Ovarian Cancer and Asbestos Exposure

Ovarian cancer is a malignant change in the cells of the ovary (which is one of a pair of female reproductive glands). The majority of ovarian cancers are either ovarian epithelial carcinomas (which begin in cells located on the surface of the ovary) or malignant germ cell tumors (which begin in egg cells inside the ovary). Most cases of ovarian cancer are diagnosed as ovarian epithelial carcinomas, which is the fifth most common cancer and cause of death in women. Older women are especially at risk.

Scientists and medical professionals cannot clearly define why some women develop ovarian cancer and why others do not. Though the exact cause(s) is not fully understood, certain risk factors have been identified that increase a woman's chance of developing ovarian cancer. Some of these factors include personal and family history of cancer, age, number of pregnancies, hormonal cycling, and environmental factors.

Though the risk associated with environmental factors is based on limited amounts of scientific data, some studies have offered profound evidence on the subject. Some potential environmental factors have included toxic solvents, organic dusts, dyes, triazine herbicides, talc, and asbestos exposure. Both talc and asbestos have been included in products that place women at risk, and asbestos has even been linked to ovarian cancer in occupational settings.

Ovarian Cancer and Asbestos Exposure

A number of studies have reported an increased mortality from ovarian cancer among women who experienced occupational exposure to amphibole forms of asbestos. To date, no increased mortality from ovarian cancer has been observed among women solely working with chrysotile asbestos.

A 1982 case-control study on ovarian cancer and talc found that women with ovarian cancer were approximately three times more likely to have used talcum powder on the genital area than control patients without ovarian malignancies. The study pointed out that cosmetic talcum powders are known to be contaminated with amphibole asbestos fibers, such as tremolite and anthophyllite. Additionally, a pathology study published in the early 1970s reported embedded talc particles in 75 percent of the ovarian tumors sampled.

Another study published in 1999 (which analyzed more than a thousand women) found that 45 percent of those with ovarian cancer reported using talc in the genital area, compared to 36 percent of women without the disease, which led to an overall increased relative risk of 60 percent. In addition, women who did not use talc themselves, but whose husbands used talc on their genitals had a 50 percent increased risk of ovarian cancer. Talc, like asbestos, is mineralogically classified as a hydrated magnesium silicate. As such, talc not only resembles asbestiform minerals, but also has a carcinogenic effect like that of asbestos. Occurring naturally in nature, anthophyllite asbestos is formed from the natural breakdown of talc.

In 1999, a study was released that assessed the cause-specific mortality of women compensated for asbestos exposure in their occupation. The study found significantly increased mortality from ovarian cancer, as well as from lung and uterine cancer.

Evidence Presented by IRAC

The International Agency for Research on Cancer (IRAC) reconfirmed in March 2009 that all commercial asbestos fibers cause lung cancer and mesothelioma. The IRAC also reconfirmed that asbestos causes laryngeal cancer and newly confirmed that sufficient evidence exists to state that asbestos exposure causes ovarian cancer.

Dr. Richard Lemen, retired Assistant Surgeon General of the United States and Deputy Director of the National Institute for Occupational Safety and Health, stated this new confirmation is the beginning of a “new chapter in the prevention of asbestos-related cancers.”

“The confirmation by IARC – the world’s leading cancer research agency – that all forms of asbestos, including its most commonly used form of asbestos chrysotile, cause lung cancer, laryngeal cancer, and mesothelioma, leave no doubt that the prevailing medical evidence is irrefutable as to asbestos’ carcinogenicity. The new findings that there is sufficient evidence that asbestos also causes ovarian cancer will have far reaching implications to all women exposed to asbestos,” said Lemen.

The recent studies on asbestos exposure and the development of ovarian cancer have offered strong evidence for a causal relationship between asbestos exposure and ovarian cancer. Naturally, further analysis of this plausible relationship and the risk factors involved must be conducted to better understand the dynamic between ovarian cancer and exposure to asbestos.

Sources: