107219-134

High-risk prostate cancer treated with pelvic radiotherapy and 36 versus 18 months of androgen blockade: Results of a phase III randomized study.

Subcategory: 
Category: 
Genitourinary Cancer
Session Type and Session Title: 
General Poster Session A: Prostate Cancer
Oral Abstract Session A: Prostate Cancer (eQ&A)
Abstract Number: 
03
Citation: 
J Clin Oncol 31, 2013 (suppl 6; abstr 3)
Author(s): 
Abdenour Nabid, Nathalie Carrier, André-Guy Martin, Jean-Paul Bahary, Luis Souhami, Marie Duclos, François Vincent, Sylvie Vass, Boris Bahoric, Robert Archambault, Céline Lemaire; Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada; Centre Hospitalier Universitaire de Québec, Québec, QC, Canada; Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal, Montreal University, Montreal, QC, Canada; McGill University, Montreal, QC, Canada; McGill University Health Centre, Montreal, QC, Canada; Centre Hospitalier Régional de Trois-Rivières, Trois-Rivières, QC, Canada; Centre de Santé et Services Sociaux de Chicoutimi, Chicoutimi, QC, Canada; Jewish General Hospital, Montréal, QC, Canada; Hôpital de Ganineau, Gatineau, QC, Canada; Hôpital Maisonneuve-Rosemont de Montréal, Montréal, QC, Canada

Abstracts that were granted an exception in accordance with ASCO's Conflict of Interest Policy are designated with a caret symbol (^).

Abstract Disclosures

Abstract: 

Background: Radiotherapy (RT) and long term androgen blockade (AB) is standard treatment for patients with high risk prostate cancer. However, the optimal duration of AB is not yet defined. The purpose of this randomized study was to compare outcomes between 36 vs. 18 months of AB in high risk prostate cancer treated with RT (PCS IV trial, Clinical Trials.gov, #NCT00223171). Methods: PCS IV randomized patients with node negative high risk prostate cancer (T3-4, PSA >20 ng/ml or Gleason score >7), to pelvic RT (whole pelvis 44 Gy/4 ½ weeks, prostate 70 Gy/7 weeks) and 36 (arm 1) vs. 18 months (arm 2) of AB (neo adjuvant, concomitant, adjuvant). AB consisted of bicalutamide 50 mg for one month plus goserelin 10.8 mg every three months for 36 vs. 18 months. Overall survival was the primary end point. Overall and cancer specific survival rates were compared between arms with Kaplan-Meier log rank test and Cox regression. Results: From October 2000 to January 2008, 310 patients were randomized to arm 1 and 320 to arm 2. Patients’ characteristics were well balanced between the two arms (median age 71 years, median PSA 16 ng/ml, median Gleason score 8). Most patients had T2-3 disease. At a median follow-up of 77 months, 71/310 patients (22.9%) in arm 1 and 76/320 (23.8%) in arm 2 had died (p=0.802). Overall, 116 patients died of causes other than prostate cancer. Overall and cancer specific survival hazard ratios were 1.15 (0.83-1.59), p=0.398 and 1.13 (0.61-2.08), p=0.153, respectively. 5 year overall and disease specific survival rates were 92.1% (89.1-95.1) vs. 86.8% (83.0-90.6), p=0.052 and 97.6% (95.9-99.4) vs. 96.4% (94.2-98.6), p=0.473 and 10 year overall and disease specific survival rates were 63.6% (55.7-71.5) vs. 63.2% (54.7-71.7), p=0.429 and 87.2% (81.0-93.3) vs. 87.2% (80.9-93.6), p=0.838 for arm 1 and arm 2, respectively. There were no significant differences in the rates of biochemical, regional or distant failure between arms. Conclusions: Our study shows that long term AB can be safely reduced from 36 to 18 months without compromising outcomes. Analysis of treatment impact on quality of life is now under review. Source of Funding: AstraZeneca Pharmaceuticals Grant. Clinical trial information: Clinical Trials.gov, #NCT00223171.