METAPHASE CYTOGENETICS AND DNA FLOW-CYTOMETRY WITH ANALYSIS OF S-PHASE FRACTION IN PROSTATE-CANCER - INFLUENCE ON PROGNOSIS

Objectives. To compare the prognostic significance of chromosome aberr ations, DNA ploidy, and S-phase fraction (SPF) in prostate adenocarcin omas and to compare the sensitivity of metaphase cytogenetics with flo w cytometry (FCM) in detecting abnormal tumor clones. Methods, Prostat e adenocarcinomas from 57 men were previously successfully analyzed wi th metaphase cytogenetics. Archival material from these tumors were fu rther analyzed with FCM for DNA content and SPF. Results. The patients were followed for 4.5 to 7.7 years. DNA ploidy was analyzed in 51, an d SPF in 45 of the 57 tumors. Clonal chromosomal aberrations, DNA aneu ploidy, and high SPF were all significantly associated with poor survi val. Of these three variables, SPF was the best predictor of survival, but compared with tumor stage and grade in multivariate analysis, SPF was not an independent prognostic factor. Patients with locally advan ced tumors or metastatic disease with SPF less than 8% had a median su rvival of 5.9 years, compared with only 1.3 years for those with SPF m ore than 8%. Twenty-eight abnormal clones were detected with FCM and 2 0 with cytogenetic analysis, but only for two of these clones could th e results from the two different methods be regarded as concordant. Co nclusions. SPF was superior to karyotype and ploidy in predicting deat h in prostate cancer, but it remains to be shown whether SPF analysis adds prognostic information to tumor stage and grade. The cytogenetic analyses correlated poorly with results of FCM, indicating low sensiti vity of both methods.