SELECTION OF MEN AT HIGH-RISK FOR DISEASE RECURRENCE FOR EXPERIMENTALADJUVANT THERAPY FOLLOWING RADICAL PROSTATECTOMY

Objectives. Following surgery, men with recurrent prostate cancer have an isolated elevation in serum prostate-specific antigen (PSA) well i n advance of measurable metastatic disease. Rational patient selection for new forms of adjuvant therapy, for example, gene therapy, is impe rative. Methods. In a retrospective study of two cohorts, we used prop ortional hazards regression analysis to develop and validate a multifa ctor model for identifying men who are at high risk of cancer recurren ce. The model cohort consisted of 216 men with clinical Stage T2b and T2c treated by 1 urologist. The validation cohort consisted of 214 men with Stage T2b and T2c disease. Results. A model for log relative ris k, R(W), used serum PSA with a sigmoidal transformation (PSA(ST)), rad ical prostatectomy Gleason score (GS), and pathologic stage (PS) as sp ecimen confined or nonspecimen confined: R(W) = (PSA(ST) x 0.06) + (GS x 0.54) + (PS x 1.87). Recurrence risk categories were determined as low risk if R(W) is less than 4.0, intermediate risk if it is 4.0 to l ess than 5.75, and high risk if R(W) is more than 5.75. The observed K aplan-Meier actuarial analysis of the three risk groups correlated wel l with the predictions determined for the model cohort. We then valida ted this model independently using a second cohort of 214 men with sim ilar age, stage, and grade treated by 3 different urologists at two di fferent institutions. Conclusions. The recurrence rates for men in the high-risk group are similar to those for men with positive lymph node s and justifies exploration of experimental adjuvant therapy within th is group using this model of patient selection.