Purpose: To 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 Methods: Prostate 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.

Results: At 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.

Conclusion: LTAD 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.