Weekly versus triweekly cisplatin plus intensity-modulated radiotherapy in locally advanced nasopharyngeal carcinoma: A propensity score analysis with a large cohort.

Purpose : To directly compare the efficacy and acute toxicities of intensity-modulated radiotherapy (IMRT) concurrent with weekly cisplatin (40 mg/m2 ) to high-dose concurrent cisplatin (100 mg/m2 ) at three-week intervals. Materials and Methods : A total of 3,799 patients diagnosed with locally advanced nasopharyngeal carcinoma (NPC) at Sun Yat-Sen University Cancer Center between January 2010 and December 2013 were retrospectively reviewed. Propensity score analysis was conducted to balance the baseline characteristics between the groups, which allowed us to draw reliable conclusions. The efficacy and safety profiles were then assessed in the well-balanced large cohort. Results : The risk of distant metastasis was lower among the patients treated with weekly concurrent cisplatin than among those treated with the triweekly regimen (hazard ratio [HR], 0.45; P = .028). However, the disease-free survival, loco-regional relapse-free survival and overall survival rates were similar. The weekly group showed significantly higher rates of grade 3-4 thrombocytopenia, but lower rates of grade 3-4 mucositis, nausea and vomiting than the triweekly group. Conclusion : IMRT concurrent with a weekly cisplatin regimen was associated with significantly improved distant metastasis-free survival in locally advanced NPC. Differences in the selected acute toxicities between the weekly and triweekly concurrent cisplatin regimens were noted.