Nasopharyngeal cancer is a malignant tumor that occurs in the mucosa of the nasopharynx. It is more prevalent in Guangdong, Guangxi, Fujian and Hunan in China, with more men than women. The age of onset is mostly middle-aged people, but there are also adolescents who have the disease. The cause of the disease is related to racial susceptibility (yellow people have more disease than white people), genetic factors and EBV infection, etc. Nasopharyngeal cancer is more malignant, and metastasis to the lymph nodes in the neck can occur at an early stage.
The etiology of nasopharyngeal carcinoma may be related to the following factors.
①EBV infection
Studies have shown that EBV infection is closely related to the development of nasopharyngeal carcinoma, and EBV is present in most keratinized squamous cell carcinomas and almost all undifferentiated squamous cell carcinomas. The mechanism of EBV pathogenesis is not fully understood. The control of EBV infection by the body’s immune system and the mechanisms by which EBV evades the body’s immune response have been the focus of research. The control of EBV infection by the immune system is mainly achieved through cellular immunity, and recent studies have shown that EBV can infect not only B lymphocytes but also T and/or NK cells, and produce a large number of cytokines I .
②Environment and diet
Environmental factors are also a cause of nasopharyngeal carcinoma. A survey in Guangdong found that the content of nickel, a trace element, in rice and water in areas with high incidence of nasopharyngeal carcinoma is higher than that in areas with low incidence. Animal experiments have shown that nickel can1 promote nitrosamines to induce nasopharyngeal cancer. People who are easily exposed to formaldehyde in their lives are also prone to nasopharyngeal cancer. It has also been reported that consumption of salted fish and pickled food is a high risk factor for nasopharyngeal carcinoma in southern China, and it is also related to the age of eating salted fish, the duration of consumption and the cooking method.
③Genetic factors
There are racial and familial clusters of nasopharyngeal cancer patients, such as the offspring of southern Chinese living in other countries still maintain a high incidence of nasopharyngeal cancer, which suggests that nasopharyngeal cancer may be a genetic disease.
Clinical manifestations
(I) Retractable aspiration blood
In early stage, there may be bleeding symptoms, such as blood in sputum after nasal aspiration or blood in snot when blowing nose, and in early stage, there is only a small amount of blood in sputum or snot, which is sometimes absent. In the late stage, there may be more bleeding and nosebleeds.
(2) Tinnitus, hearing loss, and sense of occlusion in the ear
If nasopharyngeal cancer occurs in the lateral fossa of nasopharynx wall or the upper lip of the opening of the eustachian tube, unilateral tinnitus or hearing loss may occur when the tumor compresses the eustachian tube, and kataric otitis media may also occur.
(III) Headache
Headache is a common symptom, accounting for 68.6%, and it may be the first or only symptom; in the early stage, the headache is intermittent with irregular location, while in the late stage, it is persistent migraine with fixed location. In early stage, the headache may be caused by neurovascular reflex or stimulation of the first peripheral nerve of trigeminal nerve, while in late stage, it is often caused by tumor destruction of skull base or intracranial spread and involvement of cranial nerve.
(4) Diplopia
Because the tumor invades the abducens nerve, it often causes double vision in the outward direction. Invasion of the talocrural nerve often causes inward strabismus and diplopia; diplopia accounts for 6.2% to 19% and is often damaged together with the trigeminal nerve.
(E) Facial numbness
It refers to the numbness of facial skin, and the clinical examination shows that the pain and touch sensation is reduced or disappeared. Tumor invading the cavernous sinus often causes damage to the 1st or 2nd branch of trigeminal nerve, and tumor invading the anterior region of the foramen ovale and the 3rd branch of trigeminal nerve often causes numbness or abnormal sensation of skin in the anterior part of the auricle, temporal region, lower lip of the cheek and chin.
(6) Nasal congestion
Nasal congestion can occur when the tumor blocks the posterior nostril. When the tumor is small, the nasal congestion is lighter, and it will increase as the tumor grows up, mostly unilateral nasal congestion.
(7) Symptoms of lymph node metastasis in the neck
Nasopharyngeal cancer is prone to cervical lymph node metastasis, which is about 60.3% to 86.1%, half of which are bilateral metastasis. Cervical lymph node metastasis is often the first symptom of nasopharyngeal cancer (23.9%~75%).
(H) Tongue muscle atrophy and tongue extension obliquity
Direct invasion of nasopharyngeal carcinoma or lymph node metastasis to the posterior region of the caudate or the sublingual nerve canal causes invasion of the sublingual nerve, resulting in deviation of tongue extension to the diseased side with tongue muscle atrophy.
(ix) Eyelid ptosis and eye fixation; loss of vision or loss of vision
The ptosis and fixation of the eyelid are related to the damage of the ophthalmic nerve, and the loss of vision is related to the damage of the optic nerve or orbital cone invasion.
(X) Distant metastasis
The rate of distant metastasis of nasopharyngeal carcinoma ranges from 4.8% to 27%, and distant metastasis is one of the main reasons for treatment failure of nasopharyngeal carcinoma.
(xi) Associated dermatomyositis
Dermatomyositis can also accompany with nasopharyngeal cancer, so patients with dermatomyositis should be carefully examined in the nasopharynx regardless of whether they have symptoms of nasopharyngeal cancer.
(XII) Menopause
It is very rare as the first symptom of nasopharyngeal carcinoma, and is related to the invasion of nasopharyngeal carcinoma into the butterfly sinus and pituitary gland.
Tips to prevent nasopharyngeal cancer
Nasopharyngeal cancer is mainly caused by mental and emotional changes, emotional discomfort, internal organ deficiency, lack of positive energy, inability to adapt to external climate and environmental changes, or due to the inhalation of viruses, smoke, dietary disorders, nasopharyngeal diseases (including infection of residual glands in nasopharynx, mucosal erosion, mucosal ulcer, nasopharyngeal hyperplasia nodules), etc. For this reason, the following points should be noted
1, pay attention to climate change, prevent colds, maintain nasal and throat hygiene, and avoid viral infections.
2, try to avoid harmful smoke inhalation, such as kerosene lamp gas, insecticide aerosol, etc., and actively quit smoking, quit drinking.
3, nasopharyngeal diseases should be treated as early as possible, such as the discovery of bloody nasal mucus or blood in the mouth after aspiration, as well as unexplained enlarged lymph nodes in the neck, middle ear effusion, etc. should be timely detailed nasopharyngeal examination.
Life conditioning
Nasopharyngeal cancer should avoid physical overwork: such as heavy physical labor, staying up late, excessive physical exercise, etc., which can imbalance the internal environment of the body and reduce the resistance, thus prompting cancer recurrence or metastasis. During the treatment, you should pay attention to local hygiene, rinse your mouth several times a day, and perform nasopharyngeal irrigation if necessary. Avoid tooth extraction within one year.
Dietary regimen
Eat a balanced diet, more vegetables and fruits, less or no salted fish, salted vegetables, bacon, preserved meat and other foods containing nitrosamines, no dry and stimulating foods, and no excessive alcohol consumption. Especially during radiotherapy for nasopharyngeal cancer, patients often have dry mouth and throat, loss of appetite, nausea and vomiting. Chinese medicine believes that this is a deficiency of qi and yin, heat and toxicity, and should avoid spicy, dry, hot and toxic stimulating products, the diet should be light, should use easily digestible, nutritious, tasty food.
Eat salted fish easily cause nasopharyngeal cancer
According to scientific analysis, rotten salted fish is a kind of food that directly causes cancer, especially nasopharyngeal cancer. The number of people suffering from nasopharyngeal cancer is relatively high among people aged fifteen to forty throughout southern China.
Participants from the American Association for the Advancement of Science clearly suggested during a conference that salted fish and nasopharyngeal cancer are highly related. Hong Kong biochemists have isolated nitrosamine components from salted fish. And according to modern scientific research, nitrosamines have been proven to be serious carcinogens, and the carcinogen nitrosamines in rotten salted fish are produced before or during the process of salting and drying with salt. If you eat this kind of rotten salted fish often, you are prone to nasopharyngeal cancer and other cancers.