The study says there's a possible association between powder and ovarian cancer among women who had no history of hysterectomy or tubal ligation, but this "finding should be considered only exploratory and hypothesis generating".
The women were asked about how they used the powder - including talcum, baby and deodorising powder - and how often. A recent lawsuit regarding ovarian cancer brought against the company in St. Louis resulted in a court ruling in favor of the company.
"Women should feel reassured by this study", says Dana R. Gossett, MD, a professor of obstetrics, gynecology, and pediatric gynecology at the University of California in San Francisco, who wrote an editorial accompanying the study but was not involved in the research. Women with cancer are more likely to remember or mention something that could be linked to cancer than women without, meaning these studies could have biased results.
While the research won't eliminate the company's legal exposure, it may help bolster J&J's argument that the link between talc and ovarian cancer found in some previous studies isn't beyond dispute.
The findings did reveal an 8% increased risk among women who used the powder products, compared with women who never used them, but head researcher Katie O'Brien says this "is not a statistically significant increase".More news: Gov. Gavin Newsom proposes selling California-brand generic drugs
The study is reassuring, although the researchers point out that as ovarian cancer is quite rare, they can not rule out a very small increase in risk even with a large study. "Thus, it is crucial to evaluate the talc-ovarian cancer association using prospective data".
Where did the story come from?
Researchers from NIH's National Institute of Environmental Health Sciences and the National Cancer Institute pooled data available for 252,745 women who answered questions about whether they used powder for genital hygiene, including the frequency and length of time they used the powder for. The study was funded by the US National Institutes of Health and the National Cancer Institute.
The study, one of the largest on this topic to date, was published in the Journal of the American Medical Association.
A study of more than 250,000 women found that those who used talc or other personal-hygiene powders weren't significantly more likely to develop ovarian cancer, news that will impact thousands of legal claims against drugmaker Johnson & Johnson over the products.More news: West Ham Still Have Hoops To Jump Through On Gedson Fernandes Deal
Only a few reports, including The Independent, make clear that the study did not rule out a small increase in risk. About 49 percent of older USA women and about 26 or 27 percent of younger women say they have used powder by sprinkling it in underwear or on menstrual pads or tampons, according to the authors of the study. Of those women, 38 percent said that they used powder-whether baby, talcum or deodorizing-in their genital area, 10 percent said they had been doing so for at least 20 years and 22 percent reported using the powder (s) at least once a week.
What did the research involve?The women were followed up to see if they developed cancer. Given the difficulty in studying rarer tumors such as ovarian cancer, it is probably the most detailed data researchers will receive in the foreseeable future.
"It's not great data", admitted study author O'Brien.
What were the basic results?Nearly 14,000 American women die of the disease per year. A total of 2,168 in the studies developed ovarian cancer, which has a lifetime risk of 1.3%. That represents 58 cases for every 100,000 women per year. That difference was deemed to be not statistically significant. "That doesn't mean that these differences were definitely zero, only that they were small enough so that they could plausibly be due only to random variation". That would require randomly assigning a large group of women to use talc powders over many years, and comparing the results with those who didn't use powders. Some studies have indicated that the use of powder products on the genitals can lead to malignant diseases, while others point to accidental inhalation of the powder as the cause of cancer mesothelioma. That risk rose to 19% among women who used baby powders at least once a week.
He concluded that what the research did establish was that if such a risk did exist, it was likely to be very small.More news: Brexit: MPs give final backing to Withdrawal Agreement Bill
The study has some limitations.