Steroid hormone receptors and flow cytometric DNA ploidy in ovarian carcinoma

The biochemical and immunohistochemical estrogen (ER) and progesterone receptor (PR) content and flow cytometric DNA ploidy was analyzed in five semimalignant and 35 malignant epithelial ovarian tumours. By biochemical assay, 67% of the tumours were ER-positive (> or = 5 fmol/mg protein) and 56% were PR-positive (> or = 10 fmol/mg protein). The corresponding values by immunohistochemical assay (with a HSCORE of 10 as the cutoff level) were 22% and 27%, respectively. DNA histogram measured from paraffin embedded specimens were diploid in 20% (7/35) and aneuploid in 80% (28/35) of the malignant tumours. All semimalignant tumours were diploid. The mean receptor values in the diploid and aneuploid tumours did not differ significantly and receptor-positive and receptor-negative tumours were evenly distributed in all stages and grades. In contrast, flow cytometric DNA ploidy was clearly associated with tumour stage (G2 = 10.52, Df = 3, P = 0.015) and histological differentiation (G2 = 20.57, Df = 3, P = 0.0001).