A January study in 2020 by researchers from the National Institute of Health’s (NIH) National Institute of Environmental Health Sciences and the National Cancer Institute found that there was no statistically significant association between talc and other powders for use on genitals and ovarian cancer in women.
Although the study found a small increase in ovarian cancer risk with genital powder use, it was not deemed statistically significant. Major limitations of the study include subject demographics, frequency of powder use, and type of powder used. Researchers studied a predominately white population, despite a much higher use of talcum powder amongst African-American populations. The only measure of frequency was at least once per week, and the brand/ingredients in the powder were neglected. Further research should take these factors into account.
The study pooled data from four different studies using four U.S. based cohorts (1976-2016, 1989-2017, 2003-2017, 1993-2017). There were a total of 252,744 women with a median age of 57, and 38% self-reported their use of powders. Powder use was tracked long term for about 20 years on average, with a frequency of at least once a week. The researchers used a median follow up of 11.2 years, representing a total of about 3.8 million person-years of risk. 2168 of the women developed ovarian cancer during this time period (58 cases/100,000 person-years). There were 62 cases/100,000 p-y among users versus 55 cases/100,000 p-y. The risk difference for ovarian cancer at age 70 was about 0.09% with a hazard ratio (HR) of 1.08. When splitting the data between long term and frequent use, long term use had a HR of 1.01 versus frequent use with an HR of 1.09. The HR between women using powders with an intact reproductive tract versus women using powder without was 1.13.
The takeaway from the study was that women who used powders had a 0.09% increased risk of ovarian cancer by age 70 versus women who never used powders. For women who used powders and still had an intact reproductive tract, they had a 0.15% increased risk by age 70 versus women who used powders and did not have an intact reproductive tract.
However, the study is severely limited. The population of women studied was mostly white, underrepresenting minority women who might or might not have a higher usage of talc powders on average compared to white women. According to Reuters, in 2006, nearly 60% of African-Americans used Baby Powder compared to about 30% for the overall population. Additionally, the study could not fully identify how often the women used powders beyond identifying those who used it at least once per week, and they did not log the duration of powder application for anyone. The study did not differentiate between different brands of powders or the ingredients in each kind of powder used. The study also had a very small sample of women who developed ovarian cancer, underpowering the study relative to the large study population.
Based on these limitations, the study cannot properly establish the presence or lack of presence of an association between talc and other genital powders and ovarian cancer. It would not be proper to use this study to say there is no association, nor would it be appropriate to reinterpret the study to say there is an association.