Screening Guidelines for nasopharyngeal Cancer

Nasopharyngeal cancer is the most common head and neck carcinoma in Singapore. It kills 6.4 males per 100,000 residents and it kills 1.7 women per 100,000 individuals. It turns out that 92 percent of all individuals with this cancer in Singapore are Chinese. The biggest risk factor for the disease is having been infected with the Epstein – Barr virus (EBV).

Delay in diagnosis is a common problem with nasopharyngeal cancer. Only 10 percent of cases are discovered in stage I. Lymphadenopathy is the first sign that a person has the disease, which puts them in stage III disease already. The outcome is dependent of the stage. The cure rare is 88 percent for those in stage I and only 50 percent for those in stage IV.

Because it is a rare condition, screening of the population—even all those who test positive for having had EBV is not recommended. This means that lymphadenopathy will continue to be the “screening test” for the disease with a survival rate of just over 50 percent. There is no microscopic or macroscopic premalignant state for nasopharyngeal cancer so swabbing for a pre-malignancy is out of the question. Biopsy of the lesion is the only real test for the disease.

Doing a smear for the EBV nuclear antigen is not recommended because it is not a reliable test. Screening for nasopharyngeal carcinoma by checking the latent membrane protein in the tissue is currently being evaluated as a possible screening test.

No studies on testing just the Chinese population, in whom the rates of nasopharyngeal cancer are higher, have shown to reduce mortality of the disease. The detection of nasopharyngeal cancer in high risk populations who were positive for the VCA IgA was found to be 7 to 80 times the risk of the general population. These might be people who should be screened with endoscopy and biopsy of suspicious lesions. Those people who are just EBV positive do not require mass screening.

Nasopharyngeal cancer tends to run in families. Between 6 and 15.5 percent of all new cases of nasopharyngeal cancer were found in those who also had a family member who suffered from the disease. In fact, this is one of the highest risks of having nasopharyngeal cancer. This still means that 90 percent or so of cases are spontaneous and are unrelated to family history. It might mean, however, that there will be guidelines for testing those people who have a first degree relative for nasopharyngeal cancer.