DEOXYRIBONUCLEIC-ACID PLOIDY OF CORE BIOPSIES AND METASTATIC LYMPH-NODES OF PROSTATE-CANCER PATIENTS - IMPACT ON TIME TO PROGRESSION

We studied 98 patients with locally confined but lymph node positive p rostatic cancer (1 stage T1, 29 stage T2, 55 stage T3 and 2 stage T4) who were not treated by radical prostatectomy. A retrospective analysi s was done of deoxyribonucleic acid (DNA) ploidy of pretreatment core biopsies of the primary tumor and lymph node metastases. While DNA plo idy has been shown to be an important prognostic factor if applied to radical prostatectomy specimens, core biopsy specimens and nodal metas tases have rarely been studied. Of the 98 patients 87 were evaluable f or DNA ploidy: 45 (52%) had diploid, 13 (15%) had tetraploid and 29 (3 3%) had aneuploid tumors. The ploidy of the primary tumor and of the l ymph node metastases correlated significantly with the rate of progres sion and interval to progression. Also, significant correlations were noted between the percentages of cells in the S phase or S plus G2 pha ses of the cell cycle and interval to progression. Most patients in th is study are part of the European Organization for Research and Treatm ent of Cancer protocol 30846, a prospective randomized study of early versus delayed treatment in lymph node positive, otherwise locally con fined prostate cancer. This study is ongoing. Early endocrine treatmen t was associated with a significantly longer interval to progression. In a Cox regression analysis of the prognostic factors involved in thi s study, early endocrine treatment was more important than ploidy or p roliferation patterns. Stage (T category) and histopathological grade did not show a correlation with progression. Followup is still too sho rt and the numbers of patients are too small for relevant subgroup ana lysis. DNA ploidy measurement by flow cytometry on archival (paraffin embedded) core biopsy and lymph node material is possible, and produce s meaningful results in predicting the prognosis of prostatic cancer. Since this information can be made available before treatment decision s, its exact value in the management of locally confined prostate canc er can be determined.