One in every eight women in this country is expected to be diagnosed with breast cancer during her life. This means it is the second most common cancer to affect women. While breast cancer can affect men, it is 100 times more common in women. It can appear in any part of the breast tissue and, if invasive enough, the cancer can spread to other surrounding tissues. Nevertheless, some forms of breast cancer are non-invasive, meaning they stay in a single area.

Causes of Breast Cancer

There are a number of risk factors associated with breast cancer, as well as a number of factors that can reduce the likelihood of someone developing the disease. Some of these factors can be controlled. For instance, smoking should be avoided because it can lead to breast cancer, but women should be encouraged to breastfeed, as it reduces the chances of developing the disease. Other factors that can contribute to the development of this form of cancer include:

• Age
• Gender
• Genetic makeup
• Family history
• Early onset of menstruation or of menopause
• Asbestos exposure

While some people still deny that there is a link between breast cancer and asbestos exposure, researchers at Penn Medicine’s Abramson Cancer Center have conclusively proven it. They and various breast cancer charities agree that the reason why the link may not appear as conclusive to some is because far fewer women worked in industries where asbestos exposure was likely before the 1970s, when asbestos was finally banned.

Breast Cancer and Asbestos Exposure

We know that asbestos is a serious and dangerous carcinogen. There is conclusive evidence that it causes mesothelioma, asbestosis, and lung cancer. The exact correlation between exposure and breast cancer, however, remains unclear. It has been ascertained that women who were exposed to asbestos are more likely to develop breast cancer, but what hasn’t been determined is how asbestos fibers affect breast tissue.

Unfortunately, it is often difficult to clearly link breast cancer and asbestos exposure, because it is impossible to achieve statistical significance. This is not because the data itself isn’t there. Rather, it is because there are so few women who were exposed that the fact that the majority of them did develop breast cancer is statistically insignificant.

However, in 2009, a study in Australia did indicate a link. They found that, if women were exposed to blue asbestos, in particular, they were more likely to develop breast, uterine, ovarian, or cervical cancer. The scientists studied some 3,000 women who lived in Wittenoom, which is where one of the world’s largest asbestos companies was located, operating until 1966. Compared to the female population of Western Australia, these women were far more likely to develop these types of cancers, particularly ovarian and cervical cancers.

Meanwhile, Cancer Research UK had commissioned a number of studies on the prevalence of breast cancer. One found that workers in factories with asbestos were at increased risk of developing breast cancer. In fact, if women were exposed to elevated levels of asbestos for two years or more, they were more likely to develop the condition. This first study went above expectations, as Cancer Research UK had expected to see 10.48 breast cancer deaths, but in fact found 12.

In the second study, which investigated the prevalence of asbestos fibers in a necropsy series in East London, the lungs of 178 women were checked to see if they contained the fibers. They were found in 30% of cases. The highest percentage, however, was in those women who also had breast cancer. Eighty-two women with breast cancer took part in the study, of which 38 had asbestos fibers in the lungs.

Because of the small number of women who have had occupational exposure to asbestos, it is difficult to truly draw any conclusion. Nevertheless, a number of scientists subscribe to the hypothesis that once asbestos fibers are ingested or inhaled, they may move to the chest wall from the lungs through retrograde lymphatic flow, eventually reaching the breast tissue. Others believe that asbestos fibers could actually pierce the lungs, passing through the chest wall’s muscles, reaching the breast tissue and causing cancer. These are conjectures at present as there is very little evidence to support them, or even to support a causal relationship. However, since there is potential link between the two, factual association is warranted and further studies should be conducted.

The American Cancer Society believes that between 5% and 10% of all cases of breast cancer are due to a mutation in inherited genes. This means that, in those cases, the woman can do nothing to prevent the disease from developing. However, it is also acknowledged that there are numerous risk factors that women can avoid, as these have been proven to be linked to breast cancer. As a result, the American Cancer Society recommends that:

1. Women drink no more than two units of alcohol per day.
2. Women should avoid having first child after age 30.
3. Women should have children.
4. Women should breastfeed.
5. Women should avoid taking DES (diethylstilbestrol), which is provided to prevent miscarriages.
6. Women should avoid hormone therapy once they reach menopause, and particularly HRT (hormone replacement therapy).
7. Women should strive not to become overweight or obese.
8. Women should avoid radiotherapy on their chest.
9. Women should avoid exposure to asbestos and other carcinogenic substances both at home and in the workplace. They should also avoid secondary exposure, for instance from the clothes, hair, or skin of their partner.
10. Women should avoid smoking, including secondary smoking at all times.