A case-control study published in 1997 of 313 women with ovarian cancer and 422 without this disease found that the women with cancer were more likely to have applied talcum powder to their external genital area or to have used genital deodorant sprays. Women using these products had a 50% to 90% higher risk of developing ovarian cancer. Storing diaphragms with powder did not significantly increase cancer risk. Since many of these women might have used products with more asbestos contamination than that in current products, the ovarian cancer risk for current users is difficult to evaluate. One study has suggested that an increased risk, if it exists, might be confined to borderline and endometrioid (uterine-like) tumors and therefore might not affect the majority of ovarian cancers.
A prospective study (considered to generally be the most informative) published in 2000 found no effect on ovarian cancer overall but a 40% increase risk in one type â€“ invasive serous cancers.
A meta-analysis which reanalyzed data from 16 studies published prior to 2003 found a 33% increase in ovarian risk among talc users. However, women with the highest exposure were at no greater risk than those with lower exposure, leading the researchers to question whether the association they observed was truly valid.
The most recent study of this subject found an overall 37% increased risk among talc users. It was interesting that the risk from talc use increased by 54% among women who had not had a tubal ligation (had their tubes”tied”) to prevent pregnancy, whereas talc had no impact on women whose tubes had been tied. Because tubal ligation is expected to block external carcinogens from reaching the ovaries via the vagina, uterus, and fallopian tubes, this finding provides some support for the idea that talc is a carcinogen.
This post was inspired by this post at Jezebel, but I think the Jezebel author is very wrong to write: “Risks apply only to talc used on the genitals, not on other parts of the body.” In fact, many scientists warn against using talcum powder at all, due to the risk of inhalation. For example, this site notes:
Talc is closely related to the potent carcinogen asbestos. Talc particles have been shown to cause tumors in the ovaries and lungs of cancer victims. For the last 30 years, scientists have closely scrutinized talc particles and found dangerous similarities to asbestos. Responding to this evidence in 1973, the FDA drafted a resolution that would limit the amount of asbestos-like fibers in cosmetic grade talc. However, no ruling has ever been made and today, cosmetic grade talc remains non-regulated by the federal government. This inaction ignores a 1993 National Toxicology Program report which found that cosmetic grade talc, without any asbestos-like fibers, caused tumors in animal subjects.1 Clearly with or without asbestos-like fibers, cosmetic grade talcum powder is a carcinogen.