Major prognostic factors adversely influencing outcome of treatment include the following:
- Large tumor size.[Level of evidence: 3iiiA]
- A higher tumor (T) stage.
- The presence of involved neck nodes.
Other factors linked to diminished survival that were present in some, but not all, studies include the following:
- World Health Organization (WHO) grade I.
- Long interval between biopsy and initiation of radiation therapy.
- Diminished immune function at diagnosis.
- Incomplete excision of involved neck nodes.
Pregnancy during treatment.
- Locoregional relapse.
- Certain EBV antibody titer patterns.
Small cancers of the nasopharynx are highly curable by radiation therapy, and patients with these small cancers have shown survival rates of 80% to 90%.
Moderately advanced lesions without clinical evidence of spread to cervical lymph nodes are often curable, and patients with these lesions have shown survival rates of 50% to 70%.
Follow-up for patients includes the following:
- Routine periodic examination of the original tumor site and neck.
- CT or PET-CT scan.
- MRI scan.
- EBV titers.
Monitoring of patients should include the following:
- Surveillance of thyroid and pituitary function.
- Dental and oral hygiene.
- Jaw exercises to avoid trismus.
- Evaluation of cranial nerve function, especially as it relates to vision and hearing.
- Evaluation of systemic complaints to identify distant metastasis.
Although most recurrences occur within 5 years of diagnosis, relapse can be seen at longer intervals. The incidence of second primary malignancies is less than after treatment of tumors at other head and neck sites.
Poorly differentiated squamous cell cancer has been associated with EBV antibodies.[4,12] High-titer antibodies to virus capsid antigen and early antigen, especially of high IgA class, or high titers that persist after therapy, have been associated with a poorer prognosis. This finding remains under evaluation.
Tumors of many histologies can occur in the nasopharynx, but this discussion, like the American Joint Committee on Cancer nasopharynx staging, refers exclusively to WHO grade I-, II-, and III-type nasopharyngeal carcinoma.
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