New Research Says There’s No Significant Link Between Talc and Ovarian Cancer, but Some Scientists Push Back Against the Study’s Data and Design

In fact, in an earlier study published in 2014 — led by one of the coauthors of the current JAMA study, Nicolas Wentzensen, MD, PhD, of the clinical genetics branch of the division of cancer epidemiology and genetics at the National Cancer Institute, Rockville, Maryland — Dr Wentzensen said at the time that “Ideally, we would want to have high-quality exposure data on talc use in a cohort setting, with periodic updates on exposure.” Without that, he wrote, “it does not seem likely that additional conventional epidemiological studies will strengthen the evidence for or against talc carcinogenicity.”⁷

And, Dr Moline also called the JAMA study’s main conclusion slightly misleading because it reported a “possible positive association” of talc and ovarian cancer among women with intact reproductive tracts, meaning they hadn’t undergone a hysterectomy or tubal ligation. That mirrors the conclusion found in the Reproductive Toxicology study published in August 2019 that found that talc use wasn’t associated with ovarian cancer in women who’d had a tubal ligation.⁶

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, called the JAMA study “rigorously conducted,” but added, “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.”⁸

In addition to studying large groups of patients, scientists are looking deeper inside the body for clues on how talc affects cells. For example, at Karmanos Cancer Center in Detroit, Michigan, Wayne State University researcher Ghassan Saed, PhD, is looking at cancer DNA to better understand whether there’s a link between talc and inflammation in normal and ovarian cancer cells — and if the powder causes dangerous mutations in certain genes.

In the meantime, how can the public, as well as physicians, make sense of so many conflicting messages? “This leaves doctors and women in a tough place. They’re told, ‘Here’s something that might cause cancer but might not.’ Right now, individual doctors have to decide whether it’s a enough of a risk factor to counsel patients,” said Rachael Casey, a lawyer and former ovarian cancer researcher who recently cowrote an article advising doctors treating patients with ovarian cancer to develop protocols to uniformly ask them about possible risk factors that may have contributed to their disease.⁹ (Her firm at the time wasn’t representing anyone involved in litigation on this topic.) “This is a risk factor that the medical profession hasn’t made up its mind about, but doctors don’t want to stop being vigilant,” said Casey.

Disclosures: In the JAMA study, author Andrew Kaunitz, MD, of the University of Florida reported receiving funding for clinical trials from Medicines360, which manufactures intrauterine devices. The current chief executive officer of Medicines360 is Jessica Grossman, MD, a former medical director at Johnson & Johnson’s medical device subsidiary Ethicon. Dr Grossman was on the advisory board at Medicines360 and working at Ethicon for a few overlapping years.

In the JAMA editorial, Dr Gossett reported working as a consultant with Bayer on the Mirena intrauterine device.

For a full list of disclosures, please refer to the original study.

References

1. O’Brien KM, Tworoger SS, Harris HR, et al. Association of powder use in the genital area with risk of ovarian cancer. JAMA. 2020;323(1):49-59.
2. US Food and Drug Administration, Notice of public meeting (Feb. 4, 2020). 
3. Penninkilampi R, Eslick GD. Perineal talc use and ovarian cancer: A systematic review and meta-analysis. Epidemiology. 2018;29(1):41-49.
4. Berge W, Mundt K, Luu H, Boffetta P. Genital use of talc and risk of ovarian cancer: A meta-analysis. Eur J Cancer Prev. 2018;27 (3):248-257.
5. Cramer DW, Vitonis AF, Terry KL, et al.The association between talc use and ovarian cancer: A retrospective case–control study in two US states. Epidemiology. 2016;27(3):334-346.
6. Kadry TM, Farhat N, Karyakina NA, et al. Critical review of the association between perineal use of talc powder and risk of ovarian cancer. Reprod Toxcol. 2019;90:88-101.
7. Wentzensen N, Wacholder S. Talc use and ovarian cancer: epidemiology between a rock and a hard place. J Natl Cancer Inst. 2014;106(9):9-10.
8. Gossett DR, del Carmen MG, Use of powder in the genital area and ovarian cancer risk: Examining the evidence.  JAMA. 2020;323(1):29-31.
9. Casey, R, Larkin TP. Ovarian cancer and ‘tainted talc’: What treating physicians need to know. Mo Med. 2019;116(2):83-86.

This article originally appeared on Cancer Therapy Advisor