Polycystic ovary syndrome and endometrial cancer risk: results from a nationwide cohort study.

Most previous studies have found an elevated risk of endometrial cancer among women with polycystic ovary syndrome (PCOS). However, these have highly varying methods for ascertainment of PCOS diagnoses and have limitations such as few exposed women and short follow-up. In this cohort study, we investigated the association between PCOS and endometrial cancer among women born in Denmark between January 1, 1940, and December 31, 1993 (N=1,719,121). Data in this study, including PCOS and endometrial cancer diagnoses and covariates, were derived from nationwide registers. We used cox proportional hazard regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 7862 endometrial cancer cases were identified during 23.7 years of follow-up (inter quartile range 37.7-61.9). We found an increased risk of endometrial cancer among women with PCOS compared with women without PCOS (HR: 3.02, 95% CI; 2.03-4.49). The risk was increased for premenopausal women (HR5.82, 95% CI: 3.64-9.30) whereas no marked association was seen for postmenopausal women. However, for postmenopausal women, results were limited by few cases and young age at end of follow-up. Mounting evidence of an increased risk for endometrial cancer among women with PCOS reinforces the need for prevention and early detection.

Investigations on hormonal changes around parturition in the dog and the occurrence of pregnancy-specific non conjugated oestrogens.

Concentrations of progesterone and estradiol-17 beta were determined throughout pregnancy in 6 to 10 bitches (exp. 1); in experiment 2 peripartal changes of estradiol-17 beta, estrone, progesterone, cortisol, prolactin and growth hormone were determined in 5 bitches; in experiment 3 total unconjugated oestrogens were determined by radioimmunoassay and radioreceptorassay in placental tissue from 25, 53, 60 and 64 days pregnant bitches. No pregnancy specific increase of estradiol-17 beta could be observed; estradiol-17 beta levels decreased prior to parturition concomitant with the decrease of progesterone, suggesting a likewise luteal origin of estradiol-17 beta in the pregnant and non pregnant dog. Cortisol and growth hormone concentrations were elevated at the time of parturition, prolactin concentrations remained unchanged but were higher in pregnant than in non pregnant dogs. No hints in respect to a specific placental oestrogen production were obtained when examining placental tissue. The hypothesis is put forward that the high sensitivity of the haematopoietic system of the dog to oestrogen was an important factor in respect to evolution of endocrine control of pregnancy and parturition in this species which-in respect to placental oestrogen production-seems to be different from most other domestic animal species.