Doctors classify oral cancer using stages 0–4, with higher numbers meaning more advanced disease. Treatments and outlooks can vary considerably in the later stages.

Doctors determine the stage of oral cancer using the TNM method.

They examine the size and extent of the primary tumor (T), whether it’s spread to nearby lymph nodes (N), or metastasized (spread) to distant sites, such as your lungs (M).

TNM findings help doctors assign a stage (0 through 4) to oral tumors. A lower number means less spread and a better outlook. Treatment options also depend on the stage and location.

Stage 0 oral cancer is also called carcinoma in situ. At this stage, the cancer hasn’t spread past the epithelium, the top layer of cells. It hasn’t grown into the deeper layers of tissue or spread to the lymph nodes or elsewhere.

Oral tumors at this stage may not cause any symptoms. Still, a medical professional can detect them during an oral exam.

Treatment

Treatment for stage 0 oral cancer involves surgical stripping or Mohs surgery. A doctor removes the top layers of the mouth lining where the cancerous cells are, along with some tissue around the cancerous cells.

If oral carcinoma in situ keeps returning after surgery, your doctor may recommend radiation therapy.

Symptoms of oral cancer

Oral cancer can cause symptoms at any stage, though they’re more pronounced in later stages. Possible symptoms include:

  • a discolored patch inside your mouth
  • a sore spot, irritation, thickening, or lump inside your mouth or on your lip
  • problems with jaw or tongue movement
  • problems chewing or swallowing
  • swelling of your jaw
  • numbness inside your mouth
  • pain or bleeding in your mouth
  • ear pain

You might want to see a doctor or dentist if you have any of these symptoms for 2 weeks or longer.

Stage 1 oral cancer is a tumor 2 centimeters (cm) or less in size. It hasn’t spread to the lymph nodes or metastasized.

Treatment

Stage 1 treatment options depend on the location of the cancer but typically begin with surgery to remove the tumor. If surgery isn’t an option due to other health concerns, radiation is just as effective.

After surgery, a doctor might recommend radiation or chemoradiation to stop the cancer from returning.

Stage 2 oral cancer is a tumor 2–4 cm in size. As with earlier stages, stage 2 oral cancer has not spread to lymph nodes or distant structures.

Treatment

Treatment for stage 2 oral cancer is similar to stage 1. A doctor might first recommend surgery, or radiation if you cannot have surgery. Postsurgery radiation or chemoradiation might be an option to prevent the cancer from coming back.

In addition to removing the tumor, a doctor might recommend removing the nearby lymph nodes.

Doctors consider stage 3 oral cancer to be a tumor larger than 4 cm that hasn’t spread to lymph nodes or a tumor of any size that has spread to one lymph node on the same side of the neck as the tumor. It still hasn’t spread to distant sites in the body.

Treatment

Stage 3 oral cancer treatment usually involves surgery, radiation, or both. A doctor will typically surgically remove the tumor and the lymph nodes. Following the surgery, you might have radiation or chemoradiation.

At this stage, a doctor may also recommend a clinical trial of chemotherapy or hypofractionated radiation therapy, which is a shorter course of radiation treatment.

Experts further divide late-stage oral cancer into stages 4A, 4B, and 4C.

Stage 4A

Stage 4A oral cancer is when the primary tumor is any size and grows into nearby structures, like your jaw bone, facial skin, or maxillary sinus. It’s not yet spread to distant sites but may have spread to the lymph nodes — usually on the same side as the tumor.

Stage 4B

Stage 4B oral cancer is when the tumor is any size and may have grown into surrounding structures. It has not metastasized to distant sites in the body but has typically spread to one or more lymph nodes on either side.

In some cases, cancer may not have spread to the lymph nodes but has grown into nearby structures, such as the base of the skull or around the carotid artery. Doctors consider this to be a very advanced stage.

Stage 4C

Stage 4C oral cancer is when the primary tumor, regardless of size, has spread to distant sites in the body, like your lungs. Even if lymph nodes aren’t involved, doctors consider any metastasis to a distant site to be stage 4C.

Treatment

Stage 4 oral cancer treatment may involve surgery followed by radiation or chemoradiation.

Other treatment options at this stage include:

If there are no curative options, a doctor may recommend radiation as palliative treatment.

How quickly oral cancer progresses varies from person to person. It can depend on:

Most oral cavity cancers are oral squamous cell carcinomas (OSCC), which can be quite aggressive. In a 2017 study, the median time for OSCC to metastasize after treating the primary tumor was 12 months, with times ranging from 3–49 months.

Survival rates for oral cancer vary depending on the stage at diagnosis, particularly how much cancer has spread. According to the American Cancer Society, 5-year survival rates for various oral cancers are as follows:

Localized
(confined to mouth)
Regional
(spread to lymph nodes)
Distant
(metastasized)
Lip94%63%38%
Tongue84%70%41%
Floor of mouth73%42%23%

The 5-year relative survival rate is the percentage of people with oral cancer who are still alive 5 years after their diagnosis compared to people without oral cancer.

Doctors detect 26.9% of oral cancers at the localized stage. Cancer has already metastasized in about 15% of oral cancer diagnoses.

Doctors use different tests to stage oral cancer and determine the extent of its spread. Options include:

Doctors determine the stage of oral cancer by considering its size and how far it has spread. Symptoms may not be immediately apparent, but oral cancer can progress quickly, so timely diagnosis and treatment are essential.

Surgery to remove the tumor is typically the primary treatment in the early stages. In later stages, doctors may also recommend radiation, chemotherapy, immunotherapy, or targeted therapy.