No significant link found between powder use, ovarian cancer
Click Here to Manage Email Alerts
Researchers did not find a significantly higher risk for ovarian cancer in women who used powder in the genital area, according to an analysis of more than 250,000 women recently published in JAMA.
However, researchers noted that their study may have been underpowered to establish a small increase in ovarian cancer risk.
“Case-control studies have reported positive associations between ever use of powder in the genital area and ovarian cancer, with an estimated odds ratio of 1.24 in a pooled analysis and 1.31 in a meta-analysis,” Katie M. O'Brien, PhD, of the epidemiology branch of the National Institute of Environmental Health Sciences, and colleagues wrote. “However, these findings may be affected by recall bias, and a recent surge in talc-related lawsuits and media coverage has increased this possibility. Thus, it is crucial to evaluate the talc-ovarian cancer association using prospective data.”
Previous cohort studies exploring the association between powder use and ovarian cancer have yielded inconsistent results, according to researchers.
Researchers did not find a significantly higher risk for ovarian cancer in women who used powder in the genital area, according to an analysis of more than 250,000 women recently published in JAMA.
O’Brien and colleagues conducted a pooled analysis of data from 252,745 women (median age at baseline, 57 years) enrolled in four large cohorts: the Nurses’ Health Study, the Nurses’ Health Study II, the Sister Study and the Women’s Health Initiative Observational Study. Among them, 38% reported ever using powder in the genital area, 22% reported using powder in the genital area at least once a week and 10% reported long-term use of powder in the genital area for 20 years or more.
During a median of 11.2 years of follow up, the incidence of ovarian cancer was 61 cases per 100,000 person-years among women who ever used powder and 55 cases per 100,000 person-years among women who never used it (estimated HR = 1.08; 95% CI, 0.99-1.17). The estimated HR in women who used powder at least once a week vs. those who never used it was 1.09 (95% CI, 0.97-1.23), while the HR in women who used powder for 20 years or more vs. those who never used it was 1.01 (95% CI, 0.82-1.25).
There was no significant evidence of heterogeneity across the study cohorts. The researchers hypothesized that women with patent reproductive tracts may be more susceptible to the effects of powder on ovarian cancer. They reported finding a “possible positive association” of powder use in the genital area and ovarian cancer among women with patent reproductive tracts and no history of hysterectomy or tubal ligation (estimated HR = 1.13; 95% CI, 1.01-1.26). However, the association did not significantly differ from the association observed among women with nonpatent reproductive tracts, so the “finding should be considered only exploratory and hypothesis generating,” O'Brien and colleagues wrote.
“The main analysis included 2,168 ovarian cancer cases that developed over 3.8 million person-years. This far exceeds a previous meta-analysis of [previously] published ... results (890 cases over 182,000 person-years),” they concluded. “However, power to investigate links to peritoneal or fallopian tube cancers or histotypes other than serous was still low. Improvements in the classification of tumor types may contribute new insights, especially for fallopian tube cancers, which may be the true point of origin for most serous ovarian cancers.”
In a related editorial, Dana R. Gossett, MD, MSCI, of the department of obstetrics, gynecology and reproductive sciences at the University of California, San Francisco, and Marcela G. del Carmen, MD, MPH, of the department of obstetrics, gynecology and reproductive biology at Harvard University Medical School, wrote that the O’Brien and colleagues’ findings should be “reassuring” to women who use or previously used powder in the genital area. They also offered a suggestion for additional research in this clinical area.
“Future analyses would be strengthened by focusing on women with intact reproductive tracts, with particular attention to timing and duration of exposure to powder in the genital area,” they wrote. “Accumulation of such data will take many years and given the low rates of current powder use among U.S. women, may not be feasible.”
Gossett and del Carmen concluded that “the rigorously conducted study by O’Brien [and colleagues] contributes important and timely data about the potential link between use of powder in the genital area and risk of ovarian cancer.” – by Janel Miller
Disclosures: Gossett reports a relationship with Bayer for expert consultancy services for the Mirena intrauterine device outside the submitted work. Please see the study and editorial for all other authors’ relevant financial disclosures.
Perspective
Back to Top
Jenn D. Oliva, JD
The results of this survey are unsurprising for several reasons and while they are sure to be relied on by the talc product manufacturers in litigation, they may not have as large of an impact on those cases as they initially appear.
Studies that aim to determine whether talc exposure leads to a statistically significant increased risk for ovarian cancer have long produced mixed results and for good reason. Cancer is an incredibly complex and frustrating disease when it comes to causation. The International Agency for Research on Cancer (IARC) has declared that talc that contains asbestos is “carcinogenic to humans” and that perineal (genital) use of talc body powder that contains asbestos is “possibly carcinogenic to humans.”
Further complicating matters is the fact that certain talc body powders contain asbestos while others do not, and even those that do contain asbestos at varying levels over varying periods of time/batches of manufacture. In addition, the IARC determined that talc that does not contain asbestos as “not classifiable as to carcinogenicity in humans.” This particular study by O’Brien and colleagues concedes at least six limitations, one of which is that “specific exposure windows could not be examined, nor could type of powder used…” In other words, there is no way to determine whom in the study cohort was or was not exposed to a talc product that contained asbestos during any particular timeframe, let alone the level of asbestos that may have been present in those particular products. This study flaw undermines its strength as a tool for talc product manufacturers that plaintiffs’ counsel are sure to exploit in the ongoing litigation.
As has been well-publicized, thousands of women have sued Johnson & Johnson on the theory that their perineal use of the company’s baby powder caused their ovarian cancer. The jury verdicts in those cases have been mixed — some have found for the plaintiffs and produced large damages awards while others have either rejected the plaintiffs’ claims or resulted in mistrials.
The question is whether the juries that have found for the plaintiffs and against Johnson & Johnson have done so because they found the plaintiff’s causation evidence compelling or because, as a 2018 Reuters report revealed, the company’s own internal documents produced in litigation indicate that certain tests have detected asbestos in samples of its baby powder and the company appears to have made all attempts to conceal those results from the public and regulators.
Further complicating the equation here and not widely reported is that the FDA caved into the talc product manufacturers in the 1970s and entirely abdicated its duty to ensure the safety of talc products. Specifically, the FDA left it to talc product manufacturers to develop their own “safe” standard for the permissible level of asbestos in talc products and has largely relied over the years on those manufacturers’ internal testing and self-interested representations that their products conformed to that standard and, therefore, were “safe.”
References:
International Agency for Research on Cancer. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Volume 93. Carbon Black, Titanium Dioxide, Talc. 2010. http://monographs.iarc.fr/ENG/Monographs/vol93/index.php. Accessed Jan. 7, 2020.
Rosner D, et al. Am J Public Health. 2019;doi:10.2105/AJPH.2019.305085.
Perspective
Back to Top
David G. Noll, JD
O’Brien and colleagues’ findings are certainly welcome news for Johnson & Johnson. A central issue in the talcum powder litigation is general causation. In other words, whether, as a general matter, the use of talc raises users' risk for cancer. This study found no statistically significant association between talc use and ovarian cancer in a sample of registered nurses who submitted reports on whether they used powder and developed ovarian cancer. This is consistent with Johnson & Johnson’s position that its use of talc is safe and subject to strict quality controls.
Those who are suing Johnson & Johnson will counter that the study does not address all of the mechanisms through which asbestos could have been introduced into talc. But ultimately, O’Brien and colleagues’ findings will strengthen Johnson & Johnson’s hand, especially in disputes over the admissibility of plaintiffs' expert evidence.
Read more about
Click Here to Manage Email Alerts