in five reported only intermittent exposure.
Moreover, the Texas study confirmed that mesothelioma could take decades to emerge. The mean age at diagnosis among the study group was 70.3 years, with a mean latency — time between first exposure and diagnosis — of 48.5 years.
However, researchers found that women had a longer latency period, 53.3 years, than men (47.9 years). The researchers said the difference is likely because women in the study group were exposed to lower levels of asbestos and were less likely to be exposed on the job.
“Our finding of a longer latency for women would support this inverse dose-latency hypothesis,” they said.
The researchers concluded that, with overall survival among the study group of less than nine months, mesothelioma remains a difficult disease to treat. However, those who underwent treatment lived almost five months longer — 11.3 months compared to 6.4 months for those who were not treated.
The researchers noted the promise of new chemotherapeutic agents and surgical techniques, as well as emerging developments in immunotherapy and gene therapy. However, they did not find a significant difference in outcomes among various treatments.
“Our data support a small but statistically significant prolongation of survival with treatment, but we were not able to detect a particular modality or combination as superior,” the researchers concluded.