Floor of the mouth cancer



Floor of the mouth cancer is cancer that starts as a growth of cells under the tongue.

Floor of the mouth cancer most often begins in the thin, flat cells that line the inside of the mouth, called squamous cells. When cancer starts in these cells it's called squamous cell carcinoma.

Floor of the mouth cancer causes changes in the look and feel of the tissue under the tongue. These changes may include a lump or a sore that doesn't heal.

Floor of the mouth cancer treatments include surgery, radiation therapy and chemotherapy.


Symptoms of floor of the mouth cancer can include:

  • Mouth pain.
  • Sores in the mouth that won't heal.
  • Trouble moving the tongue.
  • Loose teeth.
  • Pain with swallowing.
  • Weight loss.
  • Ear pain.
  • Swelling in the neck that may hurt.
  • White patches in the mouth that won't go away.

When to see a doctor

Make an appointment with a doctor or other health care professional if you have any symptoms that worry you.


Floor of the mouth cancer happens when cells under the tongue develop changes in their DNA. A cell's DNA holds the instructions that tell a cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions also tell the cells to die at a set time. In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to make many more cells quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells.

The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread to other parts of the body. When cancer spreads, it's called metastatic cancer.

Risk factors

The most common factors that can increase the risk of floor of the mouth cancer include:

  • Using tobacco. All forms of tobacco increase the risk of floor of the mouth cancer. This includes cigarettes, cigars, pipes, chewing tobacco and snuff.
  • Drinking alcohol. Frequent and heavy drinking increases the risk of floor of the mouth cancer. Using alcohol and tobacco together increases the risk even more.
  • Being exposed to human papillomavirus. Human papillomavirus, also called HPV, is a common virus that's passed through sexual contact. For most people, it causes no problems and goes away on its own. For others, it causes changes in cells that can lead to many types of cancer.
  • Having a weak immune system. If the body's germ-fighting immune system is weakened by medicines or illness, there might be a higher risk of floor of the mouth cancer. People with a weakened immune system include those taking medicines to control the immune system, such as after an organ transplant. Certain medical conditions, such as infection with HIV, also can weaken the immune system.


To lower the risk of floor of the mouth cancer:

  • Don't use tobacco. If you don't use tobacco, don't start. If you currently use tobacco of any kind, talk with a health care professional about strategies to help you quit.
  • Limit alcohol intake. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
  • Ask about the HPV vaccine. Receiving a vaccination to prevent HPV infection may reduce your risk of HPV-related cancers. Ask your doctor or other health care professional whether an HPV vaccine is right for you.
  • Have regular health and dental exams. During your appointments, your dentist, doctor or other health care professional can check your mouth for signs of cancer and precancerous changes.


Tests and procedures used to diagnose floor of the mouth cancer may include:

  • Examining your mouth and neck. In a physical exam, a health care professional looks at your mouth and neck. The health professional checks for any lumps in the mouth and on the neck. Your neck also is checked for swollen lymph nodes. When floor of the mouth cancer spreads, it often goes to the lymph nodes first.
  • Removing a tissue sample for testing. Called a biopsy, this test involves taking a sample of cells from the mouth. There are different types of biopsy procedures. A sample may be collected by cutting out a piece of the suspicious tissue or the entire area. Another type of biopsy uses a thin needle that's inserted directly into the suspicious area to collect a sample of cells. The samples are sent to a lab to be tested. In the lab, tests can show whether the cells are cancerous.
  • Imaging tests. Imaging tests capture pictures of the inside of the body. The pictures can show the size and location of a tumor. Imaging tests used for floor of the mouth cancer may include X-rays and scans such as CT, MRI and positron emission tomography, also called PET.


Treatment for floor of the mouth cancer often begins with surgery. Surgery might be followed by radiation, chemotherapy or both.

Your health care team considers many factors when creating a treatment plan. These might include the cancer's location and how fast it's growing. The team also may look at whether the cancer has spread to other parts of your body and the results of tests on the cancer cells. Your care team also considers your age and your overall health.


Surgery is the most common treatment for floor of the mouth cancer. Operations used to treat floor of the mouth cancer include:

  • Surgery to remove the cancer. The surgeon removes the cancer and some of the healthy tissue around it. This ensures that all the cancer cells are removed. If the cancer grows to involve the jaw or tongue, the surgeon may remove parts of those structures. Sometimes surgery causes trouble with speaking and swallowing. Physical therapy and other rehabilitation services can help you cope with these changes.
  • Surgery to remove lymph nodes in the neck. When floor of the mouth cancer spreads, it often goes to the lymph nodes in the neck first. If there are signs that the cancer has spread to the lymph nodes, you might need surgery to remove some lymph nodes, called a neck dissection. Even if there are no signs of cancer in the lymph nodes, you may have some of them removed as a precaution. Removing the lymph nodes removes the cancer and helps your health care team decide if you need other treatments.

    To get to the lymph nodes, the surgeon makes a cut in the neck and removes the lymph nodes through the opening. The lymph nodes are tested for cancer. If cancer is found in the lymph nodes, treatments might be needed to kill any cancer cells that are left. Options might include radiation or radiation combined with chemotherapy.

    Sometimes it's possible to remove only a few lymph nodes for testing. This is called a sentinel node biopsy. It involves removing the lymph nodes to which cancer is most likely to spread. The lymph nodes are tested for cancer. If there's no cancer detected, it's likely that the cancer hasn't spread. Sentinel node biopsy isn't an option for everyone with floor of the mouth cancer. It's only used in certain situations.

  • Reconstructive surgery. Reconstructive surgery may be used for people who had parts of the face, jaw or neck taken out during surgery. Healthy bone or tissue may be taken from other parts of the body and used to fill gaps. This tissue can replace part of the lip, tongue, palate or jaw, face, throat, or skin. Reconstructive surgery is often done at the same time as surgery to remove the cancer.

Other floor of the mouth cancer treatments

Other forms of treatment may include:

  • Radiation therapy. Radiation therapy uses powerful energy beams to kill cancer cells. The energy can come from X-rays, protons or other sources. During radiation therapy, a machine directs beams of energy to specific points on the body to kill the cancer cells there.

    Radiation might be used after surgery to kill any cancer cells that remain. Sometimes radiation is done at the same time as chemotherapy. If you can't have surgery or don't want surgery, radiation might be used instead.

  • Chemotherapy. Chemotherapy uses strong medicines to kill cancer cells. Chemotherapy may be used after surgery to kill any remaining cells. Sometimes chemotherapy is done at the same time as radiation therapy because it makes the radiation work better.
  • Targeted therapy. Targeted therapy uses medicines that attack specific chemicals in the cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die. Targeted therapy is used to treat floor of the mouth cancer that spreads to other parts of the body or comes back after treatment.
  • Immunotherapy. Immunotherapy is a treatment with medicine that helps your body's immune system kill cancer cells. Your immune system fights off diseases by attacking germs and other cells that shouldn't be in your body. Cancer cells survive by hiding from the immune system. Immunotherapy helps the immune system cells find and kill the cancer cells. Immunotherapy might be used when the cancer spreads to other parts of the body and other treatments haven't helped.
  • Photodynamic therapy. Photodynamic therapy uses a medicine that makes cancer cells sensitive to light. After giving the medicine, a health care professional shines high-intensity light on the cancer cells. The light activates the medicine and causes the cancer cells to die. Photodynamic therapy might be an option for a very small floor of the mouth cancer.

Treatment for advanced floor of the mouth cancer can affect your ability to speak and eat. Working with a skilled rehabilitation team can help you cope with changes that result from cancer treatment.

Coping and support

People facing a serious illness often say they feel worried about the future. With time, you'll find ways to cope with these and other feelings. Until then, you may find comfort in these strategies:

  • Ask questions about floor of the mouth cancer. Write down questions you have about your cancer. Ask these questions at your next appointment. Also ask your health care team for reliable sources where you can get more information.

    Knowing more about your cancer and your treatment options may make you more comfortable when you make decisions about your care.

  • Stay connected to friends and family. Your cancer diagnosis can be stressful for friends and family too. Try to keep them involved in your life.

    Your friends and family will likely ask if there's anything they can do to help you. Think of tasks you might like help with. Examples include caring for your home if you have to stay in the hospital or just listening when you want to talk.

    You may find comfort in the support of a caring group of your friends and family.

  • Find someone to talk with. Find someone you can talk with who has experience helping people facing a life-threatening illness. Ask your health care team to suggest a counselor or medical social worker you can talk with. For support groups, contact the American Cancer Society or ask your health care team about local or online groups.

Preparing for an appointment

Make an appointment with a doctor or other health care professional if you have any symptoms that worry you.

If you might have mouth cancer, you may be referred to a doctor who specializes in diseases of the face, mouth, teeth, jaws, salivary glands and neck. This doctor is called an oral and maxillofacial surgeon. You also may be referred to a doctor who specializes in diseases that affect the ears, nose and throat. This doctor is called an ENT specialist or otolaryngologist.

Because appointments can be brief, it's a good idea to prepare. Here's some information to help you get ready.

What you can do

  • Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet before a test.
  • Write down symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Write down key personal information, including major stresses or recent life changes.
  • Make a list of all medicines, vitamins or supplements you're taking and the doses.
  • Take a family member or friend along. Sometimes it can be hard to remember all the information provided during an appointment. Someone who goes with you may remember something that you missed or forgot.
  • Write down questions to ask your health care team.

Your time with your health care team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For floor of the mouth cancer, some basic questions to ask include:

  • What is the stage of my cancer?
  • What other tests do I need?
  • What are my treatment options?
  • Is there one treatment that's best for my type and stage of cancer?
  • What are the potential side effects of each treatment?
  • Should I seek a second opinion? Can you give me the names of specialists you recommend?
  • Am I eligible for clinical trials?
  • Are there brochures or other printed material that I can take with me? What websites do you recommend?
  • What will determine whether I should plan for a follow-up visit?

What to expect from your doctor

Be prepared to answer questions about your symptoms and your health, such as:

  • When did you begin experiencing symptoms?
  • Have your symptoms been continuous or occasional?
  • How severe are your symptoms?
  • What, if anything, seems to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?