Outcome of salvage radiotherapy for biochemical failure after radical prostatectomy with or without hormonal therapy.
BACKGROUND
This study analyzed the outcome of salvage radiotherapy for biochemical failure after radical prostatectomy (RP). By comparing the outcomes for patients who received RT alone and for those who received combined RT and hormonal therapy, we assessed the potential benefits of hormonal therapy.


METHODS
This cohort was comprised of 101 patients who received salvage RT between 1990 and 2001 for biochemical failure after RP. Fifty-nine of these patients also received hormone. Margin status (positive vs. negative), extracapsular extension (yes vs. no), seminal vesicle involvement (yes vs. no), pathologic stage, Gleason score, pre-RP PSA, post-RP PSA, pre-RT PSA, hormonal use, radiotherapy dose and technique, RP at M. D. Anderson Cancer Center, and time from RP to salvage RT were analyzed. Statistically significant variables were used to construct prognostic groups.


RESULTS
Independent prognostic factors for the RT-alone group were margin status and pre-RT PSA. RP at M. D. Anderson Cancer Center was marginally significant (p = 0.06) in multivariate analysis. Pre-RT PSA was the only significant prognostic factor for the combined-therapy group. We used a combination of margin status and pre-RT PSA to construct a prognostic model for response to the salvage treatment based on the RT group. We identified the favorable group as those patients with positive margin and pre-RT PSA < or = 0.5 ng/mL vs. the unfavorable group as otherwise. This stratification separates patients into clinically meaningful groups. The 5-year PSA control probabilities for the favorable vs. the unfavorable group were 83.7% vs. 61.7% with radiotherapy alone (p = 0.03). Androgen ablation seemed to be most beneficial in the unfavorable group.


CONCLUSIONS
After prostatectomy, favorable-group patients may fare well with salvage radiotherapy alone. These patients may be spared the toxicity of androgen ablation. The other patients may benefit most from a combined approach with hormonal treatment. We further suggest that salvage radiotherapy should be given early when the PSA is still low.
Cheung
Rex
R
Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA. mrcheung@mdanderson.org
Kamat
Ashish M
AM
de Crevoisier
Renaud
R
Allen
Pamela K
PK
Lee
Andrew K
AK
Tucker
Susan L
SL
Pisters
Louis
L
Babaian
Richard J
RJ
Kuban
Deborah
D
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000726:Androgen Antagonists / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D011879:Radiotherapy Dosage; D016879:Salvage Therapy / Q000379:methods*; D016896:Treatment Outcome
D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen