Flow cytometric measurements of DNA index and S-phase on paraffin-embedded early stage endometrial cancer: an important prognostic indicator.

Paraffin-embedded curettage material from 120 patients with stage I and II endometrial cancer were analyzed by flow cytometry. The follow-up time in all cases was at least 5 years or until death. It was possible to determine DNA ploidy in 111 cases and S-phase was also evaluated in 92/111 cases. DNA ploidy and S-phase were then compared with the FIGO grading and clinical outcome. DNA ploidy results showed that 11% of grade 1 tumors were aneuploid, 14% of grade 2, 42% of grade 3, and 85% of the cases of uterine papillary serous carcinoma (UPSC) were aneuploid. Patients with tumors that showed an S-phase fraction below 5% had a cumulative 5-year cancer mortality of 7% whereas 49% of the patients with tumors having S-phase fraction above 10% died of their cancer. The prognostic significance of DNA and S-phase correlated fairly well with the FIGO grading as determined by a pathologist with special interest in gynecologic oncology and the DNA parameters added prognostic information independent of the FIGO grading.