The nasopharynx is located at the very back of the nose and is behind and above the soft palate. Nasopharyngeal carcinoma (NPC) is more common in Southeast Asia and is strongly associated with Epstein-Barr virus (EBV).
NPC is the 7th most common cancer among men and the 17th most common cancer among women in Hong Kong. According to the Hong Kong Cancer Registry of the Hospital Authority, there were 791 new cases in 2019, with 588 cases in men and 203 cases in women, a male to female ratio of about 2.9 to 1. Before the age of 75 years, the cumulative risk of NPC is 1 in 88 for men and 1 in 317 for women. The median age of diagnosis is 55.
Rapid declining age-standardized incidence was observed in NPC. On average of the previous 10 years, there has been a decrease per year in the age-standardized incidence by 1.9% in males and 4.3% in females.
At diagnosis, only 16.4% were early stages (stage I or II) and most of the rest were late stage (stage III or IV) .
Causes of NPC are still unclear, but the risk factors include:
- Having Chinese or Asian ancestry.
- Family history of NPC
- Regular consumption of foods such as salted fish and pickled vegetables
- Having been infected with EBV, which increases the risk by 30 times
- Drinking large amounts of alcohol
Due to the fact that the nasopharynx is located deep inside the head, special medical equipment and techniques must be used to examine it clearly. If you experience the following symptoms or any unusual changes, seek medical attention as soon as possible:
- Nasal congestion, runny nose
- Hearing loss, tinnitus, or pus-like drainage from the ear canal
- Blood-stained sputum
- Headache or persistent migraine, particularly at night
- Facial paralysis or lock jaw (tetanus)
- Hoarseness of voice
- Sudden weight loss, loss of physical strength
- Swelling of lateral neck lymph nodes
NPC examinations and diagnosis:
- EBV antibody blood test
- Test for concentration of EBV DNA in the blood
- Biopsy test: extraction of tissue at the suspected location
Examinations to determine the degree of metastasis and stage of cancer:
- Magnetic resonance imaging (MRI): determines tumour location, size, and regional extension
- Positron emission tomography and computerized tomography (PET-CT) scan: determine the extent of the cancer and is particularly useful in detecting metastasis
- Nasopharyngeal carcinoma typically responds well to radiation therapy. Depending on the size and extent of the cancer, chemotherapy may be combined with radiation therapy.
- Recurrent nasopharyngeal carcinoma (cancer that comes back after treatment), if small and localized in the nasopharynx can be removed either with an endoscope or by an open surgical approach.
- Sometimes radiation therapy, proton beam therapy, or chemotherapy are incorporated into the treatment of recurrent nasopharyngeal carcinoma. The use of immunotherapy for metastatic or recurrent nasopharyngeal carcinoma patients is promising.