The growing repercussions of the global use of asbestos continue to be discovered, and the reports are often jarring. Asbestos exposure has been linked to numerous cancers, including gastrointestinal and lung, but a new study illuminates the relationship between ovarian cancer and occupational asbestos exposure. The researchers involved in this study refer to it as a ‘meta-analysis,’ meaning they combined the results from independent studies to provide a precise estimate and coverage of effects. This meta-analysis was performed in the wake of the International Agency for Research on Cancer’s conclusion that evidence of connection between asbestos exposure and ovarian cancer was enough for a causal association. Asbestos attorneys at Pintas & Mullins Law Firm urge those with past asbestos exposure to seek medical testing. The potential for developing a related illness is high and continues to expand to encompass more and more serious diseases.
Ovarian cancer in the United States affects white females at the highest rates. Globally, the highest incidences are in North America and Northern Europe. According to a 2009 study, 125 million people worldwide are documented to be occupationally exposed to asbestos, and more than 90,000 people die each year from asbestos-related lung cancer, asbestosis, and mesothelioma.
The meta-analysis incorporated all studies of women who were occupationally exposed to asbestos meeting two criteria: first, an estimate of relative risk for ovarian cancer, and second, of a population with clear and unequivocal evidence of occupational asbestos exposure. They identified 15 references that met the criteria and three cohort studies, and excluded studies conducted among workers who were predominately exposed to other known carcinogens along with asbestos.
The association between asbestos and ovarian cancer was assessed in this meta-analysis among studies of workers in which a major portion of the cohort is presumed to have been exposed to asbestos. Our results demonstrate an increase in the pooled estimate for ovarian cancer in relation to exposure to asbestos.
The results from the analysis of highly exposed workers indicate a stronger effect than among all workers combined. Similarly, occupational exposure was more strongly associated with ovarian cancer among cohorts with a lung cancer standard mortality rate of greater than 2.0. They found a suggestive but non-significant association between asbestos type and the pooled ovarian cancer standard mortality rates. Cohorts predominantly exposed to crocidolite or mixed asbestos showed larger mortality rates than did those exposed only to chrysotile asbestos.
Pathophysiologic methods by which asbestos may present susceptibility to ovarian cancer have been proposed. They relate mainly to the hypothesis that the persistent presence of asbestos fibers in ovarian tissue causes chronic inflammation. This hypothesis is supported by reports of asbestos fibers in the ovaries of women occupationally and non-occupationally exposed to asbestos. The mechanism of transportation of asbestos fibers to the ovary is not clearly understood. Retrograde movement of particles through the reproductive tract to the ovaries has been suggested.
A major concern in interpreting the findings is that until recently it
has been very difficult to distinguish pathologically between peritoneal
mesothelioma and ovarian cancer. A further limitation of the analysis
was its inability to account for non-occupational risk factors for ovarian
cancer other than age. Finally, of even greater potential concern was
the fact that some of the published studies failed to include findings
for ovarian cancer or only reported results for cancers of the female
genital organs. We identified 20 cohort studies of asbestos-exposed women
that failed to report findings for ovarian cancer.
This meta-analysis mainly represents studies conducted in developed areas, particularly among European populations. It is possible that studies conducted in other geographic regions (e.g., developing countries) may be available through other biomedical literature databases. However, the previous meta-analysis by Li et al., which searched Chinese literature, found no articles on ovarian cancer published in that language.
The findings from this analysis are consistent with the hypothesis that exposure to asbestos is associated with an increased risk of ovarian cancer. This new causal link is just one in an increasing line of like-studies attempting to link asbestos exposure with illnesses. Asbestos attorneys at Pintas & Mullins Law Firm applaud the efforts of researchers around the globe who are unearthing new relationships between asbestos exposure and negative health effects. If you are the victim of any illness related to asbestos exposure, contact one of our lawyers today for a free consultation.