It's still pollen allergy season, and many people are still suffering from rhinitis. We found from outpatient cases that some patients with "rhinitis" who self-reported unilateral nasal congestion actually ended up being diagnosed with nasopharyngeal cancer. The main reason for the misunderstanding of patients is that the early symptoms of nasopharyngeal cancer can have nasal congestion similar to rhinitis symptoms, with blood in the nose, in addition, nasopharyngeal cancer can also show similar symptoms with otitis media and lymphadenitis.

So, how can the "cunning" nasopharyngeal cancer be found earlier, and what symptoms need to be paid special attention to?

1. Epstein-barr virus is the main cause

Generally speaking, the incidence of nasopharyngeal cancer is related to factors such as genetics, ethnicity, viral infection, environment and dietary habits.

First of all, the incidence of nasopharyngeal carcinoma has a clear geographical and ethnic distribution. The incidence is 2-3 times higher in men than in women, and the incidence peaks between the ages of 50 and 59, after which the incidence decreases. Studies have shown that people from areas with a high incidence of nasopharyngeal cancer migrate to other areas, although there is still a high incidence, but the incidence of their descendants decreased, and the farther the migration area, the more obvious this change. This also suggests that the incidence of nasopharyngeal cancer is the result of a combination of factors, and race is only one of the risk factors.

Secondly, nasopharyngeal carcinoma has certain heritability and familial aggregation. If there is a nasopharyngeal cancer patient in the immediate family, the individual's risk of developing nasopharyngeal cancer increases to 7 times.

Third, Epstein-Barr virus is very active, can cause repeated infection, it is the main cause of nasopharyngeal cancer. Some studies believe that Epstein-Barr virus plays a major role in the pathogenesis of nasopharyngeal carcinoma and is the most common factor causing nasopharyngeal carcinoma. It is a common human infection of the herpes virus, mainly transmitted through saliva. Asymptomatic infection occurs in young children, more than 90% of children aged 3 to 5 years have been infected with Epstein-Barr virus, and more than 90% of adults have antibodies to the virus.

Fourth, living environment and eating habits. Passive inhalation of tobacco smoke, long-term consumption of pickled foods, and early childhood consumption of salted fish are also risk factors for nasopharyngeal cancer, because these foods will release volatile nitrosamines, which are carried by steam and distributed in the human nasopharyngeal mucosa, leading to cancer. High consumption of preserved or fermented foods (including meat, eggs, fruits and vegetables) is also a contributing factor, and these foods contain high amounts of nitrosamines, as well as bacterial mutagens, direct-acting genotoxins and Epstein-Barr virus reactivators. In addition, smoking is also associated with nasopharyngeal cancer and may participate in the pathogenesis of nasopharyngeal cancer by causing Epstein-Barr virus reactivation.

It can be seen that the etiology of nasopharyngeal cancer is quite complex. From the point of view of cell biology, Epstein-Barr virus may be the main cause, which causes mutations of genes in cells, and eventually causes malignant changes in cells.

2. It is easily confused with many common diseases

Nasopharyngeal cancer often originates in the pharyngeal recess at the back of the nasal cavity, which is relatively hidden and patients may be asymptomatic for a long time. As the growth site of nasopharyngeal carcinoma is adjacent to the eyes, nose and skull base, it is easy to infiltrate and spread directly from the submucosa to neighboring tissues and organs, which can invade and destroy the skull base bone upward, and can also cause cervical lymph node enlargement through lymphatic metastasis, and can also be distant metastasis to the lung, bone and liver, etc., which leads to about 4%-10% of nasopharyngeal carcinoma patients have been accompanied by distant metastasis at the first diagnosis.

Therefore, it is said that nasopharyngeal carcinoma has a certain degree of concealment in clinical practice, and most patients are already local and/or regional advanced diseases at the time of treatment.

Most of the symptoms of early nasopharyngeal carcinoma are not typical, and it is easy to be confused with the following common diseases.

■ Confusion with rhinitis The primary site of nasopharyngeal cancer is deep and hidden, and the primary lesion is small in the early stage, which is not easy to observe. The early symptoms such as nasal congestion caused by the enlargement of the nasopharyngeal tumor, headache, and bloodline in the nose from time to time are easily misdiagnosed as rhinitis. Nasal mucus with blood in patients with rhinitis, because excessive force to blow the nose caused by capillary damage, about a few minutes to stop bleeding, but patients with nasopharyngeal cancer because back to the nasal mucus and cough up when the nose appears, bleeding for a long time, often accompanied by neck mass and unexplained tinnitus.

■ Secretory otitis media When the tumor compresses the pharyngeal opening of the eustachian tube, it will cause ear occlusion and hearing loss, and it is easily misdiagnosed as secretory otitis media.

■ Lymphadenitis Due to the characteristics of early metastasis of nasopharyngeal cancer, the first symptom of nasopharyngeal cancer is usually found in a single neck lymph node enlargement, which accounts for 60% of nasopharyngeal cancer patients. However, cervical lymph node enlargement is often misdiagnosed as lymphadenitis.

In addition, patients with nasopharyngeal cancer often have headaches, facial numbness, limited eye abduction, and ptosis of the upper eyelid due to cancer cells invading the cranial nerves. The tumor can also cause soft palate paralysis, cough, hoarseness, tongue extension and other symptoms.

3. See a doctor for any of the following symptoms

In order to avoid the neglect of nasopharyngeal cancer as much as possible, it is recommended that patients with any of the following conditions go to the Department of Otolaryngology for professional examination.

■ Unilateral progressive nasal congestion, blood in the nose, especially a small amount of blood in the nose after getting up every morning.

■ Unilateral ear occlusion and hearing loss.

■ Found painless lymph node enlargement on one side of the neck with poor motion. If you look in the mirror and find asymmetry on both sides of the neck, or inadvertently feel a lump on the neck, especially a hard texture, poor motion, and a number of painless neck bumps that merge into a group, it is likely to be enlarged lymph nodes. In the diagnosis of nasopharyngeal carcinoma, biopsy and pathological diagnosis of local tissue should be considered.

■ Blood test found positive EB virus antibody. Epstein-barr virus (EBV) positive is a necessary but not sufficient condition for nasopharyngeal carcinoma. Plasma EBV DNA analysis is helpful to screen the risk population for nasopharyngeal carcinoma, and can also detect early cancer, which can bring better treatment outcomes than no screening.

The main methods of nasopharyngeal carcinoma examination include fiber nasopharyngoscopy, cervical lymph node ultrasonography, nasopharyngeal imaging examination and so on. For patients with positive Epstein-Barr virus antibody test, in the case of preliminary exclusion of nasopharyngeal cancer, it is recommended to review the fiber nasopharyngoscopy every six months or a year.