Integrating Biomarkers From Serum/Plasma and Molecular Images to Predict Occult Distant Metastases in Nasopharyngeal Carcinoma Patients With M0 Disease

1. Background:

Nasopharyngeal carcinoma (NPC) differs from other head and neck malignancies terms of its epidemiology, pathology, and treatment outcome. NPC has a good local tumor control rate but a higher incidence of distant metastasis compared with squamous cell carcinomas of other regions of the head and neck. Thus, it's usually considered a distinct study group.

A good prognostic model for the development of distant failure for NPC patients is still lacking. It is well known that Epstein-Barr virus (EBV) genomes are present in almost every NPC tumor cell, irrespective of histologic differentiation and geographic distribution. Various EBV-derived/related factors, therefore, have been used as NPC tumor markers, including EBV-specific viral capsid antigen (VCA) IgA and cell-free EBV DNA. The measurement of cell-free EBV DNA load has already been shown to be a good pretreatment prognostic indicator. Another important feature of NPC is that the tumors are characterized by heavy infiltration of nonmalignant lymphocytes and might play an important role in tumorigenesis; and cytokines and chemokines may represent the key mediators of this interaction. Compelling evidence has also emerged in recent years suggesting that cytokines and chemokines play important roles in regulating processes critical to tumor progression, such as proliferation and metastasis.

Beyond blood biomarkers, standard uptake value (SUV) from FDG PET could predict treatment failure in NPC patients. On the other hand, apparent diffusion coefficient (ADC) from diffusion-weighted MRI (DWI) has been shown to be an important prognostic marker in cancer patients, including head and neck cancer. 2. Aim:

To investigate the roles of imaging and blood biomarkers in predicting distant failures, recurrences, and survival in NPC patients. 3. Study design: