Nasopharyngeal carcinoma is a rare tumor of the epithelial layer lining the nasopharynx. It can occur at any age, although most reported cases are in the age group 50-60 years. Children may also be affected, but very rarely. Nasopharyngeal carcinoma accounts for less than 1% of all childhood malignancies. Some parts of the world have been considered as endemic areas where nasopharyngeal cancer comprises 18-25% of all cancers such as southern China, Hong Kong, Taiwan, Kenya, the Philippines, Singapore, Tunisia, Sudan and Uganda. In general, the disease is more predominant in males with a male: female ratio of 2:1. Based on microscopic findings, nasopharyngeal carcinoma is classified into three types. Type I is squamous cell carcinoma which comprises 25% of nasopharyngeal carcinomas and is typically found in the older adult population. The second type (type II) is known as non-keratinizing carcinoma that involves 12% of the cases with nasopharyngeal carcinoma. About 60% of the patients have type III, or undifferentiated carcinoma, which includes lymphoepitheliomas, anaplastic, clear cell, and spindle cell variants. Patients usually present trismus, pain, otitis media, nasal regurgitation due to paresis of the soft palate, hearing loss and cranial nerve palsies.
Nasopharyngeal carcinoma is a multifactorial disease linked to genetic and environmental factors, as well as viral infection (Epstein-Barr virus). Multiple loci have been identified that show association with nasopharyngeal carcinoma predisposition. These include 4p, 6p21, and MST1R gene on chromosome 3p21.
Al-Bareeq (1981) reported two Bahraini males with nasopharyngeal carcinoma over three years span. The patients were smokers and village residents. The first patient was 40 years old and his lateral wall of the nasopharynx was involved. The other case was 50 years old whose affected parts were the posterior wall of the nasopharynx, posterior pillar of the right tonsil, and right fossa of rossenmullar. Both patients received radiotherapy and one, in addition, received chemotherapy. One patient had recurrence of the disease after treatment. Since there were only two cases with nasopharyngeal carcinoma in a three year period, Al-Bareeq (1981) suggested that nasopharyngeal carcinoma was rare in Bahrain.
[Al-Bareeq JM. Carcinoma of nasopharynx. Bahrain Med Bull. 1981; 3(3):97.]
Morris et al. (2000) conducted a retrospective review of malignant neoplasms of the head and neck based on the Kuwait Cancer Registry for the years between 1979 and 1988. The review revealed 784 total recorded cases of head and neck cancers, of which nasopharyngeal cancers were the most common, constituting 25% of the cases. The age-adjusted rate of nasopharyngeal cancer in Kuwait was found to be higher than that reported globally. This rate was 1.6 to 2.8 times greater among Kuwaiti males, 1.3 to 3.3 times greater among non-Kuwaiti males, 2.7 to 6.3 times greater among Kuwaiti females, and 4 to 9.5 times greater among non-Kuwaiti females. For Kuwaiti males, the incidence rate of nasopharyngeal carcinoma was found to peak in the fifth, sixth and seventh decades, while for Kuwaiti females, this peak was noticed in the third to sixth decades.
[Morris RE, Al Mahmeed BE, Gjorgov AN, Al Jazza HG, Al Rashid B. The epidemiology of head and neck cancer (ICD-O-140-149) in Kuwait 1979-1988. Saudi Dental J. 2000; 12(2):88-94.]
[See also: Saudi Arabia > Andejani et al., 2004].
Sawardekar (2005) conducted a study to establish the prevalence of major congenital malformations in children born during a 10-year period in an Omani hospital in Nizwa. Of the 21,988 total births in the hospital, one child was born with nasopharyngeal teratoma.
Andejani et al. (2004) reviewed epidemiological data on nasopharyngeal cancer in Kuwait for the period between 1994 and 1996 from the National Cancer Registry, and compared this to data from other countries. In this period, there were a total of 373 Saudi patients diagnosed with the disease, with the population under 20-years of age showing a high incidence. In fact, the incidence showed an increase with age in both genders, reaching a peak at about 12-14 years, and then plateauing, interminably in the case of females, and with another peak in the fifth decade in males. The early onset of the condition pointed towards the possibility of an underlying genetic susceptibility in the Saudi population. The IARC data for nasopharyngeal cancer in Kuwait contrasted with this finding, in that although there was an early incidence, the male peak was not so well-formed and appeared in the sixth decade.