Prognostic significance of DNA ploidy in carcinoma of prostate: relationship between DNA ploidy, granular differentiation, and stage

Lee, Kyu Seung; Lee, Sung Won; Lee, Sang Eun; Kim, Si Whang

Abstract

Flow cytometry was used to measure the DNA content in archived paraffin-embedded human prostatic cancer tissue for 93 patients with known outcomes that presented between 1980 and 1988 Of these. 25 patients had clinically localized lesions, while 68 patients presented with advanced diseases. Fifty seven tumors (61%) contained a aneuploid stem line. The Frequency of aneuploid in creased with advancing stage and most tumors confined to the prostate gland were diploid. The degree of glandular differentiation was characterized by the Gleason sum. One-third of tumors with a Gleason sum of 2 to 4 were aneuploid. whereas 78% of tumors with a Gleason sum of 8 to 10 were aneuploid. Among aneuploid tumors. 11% were localized carcinomas. 89% were advanced status. When tumors were classified according to both DNA ploidy and degree of glandular differentiation. the subgroups of tumors with the highest and lowest degree of malignant potential became apparent. Only 27% of diploid tumors with Gleason sum of 2 to 4 were advanced tumors. but 100% of aneuploid tumors with Gleason sum of 8 to 10 were advanced tumors. The influence of DNA ploidy on survival was examined with Kaplan-Meier method and the generalized Wilcoxon test. Overall, patients with diploid tumors had a survival advantage over patients with aneuploid tumors(p<0.05) However. when adjusted for stage, glandular differentiation, the difference in survival curves for aneuploid and diploid was not significant(p>0.05). But, in patients of Stage D with intermediate grade tumors, the survival difference between diploid and aneuploid tumors were obvious. In conclusion, flow cytometry can be expected to become a valuable adjunct to clinical staging and morphologic grading (Gleason sum) in the assessment of the malignant potentials of prostatic cancer.