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, NO or NX, MO 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 < 0.00001).
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.