Defining Long Term Failure Risk in Patients With an Undetectable PSA After Salvage Radiation

adjuvant therapy. Kaplan-Meier and Cox multivariate analyses (MVA) were used to compare tBCR rates. Results: First post-op uPSA 0.03, iPSA, Gleason grade, and T-stage predicted tBCR. First post-op uPSA < 0.03 vs. 0.03 predicted 5-year tBCR-free rates of 70% vs. 15% (p < 0.0001). On MVA, only Gleason grade, T-stage, and first post-op uPSA 0.03 independently predicted tBCR. First post-op uPSA 0.03 conferred the highest risk (HR Z 9.1, p < 0.0001). First post-op uPSA 0.03 discerned tBCR with twice the sensitivity of an undetectable first conventional PSA (72% vs. 37%). Any post-op PSA 0.03 captured all failures missed by analyzing only the first post-op value (100% sensitivity, 96% specificity) and detects failure with extreme accuracy, as 98% of patients progressed to tBCR. Using uPSA 0.03 yields a lead time advantage of 33 months over conventional PSA failure definition of 0.2 (median time to BCR 15 months vs. 48 months in favor of uPSA 0.03). Conclusions: First post-op uPSA 0.03 is an independent factor on MVA and predicts tBCR more accurately and expediently than any risk factors. Biochemical failure can be called at uPSA 0.03 with excellent sensitivity and specificity and adopting it offers a lead time advantage of 33 months. The evidence indicates that integrating uPSA into the immediate and continued surveillance of high-risk RP patients will improve post-op RT outcomes by correctly identifying true failures, promoting an early salvage strategy, and minimizing overtreatment. Author Disclosure: J. Kang: None. R. Reiter: None. M.L. Steinberg: None. C.R. King: None.