Risk-adapted androgen deprivation and escalated three-dimensional conformal radiotherapy for prostate cancer: Does radiation dose influence outcome of patients treated with adjuvant androgen deprivation? A GICOR study.
OBJECTIVE
Multicenter study conducted to determine the impact on biochemical control and survival of risk-adapted androgen deprivation (AD) combined with high-dose three-dimensional conformal radiotherapy (3DCRT) for prostate cancer. Results of biochemical control are reported.


METHODS
Between October 1999 and October 2001, 416 eligible patients with prostate cancer were assigned to one of three treatment groups according to their risk factors: 181 low-risk patients were treated with 3DCRT alone; 75 intermediate-risk patients were allocated to receive neoadjuvant AD (NAD) 4-6 months before and during 3DCRT; and 160 high-risk patients received NAD and adjuvant AD (AAD) 2 years after 3DCRT. Stratification was performed for treatment/risk group and total radiation dose.


RESULTS
After a median follow-up of 36 months (range, 18 to 63 months), the actuarial biochemical disease-free survival (bDFS) at 5 years for all patients was 74%. The corresponding figures for low-risk, intermediate-risk, and high-risk disease were 80%, 73%, and 79%, respectively (P = .847). Univariate analysis showed that higher radiation dose was the only significant factor associated with bDFS for all patients (P = .0004). When stratified for treatment group, this benefit was evident for low-risk patients (P = .009) and, more interestingly, for high-risk patients treated with AAD. The 5-year bDFS for high-risk patients treated with AAD was 63% for radiation doses less than 72 Gy and 84% for those > or = 72 Gy (P = .003).


CONCLUSIONS
The results of combined AAD plus high-dose 3DCRT are encouraging. To our knowledge, this is the first study showing an additional benefit of high-dose 3DCRT when combined with long-term AD for unfavorable disease.
Zapatero
Almudena
A
Department of Radiation Oncology, Hospital Universitario de la Princesa, Diego de León 62, 28006 Madrid, Spain. azapatero.hlpr@salud.madrid.org
Valcárcel
Francisco
F
Calvo
Felipe A
FA
Algás
Rosa
R
Béjar
Amelia
A
Maldonado
Javier
J
Villá
Salvador
S
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000726:Androgen Antagonists / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011336:Probability; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods*; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D017430:Prostate-Specific Antigen