PurposeTo evaluate the effectiveness of nutrition intervention during radiation for patients with locoregionally advanced (III-IVa) nasopharyngeal carcinoma (NPC).Materials and MethodsWe retrospectively reviewed 117 patients with locoregionally advanced (III-IVa) NPC treated between December 2015 and March 2016 in Zhejiang Cancer Hospital. All the patients underwent radical chemo-radiotherapy. First, all the patients were divided into the nutrition intervention group and the control group, depending on whether they accepted nutrition intervention. Repeated measures were used to analyze the change of nutritional indicators before, during, and after radiation therapy and to simultaneously compare the difference in nutritional status between the two groups at the same time point. Subsequently, the 117 patients were divided into the malnourished group (weight loss > 5%) and the non-malnourished group (weight loss ≤ 5%) according to whether their weight loss was over 5% of their body weight during radiotherapy. Chi-square tests and logistic regression analysis were used to explore the influence factors for the weight loss.ResultsThe repeated measures showed that all indicators including weight, body mass index (BMI), albumin, pre-albumin(PA), and prognostic nutritional index (PNI) dramatically declined in both groups compared with their levels before radiation therapy (All p < 0.001). However, there was no significant difference between the intervention and non-intervention groups regarding the mean values of nutritional indicators at the same time point, that before, during, and after radiation therapy, except BMI (All p > 0.05). Logistic regression analysis revealed grade ≥ 3 radiation-induced oral mucositis as the prognostic factor for a poor nutrition status (odds ratio, OR = 3.232, p = 0.021, confidence interval, CI [1.198, 8.820]). Besides this, patients with a decrease of >15% in pre-albumin level were more likely to be malnourished (OR = 2.442, p = 0.041, CI [1.036, 5.757]). Similar to that observed in our former analysis, we did not find that existing nutrition intervention can significantly improve nutritional status (OR = 1.217, p = 0.704, CI [0.042, 3.348]).ConclusionsOur study shows that the nutritional status of the patients gradually declined during treatment. We concluded that grade ≥ 3 radiation-induced oral mucositis would aggravate the extent of malnutrition during radiation therapy in patients with locoregionally advanced NPC. Pre-albumin level was a predictive marker for weight loss in patients with NPC. However, current nutrition intervention during radiation therapy can't significantly reverse nutritional status.