In a Chinese phase II trial reported in the Journal of Clinical Oncology, Li et al found that treatment with two cycles of concurrent cisplatin and intensity-modulated radiotherapy (IMRT) was noninferior to three cycles in progression-free survival and associated with reduced toxicity in patients with Epstein-Barr virus (EBV) DNA–selected low-risk locoregionally advanced nasopharyngeal carcinoma.
In the open-label multicenter trial, 332 patients with pretreatment EBV DNA levels < 4,000 copies/mL were randomly assigned between September 2016 and October 2018 to receive two cycles of concurrent cisplatin (100 mg/m2 on days 1 and 22) and IMRT (n = 166) or three cycles (cisplatin on days 1, 22, and 43) of concurrent chemoradiation (n = 166). The prescribed radiotherapy doses for planning target volumes ranged from 68–70 Gy to 50–54 Gy in 30 to 33 fractions daily at 5 fractions per week over 6 to 7 weeks. The primary endpoint was 3-year progression-free survival.
Median follow-up was 37.7 months (interquartile range = 33.0–46.1 months). Estimated 3-year progression-free survival rates were 88.0% (95% confidence interval [CI] = 83.1%–92.9%) in the two-cycle group vs 90.4% (95% CI = 85.7%–95.1%) in the three-cycle group (difference = 2.4%, 95% CI = –4.3% to 9.1%, P = .014 for noninferiority).
No significant differences between the two-cycle group vs three-cycle group were observed in progression-free survival (hazard ratio [HR] = 1.20, 95% CI = 0.63–2.29, P = .59), overall survival (HR = 1.00, 95% CI = 0.20–4.94, P = 1.00), cumulative incidence of locoregional relapse (HR = 1.15, 95% CI = 0.42–3.15, P = .79), or cumulative incidence of distant metastasis (HR = 1.22, 95% CI = 0.53–2.82, P = .64).
Grade 3 or 4 acute toxicities occurred in 74.7% of the two-cycle group vs 80.0% of the three-cycle group, with mucositis (24.8% vs 15.1%), hyponatremia (15.8% vs 8.4%), and dermatitis (5.5% vs 1.2%) being significantly more common in the three-cycle group. Any-grade dry mouth, dysphagia, weight loss, and fatigue were more common in the three-cycle group. The overall any-grade toxicity burden (T score = 12.33 vs 10.57, P < .001) and grade 3 or 4 toxicity burden (T score = 1.76 vs 1.44, P = .05) were greater in the three-cycle group. Among late toxicities, the three-cycle group had increased rates of any-grade hearing impairment (35.2% vs 22.9%), dry mouth (78.8% vs 63.9%), and skin fibrosis (29.7% vs 18.7%), with rates of grade 3 or 4 events being similar in the two groups. No treatment-related deaths were observed.
The investigators concluded: “Intensity-modulated radiotherapy plus two cycles of concurrent [cisplatin at] 100 mg/m2 could be an alternative treatment option for patients with low-risk [locally advanced nasopharyngeal carcinoma].”
Hai-Qiang Mai, MD, PhD, Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the National Key R&D Program of China, National Natural Science Foundation of China, and others. For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.