PROSTATE-SPECIFIC ANTIGEN AFTER RADIOTHERAPY FOR PROSTATE-CANCER - A REEVALUATION OF LONG-TERM BIOCHEMICAL CONTROL AND THE KINETICS OF RECURRENCE IN PATIENTS TREATED AT STANFORD-UNIVERSITY

Purpose: We evaluated prostate specific antigen (PSA) evidence for con trol of prostatic cancer after irradiation. Materials and Methods: We studied 110 patients for whom more than 2 PSA measurements were obtain ed to establish trends and the initial measurement was done between Ap ril 1985 and January 1988. Results: A total of 42 patients (38%) had s table, normal PSA levels with followup averaging 12.4 years (range 4.4 to 24.8). Increasing clinical stage or Gleason score correlated signi ficantly with risk for PSA relapse, as did pretreatment PSA level. Sho rt PSA doubling times were associated with distant metastasis rather t han with local recurrence. Conclusions: We found that irradiation dura bly controlled 38% of prostatic cancers of various stages and grades a nd is unlikely to accelerate tumor growth.