Oral cancer

Oral cancer is a type of head and neck cancer that occurs in the mouth or lips, and is most often a squamous cell carcinoma.

Overview

Oral cancer, or mouth cancer, is cancer that develops in any of the parts of the oral cavity:

  • Lips
  • Gums
  • Tongue
  • Inner lining of the cheeks
  • Roof of the mouth
  • Floor of the mouth under the tongue

We still don’t know the exact cause, but oral cancer develops when cells from the lips or in the mouth develop mutations in their DNA and grow out of control. These abnormal mouth cancer cells can form a tumor and may spread inside the mouth and to other areas of the head and neck, or other parts of the body.

Mouth cancers most commonly begin in the flat, thin squamous cells that line your lips and the inside of your mouth, so most oral cancers are squamous cell carcinomas.

Symptoms, risk factors, and FAQs

Symptoms

You should see your provider right away if you experience any of these common symptoms of oral cancer:

  • A growth or lump inside your mouth
  • A lip or mouth sore that doesn’t heal
  • A white or reddish patch on the inside of your mouth
  • Loose teeth
  • Mouth pain
  • Ear pain
  • Difficult or painful swallowing

Risk factors

Research has identified factors that may increase the risk of mouth cancer:

  • Tobacco use of any kind, including cigarettes, cigars, pipes, chewing tobacco and snuff.
  • Drinking alcohol heavily
  • Sun exposure to your lips
  • Human papillomavirus (HPV)
  • A weakened immune system

Questions and answers (FAQs)

Yes, a dentist can identify the early signs of oral cancer. According to the American Cancer Society, many pre-cancers and oral cancers can be detected through routine screening exams by dentists, dental hygienists and even self-exams.

No, kissing cannot spread oral cancer. It is not contagious, so it cannot spread to another person through any means like kissing or sharing eating utensils.

In the U.S., oral cancer most often occurs in the tongue.

Diagnosis and staging

Oral cancer diagnosis

Because no two people develop head and neck cancer in the same way, we offer a wide array of resources for proper evaluation of your case.

Your UCHealth provider will start by taking your medical history and performing a physical exam to feel for swollen lymph nodes in the neck, look down your throat with a small, long-handled mirror, and check your lips and oral cavity for abnormal areas.

Then, we may use any combination of these tests and procedures to find and stage oral cancer:

  • Barium swallow (upper GI series). A liquid containing barium coats the lining of the esophagus and stomach for diagnostic X-rays.
  • Biopsy. The only definitive way to diagnose cancer cells. We remove cells or tissues for viewing under a microscope.
  • Bronchoscopy. We insert a thin, lighted tube called a bronchoscope into the trachea and lungs through the nose or mouth to check for abnormal areas or to take tissue samples for biopsy.
  • Computed tomography scan (CT). A type of X-ray creates detailed, highly accurate, cross-sectional images of the body.
  • Endoscopy. We insert a thin, lighted tube called an endoscope through a body opening or a small incision in the skin to examine internal organs and tissues for abnormalities; may also be used to take tissue samples or lymph nodes for biopsy.
  • Esophagoscopy. We insert a thin, lighted tube called an esophagoscope into the esophagus through the nose or mouth to check for abnormal areas or take tissue samples for biopsy.
  • Exfoliative cytology. We use a piece of cotton, a brush or a small wooden stick to gently scrape cells from the lips, tongue, mouth, or throat to check for abnormalities by viewing under a microscope.

  • Laryngoscopy. We use a thin, lighted tube called a laryngoscope or a hand-held mirror to examine the voice box, or larynx.
  • Magnetic resonance imaging (MRI). A magnetic field instead of X-rays provides detailed images of body structures.
  • Positron emission tomography (PET scan). An injection of a short-lived radioactive substance creates detailed images of body structures that help identify cancer and areas of inflammation in different parts of the body.
  • Serum tumor marker test. We check a blood sample for amounts of certain substances called tumor markers released by organs, tissues, or tumor cells in the body that indicate specific types of cancer when found at increased levels.
  • Ultrasound. High-energy sound waves bounce off internal tissues or organs and make images of body tissues, called a sonogram.
  • X-ray.

Oral cancer staging

UCHealth follows the American Joint Committee on Cancer (AJCC) TNM system to stage oral and throat cancer, which is based on three key pieces of information:

  1. The extent of the tumor (T): How large is the main (primary) tumor and which, if any, tissues of the oral cavity or oropharynx it has spread to?
  2. The spread to nearby lymph nodes (N): Has the cancer spread to nearby lymph nodes?
  3. The spread (metastasis) to distant sites (M): Has the cancer spread to distant organs such as the lungs?

Cancer staging can be complex, so ask your doctor to explain it to you in a way you understand.

AJCC stage Stage grouping Lip, oral cavity and p16 negative oropharynx stage description*
0 Tis
N0
M0
The cancer is still within the epithelium (the top layer of cells lining the oral cavity and oropharynx) and has not yet grown into deeper layers.

It has not spread to nearby lymph nodes (N0) or distant sites (M0). This stage is also known as carcinoma isitu (Tis).

I T1
N0
M0
The cancer is 2 cm (about ¾ inch) or smaller. It’s not growing into nearby tissues (T1). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
 

II

T2
N0
M0
The cancer is larger than 2 cm but no larger than 4 cm (about 1½ inch). It’s not growing into nearby tissues (T2). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
III

 

T3
N0
M0
The cancer is larger than 4 cm (T3). For cancers of the oropharynx, T3 also includes tumors that are growing into the epiglottis (the base of the tongue). It has not spread to nearby lymph nodes (N0) or to distant sites (M0).
–OR–
T1, T2, T3
N1
M0
The cancer is any size and may have grown into nearby structures if oropharynx cancer(T1-T3) AND has spread to 1 lymph node on the same side as the primary tumor. The cancer has not grown outside of the lymph node and the lymph node is no larger than 3 cm (about 1¼ inch) (N1). It has not spread to distant sites (M0).
IVA T4a
N0 or N1
M0
The cancer is any size and is growing into nearby structures such as:

For lip cancers: nearby bone, the inferior alveolar nerve (the nerve to the jawbone), the floor of the mouth, or the skin of the chin or nose (T4a)

For oral cavity cancers: the bones of the jaw or face, deep muscle of the tongue, skin of the face, or the maxillary sinus (T4a)

For oropharyngeal cancers: the larynx (voice box), the tongue muscle, or bones such as the medial pterygoid, the hard palate, or the jaw (T4a).

This is known as moderately advanced local disease (T4a).

AND either of the following:

It has not spread to nearby lymph nodes (N0)

It has spread to 1 lymph node on the same side as the primary tumor, but has not grown outside of the lymph node and the lymph node is no larger than 3 cm (about 1¼ inch) (N1).

It has not spread to distant sites (M0).

–OR–
T1, T2, T3 or T4a
N2
M0
The cancer is any size and may have grown into nearby structures (T0-T4a). It has not spread to distant organs (M0). It has spread to one of the following:

1 lymph node on the same side as the primary tumor, but it has not grown outside of the lymph node and the lymph node is larger than 3 cm but not larger than 6 cm (about 2½ inches) (N2a) OR

It has spread to more than 1 lymph node on the same side as the primary tumor, but it has not grown outside of any of the lymph nodes and none are larger than 6 cm (N2b) OR

It has spread to 1 or more lymph nodes either on the opposite side of the primary tumor or on both sides of the neck, but has not grown outside any of the lymph nodes and none are larger than 6 cm (N2c).

 

IVB

Any T
N3
M0
The cancer is any size and may have grown into nearby soft tissues or structures (Any T) AND any of the following:

It has spread to 1 lymph node that’s larger than 6 cm but has not grown outside of the lymph node (N3a) OR

It has spread to 1 lymph node that’s larger than 3 cm and has clearly grown outside the lymph node (N3b) OR

It has spread to more than 1 lymph node on the same side, the opposite side, or both sides of the primary cancer with growth outside of the lymph node(s) (N3b) OR

It has spread to 1 lymph node on the opposite side of the primary cancer that’s 3 cm or smaller and has grown outside of the lymph node (N3b).

It has not spread to distant organs (M0).

–OR–
T4b
Any N
M0
The cancer is any size and is growing into nearby structures such as the base of the skull or other bones nearby, or it surrounds the carotid artery. This is known as very advanced local disease (T4b). It might or might not have spread to nearby lymph nodes (Any N). It has not spread to distant organs (M0).
IVC Any T
Any N
M1
The cancer is any size and may have grown into nearby soft tissues or structures (Any T) AND it might or might not have spread to nearby lymph nodes (Any N). It has spread to distant sites such as the lungs (M1).

Source: American Cancer Society

Oral cancer treatment

Treatment for head and neck cancers, like oral cancer, varies greatly from person to person. Your multidisciplinary team may use any combination of surgery, chemotherapy, radiation, targeted therapy, or new immunotherapies to treat or control your oral cancer:

Surgery. Surgery may be part of an overall plan for treating a recurrence or new tumors. Specially trained head and neck surgical oncologists remove a tumor and some surrounding tissue, as well as some nearby lymph nodes. Your surgery may involve lasers for precise removal of cancer or precancerous growths or to relieve symptoms of cancer. Laser surgery is used most often to treat cancers on the surface of the body or in the lining of internal organs.

Radiation therapy (radiotherapy). We use X-rays and other types of medical radiation aimed at specific parts of the body. The radiation kills cancer cells, prevents cancer cells from developing or recurring, and improves many of cancer’s symptoms. For certain cancers, radiation therapy is combined with chemotherapy and called chemo-radiotherapy.

Chemotherapy. Drugs that slow down, damage, or kill cancer cells. It may involve single drugs or combinations of drugs taken intravenously or by mouth. Chemotherapy is often taken in cycles lasting three or four weeks each. Your team may also prescribe drugs to reduce or eliminate chemotherapy’s side effects.

Anti-cancer drug therapy. Single drugs or combinations of drugs taken through intravenous injections or as prescribed tablets/capsules help fight the cancer itself or side effects from chemotherapy. Drugs may be taken in repeating patterns that usually last three to four weeks.

Targeted therapy. Anti-cancer drugs or other substances that directly interfere with cancer growth and progression at the molecular level may be taken—with few side effects—on their own or combined with standard chemotherapy. Many new targeted therapies, including vaccines and gene therapies, are currently in development.

Types of oral cancer

Squamous cell carcinomas. More than 90% of oral cancers. The earliest form of squamous cell cancer is called carcinoma in situ, meaning that the cancer cells are only in the layer of cells called the epithelium. This is different from invasive squamous cell carcinoma, where the cancer cells have grown into deeper layers of the oral cavity.

Verrucous carcinoma. Less than 5% of all oral cancers. A low-grade or slow growing cancer that rarely spreads to other parts of the body, but it can grow deeply into nearby tissue.

Minor salivary gland carcinomas. Can start in the glands in the lining of the mouth and throat. There are many types of minor salivary gland cancers, including adenoid cystic carcinoma, mucoepidermoid carcinoma, and polymorphous low-grade adenocarcinoma.

Lymphomas. The tonsils and base of the tongue contain immune system tissue, or lymphoid tissue, where lymphomas can start.

Couple walking in the woods

Five-year oral cancer survival rates

Gum

Chart comparing all stages Gum Cancer UCHealth 53.8% survival rate to Colorado state average of 60.1%

Number of Patients Diagnosed –
UCHealth 48 – State of Colorado – 236
Number of Patients Surviving –
UCHealth 26 – State of Colorado – 142

Major salivary gland

Chart comparing all stages Major Salivary Gland Cancer UCHealth 49.8% survival rate to Colorado state average of 56.2%

Number of Patients Diagnosed –
UCHealth 56 – State of Colorado – 240
Number of Patients Surviving –
UCHealth 28 – State of Colorado – 135

Tongue

Chart comparing all stages Tongue Cancer UCHealth 63.6% survival rate to Colorado state average of 66.5%

Number of Patients Diagnosed –
UCHealth 153 – State of Colorado – 705
Number of Patients Surviving –
UCHealth 97 – State of Colorado – 469

*n<30, 5 Year Survival – (Date of diagnosis 1/1/2010–12/31/2014)

National Institute of Dental and Craniofacial Research (NIDCR). Oral Cancer (https://www.nidcr.nih.gov/health-info/oral-cancer)

MedlinePlus: National Library of Medicine. Oral Cancer (https://medlineplus.gov/oralcancer.html)

National Cancer Institute (NCI). Lip and Oral Cavity Cancer Treatment (Adult) (https://www.cancer.gov/types/head-and-neck/patient/adult/lip-mouth-treatment-pdq)