Risk factors for invasive epithelial ovarian cancer by histologic subtype

It is unclear whether the different histologic subtypes of epithelial ovarian carcinoma have different risk factors. We investigated the relationships between selected epidemiologic variables (i.e., parity, family history of ovarian cancer, oral contraceptive use, a history of tubal ligation and noncontraceptive estrogen use) and the major histologic subtypes of epithelial ovarian cancer in a hospital-based casecontrol study of adult women at Roswell Park Cancer Institute in Buffalo, NY, USA. Multivariate unconditional logistic regression models were used for statistical analysis. We observed a pattern of increased risk associated with family history and a pattern of risk reduction associated with parity, noncontraceptive estrogen use and tubal ligation across all histologic subtype groups. However, we did not observe a consistent pattern of risk associated with oral contraceptive use. These results provide some additional support for the hypothesis that the effects of various ovarian cancer risk factors may differ according to the histologic subtype.