Predictors of biochemical outcome with salvage conformal radiotherapy after radical prostatectomy for prostate cancer.
OBJECTIVE
To identify predictors of biochemical outcome following radiotherapy in patients with a rising prostate-specific antigen (PSA) after radical prostatectomy for prostate cancer.


METHODS
One hundred fifteen patients with a rising PSA after radical prostatectomy received salvage three-dimensional conformal radiotherapy (3D-CRT) alone or with neoadjuvant androgen deprivation. Tumor-related and treatment-related factors were evaluated to identify predictors of subsequent PSA failure.


RESULTS
The median follow-up time after 3D-CRT was 42 months. The 4-year actuarial PSA relapse-free survival, distant metastasis-free survival, and overall survival rates were 46%, 83%, and 95%, respectively. Multivariate analysis, which was limited to 70 patients receiving radiation without androgen deprivation therapy, showed that negative/close margins (P =.03), absence of extracapsular extension (P <.01), and presence of seminal vesicle invasion (P <.01) were independent predictors of PSA relapse after radiotherapy. Neoadjuvant androgen deprivation did not improve the 4-year PSA relapse-free survival in patients with positive margins, extracapsular extension, and no seminal vesicle invasion (P =.24). However, neoadjuvant androgen deprivation did improve PSA relapse-free survival when one or more of these variables were absent (P =.03).


CONCLUSIONS
Salvage 3D-CRT can provide biochemical control in selected patients with a rising PSA after radical prostatectomy. Among patients with positive margins and no poor prognostic features, 77% achieved PSA control after salvage 3D-CRT. Salvage neoadjuvant androgen deprivation therapy may improve short-term biochemical control, but it requires further study.
Katz
Matthew S
MS
Departments of Radiation Oncology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Zelefsky
Michael J
MJ
Venkatraman
Ennapadam S
ES
Fuks
Zvi
Z
Hummer
Amanda
A
Leibel
Steven A
SA
D000328:Adult; D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D018572:Disease-Free Survival; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D017430:Prostate-Specific Antigen / Q000032:analysis*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D020266:Radiotherapy, Conformal; D016879:Salvage Therapy
D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen