Nasopharyngeal Carcinoma (NPC)

The nasopharynx is part of the upper aerodigestive tract and it lies at the back of the anterior nasal space. Due to its inaccessible location, lesions of the nasopharynx are not easily detected, and hence tumours of the nasopharynx may present only at a later stage. NPC is a malignant neoplasm that arises from the epithelium of this anatomical site. It has a low incidence in the western population but in the local context, it is seen more commonly amongst people of Southern Chinese and Javanese descent.

Types of NPC

World Health Organisation (WHO) classifies NPC into the following three types, based on their histological appearance:

1. Type I – Keratinising Squamous Cell Carcinoma (SCC)
2. Type II – Non-keratinising Squamous Cell Carcinoma (SCC)
3. Type III – Undifferentiated Carcinoma

In the local context, it is Type III that is by far the most common of the three.

Common presentations

The following are some ways in which NPC can present in patients:

1. Neck lump (Cervical lymphadenopathy), usually upper neck in levels II and Va.
2. Blood-stained sputum
3. Epistaxis (Nose bleed)
4. Blocked hearing (Middle ear effusion)
5. Diplopia (Cranial nerve IV involvement)
6. Numbness over cheek (Cranial nerve V2 involvement)
7. Nasal obstruction

What are the risk factors?

Risk factors include:

1. Family history of NPC – persons with first-degree relatives who had NPC are 20-25 times more likely to develop NPC
2. Diet high in preserved foods early in life (Eg. salted fish, preserved vegetables)
3. Prior Epstein-Barr virus infection – this is almost ubiquitous in adults

Diagnosis

Patients require nasoendoscopic examination and diagnosis are confirmed when a biopsy performed showed histological evidence of NPC. Post-nasal space biopsy is usually performed under topical local anaesthesia and nasoendocopic guidance in the outpatient setting.

The procedure is often uncomplicated and takes less than 10 minutes. For patients on anti-coagulants or anti-platelets, their medication may be stopped prior to the procedure to prevent excessive bleeding.

Screening

Blood investigations such as serum EBV VCA-IgA (viral capsid antigen), EBV Ea-IgA (early antigen) and EBV DNA have been used as a method for screening for NPC but routine screening of the general population who is not at increased risk is not advised.

NPC is treated primarily with radiotherapy or concurrent chemoradiotherapy. The role of surgery is only necessary in recessive or recurrent setting.