Perineal talc use and ovarian cancer: a critical review

Abstract

Talc, like asbestos, is a silicate that has been studied in relation to cancer risk. Several studies conducted over the past 25 years found an association between perineal talc powders and ovarian cancer. The summary relative risk is about 1.3 (95% confidence intervals 1.2-1.5) and these data have been interpreted as supporting a causal role. In this review article, we discuss the chemical and morphological features of talc and asbestos, and explain why despite their similar chemical classification talc does not possess asbestos-like carcinogenic properties. The heterogeneity in the perineal dusting studies has raised important concerns over the validity of the exposure measurements, and the lack of a consistent dose-response effect limits making causal inferences. Perhaps more importantly, whereas it is unknown whether external talc dust enters the female reproductive tract, measures of internal talc exposure such as talc-dusted diaphragms and latex condoms show no relationship with ovarian cancer risk. In addition, the therapeutic use of high dose cosmetic grade talc for pleurodesis has not been shown to cause cancer in patients receiving these treatment modalities. Talc is not genotoxic. Mechanistic, pathology and animal model studies have not found evidence for a carcinogenic effect. In summary, these data collectively do not indicate that cosmetic talc causes ovarian cancer.

Epidemiology of ovarian cancer: a review

“…While mechanistic, pathology, and animal studies do not support evidence for the carcinogenicity of talc on the ovarian epithelium 329 , epidemiological studies have indicated an association with talc use and increased OC risk. In 2006, a meta-analysis of 21 studies 330 reported an approximately 35% increase in risk with genital exposure to talc and an earlier meta-analysis had similar findings 331 .…”

The biology of ovarian cancer: new opportunities for translation

“…Chemical carcinogens with mutagenic potential have generally not been linked to ovarian cancer risk, although exposure to the chronic inflammation produced by talc has been cited as a risk factor in some studies14, 15. Consistent with an absence of strong exogenous chemical carcinogens, the pattern of TP53 mutations in sporadic ovarian cancers is most consistent with spontaneous mutations that occur during cell proliferation16.…”

Perineal talc use and ovarian cancer risk

“…Finally, other human data, such as the demonstration that talc inhaled in mining and milling operations is not associated with increased pulmonary tumors, and the likelihood that talc could selectively induce ovarian cancer and not lung cancer at exposure concentrations orders of magnitude lower than that experienced in occupational settings, argue against its toxicity (Muscat and Huncharek, 2008).…”

“…This is a common procedure in the United States and elsewhere and talc slurry is applied directly to the pleura (through chest tube placement) to induce obliteration of the pleural space by scarring and prevent the reaccumulation of fluid secondary to tumor or benign causes. Multiple long-term clinical studies, as reviewed by Muscat and Huncharek (2008), have not shown a single case of cancer secondary to direct talc application to the human pleura (Shaw and Agarwal, 2004). There are also data showing that talc has demonstrated antitumor properties secondary to the induction of endostatin when used in pleurodesis (Najmunnisa et al, 2007).…”

“…The work by Stanton et al (1981) shows that the carcinogenic ability of fibrous asbestos is due to its structure, not its chemical composition. Although talc and asbestos are both magnesium silicates, they are structurally distinct and belong to different mineral groups and subgroups, as detailed by Muscat and Huncharek (2008). Amphibole asbestos minerals are inosilicates while talc is a member of the silicate subclass phyllosilicate and group clay or montmorillonite/smectite.…”