The JAMA study is just the latest addition to the scientific literature on talc and ovarian cancer for which findings aren’t clear-cut. While one 2018 meta-analysis of more than 24 case-control studies and 3 cohort studies found “a consistent association between perineal talc use and ovarian cancer,”3 another 2018 review of a similar size concluded that the current scientific evidence pointing to a link between use of talcum powder in the genital region and ovarian cancer resulted in a “weak but statistically significant association.”4 (One of the coauthors of the second paper, Paolo Boffetta, MD, MPH of the Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai in New York, New York, had previously received funding for a review on mouthwash and oral cancer from Johnson & Johnson.)
Yet some experts say the JAMA study’s data limitations weaken its impact in the field. “There really isn’t anything new here,” said Daniel Cramer, MD, ScD, professor of obstetrics, gynecology, and reproductive biology at Brigham and Women’s Hospital and Harvard Medical School in Boston, Massachusetts. (Dr Cramer has also served as an expert witness for the plaintiff’s position in multiple talc litigation cases.) “The main issue is that the quality of exposure data is really quite poor,” he said.
For example, the study defined “frequent” use as more than once a week, which wouldn’t capture the difference between an occasional user and someone who applies talc daily. In Dr Cramer’s 2016 study of 2041 women living in Massachusetts and New Hampshire who had been diagnosed with ovarian cancer, he determined there was a connection between higher amounts of genital talc used and increased cancer risk.5
Dr Cramer also argued that the JAMA study focused on postmenopausal women (the median patient age at baseline was 57 years) and failed to consider the important role of estrogen on a woman’s cancer risk. His own research found a stronger association between cancer risk in premenopausal women and those who are taking hormone replacement therapy in menopause. So did a review study published in Reproductive Toxicology in August 2019.6
“I think this [JAMA] study contributes to the literature, but it raises a lot of unanswered questions,” noted Jacqueline Moline, MD, an occupational medicine physician at Northwell Health in New York who studies the health effects of talcum powder. (She also worked as an expert witness for the plaintiff in a 2018 ovarian cancer and talc trial against Johnson & Johnson.)
Although the JAMA study reported a median of 11.2 years of follow-up, it was inconsistent among the cohort studies. For example, in the Nurses’ Health Study II, the investigators only started asking subjects about their talc use in 2013 — making it impossible to see any long-term effects that could potentially be associated with product use.