Oral cancer is a malignant neoplasm originating from the epithelium and soft tissues of the oral cavity. In the early stages, it is asymptomatic, it is a nodule or an ulcer. Subsequently, oral cancer increases in diameter, pain appears, first local, then radiating to the head and ears. Salivation increases. When disintegrating, an unpleasant smell from the mouth occurs. Secondary infections are often added. With lymphogenic metastasis, there is an increase in regional lymph nodes. The diagnosis is made taking into account the examination and biopsy data. Treatment – radiotherapy, surgical removal, chemotherapy.
Meaning
Oral cancer is a malignant tumor localized in the area of the tongue, the mucous membrane of the cheeks, gums, bottom, palate or alveolar processes of the jaws. The incidence rate depends on the region, the disease more often affects residents of Asian countries. In the USA – 8% (probably due to the large number of emigrants from Asian countries), in India – 52%. It is usually found in patients over 60 years of age. It is rarely diagnosed in children. There is a pronounced predominance of males.
65% of oral cancer is represented by neoplasms of the tongue, 13% – the mucous membrane of the cheeks, 11% – the bottom of the oral cavity, 9% – the hard palate and the mucosa of the alveolar processes of the upper jaw, 6.2% – the soft palate, 6% – the mucosa of the alveolar processes of the lower jaw, 1.5% – the uvula, 1.3% – palatine arches. Epithelial tumors are detected more often than sarcomas. Oral cancer often develops against the background of precancerous processes, usually occurring at the age of 40-45 years. Treatment is carried out by specialists in the field of oncology and maxillofacial surgery, sometimes with the participation of otolaryngologists.
Causes
The causes of oral tumors are not precisely established, however, experts were able to identify a number of factors contributing to the development of this pathology. The leading role in the occurrence of oral cancer is played by bad habits, especially the combination of smoking and alcohol abuse. Chewing betel and eating nasa are of great importance for residents of Asian countries. Oncologists consider repeated mechanical injuries as the second most important factor provoking oral cancer: the use of poor-quality dentures, wounds that occur when in contact with the sharp edge of the filling or a fragment of a tooth.
Less often, in the anamnesis of patients with oral cancer, single mechanical injuries are detected: maxillofacial injuries or injury to dental instruments during tooth extraction or treatment. Oncologists and dentists point out the importance of oral hygiene, removal of tartar, treatment of caries and periodontitis and the inadmissibility of installing dentures made of different materials (this causes galvanic currents and contributes to the development of diseases of the oral cavity).
Recent studies by American oncologists indicate that there is a connection between neoplasms of the mouth and nasopharynx and the sexually transmitted human papillomavirus, during kissing or (less often) during household contacts. The virus does not always provoke tumors, but increases the risk of their occurrence. In some patients with oral cancer, there is a connection with occupational hazards: work in heavily polluted rooms, contact with carcinogenic substances, prolonged stay in conditions of high humidity, high or low temperature. In addition, the development of oral cancer is promoted by the use of spicy or too hot food and vitamin A deficiency, in which the processes of keratinization of the epithelium are disrupted. Neoplasms often appear against the background of chronic inflammatory and precancerous lesions.
Classification
Taking into account the features of the histological structure , the following types of squamous cell carcinoma are distinguished:
- Oral cancer in situ. It is rarely detected.
- Keratinizing squamous cell carcinoma. The presence of large areas of keratinized epithelium (“cancer pearls”) is revealed. Rapid aggressive local growth is characteristic. It is diagnosed in 95% of cases.
- Non-keratinizing squamous cell carcinoma of the oral cavity with the proliferation of atypical epithelium without clusters of keratinized cells.
- Low-grade cancer, whose cells resemble sarcomatous. It proceeds most malignantly.
Taking into account the peculiarities of tumor growth, there are three forms of oral cancer: ulcerative, nodular and papillary. The ulcerative form is the most common, manifested by the formation of slowly or rapidly growing ulcers. Nodular cancer of the oral cavity in appearance is a dense knot covered with whitish spots. With papillary neoplasms in the oral cavity, rapidly growing dense outgrowths occur.
To determine the tactics of treatment of the disease, a four-stage classification of oral cancer is used:
- Stage 1 – the diameter of the tumor does not exceed 1 cm, the neoplasm does not extend beyond the mucous and submucosal layers. The lymph nodes are not changed.
- Stage 2A – a neoplasm with a diameter of less than 2 cm is detected, sprouting tissues to a depth of no more than 1 cm. Regional lymph nodes are intact.
- Stage 2B – there is a picture of oral cancer of stage 2A and a lesion of one regional lymph node.
- Stage 3A – the diameter of the tumor does not exceed 3 cm. Regional lymph nodes are not involved.
- Stage 3B – numerous metastases in regional lymph nodes are detected.
- Stage 4A – oral cancer spreads to the bones and soft tissues of the face. There are no regional metastases.
- Stage 4B – a tumor of any size is detected, there are distant metastases or immobile affected lymph nodes.
Oral cancer symptoms
In the early stages, the disease is asymptomatic or manifests itself with scant clinical symptoms. Patients may notice unusual sensations in the oral cavity. An external examination reveals an ulcer, a crack or a sealing area. A quarter of patients with oral cancer complain of local pain, explaining the appearance of pain syndrome by various inflammatory diseases of the nasopharynx, teeth and gums. With the progression of the oncological process, the symptoms become more vivid. The pain increases, radiating to the forehead, ear, zygomatic or temporal areas.
There is an increase in salivation due to irritation of the mucous membrane by decay products of oral cancer. Due to the decay and infection of the neoplasm, a putrid smell from the mouth appears. Over time, the tumor affects neighboring anatomical structures, causing facial deformities. An increase in one or more regional lymph nodes is detected. At first, the lymph nodes are mobile, then they are soldered to the surrounding tissues, sometimes with decay phenomena. Hematogenous metastases are detected in 1.5% of patients, usually affecting the brain, lungs, liver and bones.
Certain types of oral cancer
Cancer of the tongue usually occurs on its lateral surface, less often located in the root zone, on the lower surface, back or tip. Already at the initial stages, oral cancer causes disorders of chewing, swallowing and speech, which facilitates timely diagnosis. Subsequently, there are pains along the course of the trigeminal nerve. If the root is affected, breathing difficulties are possible. Early formation of secondary foci in regional lymph nodes is characteristic.
Cancer of the bottom of the oral cavity in the early stages is asymptomatic. Patients turn to the dentist after the detection of a tumor-like formation, felt as a painless growth. Oral cancer germinates nearby tissues early. With progression, regional lymph nodes are affected, pain and increased salivation occur. Bleeding is possible.
Cancer of the cheek mucosa is usually localized at the level of the mouth line. In the early stages, patients with oral cancer may not consult a specialist, mistaking the tumor for an aphthous ulcer. Subsequently, the ulcer increases in diameter, patients note pain when chewing, swallowing and speaking. When the masticatory muscles germinate, there are restrictions when trying to open the mouth.
Palate cancer is usually accompanied by an early onset of pain syndrome. In the area of the palate, an ulcer or a growing, rapidly ulcerating node is detected. Sometimes, at first, oral cancer is asymptomatic, and pain occurs when the process spreads to nearby tissues and the infection joins.
Cancer of the mucosa of the alveolar processes early provokes toothache, loosening and loss of teeth. Accompanied by frequent bleeding.
Diagnostics
The diagnosis is made taking into account the external examination data and the results of the biopsy. Ultrasound, CT and MRI for oral cancer are uninformative. If a lesion of bone structures is suspected, radiography of the facial skeleton is prescribed. To identify distant secondary foci, abdominal ultrasound and chest x-ray are performed. Differential diagnosis of oral cancer is carried out with precancerous processes, specific (tuberculosis, syphilis) and nonspecific inflammatory lesions.
Oral cancer treatment
Treatment of oral cancer – radiotherapy, chemotherapy and surgical interventions. It is possible to use combination therapy or isolated techniques. With oral cancer of stage 1-2, brachytherapy provides a good effect. Most specialists prefer this method because it excludes the formation of functional and cosmetic defects and is quite easily tolerated by patients. At the same time, the technique does not allow to achieve long-term remission in distally located neoplasms and tumors of stage 3-4.
The volume of surgery for oral cancer is determined by the prevalence of the neoplasm. The node is excised together with unchanged tissues. In the process of radical removal of oral cancer, excision of muscles or bone resection may be required. In the event of gross cosmetic defects, plastic surgery is performed. If breathing is difficult, a temporary tracheostomy may be applied until the obstacle to air movement is removed. Chemotherapy for oral cancer is less effective. The technique makes it possible to reduce the volume of the tumor by 50 percent or more, but does not provide a complete cure, so it is usually used in combination with surgery and radiotherapy.
Forecast
The prognosis for oral cancer is determined by the location and stage of the process, the degree of damage to certain anatomical structures, the age and condition of the patient. Tumors of the posterior parts of the oral cavity are more malignant. The five-year relapse-free period for tongue neoplasms of stage 1-2 after a course of isolated radiotherapy is 70-85%. With tumors of the bottom of the oral cavity, this indicator is 46-66%, with cheek cancer – 61-81%. In stage 3 oral cancer, the absence of relapses for 5 years is observed in 15-25% of patients.