A large number of lawsuits and a long debate have been dragging out the theory of whether talc plays any key role in the development of some types of cancer. A new analysis conducted by U.S. government researchers at the National Institute of Environmental Health Sciences has found no link between talc powder and cancer. Despite the fact that data was collected from more than 250,000 women (252,745 exactly and with an average age of 57) the authors recommend caution observing that the study may not be large enough. The controversy is far from resolved in the short term.
For decades, some women have used talcum powder for genital hygiene to absorb odour and moisture, either by direct application or through underwear, sanitary pads, tampons, or diaphragms. The practice is more common among older generations than younger ones, but its use has become controversial because of possible cancer risks.
In a recent study, scientists found no evidence that talc was dangerous when used as a feminine hygiene product. It is likely that after the publication of this study in the Journal of the American Medical Association (JAMA), the pharmaceutical company Johnson & Johnson, which in recent years has been forced to pay billions of euros in compensation for women who claim to have developed ovarian cancer after using Johnson's Baby Powder, will take the opportunity to appeal each of the court rulings against it.
Of the 252,745 American women studied, 38% said they used talcum powder in their genital area; 10% said they did so for at least 20 years and 22% said they used it at least once a week.
After approximately 11 years, 2,168 had developed ovarian cancer: 61 cases per 100,000 people per year among those who ever used talcum powder around their genital areas and 55 cases per 100,000 people per year among those who did not.
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 hypothesized. They explain that in women with intact reproductive tracts, dust can travel directly to affected areas and cause irritation or inflammation. In women who have had their uterus removed or their fallopian tubes blocked, the dust has no physical access to the ovaries.
Therefore, no statistically significant association was found when comparing women who had used talcum powder and those who had never used it. We also found no significant association when comparing the frequency or duration of use.
Limitations of the study
According to the experts, since this is an observational study, there are limitations. Each cohort study measured dust use differently. The way in which exposure was evaluated and the frequency of use of talcum powder varied, so it is difficult to know if there is a connection between the amount of talcum powder used and ovarian cancer. Furthermore, the study does not specify what type of talcum powder was used by the women in the study and, despite being a considerable sample, it included mainly white women with studies and half of them not overweight, so it is difficult to generalise with this very specific population group.
The authors urge caution: "the study may have had little power to identify a small increase in risk.
Why is talc associated with cancer?
Talc is a mineral that sometimes occurs naturally in areas that also contain asbestos, and asbestos is a known carcinogen. However, U.S. manufacturers of talc cosmetic products agreed to ban asbestos in 1976. Since that time, the International Agency for Research on Cancer has stated that there is "possible" evidence that genital use of talcum powder may be linked to cancer. Over time, talcum powder use has also been linked to other cancers, such as mesothelioma, which affects the tissue lining the lungs and other organs.
Since the 1980s, asbestos/amianth related products have been shown to cause cancer. The European Union's Technical Commission banned the use of any type of asbestos from 1 January 2005 for those countries that had not yet banned it. Therefore, all Member States have had to ban the marketing and use of any type of asbestos.
Expert opinions from ScienceMediaCentre:
"This is a very well done study by a highly respected group of researchers Proving causal links of this kind is very difficult and the authors are very careful to highlight the potential limitations of the work. However, this research is robust, analyzes data from 250,000 women with an average follow-up of more than 11 years, and has concluded that there is no statistically significant relationship between talc use and the development of ovarian cancer," explained Iain McNeish, director of the Ovarian Cancer Action Research Centre at Imperial College London, who was not involved in the study.
"One thing this research clearly shows is how difficult it is to determine whether something like this is really a risk factor for cancer. Even though we are talking about a competent and careful study with more than a quarter of a million women in the sample, it still leaves room for doubt about the association, if any, between the use of dust in the genital area and ovarian cancer. There is still uncertainty. There is doubt about whether dust itself causes an increased risk of cancer. And there is also uncertainty about what size of the increased risk, if any, is. But what the research says is that if using talc or other powder on that part of a woman's body really does increase the risk of ovarian cancer, the increase in risk is likely to be small. Not being a woman, I can't worry about my own health in this regard, but if I were one, this wouldn't be on my list of concerns," said Kevin McConway, professor emeritus of applied statistics at The Open University.
Reference: : Asociación de uso de polvos en el área genital con riesgo de cáncer de ovario. Katie M. O'Brien, PhD1; Shelley S. Tworoger, PhD2,3; Holly R. Harris, ScD4,5; et al Garnet L. Anderson, PhD6; Clarice R. Weinberg, PhD7; Britton Trabert, PhD8; Andrew M. Kaunitz, MD9; Aimee A. D'Aloisio, PhD10; Dale P. Sandler, PhD1; Nicolas Wentzensen, MD, PhD11 JAMA. Journal of the American Medical Association 2020;323(1):49-59. doi:10.1001/jama.2019.20079