The association between douching, genital talc use, and the risk of prevalent and incident cervical cancer

A systematic review of the epidemiology evidence on talc and cancer

Over the past several decades, there have been many epidemiology studies on talc and cancer published in the scientific literature, and several reviews and meta-analyses of talc and respiratory, female reproductive, and stomach cancers, specifically. To help provide a resource for the evaluation of talc as a potential human carcinogen, we applied a consistent set of examination methods and criteria for all epidemiology studies that examined the association between talc exposure (by various routes) and cancers (of various types). We identified 30 cohort, 35 case-control, and 12 pooled studies that evaluated occupational, medicinal, and personal-care product talc exposure and cancers of the respiratory system, the female reproductive tract, the gastrointestinal tract, the urinary system, the lymphohematopoietic system, the prostate, male genital organs, and the central nervous system, as well as skin, eye, bone, connective tissue, peritoneal, and breast cancers. We tabulated study characteristics, quality, and results in a systematic manner, and evaluated all cancer types for which studies of at least three unique populations were available in a narrative review. We focused on study quality aspects most likely to impact the interpretation of results. We found that only one study, of medicinal talc use, evaluated direct exposure measurements for any individuals, though some used semi-quantitative exposure metrics, and few studies adequately assessed potential confounders. The only consistent associations were with ovarian cancer in case-control studies and these associations were likely impacted by recall and potentially other biases. This systematic review indicates that epidemiology studies do not support a causal association between occupational, medicinal, or personal talc exposure and any cancer in humans.

Examining differences in menstrual and intimate care product use by race/ethnicity and education among menstruating individuals

Introduction

United States consumers spend over two billion dollars a year on intimate care products. These products, along with scented menstrual products, are marketed for odor control, perceived "freshness," and vaginal/vulvar cleanliness. However, these scent-altering products may increase exposure to carcinogenic and endocrine-disrupting chemicals. Prior research has not adequately characterized demographic differences in product use. The objective of our study is to examine racial/ethnic and educational differences in menstrual and intimate care product use among people who menstruate.

Methods

We pooled data from two US-based cross sectional studies to examine demographic characteristics and product use in 661 participants aged 18-54 years. Participants reported use of scented and unscented menstrual products (tampons, sanitary pads, and menstrual cups) and intimate care products (vaginal douches, sprays, wipes, and powders). We examined differences by race/ethnicity and education using log-binomial regression and latent class analysis (LCA), which can identify groups based on product use patterns.

Results

Our sample was 33.4% Black, 30.9% Latina, 18.2% White, and 16.2% another identity. Approximately half the population had a bachelor's degree or more; 1.4% identified as transgender and 1.8% as non-binary. In adjusted models, scent-altering products (i.e., scented menstrual and intimate care products) were more likely to be used by those with less formal education (p < 0.05). Unscented menstrual products were more likely to be used by those with more formal education. Compared to Black participants, White participants were more likely to use unscented tampons and menstrual cups and less likely to use douches and wipes (p < 0.05). Using LCA we identified two groups: one more likely to use scent-altering products, and a second more likely to use unscented menstrual products. Less education and older age, but not race/ethnicity, was significantly associated with membership in the group more likely to use scent-altering products. While sex/gender composition did not statistically vary across groups, all non-binary participants fell in the unscented menstrual product group.

Discussion

Lower educational attainment was consistently associated with greater use of scent-altering menstrual and intimate care products. Future research should examine associations between body odor stigma, product use, and health risks at intersections of race, class, and gender.

Association of genital talc and douche use in early adolescence or adulthood with uterine fibroids diagnoses

BACKGROUND

Genital talc and douching are practices that can involve exposure to chemical compounds linked to certain gynecologic cancers. However, it is unclear if they are associated with fibroid risk or age at fibroid diagnosis among women.

OBJECTIVE

This study aimed to evaluate the impact of early-adolescence genital talc use and douching on prevalence of fibroids diagnosed before the age of 35 and 50 years among Black/African American and non-Hispanic White women.

STUDY DESIGN

Data were derived from the Sister Study (2003-2020), a prospective cohort of 50,884 US women aged 35 to 74 years at enrollment. Participants were asked if they ever had a fibroid diagnosis and at what age, and if they used genital talc and/or douched between the ages of 10 and 13 years or in the past 12 months. After applying predefined exclusion criteria, our analytical sample size was n=46,316 (Black, n=4310; non-Hispanic White, n=42,006). Multivariable logistic regression was used to compute adjusted odds ratios and 95% confidence intervals for having vs not having early-onset fibroids diagnosed before age 35 among women aged 35 to 74 years at enrollment, and fibroids diagnosed before age 50 among women aged 50 to 74 years at enrollment. We adjusted for early life factors (in utero diethylstilbestrol exposure, singleton or multiple birth, fed soy formula during infancy), childhood socioeconomic status, and relative weight and height compared with peers at age 10. We used multiple imputation (<10% missing in all analyses). Results were stratified by race/ethnicity given that Black women are more likely to develop fibroids at a younger age than non-Hispanic White women.

RESULTS

Among Black/African American women, 29% had fibroids diagnosed before age 35. Both genital talc use at age 10 to 13 (adjusted odds ratio, 1.23; confidence interval, 1.06-1.41) and douching (adjusted odds ratio, 1.19; 95% confidence interval, 0.95-1.48) were associated with higher odds of having a fibroid diagnosed before age 35. Douching without talc use was not associated with increased odds, but combined use of genital talc and douche was associated with 52% increased odds of fibroids (confidence interval, 1.14-2.01). Among non-Hispanic White women, 9% reported fibroids diagnosed before age 35. Genital talc use (1.31; 1.20-1.44) but not douching (0.96; 0.77-1.20) at age of 10 to 13 years was associated with having a fibroid diagnosed before age 35. We observed similar patterns for non-Hispanic White women when we considered fibroids diagnosed before age 50, but neither practice was associated with fibroids diagnosed before age 50 in Black women.

CONCLUSION

Genital talc use in early adolescence, alone and in combination with douching (but not douching alone), is associated with prevalence of fibroids diagnosed before age 35 among Black/African American women and before ages 35 and 50 among non-Hispanic White women. Early adolescence may be a window of susceptibility for fibroid development, suggesting that adolescent girls should be educated on abstention from or alternatives to talc use and douching.

Systematic review of the association between talc and female reproductive tract cancers

Talc is a hydrous magnesium sheet silicate used in cosmetic powders, ceramics, paints, rubber, and many other products. We conducted a systematic review of the potential carcinogenicity of genitally applied talc in humans. Our systematic review methods adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and incorporated aspects from the US Institute of Medicine (IOM, now the National Academy of Medicine) and several US EPA frameworks for systematic reviews, evaluating and integrating the epidemiological, animal, and mechanistic literature on talc and cancer. We conducted a comprehensive literature search. Detailed data abstraction and study quality evaluation, adapting the Toxic Substances Control Act (TSCA) framework, were central to our analysis. The literature search and selection process identified 40 primary studies that assessed exposure to talc and female reproductive cancer risks in humans (n = 36) and animals (n = 4). The results of our evaluation emphasize the importance of considering biological plausibility and study quality in systematic review. Integrating all streams of evidence according to the IOM framework yielded classifications of suggestive evidence of no association between perineal application of talcum powders and risk of ovarian cancer at human-relevant exposure levels. We also concluded that there is suggestive evidence of no association between genital talc application and endometrial cancer, and insufficient evidence to determine whether a causal association exists between genital talc application and cervical cancer based on a smaller but largely null body of literature.

Douching and Genital Talc Use: Patterns of Use and Reliability of Self-reported Exposure

BACKGROUND

Feminine hygiene products contain chemicals that may be harmful to human health. Observational studies of the long-term health effects of such products largely rely on self-reported, recalled exposure. We sought to capture patterns of use over the life course and evaluate the reliability of self-reported data.

METHODS

We collected retrospective data on douching and genital talc use in the US-based Sister Study at two-time points and evaluated the consistency of reporting. At enrollment (2003-2009), participants were asked to report use in the last year and during ages 10-13. On a follow-up questionnaire (2017-2019), participants were asked about their use of douche or genital talc over their lifetimes.

RESULTS

Among 36,202 women who completed both questionnaires, 14% initially reported ever douching and 27% initially reported ever using genital talc. On the follow-up questionnaire, 51% of participants reported ever douching and 32% reported ever using genital talc. Comparisons across the two questionnaires for use in the year before enrollment showed good consistency, with 90% providing the same responses about douching and 87% providing the same responses about genital talc use. Reliability did not vary by cancer status, race and ethnicity, attained education, or age, though there was some evidence of recall bias for genital talc use among ovarian cancer survivors.

CONCLUSIONS

Classification of ever use of feminine hygiene products may be recalled with good consistency, but agreement was lower for specific time periods and trends may vary by subgroup. These potential differences warrant careful consideration in future studies.