Predicting the outcome of salvage radiation therapy for recurrent prostate cancer after radical prostatectomy.
OBJECTIVE
An increasing serum prostate-specific antigen (PSA) level is the initial sign of recurrent prostate cancer among patients treated with radical prostatectomy. Salvage radiation therapy (SRT) may eradicate locally recurrent cancer, but studies to distinguish local from systemic recurrence lack adequate sensitivity and specificity. We developed a nomogram to predict the probability of cancer control at 6 years after SRT for PSA-defined recurrence.


METHODS
Using multivariable Cox regression analysis, we constructed a model to predict the probability of disease progression after SRT in a multi-institutional cohort of 1,540 patients.


RESULTS
The 6-year progression-free probability was 32% (95% CI, 28% to 35%) overall. Forty-eight percent (95% CI, 40% to 56%) of patients treated with SRT alone at PSA levels of 0.50 ng/mL or lower were disease free at 6 years, including 41% (95% CI, 31% to 51%) who also had a PSA doubling time of 10 months or less or poorly differentiated (Gleason grade 8 to 10) cancer. Significant variables in the model were PSA level before SRT (P < .001), prostatectomy Gleason grade (P < .001), PSA doubling time (P < .001), surgical margins (P < .001), androgen-deprivation therapy before or during SRT (P < .001), and lymph node metastasis (P = .019). The resultant nomogram was internally validated and had a concordance index of 0.69.


CONCLUSIONS
Nearly half of patients with recurrent prostate cancer after radical prostatectomy have a long-term PSA response to SRT when treatment is administered at the earliest sign of recurrence. The nomogram we developed predicts the outcome of SRT and should prove valuable for medical decision making for patients with a rising PSA level.
Stephenson
Andrew J
AJ
Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, OH 44195-0001, USA. stephea2@ccf.org
Scardino
Peter T
PT
Kattan
Michael W
MW
Pisansky
Thomas M
TM
Slawin
Kevin M
KM
Klein
Eric A
EA
Anscher
Mitchell S
MS
Michalski
Jeff M
JM
Sandler
Howard M
HM
Lin
Daniel W
DW
Forman
Jeffrey D
JD
Zelefsky
Michael J
MJ
Kestin
Larry L
LL
Roehrborn
Claus G
CG
Catton
Charles N
CN
DeWeese
Theodore L
TL
Liauw
Stanley L
SL
Valicenti
Richard K
RK
Kuban
Deborah A
DA
Pollack
Alan
A
D015331:Cohort Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy*; D049451:Nomograms; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D012189:Retrospective Studies; D016879:Salvage Therapy; D016896:Treatment Outcome
D017430:Prostate-Specific Antigen