The roof, sloping downward from anterior to posterior, is bordered by the pharyngeal hypophysis, pharyngeal tonsil, and pharyngeal bursa with the base of skull above. Anteriorly, the nasopharynx abuts the posterior choanae and nasal cavity, and the posterior boundary is formed by the muscles of the posterior pharyngeal wall. Inferiorly, the nasopharynx ends at an imaginary horizontal line formed by the upper surface of the soft palate and the posterior pharyngeal wall. Unlike other squamous cell cancers of the head and neck, nasopharyngeal cancer does not appear to be linked to excess use of tobacco and alcohol. Tumors of many histologies can occur in the nasopharynx but this discussion, like the American Joint Committee on Cancer nasopharynx staging, refers exclusively to those of squamous cell type.
Diagnosis is made by biopsy of the nasopharyngeal mass.
Any clinical or laboratory suggestion of distant metastasis may prompt further evaluation of other sites. Careful dental and oral hygiene evaluation and therapy is particularly important prior to initiation of radiation treatment. Other factors linked to diminished survival in some, but not all, studies include age, nonlymphoepithelial histology, long interval between biopsy and initiation of radiation therapy, diminished immune function at diagnosis, incomplete excision of involved neck nodes, pregnancy during treatment, loco-regional relapse, and certain EBV antibody titer patterns. Although most recurrences occur within 5 years of diagnosis, relapse can be seen at longer intervals. This finding remains under evaluation.