Base of tongue cancer

Overview

Base of tongue cancer is a type of head and neck cancer. The base is the back one-third of the tongue that extends down the throat. Cancers of this type are usually squamous cell carcinomas, which form in the thin, flat cells that line the larynx. Squamous cells also make up the top layer of skin and other body parts such as the lungs and oesophagus. The location of the tongue cancer impacts the treatment plan. Tongue cancer can occur:

In the mouth, where it may be more likely to be seen and felt (oral tongue cancer). This type of tongue cancer tends to be diagnosed when the cancer is small and more easily removed through surgery.
In the throat, at the base of the tongue, where tongue cancer may develop with few signs and symptoms (hypopharyngeal tongue cancer). Ear pain is the only early symptom. Base of tongue cancer is associated with human papillomavirus (HPV) infection, and this association has a profound effect on the prognosis and treatment of this cancer.

Symptoms

Base of tongue cancer shows very few signs and symptoms in its early stages. It is for this reason that this cancer is usually diagnosed at an advanced stage when the tumour is larger and the cancer has spread into the lymph nodes in the neck.

A few patients show symptoms, while a few do not show any symptoms. It is important to see a doctor if any of the below symptoms are experienced persistently:

Swallowing difficulties

Difficulty moving the tongue

Pain in the ear

A sense of fullness in the throat

Sore throat

White or red patches on the tongue or lining of the mouth

Lump in the back of the mouth, throat, or neck

Pain or sores in the mouth

Changes in the voice, such as hoarseness

Causes

The exact causes of the base of tongue cancers are not fully known. However, certain risk factors can increase the chances of developing this cancer. It is also important to note that not everyone with the risk factors will develop tongue cancer, and people who don’t have risk factors can develop the disease.

Consumption of Tobacco and Alcohol: Smoking and alcohol drinking is reported to be a direct risk factor for tongue cancer. Studies show that smokers are 5 times more likely to develop tongue cancer than non-smokers.

Human papillomavirus (HPV) infection: Infection with HPV 16 and HPV 18 increase the risk of tongue cancer.

Age: This cancer is common in older age groups, starting from age 40 and above. However, young people may also develop this cancer.

Gender: This cancer is twice as common among men.

Betel nut chewing: WHO has considered betel nut to be a carcinogen. Long term betel nit chewing can cause tongue cancer.

Diagnosis

To confirm the diagnosis of the base of tongue cancer, the patient might be asked to undergo one or more tests discussed below:

Laryngoscopy: During this procedure, a laryngoscope (a thin, flexible tube with a lighted camera), is inserted through the nose or mouth for a closer look into the throat at the base of the tongue. If the doctor suspects abnormality, he/she may also collect the tissue samples during this procedure for further testing.

Barium Swallow: The patient is made to swallow liquid barium and is made to undergo an X-ray. Barium swallows help in detecting any abnormalities in the throat.

Imaging tests: Imaging tests like CT scan, MRI and PET scan help in obtaining detailed images of the mouth and throat, which help in detecting cancer masses, if any.

Biopsy: A small tissue sample is collected from the suspicious area and sent to the laboratory. These cells are examined for HPV infection and signs of cancer.

Treatment

The treatment plan for the base of tongue cancer is made considering various factors like the stage of the cancer, the location, its aggressiveness, patient’s age and the overall condition of the patient. Following are key treatment modalities used in treating tongue cancer.

Surgery: Surgery involves the removal of the tumours and surrounding lymph nodes if the cancer is in its advanced stages. In the case of early-stage cancers or small cancers, the surgery leaves little cosmetic or functional changes in the mouth region. However, in the case of larger tumours, the surgery may affect the patient’s speech and swallowing abilities. In these situations, the cancer surgery is often followed by a reconstruction surgery, which helps in restoring speech and swallowing problems.

Radiation Therapy: Radiation therapy is a treatment modality that stops cancer cells from dividing and slows the growth of the tumour. It also destroys cancer cells and shrinks tumours. Through advanced technology, the dose of radiation can be carefully adjusted such that the radiation is delivered to the target area precisely with least damage to the surrounding healthy tissues.

Chemotherapy: During chemotherapy, specific chemicals are administered into the body, and these chemicals destroy the cancer cells throughout the body. Chemotherapy is usually prescribed in the following cases:

Along with radiotherapy as an alternative to surgery (called chemoradiation)

After surgery to decrease the risk of the relapse

To slow the growth of a tumour and control symptoms when the cancer cannot be completely treated (palliative treatment)