What Are the Signs and Symptoms of Oral Cancer?

Oral cancer, commonly known as mouth cancer, is a type of head and neck cancer that originates in the squamous cells of the epithelial tissues that line the mouth and throat.

Oral cancer can affect the following:

• Lips
• Tongue
• Palate
• Gums
• Cheeks
• The floor of the mouth

Oral cancer usually begins as a small mouth sore and goes undiagnosed even after it becomes cancerous. Cancer can then spread to other parts of the body and cause death. 

Oral cancer can occasionally develop from precancerous cells in the mouth's lining, known as the mucosa.

1. Squamous cell carcinoma
   • Most frequently diagnosed oral cancer.
   • Responsible for more than 90 percent of all mouth malignancies. 
   • Abundant in the throat and mouth.
2. Verrucous carcinoma
   • Slow-growing malignancy accounts for approximately five percent of all oral malignancies.
3. Minor salivary gland carcinomas
   • Refer to various tumors that have arisen in the (minor) salivary glands.
4. Lymphoma
   • Originates in the lymph nodes behind the tongue.
5. Oral benign tumors
   • In certain circumstances, tumors that appear to be malignant are benign. 
   • The only way to know if the tumor is benign is to have it removed and tested.

The survival rates of oral cancer are higher if detected and treated in the early stages. Stages I and II have a survival rate of more than 80 percent; it is about 65 percent for stage III and 30 to 38 percent for stage IV.

Oral cancer kills an estimated 9,750 people yearly, not because it is incurable but because it is often diagnosed too late for treatment.

• According to the National Institutes of Health, the rate of oral cancer has increased in the past few years, and currently, the incidence rate is 10.5 per 100,000 adults.
• The risk of oral cancer increases with age, with higher rates between 60 and 70 years. 
• Men are more prone to developing oral cancer than women. Hispanic and Africans are at a higher risk of oral cancer than Americans.

Tobacco usage, such as smoking cigarettes or chewing tobacco, is considered the primary cause of oral cancer. Consumption of alcohol with tobacco further increases your risk.

Other causes of oral cancer include:

• Poor nutrition, especially a diet low in fruits and vegetables
• Infection with human papillomavirus
• Prolonged exposure to the sun

Risk factors for oral cancer include:

• Male gender (men are more prone to developing oral cancer than women)
• Age (oral cancer is often found in people older than 45 years)
• Long-term irritation caused by ill-fitting dentures
• History of head and neck cancer
• Radiation exposure to treat a prior cancer
• Immunosuppressive drugs
• History of oral lichen planus
• Chewing betel, a stimulant common in Asia
• Genetic disorders such as:
  • Fanconi anemia
  • Dyskeratosis congenita

Most oral malignancies are identified by evaluating the signs and symptoms, including tumors, ulcers, sores, and abnormal swellings. If your doctor suspects you have oral cancer, they may evaluate you and prescribe additional testing such as X-rays, laboratory tests, ultrasounds, scans, or a biopsy. A biopsy involves the removal of a small sample of tissue for examination under a microscope.

These tests help confirm an oral cancer diagnosis and identify whether the disease has spread. Oral cancer can potentially spread to the lymph nodes in the neck. Additionally, it can extend to the bone, liver, and lungs in rare cases.

Because oral cancer can be painless and present without symptoms at first, it is crucial to get frequent dental examinations with your doctor or dentist to detect early oral cancer. Identifying the early indications of mouth cancer is the most significant approach to enhance your chances of survival, as treatment is more successful in the early stages of oral cancer.

Doctors use the TNM staging method to determine the severity of the condition, and it helps with planning the appropriate treatment.

In the TNM staging system:

• T stands for tumor and determines how large the tumor is
• N stands for node and shows how many lymph nodes are involved
• M signifies metastasis and gives details about the spread of cancer to other parts of the body and organs involved

Oral cancer can be classified into five stages:

1. Stage 0
   • Called carcinoma in situ.
   • Indicates the presence of abnormal cells in the lining of the oral cavity, which can become cancerous (Tis, N0, M0).
2. Stage I
   • The early stage of oral cancer is where the tumor is not larger than 2 cm, and there is no lymph node involvement (T1, N0, M0).
3. Stage II
   • The tumor is larger than 2 cm but less than 4 cm, and no lymph node involvement is seen (T2, N0, M0).
4. Stage III
   • The size of the tumor is larger than 4 cm (or it can be of any size) with no lymph node involvement (T3, N0, M0).
   • The tumor can be equal to or smaller than 3 cm, and there is the involvement of one lymph node on the same side of the cancer ([T1, T2, T3], N1, M0).
5. Stage IV
   • Most advanced stage of cancer.
   • Can further be divided into three substages:
     • Stage IVa
       • The tumor has spread to nearby tissues such as other parts of the mouth, jaw, sinuses, or skin on the face. One large lymph node (more than 3 cm) on the same side of the neck as the tumor; no distant metastasis is seen (T4a, N0, or N1 M0).
       • The tumor invades nearby structures and one or more lymph nodes (not larger than 6 cm); no distant metastasis is seen (T1 to T4, N2, M0).
     • Stage IVb 
       • The tumor may be of any size. The malignancy is identified in a lymph node that is larger than 6 cm in size, with no distant metastasis (any T, N3, M0).
       • Involvement of multiple lymph nodes on the same side of the neck or tumor has spread to nearby structures; no distant metastasis (T4b, any N, M0).
     • Stage IVc
       • Distant metastasis is seen (any T, any N, M1).

Cancer in stages III and IV have a high risk of relapse.

Oral cancer is highly treatable when detected early. Surgery and radiation therapy are the most often used treatment methods. More advanced malignancies are often treated with a combination of various therapy methods.

• Surgery
  • Surgically, the abnormal mass in the oral cavity is removed along with a small portion of healthy tissue surrounding the tumor. 
  • Surgical reconstruction of the mouth after clinical therapy or removal of oral malignancies that have spread to other parts of the body, such as the neck, may be necessary.
• Radiation treatment
  • Uses precisely focused X-rays and protons to kill cancer cells.
  • Is often used as a supportive treatment of oral cancer following surgery or is given as a standalone treatment.
• Chemotherapy
  • Involves the systemic administration of certain drugs that are potent chemicals to kill cancer cells throughout the body.
  • Can be given alone or in combination with other treatments.
  • Usually follows surgery to eliminate remnant cancer cells or may be given before surgery to shrink the tumor for its easy removal.
• Targeted therapy
  • A newer type of treatment can help stop or delay the growth or spread of cancer by targeting specific parts of your tumor's biology.
  • Is frequently used with other treatments such as chemotherapy or radiation and can be administered as pills or by onsite intravenous (IV) infusion.
  • Drug cetuximab works by preventing specific processes that promote the growth of oral cancer.
• Immunotherapy
  • A relatively new therapeutic approach that uses a person's immune system to help eliminate cancer cells. 
  • Various FDA-approved solutions may be administered orally or by IV infusions.
  • May be recommended alone or in combination with another form of therapy, such as chemotherapy, depending on each person's cancer type and stage, treatment history, and overall health.

It is not possible to prevent oral cancer, but you can reduce its risk by following these preventive measures:

• Avoid or quit smoking and use of tobacco products
• Avoid overexposure to sunlight
• Limit or quit alcohol intake
• Maintain a healthy diet
• Clean dentures regularly, and remove them before sleep
• Practice safe sex