Radiation with or without 6 months of androgen suppression therapy in intermediate- and high-risk clinically localized prostate cancer: a postrandomization analysis by risk group.
OBJECTIVE
Six months of androgen suppression therapy (AST) plus radiation (RT) prolongs survival vs. RT alone in men with unfavorable risk localized prostate cancer (PCa), but it is unknown if this benefit applies to all risk subgroups and, in particular, the intermediate-risk group.


METHODS
Among 206 men with stages T1b to T2b PCa and either a prostate-specific antigen level of >10 or a Gleason score of > or =7 or MRI evidence of T3 disease randomized to receive 70 Gy of RT with or without 6 months of AST, Cox multivariable analysis was used to assess the impact of AST on overall survival in intermediate- and high-risk localized PCa, adjusting for age, Adult Comorbidity Evaluation 27 comorbidity score, interaction between comorbidity and treatment, and known prognostic factors. Survival estimates were compared using a two-sided log-rank test.


RESULTS
After an 8.2-year median follow-up, 74 men died. Compared to treatment with AST plus RT, treatment with RT alone was associated with an increased risk of death in intermediate-risk (adjusted hazard ratio, 3.0 [95% confidence interval, 1.3-7.2]; p = 0.01) and high-risk PCa (adjusted hazard ratio, 3.3 [95% confidence interval, 0.94-11.3]; p = 0.06). The survival benefit of adding AST was restricted to men with no or mild comorbidity in both the intermediate-risk (90.9% vs. 85.8% survival, respectively, at 7 years for AST plus RT vs. RT alone; p = 0.009) and high-risk (88.9% vs. 51.2% survival, respectively, at 7 years for AST plus RT vs. RT alone; p = 0.007) subgroups.


CONCLUSIONS
In men with localized PCa who have no or mild comorbidity, adding 6 months of AST to RT was associated with improved survival for those with both intermediate-risk and high-risk disease, but in men with moderate to severe comorbidity, no benefit was observed in either risk group.
Department of Radiation Oncology, Dana Farber Cancer Institute and Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. pnguyen@LROC.harvard.edu
Paul L
PL
Nguyen
Ming-Hui
MH
Chen
Clair J
CJ
Beard
W Warren
WW
Suh
Andrew A
AA
Renshaw
Marian
M
Loffredo
Elizabeth
E
McMahon
Philip W
PW
Kantoff
Anthony V
AV
D'Amico
D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D003131:Combined Modality Therapy / Q000379:methods / Q000401:mortality; D005485:Flutamide / Q000627:therapeutic use; D005500:Follow-Up Studies; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D018570:Risk Assessment; D016019:Survival Analysis
D000726:Androgen Antagonists; D007987:Gonadotropin-Releasing Hormone; D005485:Flutamide; D017430:Prostate-Specific Antigen