Conversion of circulating estrone sulfate to 17beta-estradiol by ovarian tumor tissue: a possible mechanism behind elevated circulating concentrations of 17beta-estradiol in postmenopausal women with ovarian tumors

• Published in: Gynecological endocrinology 2007-01, Vol.23 (1), p.25-28
• Main Authors: Kirilovas, Dmitrijus, Schedvins, Kjell, Naessén, Tord, Von Schoultz, Bo, Carlström, Kjell
• Format: Article
• Language: English
• Subjects: Estradiol - blood; Estradiol - metabolism; Estrone - analogs & derivatives; Estrone - blood; Estrone - metabolism; Female; Humans; Medicin och hälsovetenskap; Middle Aged; Ovarian Neoplasms - blood; Ovarian Neoplasms - metabolism; Postmenopause
• ISSN: 0951-3590
• DOI: 10.1080/09513590601058333

Elevated serum levels of 17beta-estradiol (E2) are frequently found in postmenopausal women with ovarian tumors not classified as estrogen-producing. Conversion of circulating estrone sulfate (E1S) to E2 is one alternative way of E2 formation in target tissues in postmenopausal women. Our aim was to find out if conversion of circulating E1S to E2 by the tumor tissue could be a reason for elevated serum E2 levels in postmenopausal women with 'non-estrogen-producing' ovarian tumors. Serum E2 was measured in 12 postmenopausal women with 'non-estrogen-producing' ovarian tumors (nine benign, three malignant). Total hydrolysis of and [3H]E2 formation from [3H]E1S by the tumor tissue homogenates was studied in vitro. Serum E2 showed significant positive correlations with total hydrolysis of and [3H]E2 formation from [3H]E1S in the total material as well as in the benign tumor subgroup. [3H]E2 formation was the most important independent variable. Conversion of circulating E1S to E2 by the tumor tissue could be one important reason for elevated S-E2 levels in postmenopausal women with 'non-estrogen-producing' ovarian tumors.