PSA confirmation of cure at 10 years of T1B, T2, N0, M0 prostate cancer patients treated in RTOG protocol 7706 with external beam irradiation.

PURPOSE This study was done to correlate prostatic specific antigen values with clinical no evidence of disease status for 28 long-term survivors of external beam irradiation from Radiation Therapy Oncology Group Study #77-06, and confirm the clinical observation of cure. METHODS AND MATERIALS One hundred and four patients in Radiation Therapy Oncology Group 77-06 with T1B T2 N0, M0 with pathologically known negative lymph node status, were previously shown to have a 10 year actuarial 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 specific antigen values of < 3.5 ngm/%, while 11 had values of < 1.5 ngm/%. Depending on which level one selects, 88% or 65% of clinical no evidence of disease 9-13 year survivors have a normal or low prostatic specific antigen. CONCLUSION Prostatic specific antigen adds to the accuracy of determining clinical long-term cure and shows that 65-88% of 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 concept and fact of cure of prostate cancer with radiation.