Overview: What is Cancer?
Cancer is the uncontrollable growth of abnormal cells that cause damage to surrounding tissues in the body. These cancerous cells spread over time through the lymph and blood systems.
There are two different categories of cancer, including:
- Squamous Cell Carcinoma — this type of cancer begins in the skin or tissues
- Sarcoma — this type of cancer begins in the bones, muscles, cartilage, fat, or blood vessels
What is Oral Cancer?
Oral cancer, also called as mouth cancer, begins with the development of abnormal carcinoma cells. Over time, growths (sores) appear in the mouth and will not disappear on their own.
In the early stages of oral cancer, the sore commonly appears as a painless white patch. Over time, a red patch or patches will form (ulcer). The ulcer will continue to grow, thicken, and typically becomes painful. The earlier the cancer is detected, the more effective treatment will be.
If you do not receive oral cancer treatment early, the disease can be deadly.
Types of Oral and Oropharyngeal Cancers
There are many types of oral and oropharyngeal cancers (head and neck cancers).
The oropharynx includes the side of the throat, back wall of the throat, the soft palate, back of the tongue, and tonsils. Head and neck cancers can also develop in the nasal cavity, salivary glands, thyroid gland, and larynx.
Oral cancer sores (oral lesions) can appear in different areas of the oral cavity. This includes:
- Mouth floor, which is the area under the tongue
- Roof of the mouth, also called the "palate"
- Throat (pharyngeal cancer)
According to the National Institutes of Health (NIH), oral cancer is the sixth most common type of cancer in the world. The disease affects 275,000 people each year. Most of the cases, however, occur in developing nations.
In the U.S. alone, about 92,000 people are living with a type of oral cancer. Doctors also diagnose approximately 53,000 new cases each year. The survival rate of oral cavity cancer depends on how early it is detected.
8,000 Americans die of oral cancer each year. However, early detection is necessary to prevent the spread of oral cancer. Treatment will also be more effective.
What are Oral Lesions?
Oral lesions are ulcers or patches that form in the oral cavity, particularly on the mucous membrane. More specifically, lesions can appear on the tongue, cheeks, gums, lips, palate, and other surrounding areas in the mouth.
Lesions are a common sign of oral cancer, although they are not always cancerous.
A general dentist examines a potentially cancerous lesion by looking for abnormal characteristics. These include:
- Size, Shape, and Color — if the lesion’s borders, colors, and architecture change after detection.
- Length of Time — if a lesion has been present for more than two to three weeks, a more serious underlying condition, such as cancer, is possible.
- Pain and Discomfort — if the lesion causes pain and discomfort frequently and for long periods of time.
- Lymph Nodes — cancerous lymph nodes are typically large and firm with no mobility.
- Patient’s Symptoms — weight loss, frail appearance, and fatigue
- Genetics and History — some diagnoses of oral cancer are not influenced by environmental factors. More specifically, if a patient has a family history of oral cancer, they are more at risk of developing cancerous lesions.
Causes & Risk Factors of Mouth Cancer
The leading cause of oral cancer is the use of smokeless and smokable tobacco products. This includes cigarettes, chewing tobacco, cigars, and pipe smoking.
“About 53,000 new cases of oral cancer are diagnosed in the U.S. every year. 8 out of 10 patients are smokers.”
Other less common risk factors of oral or mouth cancer include:
- Tobacco products (cigarettes, pipes, and cigars)
- Smokeless tobacco (chewing tobacco)
- Genetics or family history of oral cancer
- Alcohol use and abuse
- Excessive, long-term exposure to the sun
- Human papillomavirus (HPV)
- Chronic, untreated dental diseases and infections
Symptoms of Oral Cancer
Most oral cancers are asymptomatic, which means a patient won’t show signs early on. Although, as the lesion grows, common signs of oral cancer include:
- Swelling of the mouth
- Sores or lesions on the lips, inside the mouth, or neck
- Development of lumps or bumps on the lips, gums, or areas inside the mouth
- White spots or a combination of white and red “speckles” in the mouth
- Unexplained numbness, pain, or tenderness in the oral cavity. This includes the face, gums, tongue, lips, or neck
- Jaw swelling that makes your dentures loose or uncomfortable
- Frequent earaches and pain
- Bleeding in the mouth without a known cause
- Pain or difficulty chewing or swallowing
- Uncontrollable weight loss
- Chronic sore throat or pain in the throat
Diagnosis and Treatment of Oral Cancer
General dentists have the experience and expertise to detect and diagnose oral cancers early on.
This is because 80 percent of dental practitioners are general dentists, which means they spend the most time treating patients. There are two steps in determining if a patient has oral cancer, including:
During a physical exam for detecting oral cancers, a dentist, oral surgeon, or doctor examines the mouth to find abnormalities, such as white patches (leukoplakia) and mouth sores (lesions or ulcers).
Next, the practitioner takes a biopsy of the abnormal growth(s) if they find anything suspicious. A doctor uses a scalpel or laser to remove a sample of cells from the lesion and surrounding tissues. Then they send it to a laboratory for testing to determine if it is cancerous.
A biopsy and pathologic evaluation are always required to properly diagnose cancer. A diagnosis of cancer is only made after a biopsy confirms the presence of invasive cells.
Biopsies are typically necessary when a lesion is raised and has asymmetric borders. The most difficult lesions to treat are “precancerous,” which means they have atypical and dysmorphic cellular characteristics.
There are a few different types of biopsies depending on where the growth or white patches are located:
- Oral Brush Biopsy — a diagnostic test that detects early oral cancer (precancer) by using a small brush to remove a tissue sample from the mouth. The sample is sent to a laboratory for further testing using computer-assisted analyses.
- Needle Aspiration Biopsy — a fine needle is used to remove cells, tissues, or fluid samples. There may be some minor pain or discomfort for a few days following the procedure.
- Incisional Biopsy — a surgical incision is made through the skin to remove a sample of tissues or cells. There may be some minor pain or discomfort for a few days following the procedure.
- Excisional Biopsy — the entire lesion is removed during an excisional biopsy, including 2mm of normal tissue around the ulcer. This treatment removes lesions that are already cancerous.
- Speculoscopy — a special blue light examines the abnormalities to help predict if the lesion is cancerous, precancerous, or noncancerous.
Cancer Stage Determination
After a doctor diagnoses mouth cancer, they determine the stage of the patient’s cancer.
First, they inspect the patient’s throat using a small camera to determine if the signs of cancer spread beyond the mouth. Image tests, such as X-rays, CT scans, and MRI’s may also be used.
Mouth and oral cancers consist of four stages, including:
- I — the cancerous tumor is smaller than 2 cm across and is only found in the oral cavity.
- II — the cancerous tumor is between 2 cm and 4 cm across and is only found in the oral cavity.
- III — the cancerous tumor is larger than 4 cm across and is only found in the oral cavity.
- IV — the cancerous tumor may be any size. Although, it is stage four when cancer spreads beyond the oral cavity to the neck or head.
Cancer Treatment Options
Depending on the stage of oral cancer and the location of the tumor or lesion, a patient will undergo a series of treatments.
This may include surgery, radiation, chemotherapy, or a combination of the three. During oral cancer treatment, your dentist will work with an oral surgeon and an oncologist to coordinate your cancer treatment. First, an oral and maxillofacial surgeon removes the cancerous oral tumor. Then a patient undergoes radiation and chemotherapy (if necessary).
There are three surgical treatment options available for oral cancer, including:
Small oral cancers, such as Stage I tumors, are typically removed through minor surgery.
An oral surgeon will remove the cancerous cells along with healthy tissues surrounding the area to ensure the cancer is removed completely. However, larger tumors may require partial removal of the jawbone or tongue depending on the location and severity.
Neck Cancer Removal (Stage IV)
Large oral cancers (stage IV) commonly spread to the lymph nodes of the neck.
The surgeon will remove the cancerous cells, lymph nodes, and surrounding neck tissues to ensure the cancer is completely removed.
Mouth Reconstruction (if necessary)
Oral cancer removal is an invasive surgical procedure.
Oral and maxillofacial surgeons may recommend skin, muscle, or bone grafts from other parts of a patient’s body to reconstruct the mouth after surgery. Many times, especially for Stage IV patients, dental implants are used to replace damaged natural teeth.
Radiation is a common treatment for all types of cancers.
This type of therapy uses external beam radiation, x-rays, and protons to kill cancer cells. For oral cancer patients, surgery comes before radiation. In early cases, though, you will undergo radiation before surgery. For more severe cases, surgery, radiation, and chemotherapy are all necessary.
Chemotherapy is the most common treatment that uses chemicals to kill cancer cells.
In many cases, radiation and chemotherapy are often combined to increase the effectiveness of both treatments. This combination is usually used when you have advanced cancer.
Common side effects of chemotherapy include hair loss, weight loss, vomiting, and nausea. However, chemo side effects are different for each person.