Optimal cumulative cisplatin dose during concurrent chemoradiotherapy among children and adolescents with locoregionally advanced nasopharyngeal carcinoma: A real-world data study.

PURPOSE: To identify an optimal cumulative cisplatin dose along with concurrent chemoradiotherapy (CC-CCD) for children and adolescents with locoregionally advanced nasopharyngeal carcinoma (CALANPC) using real-world data. MATERIALS AND METHODS: Using an NPC-specific database at our center, 157 patients younger than 19 years old with non-disseminated CALANPC and receiving neoadjuvant chemotherapy (NAC) plus cisplatin-based concurrent chemoradiotherapy (CCRT) were enrolled. Confounding factors were controlled by conducting propensity score matching analysis. Primary endpoints include disease-free survival (DFS) and distant metastasis-free survival (DMFS). RESULTS: The optimal threshold for CC-CCD with respect to DFS was 160 mg/m2 based on recursive partitioning analyses (RPA). Therefore, a uniform threshold of 160 mg/m2 (≥160 vs. <160 mg/m2) was selected to classify patients between high and low CC-CCD groups for survival analysis. Patients receiving low CC-CCD showed a significant decrease in 5-year DFS (76.6% vs 91.3%; P = 0.006) and DMFS (81.3% vs 93.5%; P = 0.009) compared to those receiving high CC-CCD. Multivariate analyses indicated that high CC-CCD as an favorable prognostic influence for DFS (P = 0.007) and DMFS (P = 0.008). Further matched analysis identified 65 pairs in both high and low CC-CCD groups. In the matched cohort, high CC-CCD was still identified as a favorable factor for prognosis in DFS (HR, 0.23; 95% CI, 0.08-0.70; P = 0.010) and DMFS (HR, 0.23; 95% CI, 0.06-0.82; P = 0.023). CONCLUSION: CC-CCD exerts significant treatment effects and 160 mg/m2 CC-CCD may be adequate to provide antitumor effects for CALANPC receiving NAC plus CCRT.

The effect of adding concurrent chemotherapy to radiotherapy for stage II nasopharyngeal carcinoma with undetectable pretreatment Epstein-Barr virus DNA: Retrospective analysis with a large institutional-based cohort.

Little is known about the value of adding concurrent chemotherapy (CC) to radiotherapy for stage II nasopharyngeal carcinoma (NPC) with undetectable (0 copies/mL) pretreatment Epstein-Barr Virus (EBV) DNA in the intensity-modulated radiotherapy (IMRT) era. To address this question, the present study retrospectively reviewed 514 patients with newly diagnosed stage II NPC and undetectable pretreatment EBV DNA from Sun Yat-sen University Cancer Center between March 2008 and October 2016. Clinical characteristics and survival outcomes between concurrent chemoradiotherapy (CCRT) and IMRT alone groups were compared. Propensity score matching analysis was conducted to control for confounding factors. Although CCRT group had significantly higher proportions of stage N1 disease than IMRT alone group before matching (85% vs. 61%, p < 0.001), no statistically significant differences were noted for OS (97.8% vs. 98.1%, p = 0.700), DFS (93.4% vs. 94.5%, p = 0.846), DMFS (96.0% vs. 96.9%, p = 0.762), and LRFS (97.3% vs. 98.1%, p = 0.701). After 1:1 propensity-score matching, 177 pairs were identified. Patients in each group were found to be well balanced in baseline characteristics and risk factors (all P > 0.05). The five-year OS (96.9% vs. 98.2%, p = 0.302), DFS (92.0% vs. 95.2%, p = 0.777), DMFS (95.2% vs. 97.6%, p = 0.896), and LRFS (97.3% vs. 97.6%, p = 0.328) rates remain comparable for both CCRT and RT alone groups. Additionally, subgroup analysis still failed to observe any significant survival benefit for the addition of CC to IMRT for N1 disease (P>0.05 for all). Our results indicated that IMRT alone appeared to achieve comparable survival to CCRT for stage II NPC with undetectable pretreatment EBV DNA.