Breast Cancer and Asbestos Exposure

Breast cancer is a form of cancer that develops in the tissues of the breast, typically in the ducts (which are tubes that carry milk) and lobules (glands that produce milk). Though this form of cancer occurs in both men and women, the occurrence in men is rare. Breast cancer is the most common form of cancer among women in the United States. Every year, more than 211,000 American women are diagnosed with this type of cancer.

Doctors cannot clearly explain why some people develop breast cancer and why others do not. What is known is that bumping, bruising, or touching the breast does not lead to cancer. Although the precise causes of breast cancer are not fully understood, a number of risk factors have been defined that increase a woman's probability of developing breast cancer. Some of these risk factors include age, personal and family history of cancer, reproductive and menstrual history, ethnicity, breast density, lack of physical activity, and consumption of alcohol, to name a few.

Though some risk factors can be managed or avoided, others, such as genetics or exposure to radiation or toxins, cannot be aptly managed or avoided. One toxin that may bear a causal relationship to breast cancer is asbestos, a naturally occurring mineral that was once widely used in thousands of domestic and industrial products.

Breast Cancer and Asbestos Exposure

One study, titled "Prevalence of Asbestos Bodies in a Necropsy Series in East London," analyzed the amount of asbestos present in lung sections of a necropsy series that excluded asbestos factory workers and cases of asbestosis and mesothelioma. The study sought to observe associations between the presence of asbestos and the patients' sex, physical address, occupation, industry, and diseases recorded at necropsy.

Of the 216 men studied, 42 percent revealed asbestos bodies in the lungs, and of the 178 women studied, 30 percent showed asbestos bodies as well. When compared with the overall necropsy series, an increased amount of asbestos was present in males with stomach cancer (which is also believed to be caused by asbestos exposure) and in women with breast cancer.

Authors of the study noted their most puzzling observation was the elevated incidence of breast cancer among women who tested positive for the presence of asbestos, as conceiving of a means of direct exposure of mammary tissue to asbestos fibers is perplexing. Though quite unlikely, the authors speculated on the obscure possibility that asbestos fibers could be carried by means of retrograde lymphatic flow from the lungs to the chest wall.

Gathering from another study's observations, the authors note that pleural plaques are typically restricted to parietal pleura overlying the ribs and these plaques are histologically made up of collagen (which are formed from extrapleural connective tissue). It may be possible for the thin, sharp asbestos fibers to pierce the lungs and penetrate the parietal pleura, where they are supported by the ribs and pass through the intercostal muscles. Thus, it would be possible for asbestos fibers to penetrate mammary tissue via the muscles that cover the chest wall.

The body of evidence to draw upon regarding a causal relationship between asbestos and breast cancer is limited, but studies such as these have revealed an intriguing and plausible connection. Further research and analysis must be conducted to better understand any possible relationship that may link exposure to asbestos and the development of breast cancer.

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