Ten-Year Follow-Up of Radiation Therapy Oncology Group Protocol 92-02: A Phase III Trial of the Duration of Elective Androgen Deprivation in Locally Advanced Prostate Cancer

Abstract

PurposeTo determine whether adding 2 years of androgen-deprivation therapy (ADT) improved outcome for patients electively treated with ADT before and during radiation therapy (RT).Patients and MethodsProstate cancer patients with T2c-T4 prostate cancer with no extra pelvic lymph node involvement and prostate-specific antigen (PSA) less than 150 ng/mL were included. All patients received 4 months of goserelin and flutamide before and during RT. They were randomized to no further ADT (short-term ADT [STAD] + RT) or 24 months of goserelin (long-term ADT [LTAD] + RT). A total of 1,554 patients were entered. RT was 45 Gy to the pelvic nodes and 65 to 70 Gy to the prostate. Median follow-up of all survival patients is 11.31 and 11.27 years for the two arms.ResultsAt 10 years, the LTAD + RT group showed significant improvement over the STAD + RT group for all end points except overall survival: disease-free survival (13.2% v 22.5%; P < .0001), disease-specific survival (83.9% v 88.7%; P = .0042), local progression (22.2% v 12.3%; P < .0001), distant metastasis (22.8% v 14.8%; P < .0001), biochemical failure (68.1% v 51.9%; P ≤ .0001), and overall survival (51.6% v 53.9%, P = .36). One subgroup analyzed consisted of all cancers with a Gleason score of 8 to 10 cancers. An overall survival difference was observed (31.9% v 45.1%; P = .0061), as well as in all other end points herein.ConclusionLTAD as delivered in this study for the treatment of locally advanced prostate cancer is superior to STAD for all end points except survival. A survival advantage for LTAD + RT in the treatment of locally advanced tumors with a Gleason score of 8 to 10 suggests that this should be the standard of treatment for these high-risk patients.