Researchers have identified associations involving certain human leukocyte antigen (HLA) genes and other genetic regions.
These genes influence how the immune system recognizes and responds to infections, including EBV.
Having a family history does not mean that cancer is inevitable.
However, people with multiple affected relatives or a strong family history should discuss their individual risk with a healthcare professional.
3. Consumption of Salted Fish and Preserved Foods
Dietary habits have also been associated with nasopharyngeal cancer risk.
In particular, traditional consumption of certain salt-preserved fish has been linked to increased NPC risk in several epidemiological studies.
Some preserved foods can contain nitrosamines and related compounds that may contribute to cancer development.
The risk appears to depend on the type of food, preparation method, frequency of consumption, and age at exposure.
This does not mean that every salted or fermented food is dangerous.
However, frequently consuming traditional foods preserved through heavy salting, particularly from an early age, may increase risk in certain populations.
A balanced diet emphasizing fresh vegetables, fruits, whole grains, and minimally processed foods is a sensible long-term approach.
4. Age and Sex
Nasopharyngeal cancer is more frequently diagnosed in men than women.
It is also more common in middle-aged and older adults, although it can occur in younger people.
The age distribution varies considerably between regions and populations.
In some high-incidence Asian populations, NPC may appear at relatively younger ages compared with many other cancers.
Therefore, younger adults should not automatically dismiss persistent warning signs simply because they are below the age typically associated with the disease.
5. Geographic and Ethnic Background
Nasopharyngeal cancer has a distinctive geographic distribution.
Higher incidence rates have historically been reported in parts of southern China, Southeast Asia, and North Africa.
Certain populations in these regions have a combination of genetic susceptibility, environmental exposures, dietary traditions, and EBV-related factors that contribute to higher disease rates.
Vietnam is among the countries where nasopharyngeal cancer is a relevant public health concern.
Nevertheless, living in a higher-incidence region does not mean that an individual has cancer.
It simply reinforces the importance of recognizing persistent symptoms and seeking appropriate medical evaluation.
6. Smoking and Occupational Exposures
Tobacco smoking has been associated with increased risk of nasopharyngeal cancer in some studies, particularly certain histological types.
Exposure to wood dust and some occupational chemicals has also been investigated as a possible risk factor.
The strength of these associations varies across studies and populations.
Avoiding tobacco smoke and using appropriate protective equipment in workplaces involving dust or chemical exposures are sensible preventive measures.
5. How Is Nasopharyngeal Cancer Diagnosed?
When a doctor suspects nasopharyngeal cancer, several investigations may be performed to determine whether a tumor is present.
The process usually begins with a detailed medical history and a physical examination.
No single symptom, blood test, or imaging scan can independently establish the diagnosis in every patient.
1. Physical Examination of the Head and Neck
The doctor will ask about symptoms such as nasal obstruction, nosebleeds, hearing changes, headaches, and neck swelling.
The examination may include:
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Inspection of the mouth and throat.
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Examination of the nasal passages.
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Palpation of the neck to identify enlarged lymph nodes.
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Examination of the ears.
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Assessment of cranial nerve function when indicated.
A neck lump may provide an important clue, particularly if it is persistent and unexplained.
However, a normal physical examination does not completely exclude a tumor hidden inside the nasopharynx.
2. Nasopharyngoscopy: A Key Diagnostic Examination
Nasopharyngoscopy is one of the most important investigations when NPC is suspected.
During the procedure, an ENT specialist uses a thin, flexible endoscope equipped with a light and camera.
The instrument is gently passed through the nose to examine the nasal cavity and nasopharynx.
The doctor looks for:
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Abnormal tissue growth.
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Ulcers or irregular mucosal surfaces.
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Unusual masses.
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Areas that bleed easily.
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Asymmetry around the Eustachian tube openings.
The procedure is generally performed under local anesthetic spray and usually takes only a few minutes.
It allows the specialist to directly inspect areas that cannot be adequately examined through an ordinary mouth and throat examination.
If suspicious tissue is identified, a biopsy may be recommended.
3. Biopsy: The Definitive Diagnostic Test
A biopsy involves taking a small sample of suspicious tissue for examination under a microscope.
It is generally the definitive method used to confirm nasopharyngeal cancer.
A pathologist examines the sample to determine whether cancer cells are present and identify the tumor type.
Most NPC cases are classified as non-keratinizing nasopharyngeal carcinoma, although other types can occur.
The biopsy may also undergo additional laboratory testing, including assessment for EBV-associated markers such as EBER using in-situ hybridization.
This helps provide further information about the tumor.
A diagnosis should never be made solely because a patient has a positive EBV blood test or a persistent sore throat.
4. MRI and CT Scans
Once cancer is confirmed or strongly suspected, imaging tests help doctors determine the size and extent of the tumor.