Flow cytometry and interactive image cytometry in endometrial carcinoma. A comparative and prognostic study.

Comparative DNA measurements were performed in 139 women with endometrial carcinoma using flow cytometry (FCM) and interactive image cytometry (ICM). Ploidy level and the percentage of S-phase cells were determined by FCM and ploidy level and the percentage of cells with a DNA content exceeding 2.5c, 3c, 4c and 5c, respectively, were calculated by ICM. The aim was to compare ploidy level obtained by the two methods and to evaluate the prognostic value of all the above-mentioned parameters. Recurrence or residual disease after completing treatment were used as end-points. Follow-up time was 18-48 months. An agreement was obtained in 85% of the cases as regards ploidy level, but in 15% the tumors were regarded as near-diploid by one method and as grossly aneuploid by the other. Both ploidy level (both methods) and S-phase rate (FCM) were correlated with histopathologic grade (p less than 0.001 and p less than 0.05, respectively). In univariate analysis, ploidy level (obtained either by FCM or ICM) correlated with recurrence rate, with a more favourable prognosis for near-diploid cases. When using multivariate models (Cox analysis) including clinical variables, ploidy level by FCM (but not ICM) was still significant as regards prognosis. In the multivariate analysis, S-phase fraction (as measured by FCM) also yielded independent prognostic information. In a separate analysis the proportion of cells with a DNA content greater than 5c gave independent prognostic information besides that of the S-phase fraction and ploidy level. We conclude that measurements of the percentage of cells exceeding 5c give prognostic information beyond the information obtained from flow cytometric determination of ploidy level and S-phase fraction.