The largest study to date to analyze the supposed link between women’s use of talcum powder in the genital region and ovarian cancer risk has found no statistically significant association, NPR reports.
Citing past research that has indicated talcum powder use is a risk factor for ovarian cancer, thousands of women have sued Johnson & Johnson, a powerful company that boasts talcum powder, aka baby powder, as one of its signature products. The state of New Mexico filed such a suit earlier this month. Some of the lawsuits have been successful, with initial awards in the billions.
Talcum powder can theoretically become contaminated with asbestos, a known carcinogen that may exist in talc, the mineral that is mined for use in the powder. In October, Johnson & Johnson issued a recall of 33,000 bottles of baby powder over concerns of its potential contamination with asbestos. In short order, however, Johnson & Johnson reported that tests indicated no contamination in its product. Investigative reporters have revealed that Johnson & Johnson higher-ups have known for decades of the risk of asbestos contamination in baby powder but kept this risk hidden from the public.
Evidence of a potential link between talcum powder and ovarian cancer has been mixed. To shed light on the subject, researchers from the National Institutes of Health’s (NIH) National Institute of Environmental Health Science and the National Cancer Institute conducted the largest study thus far of women’s use of powder on the genitals. Publishing their findings in the Journal of the American Medical Association, the researchers pooled data from four large cohort studies of nearly 253,000 American women that dated back as far as 1976.
The participants of these studies responded to questions about their genital talcum powder use—38% reported such use—and were followed for a median of 11.2 years, for 3.8 million cumulative years of follow-up. During that time, 2,168 of the women developed ovarian cancer, for a rate of 58 diagnoses per 100,000 cumulative years of follow-up—a very low rate. Among women who never used genital talc, the rate was 55 diagnoses per 100,000 cumulative years of follow-up. However, the 8% increased risk among talc users was not statistically significant, meaning it could have been driven by chance.
Women’s lifetime risk of ovarian cancer is quite low, at 1.3%. Even if that figure were increased by 8%, the risk would be only 1.4%. Restricting their analysis to women who had an intact uterus and intact fallopian tubes, the researchers determined that use of genital talc was associated with a 13% increased risk of ovarian cancer. This difference was not statistically significant, however, and is considered quite small.
The study’s findings are bolstered by the fact that the women were surveyed about their talc use before they ever got ovarian cancer. If the sequence had been reversed, women with ovarian cancer might have been subject to what is known as recall bias, in which they might have wound up inflating their recollections of talcum use as a way to explain why they developed the cancer.
The past half century has seen a decline in women’s use of talcum powder. However, reports have indicated that African-American women are more likely than their white counterparts to use talc. That points to a weakness of the new study: The majority of its participants were white women.
In their conclusion, the paper’s authors noted that their study may have been underpowered to detect a true increased of ovarian cancer associated with genital talc use. In other words, if the already very large cohort of women analyzed had been even larger, it is possible that the study would have identified a statistically significant association between use of talc on the genitals and ovarian cancer. Additionally, future studies could focus only on women who have not had their uterus and fallopian tubes removed and possibly identify talcum powder as a true ovarian cancer risk.
Given the lack of a medical use for powder on the genitals, the lead author of the new paper, Katie M. O’Brien, PhD, of National Institute of Environmental Health Sciences, in Research Triangle Park, North Carolina, suggested that women weigh the benefits of using talc versus the possible health risks. According to the American College of Obstetricians and Gynecologists, “because of concerns regarding potential discomfort or pain, obstetrician-gynecologists do not recommend use of vaginal treatments such as douche, vaginal sprays or talcum powder.”
For babies, the American Academy of Pediatrics (AAP) warns against using baby powder, any potential cancer risks tied to talc aside, because it poses a choking hazard to infants. Some baby powder is made from cornstarch, but this too poses a choking hazard. The AAP instead recommends use of an oil-based ointment if needed for the prevention of diaper rash.
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To read the NPR article, click here.
To read the study abstract, click here.