Tongue Cancer: Information on Causes, Diagnosis & Treatments
Tongue cancer is a subset of cancer that develops within the tissues of one or more parts of both the tongue base and the oral tongue. The tongue base includes the under-tongue, the portion of tissue that connects the tongue to the soft palate underneath the tongue (frenulum), and the salivary glands. The oral tongue includes the lip, the uvula, and the top of the tongue.
About 90% of tongue cancer cases occur in the tongue base, under the tongue and on the soft palate. Tongue cancer is invasive and often spreads to different parts of the body if left undiagnosed. Overall, the occurrence of tongue cancers has decreased worldwide by 2% over a nine-year span - however, the rate has gone up 1% among Caucasian males. Tongue cancer does not
Who is at Risk for Tongue Cancer?
Though tongue cancer is not an extremely common form of cancer, several risk factors determine its individual incidence:
- Age - The average age of diagnosis is 62-years-old, though nearly two-thirds of diagnosed cases occur in individuals over 55.
- Gender - Males are twice as likely to develop tongue cancer as females.
- Smoking tobacco
- Consuming tobacco-related products
- Poor diet and nutritional habits
- Exposure to ultraviolet light via excessive sun exposure or use of tanning beds
- Inherited genetic mutations (Fanconi anemia, Dyskeratosis congentia)
- Human papillomavirus (HPV)
A large portion of these risk factors result from poor lifestyle choices and health decisions, though one of the major causes – UV exposure – can occur unknowingly within the workplace.
Tongue Cancer Types
Tongue cancer is most often expressed via squamous cell carcinomas, accounting for 95% of all tongue cancer cases. This type of cancer impacts the surface cells of any portion of the tongue base or oral tongue.
Developing in less than 5% of tongue cancer cases, verrucous carcinomas are similarly made of squamous cells, but are slow-growing. This type of tongue cancer rarely spreads past nearby tissue.
Salivary gland cancer/adenocarcinomas are the least common type of cancer. Adenocarcinomas originate in mucus-secreting glands – this occurs within the glands of the tongue but can also occur within the lining of the lips.
Symptoms of tongue cancer are some of the most noticeable of all smoking-related cancer symptoms. Rather than presenting ambiguous symptoms, like a hoarse cough, most of its symptoms are directly expressed through the tongue and its functioning:
- Red or white patches on the surface of the tongue that do not fade over time
- A sore throat
- An ulcer, tender spot, or lump on the tongue
- Chronic numbness of the mouth or tongue
- Unexplained bleeding of the tongue
- Pain in either of the ears, though this symptom is rare
Because the symptoms of tongue cancer are so straightforward, medical evaluation should follow if an individual experiences any of the symptoms for more than several weeks with no improvement.
Diagnosing Tongue Cancer
Tongue cancer is first assessed via physical exam by a primary care provider. The physical examination will consist of the following:
- Oral examination – An oral examination will be conducted to visually assess the physical symptoms communicated by the patient.
- Palpation – The doctor will use palpation, or light pressing, to detect abnormal lymph node size or tenderness.
- Dental assessment – If necessary, the doctor will refer the patient to a dental hygienist to rule out factors like infection or general hygiene-related issues.
If no other cause for the patient’s symptoms presents itself, diagnostic tests will be conducted to determine if cancer is the cause of their symptoms:
- Biopsy – In most cases, a biopsy will be needed to determine if tongue cancer is present. The doctor will apply local anesthetic and remove a small sample of tissue from the mouth.
- Endoscopy – An endoscopy is conducted with a small tube and a camera attached to it. It is used to visually determine if the cancer has spread to the throat.
- Imaging tests – One of several imaging tests (x-ray, CT, MRI, PET) will be done determine if the cancer has spread to further parts of the body.
After a definitive diagnosis is made, the doctor will assign one of the following stages to the status of the cancer:
- Stage 0 – This stage indicates that the cancer is only present in the outermost layer of skin cells. It has not spread, nor has it penetrated into deeper layers of tissue.
- Stage 1 – A small tumor has been formed (less than 2 cm), though cancer cells have not spread to nearby mouth structures.
- Stage 2 – The tumor has increased in size (2cm - 4cm) but has still not spread to any other structures.
- Stage 3 – The tumor has continued to increase in size, but has not spread to other mouth structures, or the tumor has remained stable in size, but has spread to one lymph node.
- Stage 4 – The tumor has spread or grown into other mouth structures and/or metastasized, and cancer cells may have spread to one lymph node. Or the tumor has remained in its original site, and cancer cells have traveled to one or more lymph nodes.
Treating the Condition
Although tongue cancer holds a gloomy prognosis in its advanced stages, it can be treated early with effective diagnosis. Treatments for tongue cancer include:
- Surgery – Elective neck dissection (END) refers to the removal of any portion of the neck/oral cavity. This method of treatment is most effective when completed in the early stages of tongue cancer but can cause complications if it does not solve the issue at once. This option is also viable in the advanced stages of tongue cancer, but it requires removing larger portions of the patient’s neck/oral cavity and will still require additional treatment like chemotherapy.
- Chemotherapy/Radiotherapy – Chemotherapy and radiotherapy that are used together (radiation and cytotoxic drugs given in succession) are used to kill the malignant cancer cells in advanced in its advanced stages.
Around 50% of patients treated for tongue cancer will suffer from relapses within two years after initial treatment. This is especially relevant for individuals whose cancer metastasized and impacted distant body parts. Tongue cancer possesses a notorious 5-year survival rate after a tumor achieves metastasis, presenting a dim prognosis for those who do not catch the cancer before it spreads. Therefore, detection and prevention of tongue cancer is essential.