Purpose: Previous studies suggest that a cumulative cisplatin dose of 200 mg/m2 might be adequate in the intensity-modulated radiation therapy (IMRT) era for locoregionally advanced nasopharyngeal carcinoma (LANPC). However, two cycles of once-every-3-weeks cisplatin at 100 mg/m2 has never been prospectively compared with standard once-a-week cisplatin regimen.
Patients and methods: This trial was conducted at three hospitals from 2011 to 2016. Patients who met the eligibility criteria were recruited (ChiCTR-TRC-12001979) and randomly assigned (1:1) via a computer-generated sequence to receive once-every-3-weeks cisplatin at 100 mg/m2 for two cycles or once-a-week cisplatin at 40 mg/m2 for six cycles concurrently with IMRT. Primary endpoint was failure-free survival and between-group absolute difference of 10% as the noninferiority margin.
Results: A total of 510 patients were enrolled. Median follow-up time was 58.3 months with 85.4% of 3-year failure-free survival in the once-every-3-weeks group and 85.6% in the once-a-week group. An absolute difference of -0.2% (95% confidence interval, -6.3 to 5.9; P noninferiority = 0.0016). Acute toxicities of grade 3 or higher occurred in 55.8% in the once-every-3-weeks group and 66.3% in the once-a-week group (P = 0.015). The most common acute toxicities were hematologic abnormalities, including leukopenia (16% vs. 27%; P = 0.0022) and thrombocytopenia (1% vs. 5%; P = 0.015). The late grade 3-4 auditory loss rate was significantly lower in the once-every-3-weeks group than the once-a-week group (6% vs. 13%; P = 0.0039).
Conclusions: Once-every-3-weeks cisplatin as concurrent chemoradiotherapy is noninferior to once-a-week cisplatin in the treatment efficacy in the LANPC. Although both regimens are well tolerated, severe acute toxicities and late-onset auditory loss are higher in the once-a-week group.
©2021 The Authors; Published by the American Association for Cancer Research.