Distant metastases from nasopharyngeal cancer

Undifferentiated carcinoma is the most frequent nasopharyngeal cancer; it has a typical pathognomonic histological pattern, a close relationship to Epstein-Barr virus (EBV), a peculiar natural history and a good prognosis. It has an early tendency to locally spread to the parapharyngeal space. Nodal involvement is highly frequent (70-90%) and bulky regardless of the size of the primary. Literature reports up to 11% distant metastases at presentation and up to 87% at autoptic studies. Pretreatment work-up should include: personal history, clinical and fiberscopic examination, magnetic resonance imaging (MRI) or computed tomography (CT) scan of the base of the skull and neck, histology of the primary and cytology of neck lumps, bone marrow aspiration and biopsy, and EBV serological profile. Clinical and pathological factors predicting possible distant spread are primary tumor and node extension, and treatment failure. Up to now no reliable predictive biological markers have been identified. After treatment, distant metastases are found in about 30% of patients within 5 years and generally have a bad prognosis. Metastatic nodes above the clavicle, in absence of locoregional failure, aggressively treated with chemoradiotherapy, have a disease-free survival longer than 5 years. The following is the suggested posttreatment work-up for early diagnosis of these salvageable patients: clinical and fiberscopic evaluation every 3 months for 2 years and later on every 6 months; skull base and neck MRI or CT scan, and chest CT scan at 6, 12, 18, 24, 36, 48 and 60 months; EBV serological evaluation.