Oral Cancer: Symptoms, Causes & Prevention

Over 53000 people are estimated to be diagnosed with oral cancer in 2019 in the United States alone. The fact that more than 20 percent of these patients will be nearly facing death, makes it extremely important to take necessary actions to know how oral cancer happens and prevent it from occurring.

What is Oral Cancer?

Oral cancer is a type of head and neck cancer, which includes cancers of the mouth and the back of the throat. It can start in the cells of any part of the mouth and cause damage to the tissue and underlying structures. The various parts of your mouth that can get affected by cancer are: ^[1]

• Tongue
• Lips
• Gums
• Cheeks (inner lining)
• Hard and soft palate
• Under the tongue (floor of the mouth)
• Throat

Cold sores are an infection caused by the herpes simplex virus. Photo Credit: Shutterstock

Symptoms of Oral Cancer

The most common signs and symptoms of oral cancer are:

• Sores or ulcers in the mouth that are not healing
• Red or white patches on the lining of the mouth
• Swelling or lump on the inside of the mouth
• A feeling of something being stuck in the throat
• Unexplained bleeding in the mouth
• Difficulty in swallowing food
• Abnormal voice (hoarseness)
• Mouth or jaw pain
• Ear and neck pain
• Loose teeth
• Persistent weight loss

Causes of Oral Cancer

There are various causes and risk factors that increase your chances of cancer. According to the American Cancer Society ^[2], tobacco use and alcohol are the two most prominent risk factors of cancer. Tobacco chewing or smoking in the form of pipe, cigars, cigarettes, etc. can elevate your risk of cancer even more. The American Cancer Society also reveals that 7 out of 10 oral cancer patients are most likely heavy drinkers. The relationship between drinking alcohol and cancer risk has been evaluated extensively and found to be directly proportional in various epidemiologic case-control and cohort studies which included populations from the U.S and other countries. ^[3]

There are other many other risk factors aside from tobacco and alcohol that are also found to cause cancer. They are: ^[4]

• Excessive exposure to ultraviolet rays
• Sexually transmitted human papillomavirus (HPV) infection
• Usage of smokeless tobacco such as betel quid, areca nut, and gutka ^[5]
•  Poor nutrition and weak immunity ^[6]
• Patients with chronic graft-versus-host disease have a higher risk of developing oral cancers secondary to immunosuppressive treatment
• Inherited defects in the genes ^[7]
• Chronic trauma from overhanging restorations, dentures, and sharp teeth

Stages of Oral Cancer

As soon as someone is diagnosed with oral cancer, one of the first things the doctor does is staging cancer which helps in planning the treatment modalities and determine the disease prognosis. ^[8]

TNM (tumor-node-metastasis) staging system: The American Joint Committee on Cancer (AJCC) and the International Union for Cancer Control (UICC), through a collaborative effort, developed cancer-specific staging systems about 60 years ago and this system has undergone various modifications, the latest one being of these was published in 2017, to be implemented to all cancers detected from January 2018. ^{[9] [10]}

Even after undergoing various modifications, the central theme of the AJCC and UICC, the TNM staging system remains consistent. Here, T refers to the extent of disease based on the size of the primary tumor and its local invasiveness. N refers to the involvement, size, and extent of regional lymph nodes. M refers to the presence or absence of distant metastasis.

Oral cancer is divided into the following stages as per the latest TNM staging. ^{[11] [12] [13]}

• Stage 0: The tumor is limited to the epithelium and has not spread to any deeper layers (Tis), has not spread to deeper layers or lymph nodes (N0), or distant organs (M0).
• The tumor size is less than 2 centimeters and it has not yet reached near the lymph nodes.
• Stage I: The tumor size is less than 2 centimeters (T1) and it has not yet reached near the lymph nodes (N0), or distant organs (M0).
• Stage II: The tumor size is between 2-4 centimeters (T2) but has not reached near the lymph nodes (N0), or distant organs (M0).
• Stage III: The tumor size is over 4 centimeters (T3) and has not spread to lymph nodes (N0) and distant organs (M0) or the tumor is of any size (T1-T3) and has spread to one lymph node measuring around 3 cm or less on the same side of the neck (N1) but the tumor has not spread to distant organs (M0).
• Stage IVA: The tumor is of any size, has spread to other parts of the mouth like lips, tongue muscles, maxillary sinus (T4a) and it has not spread to nearby lymph nodes (N0) or has spread to one lymph node on the same side with the lymph node not exceeding 3cm (N1) and has not spread to distant organs (M0). Alternatively, the stage 4A can also indicate a tumor of any size (T0-T4a), has not spread to distant organs (M0), but has spread to one lymph node on the same side as primary tumor and the lymph node measures 3cms-6cms (N2a), or has spread to more than one lymph node on the same side as primary tumor with the lymph node not exceeding 6cms (N2b), or has spread to more than one lymph node on either or both sides of the primary tumor but has not grown outside the lymph nodes and none are larger than 6cms (N2c).
• Stage IVB: The tumor can be of any size (Any T) with no spread to distant organs (M0) but has spread to one lymph node larger than 6cms but hasn’t grown out of it (N3a) or has spread to one lymph node larger than 3 cm but has grown outside the lymph node (N3b) or has spread to more than 1 lymph node on the same side, the opposite side, or both sides of the primary cancer and has grown outside the lymph node(s) (N3b). Stage 4B could also be designated to a tumor which is of any size and growing into nearby structures like nearby bones or the base of the skull, or it surrounds the carotid artery (T4b). The tumor may or may not have spread to nearby lymph nodes (Any N) but has not spread to distant organs (M0).
• Stage IVC: The tumor is of any size and may have grown into nearby soft tissues or structures (Any T) and it may or may not have spread to nearby lymph nodes (Any N) as well as spread to distant sites such as the lungs (M1).

How Fast Does Oral Cancer Spread?

If oral cancer is found detected at its initial stage i.e before it has spread or invaded to other tissues and structures, 9 out of 10 people will be cured. However, timely detection and diagnosis happen only in less than half of the oral cancer cases.

A report published in the Cancer Causes Control journal suggests that people with less than 10 years of smoking history may show better results. But if a person keeps using alcohol and tobacco even after treatment, cancer can recur. ^[14]

How To Prevent Oral Cancer?

There are simple ways to protect yourself and your family from oral cancer. ^{[15] [16]}

• Try to avoid using tobacco as much as possible or better still, consider quitting tobacco entirely.
• Limit your alcohol consumption.
• Practice safe sex to avoid HPV infection.
• Use a sunscreen if you stay out during the middle of the day.
• Make sure to get your dental problems treated.
• Eat a wholesome diet.
• Follow good oral hygiene.
• See your dentist regularly.

Moreover, there are timely reminders in the form of campaigns like Oral Cancer Awareness Month, which takes place in April every year to ensure good oral health.

Ultimately, the best you can do is look at this condition holistically and take imperative measures. As precisely said by Dr. Rengaswamy Sankaranarayanan, MD, in his book Disease Control Priorities, “A multifaceted approach that integrates health education, tobacco and alcohol control, early detection, and early treatment is needed to reduce the burden of this eminently preventable cancer.” ^[17]