OVERVIEW

What is nasopharyngeal carcinoma?

Nasopharyngeal carcinoma is a malignant tumor that commonly occurs in the top and side walls of the nasopharyngeal cavity. General symptoms may include nasal congestion, nosebleeds, tinnitus, hearing loss, headaches, facial numbness, swollen neck lymph nodes, blurred vision, and other symptoms^[1]. It poses a serious threat to human life and health.

Due to the abundant lymphatic tissue and unique anatomical location of the nasopharynx, nasopharyngeal carcinoma can metastasize to cervical lymph nodes and invade cranial nerves at an early stage, causing severe damage to the body. Therefore, once symptoms are detected, prompt diagnosis and treatment are essential. This disease is sensitive to radiation therapy, which is often the preferred treatment option^[1].

Is nasopharyngeal carcinoma common?

No, it is not common. There are approximately 80,000 new cases of nasopharyngeal carcinoma worldwide each year. The incidence rate in China is about 1.9 per 100,000 people, meaning there are roughly two nasopharyngeal carcinoma patients per 100,000 people in China. This disease is more prevalent in middle-aged men, with a rising incidence and a trend toward affecting younger individuals. In China, regions such as Guangdong, Guangxi, Hunan, Fujian, and Jiangxi are high-risk areas for nasopharyngeal carcinoma^[1,2].

Is there a gender difference in the incidence of nasopharyngeal carcinoma?

Among nasopharyngeal carcinoma cases, men are more affected than women, with the incidence rate in men being about 2–3 times higher than in women^[1].

Does nasopharyngeal carcinoma primarily affect young people or the elderly?

Nasopharyngeal carcinoma is most common in the 45–60 age group, and its incidence increases with age after 20^[2].

SYMPTOMS

What are the common symptoms of nasopharyngeal cancer?

• Common symptoms of nasopharyngeal cancer include: nasal congestion, ear fullness, blood-stained nasal discharge, double vision, and headaches.
• Nasal symptoms: Manifest as bleeding when forcefully inhaling through the nose, often occurring in the morning, which is one of the early typical symptoms; progressive unilateral or bilateral nasal congestion may also occur, with severe cases leading to mouth breathing^[1].
• Ear symptoms: Also one of the early signs of nasopharyngeal cancer. Typically presents as tinnitus, a feeling of fullness, ear blockage, or hearing loss on the affected side^[1].
• Symptoms of cranial nerve involvement: Tumor compression or invasion of cranial nerves may cause migraines, facial numbness, double vision (seeing overlapping images), blurred vision, choking while drinking, or tongue deviation^[3].
• Nasopharyngeal cancer frequently metastasizes to lymph nodes, often leading to symptoms like swollen cervical lymph nodes or neck masses^[3].
• Distant metastasis in advanced stages may cause chest pain, coughing, blood in sputum, liver pain, or bone pain^[3].

What are the early or warning signs of nasopharyngeal cancer?

Due to its hidden location, early symptoms of nasopharyngeal cancer are often atypical, requiring heightened vigilance.

Early symptoms include blood-stained nasal discharge when sniffing or blowing the nose, tinnitus, ear blockage, or hearing loss. If these symptoms appear without obvious cause, prompt medical consultation is advised to rule out nasopharyngeal cancer^[1].

Why does hearing loss occur with nasopharyngeal cancer?

When nasopharyngeal cancer occurs near the pharyngeal recess, the tumor can compress or block the Eustachian tube opening early on, disrupting middle ear ventilation and drainage, leading to tinnitus, ear blockage, and hearing loss.

Why does hoarseness occur with nasopharyngeal cancer?

Nasopharyngeal cancer in the nasopharynx can extend to the skull base, compressing the vagus nerve and causing hoarseness. Additionally, metastatic cervical lymph nodes may also press on the vagus nerve, leading to voice changes.

Is nasopharyngeal cancer prone to distant metastasis?

Advanced nasopharyngeal cancer can metastasize distantly, with the rate increasing due to improved diagnostic techniques. Some cases are diagnosed due to distant metastasis. Common sites include cervical lymph nodes, bones, lungs, and liver, often involving multiple organs simultaneously^[3].

What harm does nasopharyngeal cancer cause to the body?

• Local tumor growth can mechanically block the posterior nasal cavity or pharynx, causing nasal congestion and narrowing.
• Enlarged tumors may compress the Eustachian tube, impairing middle ear ventilation and causing hearing loss or tinnitus.
• Due to proximity to the skull base and orbits, the cancer often invades cranial nerves and erodes skull bones.
• Invasion of the orbits or related nerves may cause vision impairment, visual field defects, eye protrusion, or movement disorders.
• Tumor spread to the parapharyngeal space can affect neck blood vessels and nerves.
• Lymphatic metastasis often leads to swollen cervical lymph nodes; distant metastasis to bones, lungs, or liver damages these organs.
• Advanced stages may lead to cachexia and death^[1-3].

CAUSES

What factors are associated with the development of nasopharyngeal carcinoma?

Currently, it is believed that the occurrence of nasopharyngeal carcinoma is related to genetics, EBV infection, and environmental factors:

• **Genetic factors:** Patients with nasopharyngeal carcinoma exhibit racial susceptibility and familial clustering. Certain genomic changes can promote the development of nasopharyngeal carcinoma, such as loss of CDKN2A/CDKN2B, amplification of CCND1, and TP53 mutations^[1].
• **EBV infection:** The detection rate of EBV is high in nasopharyngeal carcinoma patients, suggesting a close association between persistent EBV infection and the disease, though the exact mechanism remains unclear^[4].
• **Multiple carcinogens:** Many chemical carcinogens, such as nitrosamines, polycyclic aromatic hydrocarbons, and trace elements like nickel, are also linked to the disease. Residents in high-incidence areas of nasopharyngeal carcinoma in southern China often consume preserved foods like salted fish and cured meats, which contain high levels of nitrites. Animal experiments have confirmed that nitrites can induce nasopharyngeal carcinoma^[4].

DIAGNOSIS

What tests are needed to diagnose nasopharyngeal carcinoma?

In addition to understanding the patient's symptoms, family history, medical history (whether infected with EB virus), and dietary habits (whether they frequently consume pickled foods), doctors also need to perform the following tests for further confirmation^[4].

1. General tests: Including complete blood count, liver and kidney function, coagulation function, thyroid function, electrolytes, blood glucose, urinalysis, and stool analysis to assess the patient's basic health condition.

2. EB virus blood test: An important auxiliary method for early screening, prognosis evaluation, treatment efficacy assessment, and follow-up of nasopharyngeal carcinoma.

3. Imaging examinations:

   • CT/MRI: Used to determine the location of the primary tumor, evaluate involvement of other tissues or organs, and check for distant metastasis.
   • Ultrasound: Primarily used to assist in diagnosing metastasis in cervical lymph nodes and abdominal organs.
   • Whole-body bone scan: Used for preliminary screening of bone metastasis.
   • Positron emission tomography-computed tomography (PET-CT): Used to assess cervical lymph node metastasis and detect hidden distant metastatic lesions throughout the body.

4. Electronic/fiberoptic nasopharyngoscopy: One of the most important diagnostic tools for nasopharyngeal carcinoma, capable of detecting abnormalities such as nasopharyngeal masses, ulcers, necrosis, and bleeding. It also allows direct observation of tumor growth, invasion of surrounding structures like the nasal cavity and oropharynx, and enables biopsy confirmation.

Why is EB virus testing necessary for nasopharyngeal carcinoma diagnosis?

The onset of nasopharyngeal carcinoma is closely related to EB virus infection. The detection rate of EB virus antigens-antibodies in the serum of nasopharyngeal carcinoma patients is significantly higher than in healthy individuals and other cancer patients. Therefore, EB virus testing has become an auxiliary diagnostic method for nasopharyngeal carcinoma in clinical practice^[4].

Why is a neck mass easily diagnosed as nasopharyngeal carcinoma?

The nasopharynx is rich in lymphatic tissue, and nasopharyngeal carcinoma can metastasize to lymph nodes early, with the most common site being the cervical lymph nodes, leading to lymphadenopathy. This manifests as a painless, hard, and poorly mobile neck mass^[1].

Initially unilateral, it may later develop bilaterally. Clinically, 40%–50% of patients seek medical attention due to asymptomatic neck masses. Thus, the appearance of a neck mass should raise suspicion of nasopharyngeal carcinoma^[1].

Which diseases are easily confused with nasopharyngeal carcinoma?

Nasopharyngeal angiofibroma: A benign tumor of the nasopharynx. Both conditions may present with symptoms such as nosebleeds, nasal congestion, tinnitus, and hearing loss, but can be differentiated through nasopharyngoscopy and contrast-enhanced MRI.

Nasopharyngeal tuberculosis: Caused by Mycobacterium tuberculosis invading the nasopharynx. Both conditions may exhibit symptoms like nasal congestion, blood-stained nasal discharge, tinnitus, hearing loss, and headaches. Differentiation can be made based on tuberculosis history, Mycobacterium tuberculosis testing, and nasopharyngoscopy.

TREATMENT

Which department should I visit for nasopharyngeal carcinoma?

Otolaryngology Head and Neck Surgery, ENT Department, Oncology Department, Radiotherapy Department.

What are the treatment options for nasopharyngeal carcinoma?

The primary lesion of nasopharyngeal carcinoma is often located in the posterior wall of the nasopharynx, which is deep and not conducive to surgical treatment. Most nasopharyngeal carcinomas are squamous cell carcinomas, which are moderately sensitive to radiotherapy, making it the best treatment option^[5].

However, for highly differentiated carcinomas, advanced-stage cases, or patients with recurrence after radiotherapy, chemotherapy, targeted therapy, and surgery are also essential to prevent distant metastasis, enhance radiotherapy sensitivity, and reduce complications^[1].

• Chemotherapy: Factors such as disease stage, age, performance status, and comorbidities must be considered. Common chemotherapy drugs include gemcitabine, taxanes, fluorouracil, cisplatin, and nedaplatin^[1].
• Molecular targeted therapy: Mainly used for advanced, recurrent, or metastatic nasopharyngeal carcinoma. Representative drugs include cetuximab and nimotuzumab^[1].
• Surgery: Primarily used for recurrent or metastatic nasopharyngeal carcinoma. Nasopharyngeal lesions can be treated with endoscopic tumor resection, while neck surgeries include radical neck dissection, modified dissection, selective dissection, and lymph node excision^[1].

Is radiotherapy effective for nasopharyngeal carcinoma?

Most nasopharyngeal carcinomas are sensitive to radiotherapy. For patients without lymph node or distant metastasis, radical radiotherapy alone can achieve satisfactory results^[1].

Does lymph node metastasis affect radiotherapy efficacy in nasopharyngeal carcinoma?

Yes. Although nasopharyngeal carcinoma is highly sensitive to radiotherapy, it is still a localized treatment confined to a specific radiation field.

Once lymph node metastasis occurs, the tumor area expands, inevitably requiring an enlarged radiation field or higher doses, increasing the risk of complications. Additionally, lymph node regression is slower with radiotherapy alone, and some large neck masses may not fully disappear even after radical doses.

How effective is chemotherapy for nasopharyngeal carcinoma?

Chemotherapy alone has limited efficacy for nasopharyngeal carcinoma. It is mainly used as adjuvant or palliative treatment for advanced cases, radiotherapy-resistant tumors, or recurrence^[1]. The main roles of chemotherapy include:

• Enhancing tumor sensitivity to radiotherapy, improving efficacy;
• Shrinking tumors to reduce tumor burden and improve radiotherapy outcomes;
• Killing metastatic cancer cells in patients with distant metastasis.

What are the complications of radiotherapy and chemotherapy for nasopharyngeal carcinoma?

Radiation encephalopathy: A common complication post-radiotherapy, manifesting as psychological and cognitive issues (e.g., depression, anxiety, dementia) or compressive symptoms (e.g., headache, dizziness, fainting).

Other complications: Dry mouth, oral mucositis, radiation caries, trismus, secretory otitis media, radiation sinusitis, radiation dermatitis, retinal damage, spinal cord injury, bone marrow suppression, hair loss, allergic reactions, etc.^[1].

When is surgery needed for nasopharyngeal carcinoma?

Surgery is not the primary treatment for nasopharyngeal carcinoma. However, salvage surgery remains effective for residual or recurrent cases post-radiotherapy. Surgery may be considered in two scenarios:

• Localized residual primary lesion 3 months after radical radiotherapy;
• Residual or recurrent neck lymph nodes after radical radiotherapy^[1].

What factors influence the treatment efficacy of nasopharyngeal carcinoma?

Treatment outcomes are mainly influenced by the tumor's biological characteristics, such as:

• Tumor differentiation: Poorly differentiated squamous cell carcinomas are more radiosensitive;
• Clinical stage: Early-stage tumors respond better;
• Primary tumor size: Larger tumors correlate with poorer efficacy and lower 5-year survival;
• Local invasion: Severe invasion of critical organs (e.g., brain) worsens prognosis;
• Metastasis: Distant metastasis reduces treatment efficacy;
• Individual tolerance: Some patients exhibit radiotherapy resistance, leading to residual or recurrent tumors.

Is nasopharyngeal carcinoma prone to recurrence?

No treatment can guarantee complete prevention of recurrence. The likelihood of recurrence depends on multiple factors. Regular follow-ups post-treatment are crucial to monitor for recurrence or metastasis.

How is recurrent nasopharyngeal carcinoma treated?

Radiotherapy remains the primary and most effective treatment for recurrent nasopharyngeal carcinoma. Other options include surgery, chemotherapy, molecular targeted therapy, and immunotherapy. Treatment selection should be individualized^[1].

DIET & LIFESTYLE

What issues should be paid attention to after radiotherapy and chemotherapy for nasopharyngeal cancer?

After radiotherapy and chemotherapy for nasopharyngeal cancer, various complications are prone to occur. Strengthening care during and after treatment helps prevent or alleviate complications^[6]. Specific measures are as follows:

• Avoid spicy and irritating foods such as chili and pepper to reduce the incidence of oral mucositis. Opt for bland, protein-rich, and nutritious foods like eggs, dairy products, legumes, and fish. Rinse your mouth promptly after meals to maintain oral hygiene, and ensure a daily water intake of 3000 mL.
• Maintain oral cleanliness by brushing morning and night and rinsing frequently. Use sodium bicarbonate or mild saltwater for rinsing if necessary.
• During radiotherapy, keep the irradiated area and surrounding skin clean and dry. Avoid scratching or wetting the skin. When washing hair or bathing, use a damp towel to wipe the body. Reduce sweating in summer, wear soft, comfortable, low-collar cotton clothing, and avoid direct sunlight.
• Keep the nasal cavity clean. If secretions are present, perform nasal irrigation when necessary.
• Perform daily exercises for the masticatory muscles and temporomandibular joint, such as puffing cheeks, blowing, and mouth-opening movements, to prevent muscle atrophy and joint stiffness.

PREVENTION

How to Prevent Nasopharyngeal Cancer?

• Enhance the body's resistance by engaging in physical exercise and outdoor activities;
• Prevent colds, avoid EB virus infection, and maintain nasal and throat hygiene;
• Actively treat inflammatory diseases of the nasal cavity and nasopharynx;
• Pay attention to diet—reduce or avoid foods containing nitrosamines, such as salted fish, pickles, smoked meat, and cured foods, while increasing intake of fresh vegetables and fruits;
• Seek medical examination promptly if suspicious symptoms arise;
• Individuals aged 40 and above should undergo regular health checkups, and those with a family history should increase the frequency of examinations.