Circulating Sex Steroids during Pregnancy and Maternal Risk of Non-epithelial Ovarian Cancer

Background: Sex steroid hormones have been proposed to play a role in the development of non-epithelial ovarian cancers (NEOC) but so far no direct epidemiologic data are available. Methods: A case–control study was nested within the Finnish Maternity Cohort, the world's largest biorepository of serum specimens from pregnant women. Study subjects were selected among women who donated a blood sample during a singleton pregnancy that led to the birth of their last child preceding diagnosis of NEOC. Case subjects were 41 women with sex cord stromal tumors (SCST) and 21 with germ cell tumors (GCT). Three controls, matching the index case for age, parity at the index pregnancy, and date at blood donation were selected (n = 171). OR and 95% CI associated with concentrations of testosterone, androstenedione, 17-OH-progesterone, progesterone, estradiol, and sex hormone–binding globulin (SHBG) were estimated through conditional logistic regression. Results: For SCST, doubling of testosterone, androstenedione, and 17-OH-progesterone concentrations were associated with about 2-fold higher risk of SCST [ORs and 95% CI of 2.16 (1.25–3.74), 2.16 (1.20–3.87), and 2.62 (1.27–5.38), respectively]. These associations remained largely unchanged after excluding women within 2-, 4-, or 6-year lag time between blood donation and cancer diagnosis. Sex steroid hormones concentrations were not related to maternal risk of GCT. Conclusions: This is the first prospective study providing initial evidence that elevated androgens play a role in the pathogenesis of SCST. Impact: Our study may note a particular need for larger confirmatory investigations on sex steroids and NEOC. Cancer Epidemiol Biomarkers Prev; 20(2); 324–36. ©2010 AACR.