In its natural form, some talc may contain asbestos, which is known to cause cancer. However, modern domestic talcum powder does not contain asbestos.
Asbestos free talc, such as that found in modern talcum powder has been suggested to increase the risk of ovarian cancer in women who apply talcum powder regularly in the genital area. Several studies in women have looked at the possible link between talcum powder and ovarian cancer, with mixed findings. Some studies report a slightly increased risk, while others have found no increase. The evidence is insufficient to conclude that use of talcum powder leads to an increased risk of ovarian cancer. It is also unclear how talcum powder might influence the development of ovarian cancer
Read more at http://www.cancercouncil.com.au/86105/cancer-information/general-information-cancer-information/cancer-questions-myths/clothing-cosmetics-tattoos/there-is-inconclusive-evidence-that-using-talcum-powder-can-cause-cancer/#M9m3vHMcvbZ01THc.99