ORAL CANCERS

What is oral cancer?

Oral cancer is a type of head and neck cancer which occurs within various sub sites of oral cavity. The sub sites are lips, inner aspect of cheeks, gums, floor of the mouth, oral tongue, hard palate and retromolar trigone (area behind wisdom tooth). It is the sixth most common cancer worldwide. In India, it is the most common cancer among men. Over, 90% of oral cancers are squamous cell carcinomas.

Stages of oral cancer?

Staging of the oral cancer tells the extent of the cancer and also helps in the planning the appropriate treatment.

There are five stages of oral cancer:

  • Stage 0: known as Carcinoma in-situ. This describes the presence of abnormal cells in the surface lining and having high potential to invade the deeper layers.
  • Stage 1: The size of the tumour is less than or equal to 2 centimetres and the cancer cells did not spread to the lymph nodes.
  • Stage II: The size of the tumour is between 2 and 4 centimetres and the cancer cells did not spread to the lymph nodes.
  • Stage III: The tumour is larger than 4cm and without spreading to lymph nodes, or is of any size and had spread to only a single lymph node(less than 3cm).
  • Stage IV: It is the most advanced stage. The tumour may be of any size, but it has spread to:
    • Adjacent tissue, skin or bone
    • Single lymph node (more than 3cm) or multiple lymph nodes.
    • Distant body parts like lungs etc.
  • The rate of recurrence is high for the cancers in stage III and IV.

Symptoms of oral cancer?

Symptoms include:

  • Non-healing ulcers in the mouth
  • Whitish or red patches in the mouth
  • Pain and discomfort in the mouth
  • Difficulty in swallowing
  • Difficulty in speaking
  • Limited tongue movements.
  • Difficulty in opening the mouth
  • Lump in the neck
  • Occasional bleeding or numbness in the mouth and lip
  • Loose teeth and ill-fitting dentures
  • Weight loss

Causes and risk factors for oral cancer?

Consumption of tobacco products and drinking alcohol are the most common causative factors of oral cancer worldwide.

Risk factors include:
  • Tobacco:

    It includes smoking tobacco by cigarettes, cigars & pipes and consuming smokeless tobacco by snuffing and chewing.

    Tobacco contains more than 19 known carcinogens; the by-products from these carcinogens are the primary mode for development of cancer. Also, the smoke and heat while smoking irritates the mucous membrane of the mouth and results in cancer.

  • Excess consumption of Alcohol:

    The risk of oral cancer for heavy drinkers is 6 times that of non-drinkers. Tobacco smoke and alcohol act synergistically in causing oral cancer.

  • Chewing Betel quid and areca nut:

    This is the most common causative factor of oral cancer in South-East Asia.

  • Prolonged exposure to sunlight:

    People who are exposed to continuous sunlight are at risk of developing lip cancer.

  • Infection with Human Papilloma Virus(HPV)
  • Chronic irritation by dentures, teeth and poor dental hygiene
  • Diet low in vegetables, fruits, vitamins A, C and E.
  • Family history of oral cancer.
  • Immunosuppression.

Diagnosing of oral cancer?

Oral cancers usually present as a chronic non-healing ulcers and rarely as a swelling below the mucosa.

History & Examination:

  • Providing a detailed medical history and any history of tobacco & alcohol consumption will help in diagnosing oral cancer.
  • Complete inspection of all sub sites of oral cavity is done to identify any abnormal tissue or growth.

Biopsy:

A small amount of suspicious growth in the oral cavity will be sent to a pathologist for microscopic examination. This helps in confirmation of the oral cancer.

  • Incisional biopsy: In this, a piece of the suspicious lesion is taken without removing it all.
  • Punch biopsy: This is a type of incisional biopsy using a ‘punch forcep’, which helps in removing a small tissue from the suspected area.
  • Excisional biopsy: In this technique, the whole area of concern is removed.
  • Brush biopsy: A few cells off the surface of a suspicious lesion are taken.

Neck Biopsy:

If needed, the lump in the neck is examined by a biopsy.

  • Fine needle aspiration cytology (FNAC): This is the most common and easiest way to do biopsy in which a tiny needle is placed into the lump over the neck and some cells are drawn out through a syringe. This will be sent to a pathologist for microscopic examination. If needed, FNAC will be done with USG or CT guidance.
  • Core biopsy: It is similar to FNAC, but a larger needle is used to remove a core of tissue from the lump.
  • Open neck biopsy: This is performed by placing an incision over the lump, and either a piece or the entire lump is taken out for the diagnosis.

Imaging:

Evaluation of the extent of oral cancer requires the use of special x-rays like Panorex, CT scans and MRI scans.

Treatment for oral cancer?

The treatment goals for oral cancer are to eradicate the cancer and restore the form and function.

The treatment modalities for achieving these goals are Surgery, radiotherapy, chemotherapy and molecular targeted therapy, either alone or in combination.

The choice of treatment depends on the tumour factors like site, size, location, stage of the oral cancer and patient factors.

In general, oral cancer is primarily treated with surgery as initial definitive treatment, either alone or in combination with radiotherapy or chemotherapy.

Preventing oral cancer?

Ways to reduce the risk of oral cancer:

  • Refrain from smoking and consuming any tobacco products.
  • Avoid excess drinking of alcohol
  • Take a balanced diet rich in fruits, vegetables, Vitamins A, C and E.
  • Avoid prolonged exposure to sun. Use UV protective glasses and skin creams.
  • Regular dental check-ups and maintaining good oral hygiene.