Tumor size, vascular density and proliferation as prognostic markers in GS 6 and GS 7 prostate tumors in patients with long follow-up and non-curative treatment.

Abstract

To investigate the prognostic value of potential markers in localized, Gleason score 6 and 7 prostate cancer (PC). From a consecutive series of men with PC diagnosed at transurethral resection (1975-1990), specimens from 132 patients without metastases, with Gleason score (GS) 6 (n=80) or 7 (n=52) tumors followed with watchful waiting were examined. The fraction of resected prostate tissue containing cancer, the micro-vessel density (v.d.) when stained for endoglin or von Willebrand factor (vWf), and the percentage of Ki-67 labeled tumor cells were measured using immunohistochemistry. High levels of vWf v.d., endoglin v.d., and percent cancer of the TURP specimen were significantly associated with short cancer-specific survival in Kaplan-Meier analysis of all patients with GS 6 and 7 tumors. Interestingly, a combined estimate of percent cancer and vWF v.d. could be used to identify a large subset (50%) of GS 6 tumors with only a 2.5% risk of PC death within 15 years. None of the tested markers gave independent prognostic information for the GS 7 tumors. Estimates of tumor size and vascular density may identify a large proportion of non-aggressive GS 6, but not GS 7, tumors.