Understanding Cancer on the Lip

Your lips help you eat, talk, and smile. Since you can see them every time you look in the mirror, you’ll likely notice if something new appears, like a spot or sore that doesn’t go away. So, if a change of some kind shows up on your lip, you might wonder what it is and if you should have it checked.

What is cancer on the lip?

Different types of cancers can be found on a person’s lips. Some start on the inside of the lips, while others start on the outer skin of the lips.

• When cancer is found on the inside of the lips, it’s most likely an oral cavity cancer, a type of head and neck cancer.
• When cancer develops on the outer skin of the lips, it’s most often a type of skin cancer like squamous cell carcinoma.

“There’s a boundary on the lip that separates an oral cavity cancer versus a skin cancer.  The wet part of the lip, which is the inner part, we consider the oral cavity. Once you get to the dry part of the lip, that’s the lip we consider skin,” said Glenn J. Hanna, MD, an American Society of Clinical Oncology (ASCO) expert and Associate Professor of Medicine at Harvard Medical School.

How common is cancer on the lip?

Overall, cancer on the lip is rare. Specific statistics depend on the actual type of cancer that’s diagnosed. But despite being uncommon and treatable, cancers that affect the lips can still have a big impact on daily life.

“Even though they might seem small and minor, lip cancers are in a really important area for function and appearance,” said Dr. Hanna.

What are the symptoms of cancer on the lip?

The most common symptom of cancer found on the lip is a sore or spot that doesn’t go away within a few weeks. These areas are particularly concerning if they are:

• Discolored
• Showing reddish or whitish changes
• Raised or creating a divot
• Bleeding
• Causing pain, numbness, or tingling around the mouth

The main difference between cancer and noncancerous (benign) conditions on the lip is that cancer doesn’t go away. Other conditions such as cold sores or canker sores typically blister, break, crust over, and heal. But spots and sores caused by cancer last longer, don’t heal, or start to heal but get worse again. They can also grow bigger over time.

Some types of cancer that develop on the lips can also cause painless swelling in the lymph nodes at the front of the neck. If you notice a lump or swelling in this area and a sore or spot on your lip, contact your doctor right away.

What causes cancer on the lip?

The causes of cancer on the lip depend on the type of cancer that’s found. Not all cancers on the lip have a clear cause, but some things are known to increase risk.  

Some oral cavity cancers that start on the inside of the lip can be caused by tobacco and alcohol use, infection with HPV (human papillomavirus), or genetic changes inherited from parents.

For skin cancer that starts on the lip, the most common cause is sun exposure, especially for people with fair skin. But like oral cavity cancers, these skin cancers can also be linked to using tobacco products and alcohol.

People sometimes ask if cosmetic procedures like lip fillers might cause cancer. So far, no studies have shown that lip fillers cause cancer or increase the risk for cancer on the lip.

What are the tests for cancer on the lip?

If you have a spot on your lip that doesn’t go away, the first step is a physical exam. Your doctor will examine the sore and the area around it. They will try to determine how deep it might be and whether other areas of the body, such as the neck or inside the mouth, might be affected. If further tests are needed, they might include:

• Biopsy: During a biopsy, a surgeon cuts out a piece of the abnormal tissue. The tissue is then tested in a lab to look for cancer cells.
• Imaging tests: Depending on the type of cancer suspected, your doctor might order a CT, MRI, or PET scan.

How are cancers on the lip treated?

Cancers found on the lip are usually treated with surgery. The doctor performing the surgery will try to remove all the cancer on the lip and determine whether it has spread to nearby lymph nodes. This will help them decide whether further treatment is needed. Additional treatments might include radiation therapy, chemotherapy, or immunotherapy.

Before surgery, your doctor might talk with you about lip reconstruction. Whether or not this is needed depends on the type and extent of the cancer, where the cancer is, and how much of the lip needs to be removed.

“If you remove a large piece of the lip, you may have to move tissue to restore the function and the bulk of the lip. And if it scars too much, it can cause a tightening so the mouth doesn’t open as wide. An experienced surgeon, sometimes a plastic surgeon or reconstructive head and neck surgeon, should definitely be involved,” said Dr. Hanna.

Common questions about cancer on the lip

If you’re concerned about your risk of cancer on the lip or about a spot or sore on your lip, talk to your doctor. You can try sending a picture to your care team to ask if a sore on your lip looks concerning, Dr. Hanna suggested. Or you can ask for an appointment.

Questions to ask your care team include:

• How can I tell if a sore on my lip might be cancer?
• Based on my history, do you think I’m at risk for cancer on the lip?
• Is there anything I can do to lower my risk of getting cancer on my lip?
• Do you recommend any type of testing that will check for cancer?

Dr. Hanna is a member of ASCO’s Cancer Communications Committee.