Where Is Cancer Most Common in the Mouth? Oral Cancer

Medically Reviewed on 10/6/2022
Where Is Cancer Most Common in the Mouth
Squamous cell carcinoma accounts for 90% of all mouth cancers

Mouth cancer can develop anywhere in the mouth but most commonly begins in the squamous cells (thin, flat cells) that line the lips and inside of the mouth. 

Also called squamous cell carcinoma, this type of oral cancer accounts for 90% of all mouth cancers.

Is mouth cancer deadly?

Each year, nearly 54,000 Americans are diagnosed with mouth cancer, with about 9,750 cases resulting in death. 

For many decades, the 5-year survival rate for mouth cancer was under 50%. However, over the last 10 years, survival rates have increased to about 57%.

This improvement in survival rates is linked to a rise in human papillomavirus (HPV) 16-caused cancers, which are more responsive to present treatment methods.

What causes mouth cancer?

Causes of mouth cancer include the following:

  • Family history of oral cancer
  • Previous history of mouth cancer
  • Human papillomavirus (HPV) (infects the skin and cells that line body cavities and can increase the risk of mouth, head, nose, and throat cancer)
  • Weakened immune system (certain diseases such as HIV, TB, or hepatitis can damage your immune system and prevent them from identifying abnormal cell proliferation)
  • Blood pressure medications (hydrochlorothiazide)
  • Alcohol and tobacco use
  • Poor nutrition (lack of vitamins and minerals)
  • Sedentary lifestyle
  • Ultraviolet (UV) radiation (overexposure to UV radiation can harm the lips and result in oral cancer.

Risk factors for mouth cancer include the following:

  • Sex: Men are more prone to develop mouth cancer than women
  • Age: Mouth cancer is commonly seen in people older than 40 years
  • Previous radiation therapy: Anyone who received radiation therapy for any cancer in the body can develop oral cancer

What are the symptoms of mouth cancer?

The most common signs of mouth cancer include the following:

  • Painful mouth ulcers that do not heal in a few weeks
  • Persistent lump in the mouth cavity
  • Persistent lumps in the lymph glands in the neck
  • Whitish or reddish patch in the mouth cavity

Other symptoms that are commonly associated with other conditions may indicate mouth cancer or progress to mouth cancer. Consult a doctor if you have any of the following symptoms:

  • Dysphagia (discomfort or trouble swallowing)
  • Changes in voice or speech issues
  • Unintentional weight loss
  • Numbness or bleeding in the mouth
  • Loss of one or more teeth due to no apparent cause
  • Tooth socket that fails to heal after a tooth extraction
  • Difficulty moving your jaw
  • Red or white areas in the mouth

How is mouth cancer diagnosed?

Early detection of mouth cancer may result in more successful treatment. While some early stage cancers have detectable signs and symptoms, this is not always the case.

If any suspicious lesion is found and thought to be cancerous, the following tests are done to rule out cancer:


A small sample of the affected tissue is removed and examined for malignant cells. The following are the most common ways for conducting a biopsy in cases of suspected oral cancer:

  • Biopsy via incision or punch
  • Cytology using tiny needle aspiration
  • Rhinoscopy
  • Endoscopy

The samples collected during a biopsy are examples under a microscope by a pathologist.

Imaging tests

If the biopsy reports that you have oral cancer, more testing may be done to determine the stage before any therapy is considered.

These tests often include scans to see whether cancer has progressed to tissues adjacent to the main tumor, such as the jaw or skin, as well as scans to determine whether cancer has spread to the lymph nodes in your neck.

Although it is uncommon for mouth cancer to spread further, you may have scans to evaluate the rest of your body:


Cancer: Symptoms of Common Cancers in Men See Slideshow

What are the different stages of mouth cancer?

Determining the stage of cancer allows doctors to decide how to proceed with treatment. Treatment may include surgery, radiation therapy, or chemotherapy.

After your physical exam and the preliminary findings of your oral tissue sample or imaging tests, your doctor will assign a stage to your cancer.

Mouth cancer is divided into five stages:

Stage 0

  • Also called carcinoma in situ 
  • Cancerous cells have developed in the lining of the lips or oral cavity

Stage I 

  • Extremely early stages of cancer
  • Tumor is no more than 2 cm in diameter, and cancer has not spread to the lymph nodes

Stage II 

  • Tumor is larger than 2 cm but smaller than 4 cm
  • Cancer has not spread to the lymph nodes

Stage III 

  • Cancer is greater than 4 cm in diameter or has progressed to a lymph node in the neck.

Stage IV 

  • Most advanced stage
  • Cancer could be of any size and has spread to other regions including adjacent tissues, such as the jaw or other parts of the oral cavity
  • Affected lymph nodes may be as follows:
    • 1 large lymph node (more than 3 cm in size) on the same side of the neck as the tumor
    • Several lymph nodes of any size on the same side of the neck as the tumor
    • 1 lymph node of any size on the opposite side of the neck as the tumor
  • Cancer has spread to distant regions such as the lungs
  • Cancer that has come back after treatment in the same region of the body where it first appeared (regional recurrence), in the lymph nodes (regional relapse), or in another part of the body (distant recurrence)
  • Tumors in stages III and IV are more likely to recur than cancers in the early stages

What are the treatment options for mouth cancer?

  • Surgery
    • Tumor resection removes the whole tumor from the mouth.
    • Depending on the location of the tumor, a tiny incision in the neck or jawbone may be made to facilitate removal.
    • When a tumor is surgically removed, a portion of the mouth may need to be rebuilt. Surgeons may conduct pedicle or free flap reconstruction in these cases.
  • Radiation therapy
    • Current radiation therapy technology uses equipment designed to protect healthy tissue and minimize process durations to treat cancerous tissues of the mouth with more precision.
    • The two most prevalent radiation treatments used to treat mouth cancer are external beam radiation therapy and brachytherapy.
  • Chemotherapy
    • Often paired with radiation therapy, chemotherapy uses drugs to eliminate cancer cells throughout the body.
    • Various chemotherapy medications may be combined to kill cancer cells at different points of their development cycles, reducing the possibility of treatment resistance.
  • Targeted therapy
    • Targeted therapy works by interfering with cancer cell proliferation at the molecular level.
    • As part of a tailored treatment strategy for oral cancer, it may be coupled with chemo and/or radiation therapy.
  • Immunotherapy
    • Immunotherapy medications work by helping the immune system identify and kill cancer cells.
Medically Reviewed on 10/6/2022
Image Source: iStock image

Oral Cancer: Risks, Symptoms, and Prevention. https://www.webmd.com/oral-health/guide/oral-cancer

Oral Cancer. https://my.clevelandclinic.org/health/diseases/11184-oral-cancer

Oral Cancer Facts. https://oralcancerfoundation.org/facts/