PSA CONFIRMATION OF CURE AT 10 YEARS OF T-1B, T-2, N-0, M(0) PROSTATE-CANCER PATIENTS TREATED IN RTOG PROTOCOL-7706 WITH EXTERNAL-BEAM IRRADIATION

Purpose: This study was done to correlate prostatic specific antigen v alues with clinical no evidence of disease status for 28 long-term sur vivors of external beam irradiation from Radiation Therapy Oncology Gr oup Study #77-06, and confirm the clinical observation of cure. Method s and Materials: One hundred and four patients in Radiation Therapy On cology Group 77-06 with T-1B T-2 N-0, M(0) with pathologically known n egative lymph node status, were previously shown to have a 10 year act uarial outcome equal to radical prostatectomy patients. Of these 104, 28 were 9-13 year survivors with clinically no evidence of disease by physical examination and imaging. Results: Prostatic specific antigen was available or obtained in 17 patients, 15 of the 17 had prostatic s pecific antigen values of < 3.5 ngm/%, while 11 had values of < 1.5 ng m/%. Depending on which level one selects, 88% or 65% of clinical no e vidence of disease 9-13 year survivors have a normal or low prostatic specific antigen. Conclusion: Prostatic specific antigen adds to the a ccuracy of determining clinical long-term cure and shows that 65-88% o f patients who are clinical no evidence of disease are ''biochemical'' cures as well. These correlation percentages are quite similar to the largest contemporary surgical series, and strongly support the concep t and fact of cure of prostate cancer with radiation.