Impact of Parenteral Glutamine Supplement on Oncologic Outcomes in Patients with Nasopharyngeal Cancer Treated with Concurrent Chemoradiotherapy.

Background: Oral mucositis (OM) is a common toxic side effect in nasopharyngeal carcinoma (NPC) patients receiving concurrent chemoradiotherapy (CCRT) that has a negative impact on treatment outcomes and patients’ survival. Our study aimed to evaluate the impact of parenteral glutamine supplement (dipeptiven) on oncologic outcomes in patients with NPC treated with CCRT. Methods: Patients who were diagnosed with pathologically proved NPC and treated with CCRT were enrolled into our study. Patients were classified as dipeptiven (+) and dipeptiven (−). Oncologic outcomes were measured, and multivariate regression analysis was performed. Grade 3−4 treatment related toxicities were also documented. Results: A total of 144 patients with NPC were recruited in this study to evaluate oncologic outcomes, with 41 dipeptiven (+) and 103 dipeptiven (−). CCRT interruption rate and severe adverse effect (SAE) rate were significant lower in the dipeptiven (+) group than in the dipeptiven (−) group. The median overall survival (OS) was not mature yet in the dipeptiven (+) group and 30 months in the dipeptiven (−) group (p < 0.01). Multivariate analysis demonstrated that dipeptiven supplementation and CCRT interruption were independent predictors associated with better survival. The OS was longest in patients with a dipeptiven supplement and patients who had CCRT interruption had significantly worst OS. As for safety profiles, grade 3 to 4 adverse effects were fewer in dipeptiven (+) than in dipeptiven (−). Conclusion: Dipeptiven supplementation is crucial in NPC patients treated with CCRT, which can ameliorate treatment-related toxicity and augment treatment efficacy. Further prospective clinical trials are warranted to validate our results.