Radiation Therapy Oncology Group (RTOG) 9413: Randomized trial comparing whole pelvic radiotherapy (WPRT) to prostate only (PORT) and neoadjuvant hormone therapy (NHT) to adjuvant hormone therapy (AHT). J Clin Oncol 2012 Feb 10;30(5_suppl):96
Date
02/10/2012Pubmed ID
28143343Abstract
: 96 Background: RTOG 9413 demonstrated that NHT+WPRT improved progression-free survival (PFS) compared to NHT+PORT, WPRT+AHT and PORT+AHT. We update primary and secondary endpoints (SE): biochemical failure (BF), time to metastasis (Mets), prostate specific survival (PSS) and overall survival (OS).
METHODS: RTOG 9413 opened on April 1, 1995, and closed on June 1, 1999, with 1275 eligible pts who were required to have a risk of lymph node (LN) involvement >15% but LN-positive pts were ineligible. They were stratified by T Stage, GS (<7 vs 7-10) and PSA (>30 vs < 30ng/ml) and randomized to PORT +/- WPRT to 70 Gy and NHT or AHT. Hormonal therapy (HT) consisted of flutamide, and leuprolide or goserelin, monthly x 4 mos, beginning 2 mos before RT and continued until RT is completed (NHT) or beginning at the completion of RT (AHT). For this analysis PFS was defined as the first occurrence of local/regional or LN progression, Mets, BF (PSA nadir+2ng/mL), or death from any cause. PSS is defined as a death due to prostate cancer, treatment toxicity or unknown causes with local progression, Mets or BF.
RESULTS: For the entire cohort WPRT or NHT did not appear to improve any endpoint compared with PORT or AHT, (although there was a trend for improvement in regional failure for WPRT vs PORT, (p=0.07)). However, there were complex sequence/volume dependent interactions between HT and RT and statistically significant differences between the 4 arms in PFS (p=0.03). There was a trend for NHT+WPRT to improved PFS compared to NHT+PO (p=0.07) and WPRT+AHT (p=0.04). NHT+WPRT was associated with an increased risk of late GI toxicity, 5% compared to 0.6%, 2% and 2% for NHT+PORT, WPRT+AHT and PORT+AHT (p<0.001) but not in GU late toxicity.
CONCLUSIONS: The failure to improve SE or definitively impact PFS may reflect sample size, pt selection, and inadequate RT doses. RTOG 0924 will test the hypotheses that modern techniques and doses will improve OS without increasing late toxicity.
