Abstract
Talc, a desiccant, has been historically used as baby powder by numerous women to enhance their feminine hygiene. However, since talc is frequently identified in proximity to asbestos, studies have implicated the role of talc use in effectuating carcinogenesis, particularly ovarian cancer. While retrospective studies have reported on the association of genital powder and an increased risk for ovarian cancer, prospective evaluations have not documented concordant findings. Moreover, the positive associations derived from the aforesaid case-control studies have been remote and the putative causal factors remain inconclusive. Consequently, given the untenable relationship between talc use and the risk for ovarian cancer in the general population, one should be circumspect regarding the continued assertion that genital powder application induces ovarian cancer development.
Keywords: talc use; ovarian cancer; risk factors, prevalence
Ovarian cancer is the most aggressive gynecologic malignancy in the United States, contributing to 14,000 deaths annually (Siegel et al. 2021). The neoplasm manifests itself in response to hereditary factors, including BRCA 1/2 gene mutations, which potentially increase a woman’s lifetime risk of the disease by approximately 50% and 30%, respectively (Biglia et al. 2016). Additionally, case-control studies have implicated talc powder as a risk factor in ovarian carcinogenesis (Schildkraut et al. 2016; Cramer et at. 1982; Godard et al. 1998).
Talc is frequently used as a desiccant in hygienic or cosmetic agents. Talc was initially purported to be carcinogenic because the silicate is encountered adjacently to asbestos and quartz (Muscat and Barish 1998), two minerals notoriously associated with malignancies (Moline et al. 2020; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans 2012). When silicates were initially detected in body powder, there was speculation that talc powder was contaminated by asbestos from mining-related procedures (Longo and Young 1979; Rohl et al. 1976).
Talc powder was further considered a relevant factor in ovarian cancer in accordance with study findings indicating that asbestos precipitated ovarian tumor development in guinea pigs (Graham and Graham 1967). Thenceforth, a case-controlled study reported that perineal talc use was associated with an increased risk for ovarian cancer (Cramer et al. 1982).
The primary mechanism for talc-induced ovarian cancer is reproductive tract inflammation, a response ostensibly engendered following talc particulate migration and embedment in ovarian epithelial tissue (Wentzensen and O’Brien 2021; Crawford et al. 2012). Consequently, increased oxidative stress levels, DNA damage, and cell division are prompted, theoretically occasioning carcinogenesis (Ness and Cottreau 1999). However, perineal application of talc does not conclusively render vaginal or cervical permeation, much less ovarian infiltration (Wright et al. 1996; Wehner 2002). Similarly, the contention that talc fibers migrate into the diaphragm via the peritoneal cavity and ultimately pervade the ovaries is quite speculative (Reid et al. 2011).
Several case-controlled studies have examined the relationship between talc use and ovarian cancer development, of which an elevated risk (relative risk: 1.1-3.9) of developing ovarian cancer was identified (Godard et al. 1998; Harlow and Hartge 1995; Hartge et al. 1983; Chen et al. 1992); alternatively, reports have not demonstrated a significant relationship (Cramer et al. 1982).
When considering these investigations, exposure prior to or following a cancer diagnosis was assessed, thereby generating confounding rates between the case and control subjects (Wentzensen and O’Brien 2021). Moreover, there was profound study variability regarding the application of talc (e.g., diaphragm, sanitary napkin, condom) and the specific exposure areas (genital or perineal) (IARC Working Group on the Evaluation of Carcinogenic Risks to Humans 2012; Ness and Cottreau 1999). Recall bias is also inherent in self-reported measures and this systematic error was potentially accentuated by the subjects’ inability to calibrate their transient (e.g., lifestyle changes, contraception use) exposure to talc (Muscat and Barish 1998).
In a prospective, pooled-data study conducted by the National Institute of Health, 252,745 women reported on their talc powder frequency of use and duration (O’Brien et al. 2020). The primary outcome measures were ever use of powder on the genitalia and incidence of ovarian cancer. Following a duration of 11.2 years, the study findings recounted an ovarian cancer incidence of 61 cases/100,000 for users and 55 cases/100,000 for never users, a difference that was not statistically significant. Similarly, another prospective analysis from the Nurses’ Health Study, examined talc use and the development of ovarian cancer with 78,630 female registered nurses (Gertig et al. 2000). The results indicated no overall association with talc use and a risk for ovarian cancer (multivariate relative risk= 1.09; 95% CI = 0.86-1.37), irrespective of talc application frequency.
Anecdotally, ovarian cancer development was predicated on the exposure of asbestos to talc, two silicates that are naturally occurring. Initially, some talc products may have contained asbestos, but cosmetic talc has been asbestos-free for numerous decades (Muscat and Barish 1998). Hence, if there were a positive relationship between talc and ovarian cancer, the extensive use of latex condoms, which contain talc and other silicates, would likely have resulted in a significant increase in ovary cancer incidence; incidentally, the Nurses’ Health Study found no association between talc-dusted condoms and an elevated risk for ovarian cancer (Booth et al. 1989).
While several case-controlled studies have purported a relationship between talc powder and the incidence of ovarian cancer, numerous epidemiological studies have gainsaid any such association. In consideration of the indeterminate impact of talc (differing amount of talc use, method of transmission and unspecified exposure duration) on ovarian cancer (Muscat and Huncharek 2008), one should be circumspect in proscribing the use of talc powder. Nevertheless, in endeavoring to attenuate potential health risks, researchers should further evaluate the effects of both prolonged exposure and specific timing (i.e., opportunistic circumstances) of talc use to conclusively determine if the silicate harbors carcinogenic potential
