Prospective study evaluating postoperative radiotherapy plus 2-year androgen suppression for post-radical prostatectomy patients with pathologic T3 disease and/or positive surgical margins.
OBJECTIVE
To determine the efficacy of a combined approach of postoperative radiotherapy (RT) plus 2-year androgen suppression (AS) for patients with pathologic T3 disease (pT3) and/or positive surgical margins (PSM) after radical prostatectomy (RP).


METHODS
A total of 78 patients with pT3 and/or PSM after RP were treated with RT plus 2-year AS, as per a pilot, prospective study. Androgen suppression started within 1 month after the completion of RT and consisted of nilutamide for 4 weeks and buserelin acetate depot subcutaneously every 2 months for 2 years. Relapse-free rate, including freedom from prostate-specific antigen (PSA) relapse, was estimated using the Kaplan-Meier method. A Cox regression analysis was performed to evaluate prognostic factors for relapse. Prostate-specific antigen relapse was defined as a PSA rise above 0.2 ng/mL, with two consecutive increases over a minimum of 3 months.


RESULTS
The median age was 61 years at the time of RP. The median interval between RP and postoperative RT was 4.2 months. Forty-nine patients had undetectable PSA (<0.2 ng/mL), and 29 had persistently detectable postoperative PSA at the time of the protocol treatment. Median follow-up from RT was 6.4 years. Relapse-free rates at 5 and 7 years were 94.4% and 86.3%, respectively. Survival rates were 96% at 5 years and 93.1% at 7 years. On Cox regression analysis, persistently detectable postoperative PSA and pT3b-T4 were significant predictors for relapse.


CONCLUSIONS
The combined treatment of postoperative RT plus 2-year AS yielded encouraging results for patients with pT3 and/or PSM and warrants a confirmatory study.
Choo
Richard
R
Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA. choo.c@mayo.edu
Danjoux
Cyril
C
Gardner
Sandra
S
Morton
Gerard
G
Szumacher
Ewa
E
Loblaw
D Andrew
DA
Cheung
Patrick
P
Pearse
Maria
M
D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D002064:Buserelin / Q000627:therapeutic use; D003131:Combined Modality Therapy / Q000379:methods; D006801:Humans; D048289:Imidazolidines / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D010865:Pilot Projects; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012044:Regression Analysis; D015996:Survival Rate
D000726:Androgen Antagonists; D048289:Imidazolidines; C021277:nilutamide; D017430:Prostate-Specific Antigen; D002064:Buserelin