Refining the American Urological Association and American Society for Radiation Oncology guideline for adjuvant radiotherapy after radical prostatectomy using the pathologic Gleason score

Recently, it has been suggested that the guideline for adjuvant radiotherapy (ART) following radical prostatectomy (RP) sponsored by the American Urological Association and American Society for Radiation Oncology (AUA/ASTRO) may result in a significant overtreatment. Thus, the objective of the present study was to refine the AUA/ASTRO guideline for ART in patients at risk for biochemical recurrence (BCR) after RP. To this end, we reviewed our prospectively maintained database and selected 193 patients who met the AUA/ASTRO ART criteria. With a median follow-up of 24.0 months, BCR rate was 17.6% (34/193). When stratified by the Gleason score, BCR rate in men with Gleason score 6 was 6.8%. There was no significant association between BCR-free survival and surgical margin (P = 0.690) and pathologic stage (P = 0.353) in patients with the Gleason score 6. However, in patients with positive surgical margins (PSMs)/pathologic stage ≥T3, there was a significant difference in BCR-free survival according to Gleason score (≤14;7 vs 8-10, P = 0.047). Multivariate Cox regression analysis demonstrated that pathologic stage ≥T3 (HR = 2.106; P= 0.018), PSMs (HR = 2.411; P= 0.003), and pathologic Gleason score 8-10 (HR = 4.715; P< 0.001) were independent predictors of BCR after RP. Therefore, in addition to pathologic stage ≥T3 and PSMs, Gleason score 8-10 predicts BCR after RP. In patients with Gleason score 6, observation rather than ART may be more appropriate regardless of stage and surgical margin status.