Outcome According to Elective Pelvic Radiation Therapy in Patients With High-Risk Localized Prostate Cancer: A Secondary Analysis of the GETUG 12 Phase 3 Randomized Trial.

PURPOSE - The role of pelvic elective nodal irradiation (ENI) in the management of prostate cancer is controversial. This study analyzed the role of pelvic radiation therapy (RT) on the outcome in high-risk localized prostate cancer patients included in the Groupe d'Etude des Tumeurs Uro-Genitales (GETUG) 12 trial.

MATERIALS AND METHODS - Patients with a nonpretreated high-risk localized prostate cancer and a staging lymphadenectomy were randomly assigned to receive either goserelin every 3 months for 3 years and 4 cycles of docetaxel plus estramustine or goserelin alone. Local therapy was administered 3 months after the start of systemic treatment. Performance of pelvic ENI was left to the treating physician. Only patients treated with primary RT were included in this analysis. The primary endpoint was biochemical progression-free survival (bPFS).

RESULTS - A total of 413 patients treated from 2002 to 2006 were included, of whom 358 were treated using primary RT. A total of 208 patients received pelvic RT and 150 prostate-only RT. Prostate-specific antigen (PSA) concentration, Gleason score, or T stage did not differ according to performance of pelvic RT; pN+ patients more frequently received pelvic RT than pN0 patients (P<.0001). Median follow-up was 8.8 years. In multivariate analysis, bPFS was negatively impacted by pN stage (hazard ratio [HR]: 2.52 [95% confidence interval [CI]: 1.78-3.54], P<.0001), Gleason score 8 or higher (HR: 1.41 [95% CI: 1.03-1.93], P=.033) and PSA higher than 20 ng/mL (HR: 1.41 [95% CI: 1.02-1.96], P=.038), and positively impacted by the use of chemotherapy (HR: 0.66 [95% CI: 0.48-0.9], P=.009). There was no association between bPFS and use of pelvic ENI in multivariate analysis (HR: 1.10 [95% CI: 0.78-1.55], P=.60), even when analysis was restricted to pN0 patients (HR: 0.88 [95% CI: 0.59-1.31], P=.53). Pelvic ENI was not associated with increased acute or late patient reported toxicity.

CONCLUSIONS - This unplanned analysis of a randomized trial failed to demonstrate a benefit of pelvic ENI on bPFS in high-risk localized prostate cancer patients.

International journal of radiation oncology, biology, physics. 2015 Sep 25 [Epub ahead of print]

Pierre Blanchard, Laura Faivre, François Lesaunier, Naji Salem, Nathalie Mesgouez-Nebout, Elisabeth Deniau-Alexandre, Frédéric Rolland, Jean-Marc Ferrero, Nadine Houédé, Loïc Mourey, Christine Théodore, Ivan Krakowski, Jean-François Berdah, Marjorie Baciuchka, Brigitte Laguerre, Jean-Louis Davin, Muriel Habibian, Stéphane Culine, Agnès Laplanche, Karim Fizazi

Radiation Oncology, Gustave Roussy Cancer Center, Villejuif, France; University of Paris-Sud, Cancer Campus, Villejuif, France. Biostatistics, Gustave Roussy Cancer Center, Villejuif, France. , Radiation Oncology, Centre Francois Baclesse, Caen, France. , Radiation Oncology, Institut Paoli Calmetté Marseille, France. , Radiation Oncology, Institut de Cancérologie de l'Ouest, Angers, France. , Centre Hospitalier La Roche sur Yon, La Roche sur Yon, France. , Medical Oncology, Institut de Cancérologie de l'Ouest, Nantes, France. , Medical Oncology, Centre Antoine Lacassagne, Nice, France. , Medical Oncology, Institut Bergonié, Bordeaux, France. , Institut Claudius Regaud, Toulouse, France. , Hospital Foch, Suresnes, France. , Centre Alexis Vautrin, Vandoeuvre-lès-Nancy, France. , Clinique Sainte Marguerite, Hyeres, France. , Centre Hospitalier de la Timone, Marseille, France. , Centre Eugène Marquis, Rennes, France. , Clinique Sainte Catherine, Avignon, France. , R&D UNICANCER, Paris, France; UNICANCER, Paris, France. , Department of Medical Oncology, Hopital Saint-Louis, APHP, Paris, France. , Biostatistics, Gustave Roussy Cancer Center, Villejuif, France. , University of Paris-Sud, Cancer Campus, Villejuif, France; Department of Cancer Medicine, Gustave Roussy Cancer Center, Villejuif, France.