Long-term multi-institutional analysis of stage T1-T2 prostate cancer treated with radiotherapy in the PSA era.
OBJECTIVE
To report the long-term outcome for patients with Stage T1-T2 adenocarcinoma of the prostate definitively irradiated in the prostate-specific antigen (PSA) era.


METHODS
Nine institutions combined data on 4839 patients with Stage T1b, T1c, and T2 adenocarcinoma of the prostate who had a pretreatment PSA level and had received >or=60 Gy as definitive external beam radiotherapy. No patient had hormonal therapy before treatment failure. The median follow-up was 6.3 years. The end point for outcome analysis was PSA disease-free survival at 5 and 8 years after therapy using the American Society for Therapeutic Radiology and Oncology (ASTRO) failure definition.


RESULTS
The PSA disease-free survival rate for the entire group of patients was 59% at 5 years and 53% at 8 years after treatment. For patients who had received >or=70 Gy, these percentages were 61% and 55%. Of the 4839 patients, 1582 had failure by the PSA criteria, 416 had local failure, and 329 had distant failure. The greatest risk of failure was at 1.5-3.5 years after treatment. The failure rate was 3.5-4.5% annually after 5 years, except in patients with Gleason score 8-10 tumors for whom it was 6%. In multivariate analysis for biochemical failure, pretreatment PSA, Gleason score, radiation dose, tumor stage, and treatment year were all significant prognostic factors. The length of follow-up and the effect of backdating as required by the ASTRO failure definition also significantly affected the outcome results. Dose effects were most significant in the intermediate-risk group and to a lesser degree in the high-risk group. No dose effect was seen at 70 or 72 Gy in the low-risk group.


CONCLUSIONS
As follow-up lengthens and outcome data accumulate in the PSA era, we continue to evaluate the efficacy and durability of radiotherapy as definitive therapy for early-stage prostate cancer. Similar studies with higher doses and more contemporary techniques will be necessary to explore more fully the potential of this therapeutic modality.
Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston 77030, USA. dakuban@mdanderson.org
Deborah A
DA
Kuban
Howard D
HD
Thames
Larry B
LB
Levy
Eric M
EM
Horwitz
Patrick A
PA
Kupelian
Alvaro A
AA
Martinez
Jeff M
JM
Michalski
Thomas M
TM
Pisansky
Howard M
HM
Sandler
William U
WU
Shipley
Michael J
MJ
Zelefsky
Anthony L
AL
Zietman
D000230:Adenocarcinoma / Q000097:blood* / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012016:Reference Values; D017211:Treatment Failure; D016896:Treatment Outcome
D017430:Prostate-Specific Antigen