7 Warning Signs of Floor of the Mouth Cancer You Should Never Ignore

Floor of the mouth cancer is a type of oral cancer that develops in the tissues located under the tongue, in the horseshoe-shaped area at the bottom of the oral cavity. This condition, sometimes referred to as under tongue cancer, accounts for approximately 10-15% of all oral cancers. Early detection is crucial for successful treatment outcomes, which is why recognizing the warning signs and symptoms is essential for anyone concerned about their oral health.

The floor of the mouth contains important structures including salivary glands, blood vessels, nerves, and muscles. When cancer develops in this area, it can affect eating, speaking, and swallowing. Most cases of floor of the mouth cancer are squamous cell carcinomas, which begin in the thin, flat cells lining the inside of the mouth.

Understanding the symptoms of this cancer can help you seek medical attention early, when treatment is most effective. Here are the key warning signs you should be aware of:

1. Persistent Sore or Ulcer Under the Tongue

One of the earliest and most common signs of floor of the mouth cancer is a sore or ulcer that doesn’t heal within two to three weeks. Unlike canker sores or minor mouth injuries that typically heal on their own, cancerous lesions persist and may gradually increase in size.

These sores may appear as:

• White or red patches on the floor of the mouth
• Open wounds that bleed easily when touched
• Rough, crusty, or eroded areas
• Painless lesions in early stages, though they may become painful as they progress

If you notice any persistent sore or unusual area under your tongue that hasn’t healed after a few weeks, it’s important to have it examined by a healthcare professional or dentist immediately.

2. Red or White Patches (Erythroplakia or Leukoplakia)

Abnormal colored patches on the floor of the mouth are significant warning signs that should never be ignored. These patches can appear in two main forms:

Leukoplakia: White patches that cannot be scraped off and don’t have another clear cause. While not all leukoplakia is cancerous, some cases can be precancerous or indicate early-stage cancer.

Erythroplakia: Red, velvety patches that are more concerning than white patches, as they have a higher likelihood of being cancerous or precancerous. These red patches may appear flat or slightly raised.

Erythroleukoplakia: Mixed red and white patches that combine features of both conditions.

Any discolored patch that persists for more than two weeks should be evaluated by a medical professional. A biopsy may be necessary to determine whether the tissue is benign, precancerous, or malignant.

3. Pain or Numbness in the Mouth or Tongue

As floor of the mouth cancer progresses, it often causes discomfort or altered sensations in the affected area. Patients may experience:

• Persistent pain in the floor of the mouth or under the tongue
• Tenderness when touching the area
• Numbness or tingling sensation in the tongue or lower lip
• Burning sensation in the mouth
• Pain that radiates to the ear on the affected side

Early-stage cancers may be painless, which is why many people delay seeking treatment. However, as the tumor grows and invades deeper tissues or affects nearby nerves, pain typically becomes more pronounced. Any unexplained, persistent pain or numbness in the mouth should be evaluated promptly.

4. Difficulty Moving the Tongue or Swallowing

The floor of the mouth is intimately connected with tongue movement and swallowing function. As cancer grows in this area, it can interfere with these essential activities, causing:

Tongue movement problems:

• Reduced range of motion when moving the tongue
• Stiffness or feeling that the tongue is “tied down”
• Difficulty protruding the tongue forward or moving it side to side
• Sensation that something is holding the tongue in place

Swallowing difficulties (dysphagia):

• Painful swallowing (odynophagia)
• Feeling that food is getting stuck in the throat
• Difficulty initiating the swallow reflex
• Choking or coughing while eating or drinking

These symptoms occur because the tumor can infiltrate the muscles of the tongue and floor of the mouth, restrict tongue mobility, or block the passage of food and liquids. If you experience progressive difficulty with tongue movement or swallowing, seek medical evaluation immediately.

5. Lump or Mass Under the Tongue or in the Neck

A palpable lump or thickening is a significant physical sign of floor of the mouth cancer. These masses can appear in different locations:

In the mouth: You or your dentist may feel a firm lump or thickened area on the floor of the mouth, under the tongue, or along the side of the tongue. The mass may be visible or only detectable by touch. It might feel hard, fixed in place, and irregular in shape.

In the neck: As floor of the mouth cancer progresses, it can spread to lymph nodes in the neck, causing swollen, firm lumps below the jaw or along the sides of the neck. These enlarged lymph nodes may be:

• Painless or tender to touch
• Fixed in place rather than mobile
• Hard or rubbery in texture
• Single or multiple nodes

Any new, persistent lump in the mouth or neck that lasts more than two weeks warrants immediate medical attention. While not all lumps are cancerous, early evaluation is essential for proper diagnosis.

6. Persistent Bad Breath or Unusual Taste

Floor of the mouth cancer can cause noticeable changes in oral hygiene and taste perception that don’t improve with regular brushing and mouthwash. These symptoms include:

Chronic bad breath (halitosis): Cancer tissue can break down and become infected, producing a persistent foul odor that doesn’t respond to normal oral hygiene practices. The odor may be particularly noticeable to others or cause embarrassment in social situations.

Unusual taste sensations:

• Persistent metallic or bitter taste in the mouth
• Loss of taste sensation in certain areas of the tongue
• Altered ability to detect sweet, salty, sour, or bitter flavors
• Unpleasant taste that doesn’t go away after eating or drinking

These symptoms occur due to tumor tissue breakdown, secondary infections, or cancer affecting the taste buds and sensory nerves. While bad breath and taste changes can have many causes, when combined with other symptoms on this list, they warrant professional evaluation.

7. Speech Changes and Loose Teeth

As floor of the mouth cancer advances, it can affect your ability to speak clearly and may even impact dental health. These late-stage symptoms include:

Speech difficulties:

• Slurred or unclear pronunciation
• Difficulty forming certain sounds, particularly those requiring tongue movement against the floor of the mouth
• Voice changes or hoarseness
• Feeling that speech requires more effort than normal

Dental problems:

• Teeth becoming loose without explanation, particularly lower front teeth
• Changes in how dentures fit
• Difficulty keeping dentures in place
• Unexplained tooth pain or sensitivity
• Swelling or changes in the jaw bone

These symptoms typically indicate that the cancer has grown large enough to affect surrounding structures or has invaded the jaw bone. The tumor can disrupt the attachment of teeth to the bone or cause bone destruction, leading to tooth mobility. Speech problems arise when the tumor restricts tongue movement or causes pain that makes normal articulation difficult.

Main Causes and Risk Factors

Understanding the causes and risk factors of floor of the mouth cancer can help with prevention and early detection. While the exact cause isn’t always clear, several factors significantly increase the risk:

Tobacco Use: Smoking cigarettes, cigars, or pipes, as well as using smokeless tobacco (chewing tobacco or snuff), is the single most significant risk factor. Tobacco contains numerous carcinogens that directly damage cells in the mouth. The risk increases with the duration and amount of tobacco use.

Alcohol Consumption: Heavy alcohol use significantly increases the risk of oral cancers. Alcohol acts as an irritant to the cells in the mouth and can make them more vulnerable to cancer-causing substances. When combined with tobacco use, the risk multiplies exponentially.

Human Papillomavirus (HPV): Certain strains of HPV, particularly HPV-16, have been linked to oral cancers. While HPV-related oral cancers more commonly affect the back of the throat and tonsils, they can also occur in the floor of the mouth.

Age and Gender: Floor of the mouth cancer is more common in people over 40 years old, with risk increasing with age. Men are affected more frequently than women, though this gap is narrowing as smoking rates equalize.

Poor Oral Hygiene: Chronic irritation from poor dental hygiene, ill-fitting dentures, or rough tooth edges may contribute to cancer development over time.

Sun Exposure: While more relevant to lip cancer, excessive sun exposure without protection can increase overall oral cancer risk.

Weakened Immune System: Conditions or medications that suppress the immune system can increase cancer risk, including HIV/AIDS and immunosuppressive drugs taken after organ transplants.

Previous Cancer History: People who have had one oral cancer are at higher risk of developing a second cancer in the mouth, throat, or nearby areas.

Nutritional Deficiencies: Diets low in fruits and vegetables may increase risk, as these foods contain protective antioxidants and vitamins.

Prevention Strategies

While not all cases of floor of the mouth cancer can be prevented, you can significantly reduce your risk by adopting healthy lifestyle habits and practicing good oral care:

Eliminate Tobacco Use: If you smoke or use tobacco products, quitting is the single most important step you can take. Numerous resources are available to help, including counseling, support groups, and smoking cessation programs. Speak with your healthcare provider about strategies that might work for you.

Limit Alcohol Consumption: If you drink alcohol, do so in moderation. The recommended limits are up to one drink per day for women and up to two drinks per day for men. Avoiding alcohol entirely further reduces risk, especially if combined with tobacco cessation.

Maintain Good Oral Hygiene:

• Brush your teeth at least twice daily with fluoride toothpaste
• Floss daily to remove plaque between teeth
• Use an antiseptic mouthwash to reduce bacteria
• Replace your toothbrush every three to four months

Regular Dental Check-ups: Visit your dentist at least twice a year for professional cleanings and oral examinations. Dentists are often the first to detect early signs of oral cancer during routine check-ups. Inform your dentist of any changes or concerns you’ve noticed.

Eat a Healthy Diet: Consume a balanced diet rich in fruits and vegetables, which contain vitamins, minerals, and antioxidants that may help protect against cancer. Limit processed foods and red meat consumption.

HPV Vaccination: The HPV vaccine can protect against strains of the virus linked to oral cancers. While primarily recommended for preteens, it can be given to adults up to age 45.

Protect Your Lips: Use lip balm with SPF protection when outdoors to reduce sun exposure damage.

Self-Examination: Perform monthly oral self-exams to check for any changes in your mouth:

• Look in the mirror and examine all visible areas of your mouth
• Use your fingers to feel for lumps or thickened areas
• Check the floor of your mouth by lifting your tongue
• Look for any white, red, or dark patches
• Note any sores that don’t heal

Address Chronic Irritation: If you have ill-fitting dentures, broken teeth, or rough dental work that constantly irritates your mouth, have these issues corrected promptly.

Frequently Asked Questions

What does floor of the mouth cancer look like in early stages?

In early stages, floor of the mouth cancer may appear as a small white or red patch, a persistent sore that doesn’t heal, or a slightly thickened area of tissue under the tongue. It may be painless initially, which is why regular dental check-ups are important for early detection.

How quickly does floor of the mouth cancer develop?

The development rate varies significantly between individuals. Some cancers may grow slowly over months or years, while others can progress more rapidly. This is why any persistent changes lasting more than two to three weeks should be evaluated by a healthcare professional.

Can floor of the mouth cancer be detected early?

Yes, floor of the mouth cancer can often be detected in early stages through regular dental examinations and self-checks. Dentists and doctors are trained to recognize suspicious lesions and can perform biopsies if needed. Early detection significantly improves treatment outcomes.

Is floor of the mouth cancer the same as tongue cancer?

While related and both classified as oral cancers, they are distinct. Floor of the mouth cancer develops in the horseshoe-shaped area under the tongue, while tongue cancer originates in the tongue tissue itself. However, cancer can spread from one area to the other, and they share similar risk factors and symptoms.

Who is most at risk for developing floor of the mouth cancer?

People at highest risk include those who use tobacco products, consume alcohol heavily (especially in combination with tobacco), are over 40 years old, male, have HPV infection, or have a history of oral cancer. However, anyone can develop this cancer, so awareness of symptoms is important for everyone.

When should I see a doctor about mouth symptoms?

You should see a doctor or dentist if you notice any persistent changes in your mouth that last more than two to three weeks, including sores that don’t heal, white or red patches, lumps, numbness, difficulty swallowing, or unexplained pain. Don’t wait for symptoms to worsen—early evaluation is key.

Can floor of the mouth cancer spread to other parts of the body?

Yes, like other cancers, floor of the mouth cancer can spread (metastasize) to other areas. It commonly spreads first to nearby lymph nodes in the neck, and in advanced cases, may spread to more distant organs. This is another reason why early detection and treatment are so important.

Are there screening tests for floor of the mouth cancer?

There is no routine screening test for the general population, but your dentist or doctor can perform an oral examination to check for suspicious areas. If you have high risk factors, your healthcare provider may recommend more frequent examinations. Some practices use special lights or dyes to help identify abnormal tissue.

What should I do if I notice symptoms of floor of the mouth cancer?

If you notice any of the warning signs described in this article, schedule an appointment with your dentist or primary care physician as soon as possible. Don’t adopt a “wait and see” approach. They can examine the area, and if necessary, refer you to an oral surgeon or oncologist for further evaluation and biopsy.

References:

• American Cancer Society – Oral Cavity and Oropharyngeal Cancer
• National Institute of Dental and Craniofacial Research – Oral Cancer
• Mayo Clinic – Mouth Cancer
• National Cancer Institute – Lip and Oral Cavity Cancer Treatment
• NHS – Mouth Cancer