An enhanced prognostic system for clinically localized carcinoma of the prostate

Abstract

BACKGROUND This investigation was conducted to develop an enhanced prognostic system based on readily available and independently predictive tumor‐related factors for patients with clinically localized prostate carcinoma. METHODS The outcome of 500 patients treated solely with irradiation for clinical TNM classifications T1‐4, N0 or NX, M0 prostate carcinoma was used to identify factors independently associated with disease relapse. Logistic regression constructed a risk score equation, and optimized cutoff points to characterize patient groups with low, intermediate, or high risks for relapse were established with receiver operating characteristic curve analysis. RESULTS Clinical tumor stage (P < 0.00001), Gleason score (P = 0.0002), and pretherapy serum prostate specific antigen (P < 0.00001) were independently associated with clinical or biochemical relapse. These factors were included in a risk score equation that defined patient groups with a distinctly different outcome. For the low, intermediate, and high risk groups, the relapse‐free probabilities at 5 years after irradiation were 92%, 67%, and 24%, respectively (P < 0.0001). CONCLUSIONS Readily available, pretherapy disease‐related characteristics formed the basis of an enhanced prognostic system for patients with clinically localized prostate carcinoma. A multivariate prognostic system of this nature estimated patient prognosis in a more exacting fashion than a system exclusively based on anatomic factors. Cancer 1997; 79:2154‐61. © 1997 American Cancer Society.