A Phase 3 Trial of 2 Years of Androgen Suppression and Radiation Therapy With or Without Adjuvant Chemotherapy for High-Risk Prostate Cancer: Final Results of Radiation Therapy Oncology Group Phase 3 Randomized Trial NRG Oncology RTOG 9902.

PURPOSE - Long-term (LT) androgen suppression (AS) with radiation therapy (RT) is a standard treatment of high-risk, localized prostate cancer (PCa). Radiation Therapy Oncology Group 9902 was a randomized trial testing the hypothesis that adjuvant combination chemotherapy (CT) with paclitaxel, estramustine, and oral etoposide plus LT AS plus RT would improve overall survival (OS).

METHODS AND MATERIALS - Patients with high-risk PCa (prostate-specific antigen 20-100 ng/mL and Gleason score [GS] ≥7 or clinical stage ≥T2 and GS ≥8) were randomized to RT and AS (AS + RT) alone or with adjuvant CT (AS + RT + CT). CT was given as four 21-day cycles, delivered beginning 28 days after 70.2 Gy of RT. AS was given as luteinizing hormone-releasing hormone for 24 months, beginning 2 months before RT plus an oral antiandrogen for 4 months before and during RT. The study was designed based on a 6% improvement in OS from 79% to 85% at 5 years, with 90% power and a 2-sided alpha of 0.05.

RESULTS - A total of 397 patients (380 eligible) were randomized. The patients had high-risk PCa, 68% with GS 8 to 10 and 34% T3 to T4 tumors, and median prostate-specific antigen of 22.6 ng/mL. The median follow-up period was 9.2 years. The trial closed early because of excess thromboembolic toxicity in the CT arm. The 10-year results for all randomized patients revealed no significant difference between the AS + RT and AS + RT + CT arms in OS (65% vs 63%; P=.81), biochemical failure (58% vs 54%; P=.82), local progression (11% vs 7%; P=.09), distant metastases (16% vs 14%; P=.42), or disease-free survival (22% vs 26%; P=.61).

CONCLUSIONS - NRG Oncology RTOG 9902 showed no significant differences in OS, biochemical failure, local progression, distant metastases, or disease-free survival with the addition of adjuvant CT to LT AS + RT. The trial results provide valuable data regarding the natural history of high-risk PCa treated with LT AS + RT and have implications for the feasibility of clinical trial accrual and tolerability using CT for PCa.

Int J Radiat Oncol Biol Phys. 2015 Jul 21. pii: S0360-3016(15)00552-0. doi: 10.1016/j.ijrobp.2015.05.024. [Epub ahead of print]

Rosenthal SA1, Hunt D2, Sartor AO3, Pienta KJ4, Gomella L5, Grignon D6, Rajan R7, Kerlin KJ8, Jones CU9, Dobelbower M10, Shipley WU11, Zeitzer K12, Hamstra DA13, Donavanik V14, Rotman M15, Hartford AC16, Michalski J17, Seider M18, Kim H19, Kuban DA20, Moughan J2, Sandler H21.

1 Radiation Oncology, Sutter Cancer Centers, Roseville, California.
2 NRG Oncology Statistics and Data Management Center, Philadelphia, Pennsylvania.
3 Tulane University Medical Center, New Orleans, Louisiana.
4 Johns Hopkins School of Medicine, Baltimore, Maryland.
5 Thomas Jefferson University Hospital, Philadelphia, Pennsylvania.
6 Indiana University, Bloomington, Indiana.
7 McGill University, Montreal, Quebec, Canada.
8 Community Clinical Oncology Program, Southeast Cancer Control Consortium, Inc, Winston-Salem, North Carolina.
9 Radiation Oncology, Sutter Cancer Centers, Roseville, California; Radiological Associates of Sacramento, Sacramento, California.
10 University of Alabama at Birmingham Medical Center, Birmingham, Alabama.
11 Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
12 Albert Einstein Medical Center, Bronx, New York.
13 University of Michigan Medical Center, Ann Arbor, Michigan.
14 Christiana Care Health Services, Inc, Wilmington, Delaware.
15 State University of New York Health Science Center-Brooklyn, Brooklyn, New York.
16 Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire.
17 Washington University, St. Louis, Missouri.
18 Akron City Hospital, Akron, Ohio.
19 Wayne State University, Detroit, Michigan.
20 University of Texas MD Anderson Cancer Center, Houston, Texas.
21 Cedars-Sinai Medical Center, Los Angeles, California.