Interphase cytogenetic study of preoperative core biopsies for the prediction of early serum prostate specific antigen recurrence after radical prostatectomy of clinically localized prostate carcinoma

Abstract

Current clinical and pathologic methods are imprecise in predicting the extent of prostate carcinoma progression. This study was conducted to evaluate the role of interphase cytogenetics (ICG) with chromosome enumeration probes relative to the role of conventional pathologic characteristics in the preoperative prediction of postoperative tumor classification and recurrence of elevated serum concentrations of prostate specific antigen (PSA). The authors performed ICG with enumeration probes for chromosomes 7, 17, and X on 6-microm sections of core biopsies from 75 patients with clinically localized adenocarcinoma of the prostate. Results were compared with pathologic findings (tumor classification, volume, and status of surgical margins) of the corresponding radical prostatectomy specimens and data on serum PSA measurements taken for 72 patients during a follow-up period of up to 42 months (mean, 19.8 months). In addition to ICG, biopsies were reviewed for primary, secondary, highest, and combined Gleason grades, number and bilaterality of positive biopsies, amount of carcinoma (percentage and core length of infiltration), amount of high grade carcinoma, and perineural invasion. Chromosome categories were unevenly distributed among pathologic tumor classification groups (P = 0.0008) and between groups with positive and negative surgical margins (P = 0.0116). Tumors with aneusomic chromosome numbers had larger volumes than those with eusomy and tetrasomy (P = 0.0022). Kaplan-Meier analysis demonstrated that PSA recurrences (> or = 0.4 ng/mL) were more frequent and observed earlier in patients with detected chromosomal aneusomies than in those with eusomic and tetrasomic chromosome numbers (P < 0.0001). Cox regression analysis indicated that ICG was the most valuable independent factor in predicting PSA recurrences. The detection of numeric chromosomal aberrations in preoperative core biopsies is an adverse prognostic sign. Grading based on the quantification of genetic changes might prove useful in the prognostic stratification of patients with clinically localized prostate carcinoma.