Objective: To study the relationship between the presence of endometrioid endometrial cancer, the degree of ovarian stromal hyperplasia and ovarian steroid production in postmenopausal women.

Design: Retrospective and prospective study, respectively.

Setting: Medical Centre Leeuwarden and the University Hospital Groningen, The Netherlands. Postmenopausal women with or without endometrial cancer, undergoing a hysterectomy with bilateral salpingo-oophorectomy.

Methods: In 112 women with endometrioid endometrial cancer, 47 women with a benign gynaecological condition and 10 women with non-endometrioid endometrial cancer, the degree of ovarian stromal hyperplasia was scored retrospectively on a semi-quantitative scale (atrophy, slight, marked). All women were postmenopausal and had undergone a hysterectomy with bilateral salpingo-oophorectomy. Prospectively, blood sampling from the ovarian veins was performed in a further 60 women. Steroid levels (oestrone, oestradiol, androstenedione, testosterone) were determined and related to the degree of ovarian stromal hyperplasia and the presence (n = 52) or absence (n = 8) of endometrioid endometrial cancer.

Main outcome measures: Degree of ovarian stromal hyperplasia and steroid levels in the utero-ovarian circulation.

Results: In the retrospective study, the degree of ovarian stromal hyperplasia was higher in the presence of endometrioid endometrial cancer (P = 0.0001). The prospective study showed that an increasing degree of ovarian stromal hyperplasia was related to higher ovarian levels of both testosterone and androstenedione (P < 0.05 and P < 0.005, respectively), but not to oestrone or oestradiol. A non-significant increase in mean ovarian vein levels of both testosterone and androstenedione was seen in patients with endometrial cancer as compared with patients with benign conditions.

Conclusion: In endometrioid endometrial cancer, higher degrees of ovarian stromal hyperplasia were found and with increasing degrees of ovarian stromal hyperplasia, levels of ovarian vein androgens were higher. A causal relationship in the origin of hormone-dependent endometrial pathology may exist between ovarian stromal hyperplasia, ovarian vein androgen levels and endometrioid endometrial carcinoma.