DNA PLOIDY, CELL-PROLIFERATION AND STEROID-HORMONE RECEPTORS IN ENDOMETRIAL HYPERPLASIA AND EARLY ADENOCARCINOMA

We determined DNA content, S-phase fraction, and estrogen (ER) und pro gesterone receptor (PR) levels in 36 stage I endometrial adenocarcinom as and in 22 hyperplastic lesions to obtain information on the genesis and progression of endometrial malignancy. DNA aneuploidy was detecte d in 12/36 (33%) carcinomas and in none of the hyperplastic lesions. D NA aneuploidy was significantly more common in poorly and moderately d ifferentiated carcinomas than in the well-differentiated ones. Similar ly, the highest number of cells in S-phase were found in poorly and mo derately differentiated carcinomas, whereas well-differentiated carcin omas and all hyperplasias had an equally small S-phase fraction. Mean ER and PR levels were highest in hyperplastic lesions, especially thos e with atypical features, whereas carcinomas of all grades had signifi cantly lower values. Thus, it is likely that the loss or decreased exp ression of steroid receptors is an early event during carcinogenesis i n human endometrium, whereas an increase in the cell proliferation rat e and the formation of DNA aneuploidy occur later during tumor progres sion.