A Prospective, Multicenter, Real-World Observational Study to Evaluate RAIRI-Guided Risk Stratification for Identifying Adjuvant Therapy Benefit After Standard Chemoradiotherapy in Nasopharyngeal Carcinoma
This prospective, multicenter, real-world observational study aims to evaluate whether a response-adapted individualized risk index, the RAIRI model, can identify patients with non-metastatic nasopharyngeal carcinoma who may or may not benefit from adjuvant therapy after standard chemoradiotherapy. Patients will receive standard treatment according to routine clinical practice. After completion of chemoradiotherapy and assessment at approximately 1 month after radiotherapy, longitudinal multimodal response data, including plasma cfEBV DNA dynamics and MRI-based tumor response, will be incorporated into the RAIRI model to estimate the predicted 5-year progression-free survival. Patients will be stratified into a RAIRI low-risk group, defined as predicted 5-year PFS ≥85%, and a RAIRI high-risk group, defined as predicted 5-year PFS \<85%. Within each RAIRI risk stratum, outcomes will be compared between patients who receive adjuvant systemic therapy, mainly PD-1 inhibitor-based adjuvant immunotherapy, and those who undergo routine surveillance without adjuvant systemic therapy. The primary endpoint is 3-year failure-free survival. Secondary endpoints include overall survival, locoregional relapse-free survival, distant metastasis-free survival, complete response rate after chemoradiotherapy, distribution of RAIRI risk groups, adverse events, late toxicities, and longitudinal health-related quality of life.
• Age 18 to 75 years, male or female.
• Histologically or cytologically confirmed EBER-positive non-keratinizing nasopharyngeal carcinoma, including differentiated or undifferentiated subtype.
• Non-metastatic nasopharyngeal carcinoma confirmed by multimodal staging, corresponding to stage I-III according to the AJCC 9th edition staging system, or stage I-IVA according to the AJCC 8th edition staging system.
• Eastern Cooperative Oncology Group performance status of 0-1.
• Availability of complete pretreatment high-quality contrast-enhanced MRI of the nasopharynx and neck, including functional MRI sequences such as diffusion-weighted imaging, and at least one measurable tumor lesion according to RECIST version 1.1.
• Availability of pretreatment quantitative plasma cfEBV DNA measurement.
• Adequate baseline laboratory function, defined as hemoglobin \>120 g/L, white blood cell count ≥4 × 10\^9/L, platelet count ≥100 ×10\^9/L, and liver and renal function parameters, including ALT, AST, total bilirubin, and serum creatinine, within 1.25 times the upper limit of normal; no severe clinically significant hearing impairment.
• Ability to fully understand the nature and follow-up procedures of this observational study, and voluntary provision of written informed consent by the patient or the patient's legally authorized representative.
• Agreement to allow the research team to use the patient's clinical data, routine diagnostic imaging data, and residual biospecimens, such as peripheral blood samples and pathological slides, for scientific research analyses.
⁃ Adequate major organ function, except for local compression or functional impairment directly attributable to nasopharyngeal carcinoma.
⁃ Good expected compliance with follow-up and reliable communication conditions, allowing completion of long-term survival follow-up.