The purpose of this study was to investigate the role of immunonutrion compared with standard nutrition in reducing oral mucositis in patients with locally advanced nasopharyngeal carcinoma.

Oral mucositis is the most common adverse reaction in patients with nasopharyngeal carcinoma receiving chemoradiotherapy, of which 40-50% of patients are severe (grade 3-4). Oral mucositis usually results in pain, dysphagia, reduced feeding, and malnutrition. Severe malnutrition in turn increases the risk of severe oral mucositis. Persistent severe oral mucositis will lead to delay and interruption of treatment, impairing patients'quality of life and prognosis. It's reported that nutritional intervention can not only reduce the risk and severity of oral mucositis and improve the nutritional status of patients with head and neck tumors, but also improve patients' tolerance to radiotherapy, quality of life, and prognosis.

Immunonutrition refers to the addition of high content of immune nutrients on the basis of sufficient calories, which not only ensures the supply of nutrition, but also takes into account the effects of anti-inflammation, regulating immunity, improving treatment tolerance, improving prognosis and so on. It has been reported that, comparing with standard enteral nutrition, the incidence of severe oral mucositis and esophagitis in patients with head and neck tumors treated with immunonutrition was lower, suffering less weight loss, and the antitumor immune response was enhanced. The 3-year OS and PFS were significantly improved in patients with good compliance.

It remains to be seen whether or not NPC patients receiving chemoradiotherapy can be benifit from immunonutritional therapy. Therefore, we conducted a prospective, multi-center, randomized controlled clinical study in patients with nasopharyngeal carcinoma who received radiotherapy and chemotherapy without metastases, to further improve the quality of life and prognosis of patients with nasopharyngeal carcinoma.

Inclusion Criteria:

1. Eastern Cooperative Oncology Group (ECOG) performance status 0-1;
2. Age 18-70 years old, male or non-pregnant women;
3. Pathologically confirmed non-keratinizing carcinoma of the nasopharynx (differentiated or undifferentiated,WHO type II or III);
4. Newly diagnosed stage III-IVa (8th AJCC/UICC stage) NPC patients;
5. The levels of major organ function meet the following criteria:

(1)Hematology: WBC ≥ 3.0 × 10^9/L, ANC ≥ 1.5 × 10^9/L, PLT ≥ 100 × 10^9/L, HGB ≥ 90 g/L; (2) Liver function: ALT, AST≤2.5 times the upper limit of normal (ULN), total bilirubin ≤ 1.5 × ULN; (3) Renal function: BUN and CRE ≤ 1.5 × ULN or an estimated glomerular filtration rate (eGFR) ≥ 60 ml/min (calculated using the Cockcroft-Gault equation); (4) Adequate coagulation function: defined as an international normalized ratio (INR) or prothrombin time (PT) ≤ 1.5 times the ULN; (5) Normal levels of cardiac enzymes; 6. The patient has signed informed consent forms and is able to comply with the study's planned visits, treatment plans, and laboratory tests.

Exclusion Criteria:

1. History of investigational Oral Impact®/ENSURE® use within the month prior to enrollment;
2. Known allergy or intolerance to any component of investigational Oral Impact®/ENSURE® or related chemotherapy drugs;
3. Poor glycemic control in patients with diabetes;
4. Patients with autoimmune diseases;
5. Patients with active infections;
6. Patients who have received radiation therapy or other anti-tumor treatments in the past;
7. Patients with a history of other malignant tumors;
8. Presence of oral mucositis at baseline;
9. Malnutrition at baseline;
10. Patients who cannot eat the required amount of food at baseline and require parenteral or enteral nutrition;
11. Inability to eat soft solid foods at baseline;
12. History of human immunodeficiency virus (HIV) or active hepatitis B/C virus infection;
13. Participation in other intervention clinical studies within one month;
14. Subjects deemed by the investigator to have other factors that may force them to terminate the study, such as having other serious illnesses (including mental illnesses) that require concomitant treatment, significantly abnormal laboratory test results, or family or social factors that may affect subject safety or data collection.