Tongue cancer

Clinical picture

Tongue cancer develops when malignant cells of the tongue undergo uncontrolled cell division. Usually, these tumours develop on the outer sides of the tongue, and originate in the mucous membrane of the tongue. This type of tumour is known as a squamous cell tumour.

The tongue consists of two parts: the front, which is muscled and mobile, and the back, or tongue base. In both parts, tumours can develop, but treatment of these cancers is different. A tumour can also affect the tongue muscle and grow into the rest of the mouth and lower jaw.

Belgium has seen a steady rise of tongue cancer diagnoses over the last few years. Around 200 patients are diagnosed with the illness every year. Despite this increase, 5-year survival rates have not changed, with 82% of patients still alive at 5 years. In stage IV this number drops to 39%.

Symptoms

Patients with a squamous cell carcinoma on the tongue can present the following symptoms:

swelling or lesions on the tongue that can be painful
pain during swallowing, talking or eating
radiating pain to the neck and ears
bad breath
swelling of the neck and throat area

Cause

No clear cause for tongue cancer has been identified. However, there is a number of risk factors that bring a larger chance of contracting the disease. These include:

smoking
prolonged use of alcohol
bad oral hygiene or unhealthy food
ill-fitting dentures
chronic inflammations and gingivitis

Diagnosis

When a patient comes to the GP, they may not immediately suspect tongue cancer, prescribing medication or antibiotics instead. Only when these have no effect will the patient be referred to a specialist. In some cases patients are referred to an ear-nose-throat specialist by their dentist. The ENT doctor will perform special tests such as a laryngoscopy and a biopsy. X-rays, ultrasounds, CT, MRI and PET scans and a sentinel node biopsy are then used in order to determine the cancer stage.
Tongue cancer is graded along four stages.
- Stage I: The tumour is less than 2 centimetres across and has not spread
- Stage II: The tumour measures between 2 and 4 centimetres but has not spread
- Stage III: The tumour is larger than 4 centimetres, or 3 centimetres plus spreading into one nearby lymph node
- Stage IV: Cancerous cells have spread to surrounding tissue and distant organs and lymph nodes
The differentiation of the tumour is an important factor in establishing a prognosis and treatment. This can be determined on the basis of a biopsy. A biopsy involves the removal of a small bit of tissue that can be examined under a microscope. Differentiation determines the degree of mutation in the cancerous cells.

Treatment

When the diagnosis has been established, a specialist will formulate a treatment strategy, depending on the tumour stage and location. Treatment options include: surgery, radiation, chemoradiation, light therapy and chemotherapy.

If possible, surgical removal of the tumour is the therapy of choice, sometimes combined with adjuvant radiation. If the tumour has grown too large, chemotherapy is in order, sometimes combined with radiotherapy. This combined approach is known as chemoradiation. In some cases, EGFR inhibitors may also be an appropriate choice of treatment. Targeted therapy remains an active area of research within this cancer setting.