By Melissa Moffitt, MD
Assistant Professor of Oncology, Department of Gynecologic Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY
Dr. Moffitt reports no financial relationships relevant to this field of study.
SYNOPSIS: In this analysis of four large cohort studies, genital talcum powder use was not found to have any association with ovarian cancer.
SOURCE: O’Brien KM, Tworoger SS, Harris HR, et al. Association of powder use in the genital area with risk of ovarian cancer. JAMA 2020;323:49-59.
This study pooled four large U.S. cohort studies, including the Nurses’ Health Study (NHS; n = 81869, enrolled 1976, followed until 2016); the Nurses’ Health Study II (NHSII; n = 61261, enrolled 1989, followed until 2017); the Sister Study (SIS; n = 40647, enrollment began 2003, followed until 2017); and the Women’s Health Initiative Observational Study (WHI-OS; n = 73267, enrollment began 1993, followed until 2017). Initial questionnaires did not inquire about powder use. When they did, each study asked about powder use differently. To pool the data, researchers grouped the participants into ever users of genital powder vs. never users of genital powder. Participants also were grouped into long-term users (> 20 years use) and frequent users (at least once weekly). Thirty-nine percent of study participants reported using powder on their genitals.
Cohort study participants who previously had been diagnosed with ovarian cancer, undergone bilateral salpingoophorectomy, or were missing powder use data or covariate data (such as age, parity, or race) were excluded, leaving 250,577 women for evaluation.
Follow-up questionnaires asked about new cancer diagnoses. There were 2,168 ovarian cancer diagnoses, 1,884 of which were confirmed with medical records. Others were self-reported, while some were garnered from the National Death Index. All cases of ovarian cancer, fallopian tube cancer, or peritoneal cancers were counted as ovarian cancer irrespective of medical confirmation. Cox proportional hazard was used to measure the association between genital powder use and ovarian cancer, adjusting for confounders, including age, ethnicity, parity, and others.
Multiple subgroup analyses were performed. They separated those with alterations to their reproductive tract patency, grouping them by those who underwent hysterectomy vs. tubal ligation vs. patent, for analysis. Additionally, analysis was performed for those whose cancer was medically confirmed, and they were divided into groups based on histology, invasive vs. borderline, and primary location (ovary, tube, or peritoneum). Additionally, women born before 1945 were looked at separately, as they had more time to be exposed to powder containing asbestos, which was removed from talcum in the United States in 1976.
The hazard ratio (HR) for ever use and ovarian cancer diagnosis was 1.08 (95% confidence interval [CI], 0.99 to 1.17). Similarly, no statistically significant difference in the rate of ovarian cancer diagnoses was identified when considering only women with patent reproductive tracts, frequent powder users, long-term powder users, or medically confirmed cancers. Even for the older study participants, the HR was 1.09 (95% CI, 0.99 to 1.19).
COMMENTARY
Frequently, patients inquire if their ovarian cancer could have been caused by talcum powder use. Commercials, billboards, and radio advertisements encourage ovarian cancer patients who have ever used talcum powder to contact a lawyer to see if they are eligible to sue for damages. Judgements against Johnson & Johnson have awarded billions of dollars to talcum powder users with ovarian cancer.1
Asbestos and talc occur together in nature, thus talcum powder contained asbestos prior to its being banned by cosmetic companies in 1976. Talcum, whether it contains asbestos or not, can increase inflammation and potentially can be a cofactor in carcinogenesis.2
Published studies that evaluate if there is an association between talcum use and ovarian cancer date back decades. Some retrospective case-control studies, asking ovarian cancer patients if they ever used talcum powder, have suggested an association between powder use and ovarian cancer, but these retrospective studies’ findings can be affected by recall bias.
It was suggested that to find a statistically significant association between talc powder use and ovarian cancer, a study of 200,000 women followed for 10 years would need to be undertaken.3 This study, the largest prospective study to date, is just that, assessing more than 200,000 women for more than 10 years. It shows no association between ovarian cancer and talcum use.
Given the lifetime incidence of 1:70, this large, pooled, cohort study still could be underpowered to identify small increased risks for ovarian cancer. It also could be biased, since two of the studies were of nurses — educated women with some medical proficiency. For instance, if the nurses used combined oral contraceptives longer than other women, this would decrease the cohorts’ risk of developing ovarian cancer, skewing the results — an example of confounding bias. Nonetheless, this study is robust enough for me to confidently reassure my patients that having used powder on the genitals does not lead to ovarian cancer.
REFERENCES
- Reuters. J&J shares drop after jury orders company to pay nearly $4.7 billion in Missouri asbestos cancer case. Updated July 13, 2018. https://www.reuters.com/article/us-johnson-johnson-cancer-lawsuit-idUSKBN1K234U
- Steffen JE, Tran T, Yimam M, et al. Serous ovarian cancer caused by exposure to asbestos and fibrous talc in cosmetic talc powders – A case series. J Occup Environ Med 2020;62:e65-e77.
- Narod SA. Talc and ovarian cancer. Gynecol Oncol 2016;141:410-412.
