Oral cancer: causes, symptoms, treatment, prognosis

general information

Oral and oropharyngeal cancers are cancers that develop on the lips, fornix, side walls or floor of the mouth, on the tongue, tonsils, or the back of the throat.

• Oral and oropharyngeal cancers may appear as open sores, growths, or discolored areas in the mouth.
• The diagnosis of cancer of the "oral cavity" or "cancer of the oropharynx" is made by a biopsy.
• Imaging tests such as computed tomography, magnetic resonance imaging, and positron emission tomography, used to determine the size of a malignant tumor and how far away it is spread.
• Treatment depends on the location, size, and extent of the cancer and may include surgery, radiation therapy, and chemotherapy.

The following types of malignant tumors have been found in the mouth and throat:

Squamous cell carcinoma, which means cancer develops in the flat cells lining the inside of your mouth or throat. Without a doubt, it is the most common type of oral cancer. Other cancers such as verrucous (verrucous) cancer, malignant 

melanoma and Kaposi's sarcoma are much less common.

Risk factors

The main risk factors for oral and throat cancer are:

• the use of tobacco products;
• alcohol consumption;
• human papillomavirus (HPV) infection.

Use of tobacco products is the cause of a large number of cases of oral and throat cancers. Tobacco use includes smoking cigarettes, cigars or pipes, and chewing tobacco or betel gum (a mixture of substances that includes tobacco; another name is paan) and the use of snuff. In Russia, smoking cigarettes (especially more than 2 packs a day) is the main risk factor for the development of oral and throat cancer associated with the use of tobacco products. Smoking cigars can also increase your risk. Pipe smoking increases the risk of developing cancer in the part of the lips that comes in contact with the mouthpiece of the pipe. Chewing or snuffing tobacco increases the risk of developing cancers of the cheeks, gums and inner lips by 50% - in places where tobacco most often comes into contact with mucous membranes.

Consistent and excessive alcohol consumption also increases the risk of developing cancer of the mouth and throat. The increase in risk is proportional to the amount of alcohol consumed. There is some evidence that the alcohol in mouthwash can contribute to the occurrence of oral cancer if the fluid is used regularly for long time.

The highest risk is associated with simultaneous abuse of alcohol and tobacco. This combination is about two to three times more likely to cause cancer than these substances alone. This combination increases the risk of oral cancer in women - 100 times, and in men - 38 times, the risk of throat cancer - 30 times. People who continue to smoke and drink alcohol after being diagnosed with oral and throat cancer have a higher risk of recurrence than the rest of the population.

HPV infection, which is an increasingly common risk factor, leads to the development of genital warts and can enter the mouth during oral sex. The number of sexual partners and the frequency of oral sex are important risk factors. Certain strains of this virus predispose to the development of throat cancer and, to a lesser extent, oral cancer. HPV infection increases the risk of throat cancer 16 times, with HPV being the cause of 60% of throat cancers.

Floor is also a risk factor. About three quarters of oral and oropharyngeal cancers occur in men.

As with most cancers, increasing age increases the risk.

TO other factorsthat increase the risk of developing oral tumors include permanent trauma to the mouth from sharp edges of broken teeth, fillings, or dentures. Past head and neck x-rays, chronic candidiasis and poor oral hygiene are also risk factors. Prolonged sun exposure can cause lip cancer.

Symptoms

The symptoms of oral and throat cancer may differ slightly depending on where the tumor is located.

Distinctive feature oral cancer is a long painless course of the disease. But in the end, the swelling grows and pain appears. Typically, pain occurs when swallowing, as during sore throats. Difficulty in speaking. Squamous cell carcinoma of the mouth looks like open sores (ulcers) and usually grows into the underlying tissue. Wounds may appear as flat or slightly raised patches that are red (erythroplakia) or white (leukoplakia).

Cancers on the lip and other parts of the mouth are usually very hard and firmly adhered to the underlying tissues. Moreover, most benign seals in these areas move freely. Discolored areas on the gums, tongue, or oral mucosa can also be signs of cancer. If a brown or dark colored area has recently appeared in your mouth, it could be melanoma. A brown, flat, freckle-like spot (smoker's spot) develops in the area where the cigarette or pipe usually adheres to the lips.

Throat cancer, usually causes a sore throat that worsens when swallowing, as well as difficulty swallowing and speaking, and ear pain. Sometimes the first sign of throat cancer is a swelling in the neck.

Symptoms of most types of tumors in the mouth and throat make it difficult for people to eat and lose weight quickly.

Diagnostics

Diagnostics may include:

• endoscopic examination;
• biopsy;
• imaging tests to determine the stage.

To diagnose cancer of the mouth and throat during the examination, the doctor makes a biopsy (taking a tissue sample for examination under a microscope) of all pathological areas found during the examination. Only a biopsy can help determine if the pathological area is malignant. If the patient has all the typical symptoms, but doctors do not find any pathological neoplasms in the mouth, they examine the throat with a special mirror and / or flexible fiber optic tube (endoscope). During this examination, doctors take a biopsy of any pathological area.

If the biopsy shows cancer, doctors do imaging tests to determine the extent (stage) of the cancer, for example:

• computed tomography (CT);
• magnetic resonance imaging (MRI);
• a combination of positron emission tomography (PET) with CT.

Imaging tests help doctors determine the size and location of cancers, and determine exactly if they have spread to nearby structures or lymph nodes in the area neck. Doctors also use an endoscope to look at the mouth and throat to see cancer in nearby structures. Doctors do laryngoscopy (to look inside the larynx), bronchoscopy (to look inside the airway), and esophagoscopy (to look inside the esophagus).

- Screening.

Because early diagnosis greatly increases the likelihood of a cure, doctors and dentists should carefully examine the mouth and throat at every medical or dental check-up. The examination should include an area under the tongue where it is very difficult to see or feel the abnormal growth until it is large enough.

Treatment

Treatment may include:

• surgical intervention;
• radiation therapy, sometimes in combination with chemotherapy (chemoradiotherapy).

Surgery and radiation therapy remain the main treatments for oral and throat cancer. Doctors choose the appropriate treatment based on the size and location of the cancer.

At oral cancer the first treatment is usually surgery. Doctors remove the cancer and, in some cases, the lymph nodes under the jaw bones, behind them, and along the neck. Thus, surgery to remove a cancerous tumor in the oral cavity can significantly change the patient's appearance and cause psychological trauma. New methods of reconstructive surgery, applied directly during the main operation, restore functions and help the patient return to a normal appearance. Extracted teeth and parts of the jaw can be replaced with dentures. After major surgery, treatment may be required to restore speech and swallowing function. If the cancer is advanced, radiation therapy or chemoradiotherapy is given after surgery.

For patients for whom surgery is contraindicated, radiation therapy is an alternative first-line treatment. Chemotherapy is not usually used as an initial treatment, but is recommended in addition to radiation therapy for people with cancer that has spread to a large number of lymph nodes.

At oropharyngeal cancer as the first method of treatment, doctors often use surgery. New techniques are allowing doctors to operate through the mouth rather than through an incision in the neck. Some methods involve using an endoscope to transmit a laser beam. Another method involves the use of a surgical robot. The surgeon controls the arms of the robot using a console and monitors the progress of the operation through cameras connected to an endoscope that is inserted into the patient's mouth.

Radiation therapy or sometimes chemoradiation therapy can be used either after surgery or as the first treatment. For oropharyngeal cancer, radiation therapy is usually given and chemotherapy is added for advanced cancer. High Precision Radiation Therapy - Intensity Modulated Radiation Therapy (IMRT) - allows doctors to target radiation to a specific area, which can significantly reduce side effects effects.

- Side effects of treatment.

Radiation therapy to the mouth and throat causes many side effects, including:

• destruction of the salivary glands, which leads to the occurrence dry mouth and can lead to the development of caries and other dental diseases;
• low ability of the jaw bones to heal in case of dental problems or injuries;
• osteoradionecrosis - loss of bone tissue and surrounding soft tissue in the irradiated area.

Because of these side effects, all pre-existing dental problems must be completely healed before radiotherapy is prescribed. Teeth that may be a source of infection are removed and allow time for the holes to heal.

Similarly, oral hygiene is especially important for people after radiation therapy because after exposure to radiation in the event of a dental operation, for example, tooth extraction, the oral cavity will be bad heal up. Hygiene includes regular check-ups and thorough local care, including daily fluoride applications. If a person still needs to remove a tooth later, hyperbaric oxygen therapy is used, which improves bone healing and does not cause osteoradionecrosis.

Forecast

Survival rates for people with oral and throat cancer differ depending on the following factors:

• the original location of the tumor;
• whether the tumor has spread or not, if so, how far (stage);
• cause.

The possibility of recovery from squamous cell carcinoma of the oral cavity remains high if all cancerous the tumor and surrounding healthy tissue are removed before the cancer has spread to the lymph nodes. On average, more than 75% of people with tongue carcinoma that has not spread to the lymph nodes live at least 5 years after diagnosis. About 75% of people with floor of the mouth carcinoma that has not spread to surrounding structures live at least 5 years after diagnosis. However, if the cancer has spread to the lymph nodes, the five-year survival rate is reduced by about half. About 90% of patients with carcinoma of the lower lip live for at least 5 years, and the tumor rarely spreads. Cancer of the upper lip is more aggressive and more likely to spread to adjacent tissues.

On average, 60% of people with throat cancer live at least 5 years after diagnosis. The incidence is more than 75% if the cause is human papillomavirus (HPV), and less than 50% if the cause is different.

Survival rates for people with HPV cancers are twice that of people with the same type of cancer due to other causes.

Prophylaxis

Avoiding excessive tobacco and alcohol use can significantly reduce your risk of mouth and throat cancer. Another preventive measure is smoothing the rough surfaces of broken teeth or restoring them. Reducing sun exposure and using sunscreen reduces the risk of lip cancer. If sun damage covers most of the lip, cancer can be prevented by removing the outer surface of the lip with surgery or laser treatment.

Current HPV vaccines target some HPV strains that cause malignant throat swelling, so childhood vaccinations may prevent some of these species cancer.