Tongue cancer is a malignant tumor of the tongue, usually originating from the epithelial cells of its mucosa. It is characterized by local or diffuse compaction of the tissues of the tongue, the formation of papillomatous outgrowths or ulcers on its surface. Disease is characterized by rapid tumor growth and its metastasis to lymph nodes, lungs, bones, brain and liver. The diagnosis is carried out according to the data of examination, palpation, radiography, examination of smear prints and biopsy material. To detect distant metastases, ultrasound of the liver, skeletal scintigraphy, MRI of the brain, and lung radiography are performed. The treatment consists in the combined use of radiation therapy, surgery and chemotherapy.
Information
According to the frequency of occurrence among oral tumors, tongue cancer is in second place. It accounts for 50-60% of malignant formations of this localization. The greatest incidence of tongue cancer is observed in people after 40 years, the average age of patients is 60 years. Among people younger than 30 years, it occurs in rare cases. In men, disease is diagnosed about 5-6 times more often than in women.
Pathology is found in all countries of the world, but it is most widespread in Asia and India. This is associated with the chewing of betel and tonic mixtures of betel leaves, ash, tobacco, vegetable oils and spices, which have a carcinogenic effect, accepted in these countries.
Causes
Among the factors provoking the development of tongue cancer, modern dentistry and oncology assigns a leading role to the following adverse effects:
- Chemical carcinogens. The first place belongs to the products formed during the combustion of tobacco. Alcohol potentiates the action of carcinogens of tobacco smoke and increases the likelihood of developing tongue cancer in a smoker by 2 times. Along with smoking and alcohol consumption, occupational hazards can also have a trigger effect on the mucous membrane with the subsequent occurrence of tongue cancer: heavy metal salts, asbestos, oil refining products, perchloroethylene.
- Chronic injury. Mechanical traumatization of the mucosa may be associated with a poorly fitted denture, the presence of a sharp tooth edge after a tooth fracture or poor treatment of the filling, regular biting of the tongue in the same place.
- Oncogenic viruses. Recent studies have revealed a link between the development of tongue cancer and chronic persistent viral infection caused by human papillomavirus (HPV), HIV or herpes simplex virus. The oncogenic effect of these viruses is associated with their ability to block the influence of tumor suppressor genes. A similar mechanism for the development of tongue cancer can be observed in patients receiving immunosuppressive drugs for a long time.
Prolonged exposure to the above trigger factors leads to damage to the DNA structure of the epithelial cells of the tongue with the development of dysplasia or hyperplasia of its mucosa. Over time, with continued exposure to a carcinogenic factor, these changes transform into cancer. In relation to cancer of the tongue , precancerous conditions include:
- chronic ulcer (erosion) of the tongue
- leukoplakia
- pappilomas
- are hyperkeratic and ulcerative erosive forms of systemic lupus erythematosus and lichen planus
- Bowen’s disease.
In addition, most benign tumors of the tongue due to constant trauma in the oral cavity can undergo malignant transformation with the development of tongue cancer.
Classification
Depending on the localization of tongue cancer, there are:
- cancer of the body of the tongue (70% of cases). It is most often located in the middle of its lateral surface.
- cancer of the tongue root (20%)
- cancer of the lower surface of the tongue (10%).
According to the macroscopic characteristics, the following clinical forms of disease are distinguished: exophytic (papillary or ulcerative) and endophytic (infiltrative, infiltrative-ulcerative):
- The papillary form has the appearance of a dense outgrowth above the general surface of the mucosa, covered with papillary or plaque-like outgrowths.
- The ulcerative form occurs in about half of cases of tongue cancer. It is characterized by the presence of a superficial ulcer of the tongue surrounded by a roller, constantly increasing in size. At the beginning of its development, a cancerous ulcer of the tongue is characterized by painlessness. As it grows, pain syndrome appears and bleeding is noted. Infection of the ulcer and the addition of inflammatory phenomena can mask the cancer of the tongue and make it difficult to diagnose.
- The infiltrative form is characterized by the growth of the tumor in the thickness of the tongue and is manifested by its densification. It may have a diffuse character. The compaction spreading to the entire tongue leads to a violation of the mobility of the tongue.
- In the infiltrative-ulcerative form of tongue cancer, along with infiltration, deep slit-like ulcers occur.
According to the microscopic structure, 95% of tongue cancers belong to squamous cell carcinoma. Other histological forms (adenocarcinoma, basal cell lymphoepithelioma, etc.) are extremely rare.
Symptoms
There are three stages in the clinical course of disease: initial, developed and neglected.
The initial stage of tongue cancer is characterized by a low-symptom course and often goes unnoticed by the patient. It can be manifested by the formation of papillary outgrowths on the surface of the tongue; whitish spots, often mistaken for plaque on the tongue; local seals or redness, most often located on the lateral surface of the tongue. There may be an increase in submandibular lymph nodes. In some cases of tongue cancer, pain syndrome is noted already in the initial stage of the disease. But it does not have a clear localization and therefore is often regarded as a manifestation of traumatic glossalgia, glossitis, caries, pulpitis, periodontitis, chronic tonsillitis or other diseases.
The advanced stage of tongue cancer is accompanied by the appearance of various symptoms. Most often there are pains with different intensity, local or diffuse character, sometimes radiating to other areas of the oral cavity, temple, ear. Irritation of the oral mucosa with tumor necrosis products causes increased salivation. As a result of the collapse of the tumor and its infection, patients have an unpleasant fetid smell from the mouth. In this stage of tongue cancer, there may be difficulties in swallowing saliva, numbness of part of the tongue, pain when swallowing or sore throat of a permanent nature, difficulties in pronouncing sounds, intermittent bleeding from the area of the tongue, unrelated to its injury.
The advanced stage of tongue cancer is characterized by a rather aggressive course with rapid invasive tumor growth, accompanied by the disintegration of the surrounding tissues and metastasis to regional lymph nodes (submandibular, chin, occipital cervical). Distant metastases of tongue cancer are most often observed in the lungs, brain, bones, liver.
Diagnostics
The almost asymptomatic course of tongue cancer in the initial stage makes its timely diagnosis very difficult for the dentist. Initial changes in the mucous membrane of the tongue, detected during a preventive examination or during the treatment of caries, are often perceived as the result of unnoticed injury and do not cause suspicion of cancer. For this reason, most cases of tongue cancer are diagnosed only in the advanced or advanced stage.
During the diagnosis, an examination and palpation of the formation are performed. If there is a suspicion of tongue cancer, the patient is referred to an oncologist for consultation. The exact diagnosis is established according to the cytological examination of a smear-print from the surface of a cancerous ulcer and histological examination of a tumor sample obtained by biopsy. To determine the depth of tumor germination and the prevalence of the process, ultrasound is performed, if a tumor is suspected of germinating into bone structures, dental x-ray, orthopantomography and CT of the facial skull are used.
Metastasis of tongue cancer is diagnosed based on the results of a lymph node biopsy. Detection of distant metastases is carried out using CT and MRI of the brain, lung x-ray, skeletal scintigraphy, liver ultrasound. Differential diagnosis of tongue cancer is performed with benign tumors of the tongue, tuberculous ulcer, solid chancre of primary syphilis, leukoplakia, etc.
Treatment
As a rule, combination therapy is used for tongue cancer, including various combinations of the following methods: surgical, radiation, chemotherapeutic.
- Chemoradiotherapy. Radiation therapy is performed before and after surgery for tongue cancer. It can be carried out remotely or by intra-tissue irradiation (brachytherapy). The primary focus and areas of metastasis are exposed to radiation. The large size of the tumor and its infiltrative growth are indications for combined chemoradiotherapy. Palliative radiation and chemotherapy (bleomycin, metatrexate, vinblastine) are performed in patients with distant metastases of tongue cancer.
- Surgical treatment. It is aimed at radical removal of the tumor. It includes partial resection of the tongue (hemiglossectomy) or complete glossectomy. When cancer germinates into the soft tissues of the bottom of the oral cavity and bone structures, the operation is accompanied by resection of the affected tissues and the jaw bone. If necessary, an orthostome is applied. In the future, plastic surgery methods are used to restore the lost structures of the maxillofacial region, plastic and reconstructive operations are performed on the patient. When the cancer of the tongue metastasizes to the lymph nodes, they are removed.
Prognosis and prevention
Prevention of tongue cancer consists in the rejection of such bad habits as smoking and alcohol intake; elimination of the causes of chronic injury to the mucous membrane of the tongue (high-quality treatment of fillings after their installation, correct selection and correct installation of dentures, timely treatment of dental chips); regular professional oral hygiene. During the examination of the oral cavity, the dentist should carefully consider any changes on the part of the mucous membrane of the tongue and promptly refer the patient to an oncologist’s consultation.
With timely diagnosis and radical combined treatment of tongue cancer, the five-year survival rate of patients is 65-80%, and according to some data it reaches 95%. At the beginning of treatment in the advanced stage with the presence of metastasis to the lymph nodes, the five-year survival rate of patients is less than 35%.
Literature
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