An international multicenter study evaluating the impact of an alternative biochemical failure definition on the judgment of prostate cancer risk

Abstract

Purpose: To evaluate the impact of an alternative biochemical failure (bF) definition on the performance of existing plus de novo prognostic models. Methods and Materials: The outcomes data of 1,458 Australian and 703 Canadian men treated with external-beam radiation monotherapy between 1993 and 1997 were analyzed using a lowest prostate-specific antigen (PSA) level to date plus 2 ng/mL (L + 2) bF definition. Two existing prognostic models were scrutinized using discrimination (Somers Dxy [SDxy]) and calibration indices. Alternative prognostic models were also created using recursive partitioning analysis (RPA) and multivariate nomogram methods for comparison. Results: Discrimination of bF w..