Lip and oral cavity cancer is a disease in which abnormal cells grow uncontrollably in the lips or mouth. This type of cancer often begins in the flat cells that line the inside of the lips and oral cavity, and while it can be life-threatening if not found early, many cases can be successfully treated when detected in their early stages.
What Is Lip and Oral Cavity Cancer?
The oral cavity refers to your mouth and includes several different areas where this cancer can develop. These areas include the front two thirds of the tongue, the gums, the lining of the inside of the cheeks, the floor of the mouth under the tongue, the hard palate which forms the roof of the mouth, and the small area behind the wisdom teeth called the retromolar trigone. The lips themselves are also part of this system and can develop cancer on either the upper or lower lip, though the lower lip is more commonly affected.[1]
Most lip and oral cavity cancers start in squamous cells, which are the thin, flat cells that line the inside of the lips and oral cavity. When cancer develops in these cells, it is called squamous cell carcinoma. As the cancer grows, these abnormal cells may spread into deeper tissue. In many cases, squamous cell carcinoma develops in areas of leukoplakia, which are white patches of cells that cannot be rubbed off.[1]
This type of cancer falls under the broader category of head and neck cancers. While it can develop anywhere within the oral cavity or on the lips, it is most commonly found on the lips themselves or the tongue. Cancer on the lower lip tends to be more frequent than on the upper lip, with lower lip lesions making up a significant portion of all lip cancer cases.[12]
How Common Is Lip and Oral Cavity Cancer?
Lip cancer is actually the most common type of oral cancer, though it makes up less than one percent of all cancer diagnoses in the United States. Only about one in every thousand people in the U.S. will be diagnosed with lip cancer at some point in their lives. When looking at all oral cavity cancers together, approximately eleven people in every 100,000 will develop this disease during their lifetime.[3][12]
Each year in the United States, approximately 48,330 people receive a diagnosis of oral or pharyngeal cancer. Unfortunately, around 9,570 people are estimated to die from the disease annually. One concerning statistic is that 66 percent of Americans discover they have oral cancer only in its late stages, which makes treatment more challenging and reduces survival chances.[23]
The disease does not affect everyone equally. Men are diagnosed with lip and oral cavity cancer about 2.3 times more often than women. In fact, men are up to three times more likely to develop lip cancer specifically. The disease typically affects people age 60 and older, with the average age at diagnosis being 63 years old. However, more than 20 percent of cases occur in patients younger than 55, and there has been a steady increase in the number of patients under 50 years old being diagnosed in recent years.[3][7][12]
People who are white are more likely to develop oral cancer than people who are Black. Additionally, those with fair skin face a higher risk of lip cancer specifically. The five-year survival rate for people diagnosed with oral cavity cancer is approximately 63 percent, though this varies significantly depending on the stage at which the cancer is found.[3]
What Causes Lip and Oral Cavity Cancer?
Lip and oral cavity cancer develops when normal cells in the lips or mouth undergo certain changes in their DNA that cause them to grow and divide uncontrollably. Squamous cells, which normally form a protective lining in the mouth, become cancerous when errors occur in their genetic material. These abnormal cells begin to multiply and accumulate, eventually forming tumors or lesions that can spread to other parts of the body.[3]
Scientists have not identified one single cause that explains why these DNA changes happen. However, they have discovered several risk factors that increase the likelihood of developing this type of cancer. It is important to understand that most risk factors do not directly cause cancer but instead increase the chance of DNA damage in cells that may eventually lead to cancer development.[1]
Before cancer fully develops, certain precancerous conditions may appear in the mouth. These include leukoplakia, which appears as white patches that cannot be scraped off; erythroplakia, which are red patches that may bleed when scraped; and erythroleukoplakia, which are patches that contain both red and white areas. Leukoplakia is the most common of these conditions and is defined by the World Health Organization as a white patch or plaque that cannot be characterized as any other disease. While leukoplakia is more common, erythroplakia is much more likely to be associated with abnormal cell changes or cancer.[9]
Risk Factors for Lip and Oral Cavity Cancer
A risk factor is anything that increases your chance of getting a disease. Some risk factors can be changed through lifestyle modifications, while others, such as age or genetics, cannot be controlled. Having one or more risk factors does not mean you will definitely develop cancer, and conversely, not having any known risk factors does not guarantee you will remain cancer-free.[1]
The most significant risk factor for lip and oral cavity cancer is tobacco use of any kind. This includes smoking cigarettes, cigars, or pipes, as well as using smokeless tobacco products such as chewing tobacco, dip, snuff, or water pipes like hookah. According to the Mouth Cancer Foundation, 90 percent of oral cancer patients are tobacco users. Tobacco use has been linked to cancer for decades and is also associated with other serious diseases including lung, throat, and stomach cancer, type 2 diabetes, and chronic obstructive pulmonary disease.[1][23]
Heavy alcohol consumption is another major risk factor. The Oral Health Foundation reports that one in three oral cancer cases is linked to excessive alcohol use. When tobacco and alcohol are used together, the risk increases dramatically. People who use both tobacco and drink heavily are at an even higher risk for mouth cancer than those who do only one or the other. In fact, the combined use of tobacco and excessive alcohol can increase the risk up to 30 times.[1][12][23]
Being exposed to natural sunlight or artificial sunlight from tanning beds over long periods of time increases the risk of developing cancer on the lips. This is especially true for cancer that develops on the outer lip. People who spend a lot of time outdoors without protecting their lips with sunblock or those who use tanning beds regularly face an elevated risk.[1][12]
Infection with human papillomavirus (HPV), which is a sexually transmitted infection, can also increase the risk of developing oral cavity cancer. While HPV is more commonly associated with oropharyngeal cancers (those affecting the back of the throat), it can account for a small portion of oral cavity cancers as well.[1][3]
Gender plays a role in risk, as men are much more likely to develop oral cancer than women. Age is another factor, with most people being diagnosed in their 50s and 60s, and those over 40 facing greater risk. Having a weakened immune system, whether from disease or medication, can also increase susceptibility to oral cancer.[3][12]
Other risk factors include having a family history of oral cancer, poor oral hygiene, and periodontal disease. A person’s risk for oral cancer goes up 2.5 times if they have periodontal disease, and it increases 60 times if they have six or more missing teeth. Additionally, people who use betel quid and gutka, which are substances chewed by people in Southeast Asia, South Asia, and other parts of the world, face increased risk.[3][23]
Recognizing the Symptoms
Lip and oral cavity cancer often starts as changes in the mouth that seem minor but do not go away. Early-stage lip cancer frequently looks like a mouth sore that refuses to heal. It is easy to mistake tumors for cold sores when they first appear, but the key difference is that cold sores typically heal on their own within about ten days, while cancer lesions persist and do not improve.[12]
The most common sign of lip cancer is a sore, blister, ulcer, or lump on the lip, particularly the bottom lip, that will not go away. This may appear as a flat or slightly raised colored spot on the lips. On people with light skin, these spots may appear white or reddish, while on people with dark skin they may look dark brown or gray.[4][12]
Within the mouth, common symptoms include sores that bleed easily and do not heal within two weeks. You may notice rough spots or crusty areas on your lips, gums, or inside of your mouth. Some people experience white, red, or mixed red and white patches in the mouth. These patches may appear on the gums, tongue, or lining of the mouth and do not heal. White patches, known as leukoplakia, are the most common and can sometimes become cancerous. Mixed red and white patches are more likely than white patches alone to develop into cancer.[3][4]
Other symptoms can include swelling, thickening, lumps, or bumps on the lips, gums, or other areas inside the mouth. Some people experience areas in their mouth that bleed for no obvious reason. Pain, numbness, or tingling on the lips or in the mouth may develop, though not everyone with oral cancer experiences pain in the early stages. Some people notice that their voice changes unexpectedly.[4][7]
As the disease progresses, additional symptoms may appear. These can include loose teeth or dentures that no longer fit properly in the mouth. You might experience difficulty or pain when chewing, swallowing, or moving your tongue or jaw. Some people develop a sore throat or have a feeling that something is caught in the back of the throat. Swelling of the jaw or swollen lymph nodes in the neck may occur. Ear pain without hearing loss can also be a symptom. In some cases, people experience dramatic weight loss.[4][7]
It is important to understand that many of these symptoms can be caused by conditions other than oral cancer. However, if you are experiencing any of these signs and they persist for more than two weeks, you should contact your doctor or dentist right away so they can diagnose and treat any problems as soon as possible. Early diagnosis is very important for effectively treating oral cancer.[7]
How Oral Cancer Affects Your Body
When cancer develops in the oral cavity, it begins in the squamous cells that form the lining of the mouth and lips. These cells normally provide a smooth, protective surface. When they become cancerous, they start to grow and multiply abnormally. Over time, if left untreated, these cancer cells accumulate and form tumors or abnormal areas of tissue.[3]
As the cancer grows, it may spread into deeper tissues beyond where it started. Cancer cells can spread into the muscles, bones, and other structures of the mouth and face. This local spread can interfere with normal functions like eating, speaking, and swallowing. The cancer may also affect the appearance of the face, particularly when it involves the lips or causes swelling.[1]
One of the most significant ways oral cancer spreads is through the lymphatic system. The main routes of lymph node drainage from the oral cavity go into what are called first station nodes, which include the submandibular and submental nodes located under the jaw. Sites close to the midline of the mouth often drain to lymph nodes on both sides of the neck. From there, cancer can spread to second station nodes including the parotid, jugular, and upper and lower posterior cervical nodes in the neck. When cancer reaches the lymph nodes, it becomes more difficult to treat.[9]
If cancer is not controlled, it can eventually spread beyond the head and neck region to other parts of the body through the bloodstream. This process is called metastasis. When oral cancer spreads to distant organs like the lungs or liver, it becomes much more challenging to treat and significantly affects survival rates. The five-year survival rate drops to 67 percent if the cancer spreads locally and to 40 percent if it spreads to distant parts of the body.[20]
The depth of invasion of the primary tumor is particularly important in determining how the cancer will behave. Tumors that grow deeper into tissues have a higher risk of spreading. A tumor depth of more than 5 millimeters significantly increases the risk of local recurrence. The depth of invasion holds such prognostic significance that it was included in tumor staging definitions in recent years.[9]
Prevention Strategies
While not all cases of lip and oral cavity cancer can be prevented, there are several important steps you can take to significantly reduce your risk. Many of the most effective prevention strategies involve making healthy lifestyle choices and maintaining good oral health practices.[20]
The single most important step you can take to prevent oral cancer is to avoid tobacco in all its forms. If you currently use tobacco products, quitting is one of the best decisions you can make for your oral health and overall well-being. This includes stopping smoking of cigarettes, cigars, or pipes, as well as discontinuing the use of smokeless tobacco products. Tobacco use is connected to the vast majority of oral cancer cases, so eliminating it dramatically reduces your risk.[20]
Moderating alcohol consumption is another crucial preventive measure. If you choose to drink alcohol, the American Cancer Society recommends no more than two drinks per day for men and one drink per day for women. Heavy alcohol use combined with tobacco use creates an especially dangerous situation, multiplying cancer risk far beyond what either substance would cause alone.[1][20]
Protecting your lips from sun exposure is important for preventing lip cancer specifically. You should limit your time in the sun and use sunscreen on your lips as well as your face. This includes avoiding excessive use of tanning beds, as artificial sunlight carries the same risks as natural sunlight. Using a lip balm with SPF protection when spending time outdoors can provide an extra layer of defense.[4][20]
Maintaining excellent oral hygiene can also help reduce your risk. Developing and maintaining good oral care habits is essential because periodontal disease significantly increases the risk of oral cancer. You should brush your teeth twice a day for two minutes or more, making sure to also brush your tongue every time you brush your teeth. Flossing daily, gently and close to your teeth, helps maintain healthy gums. Regular dental check-ups allow dentists to spot potential problems early.[23]
Making dietary changes can also contribute to prevention. A simple thing that everyone can do to decrease the risk of oral cancer is to increase fruit and vegetable consumption. A diet rich in fruits and vegetables provides important nutrients and antioxidants that may help protect cells from damage.[18][20]
Other lifestyle factors that can help reduce risk include reducing stress and exercising on a regular basis. These habits contribute to overall health and may help the body’s immune system function more effectively. Maintaining a healthy immune system is important because a weakened immune system can increase susceptibility to cancer.[18]
Beyond these personal measures, you should perform monthly self-examinations of your lips, gums, and cheeks. Look carefully for changes in appearance, such as red or white patches or lesions in your mouth, especially if they are painful or bleed. Check for lumps or enlarged lymph nodes in the sides of your neck or under your lower jaw. If you notice any concerning changes, call your doctor promptly.[4]
It is worth remembering that many people who develop oral cancer have done all the right things by avoiding tobacco and limiting alcohol consumption. This does not mean prevention efforts are not worthwhile—they dramatically reduce risk for most people. However, it does underscore the importance of remaining vigilant about oral health and seeking medical attention for any concerning symptoms, regardless of your lifestyle choices.[20]