Outcome comparisons of four radiation therapy oncology group (RTOG) trials in patients with stage IV-T4 head and neck (H/N) cancer: Encouraging results using intra-arterial (IA) cisplatin (P) and concurrent radiation therapy (RT)

Abstract

5527 Background: We conducted a comparison of overall survival (OS) and local-regional tumor control (LC) outcomes in patients with stage IV-T4 disease originating from the oral cavity, oropharynx or hypopharynx among 4 RTOG H/N trials using RT +/- chemotherapy. Methods: The four compared RTOG trials and their treatment regimens were as follows: 1. RTOG 8117–standard fractionated (SFX) RT [66 –73.8 Gy] & 3 cycles of concurrent IV P (100 mg/m2); 2. RTOG 9003 –SFX RT (70 Gy in 7 weeks) alone [Arm 1], & accelerated fractionated (fx) RT with concomitant boost (AFX-C) [72 Gy in 42 fxs over 6 weeks] [Arm 4]; 3. RTOG 9703–concurrent SFX RT (70 Gy/7 weeks in arms 1 and 3, and q other week over 13 weeks in arm 2] with IV daily P (10 mg/m2) / 5-FU (400 mg/m2 d/ CI last 2 wks of RT) [Arm 1], q other week of IV 5-FU (800 mg/m2/d x 5 days) / Hydroxyurea (1 gm po bid x 6 days) [Arm 2], or weekly IV P (20 mg/m2) / Taxol (30 mg/m2) [Arm 3]; & 4. RTOG 9615 –intra-arterial (IA) weekly P (100 mg/m2) x 4 weeks with SFX RT (70 Gy/7 weeks) [RADPLAT therapy]. Results: The estimated 2 year LC rates & OS are shown in Table 1. Using a Cox proportional hazards model stratified by RPA class, RADPLAT therapy reduced death rates by > 50% when compared with Protocols 9003 & 8117, and by 21% when compared to arm 1 of Protocol 9703; there was virtually no reduction in death rates when compared with arms 2 & 3 of Protocol 9703 (0.8% and 1.8%, respectively). Conclusions: RADPLAT therapy improves LC and OS when compared to RT alone (SFX or concomitant boost) and improves OS when compared to IV cisplatin and SFX RT. Additionally, LC and OS using RADPLAT therapy appear comparable to contemporary chemoradiation regimens. Further testing in a phase III randomized trial comparing RADPLAT therapy to IV chemotherapy and RT is warranted to validate our findings. No significant financial relationships to disclose.