What is Oral Cancer?
Oral cavity and oropharyngeal cancer, also known as throat and mouth cancer, is a type of cancer that begins in a part of the oral cavity or the oropharynx, a part of the throat found behind the mouth.
Many types of cells make up the various parts of the oral cavity and oropharynx, and for each kind, different cancer can develop. These cancer cells can include squamous cell carcinomas.
According to the American Cancer Society, over 90 percent of oral cancers are squamous cell carcinomas, which are flat and scale-like cells forming the mouth and throat's lining. A squamous cell cancer called carcinoma in situ is in the cell layer called the epithelium at its earliest form.
An invasive squamous cell carcinoma has grown into the oral cavity or oropharynx's deeper layers. Meanwhile, a verrucous carcinoma, a type of squamous cell cancer, is slow-growing cancer that rarely spreads to other body parts. However, it can deeply grow into a nearby tissue that immediate removal of this type must be down along with a wide edge of surrounding normal tissue as parts of ordinary squamous cell carcinoma may grow inside verrucous carcinomas. Verrucous carcinomas that may already have areas of ordinary squamous cell cancer may spread to other body parts.
Other types of cancer that can grow in the oral cavity and oropharynx include minor salivary gland carcinomas, lymphomas, cancers of the nasopharynx, and laryngeal and hypopharyngeal cancer.
Cancer History, Facts, and Figures
Cancer has existed from the dawn of history, with evidence found among ancient manuscripts and fossils. The Edwin Smith Papyrus, an ancient medical text dating back to 3,000 B.C., has described eight cases of breast tumors and ulcers, reportedly removed via a cauterization using a fire drill.
Meanwhile, Hippocrates is credited for the term "cancer." The recognized "Father of Medicine" described non-ulcer and ulcer forming tumors as carinos and carcinoma, which are Greek words referring to a crab. Celsus, a Roman physician, translated the Greek term into the Latin word for crab, arriving at the present term used to describe the condition — cancer. Such words were probably used due to the finger-like spreading projections from cancer reminiscent of a crab.
The specific cause of cancer remains unknown. It can start in almost any body part and is characterized by irregular cell growth, which disrupts the human cells' orderly and normal processes.
Cancer is not a single disease of various types. The American Cancer Society listed down more than 60 types of cancers, while the National Cancer Institute has identified more than 100 types.
Cancer, which can spread to other body parts, is estimated to see more than 1.7 million new cases in 2018 based on the Cancer Facts & Figures of the American Cancer Society with more than 600,000 estimated deaths.
According to the North American Association of Central Cancer Registries, cancer incidence among men reached 501.9, while among women, it reached 417.9 per 100,000 people from 2010 to 2014. In the United States, death rates per 100,000 people from 2011 to 2015 were recorded at 196.7 in men and 139.5 in women.
What are the Causes of Oral Cavity and Oropharyngeal Cancer?
Like other types of cancer, the identified cause of oral cancer is also unknown. What is known is that there are factors that increase the likelihood of an individual in getting a disease like oral cancer.
Risk factors may include age and sex, personal choices, and lifestyle activities including smoking, drinking, and diet.
- People diagnosed with oral cavity and oropharyngeal cancer have an average age of 62 years old. Still, about a quarter of mouth and throat cancer patients are younger than 55 years old.
- Men are more likely to get oral cancer — two times than women.
- Smokers are more likely to develop oral cancer, which is also dependent on the quantity and length that the person has exposed himself to the tobacco.
- Like smoking, drinking alcohol also heightens the risk of an individual getting oral cancer. Figures suggest that seven out of ten oral cancer patients are heavy drinkers. Smoking partnered with drinking increases the risk of developing oral cancer by as much as 100 times more than those who do not smoke or drink.
- Human papillomavirus (HPV) infection causes some forms of cancer, including mouth and throat.
- A low-fruit and low-vegetable diet can also contribute to the increased risk of oral cancer, based on several studies.
- A weak immune system increases the likelihood of oral cancer as the immune system serves as the body's defense against viruses, bacteria, and other foreign bodies that can cause infections and diseases. The system is made up of cells, tissues, and organs connecting into a network to work together to defend the body.
What are Indications of Oral Cancer?
Possible indications of mouth and throat cancer include:
- Soreness in the mouth that does not go away
- Persistent mouth pain
- Thickening or swelling of the lips, gums, or other parts of the oral cavity, particularly the inside of the mouth
- Observable lumps or bumps or eroded or crust areas
- Red or white spots on the mouth's lining, tongue, gums, or tonsil
- A sore throat
- Difficulty in chewing or swallowing, jaw and tongue movement
- Numbness of areas of the mouth such as the tongue
- Swelling of the jaw
- Loose teeth
- Pain around the jaw or teeth
- Changes in the voice
- Lump in the neck
- Bad breath that does not go away
- Weight loss
Still, note that experiencing any of these symptoms does not automatically merit a cancer diagnosis. It remains essential to consult a doctor or dentist when these conditions have been observed, especially when they have lasted more than two weeks.
How can Oral Cancer be Detected?
Oral cancer can be detected through a routine dental examination where the dentist will feel the oral cavity for indications of irregularity in the face, head, neck, and other oral and maxillofacial region areas.
Dentists and doctors can also use special dyes or lights to check for abnormalities, particularly for individuals with a higher risk of developing cancer.
If a lump or suspicious-looking area has been detected, the dentist or doctor will direct the patient to an ear, nose, and throat doctor or an oral and maxillofacial surgeon who will do a complete head and neck exam.
Procedures that may be done to examine the areas correctly include an indirect pharyngoscopy and laryngoscopy and direct pharyngoscopy and laryngoscopy. For the former, small mirror with long and thin handles will be used to view the throat, base of the tongue, and voice box. For the latter, a flexible fiber-optic scope called an endoscope would be put through the mouth or nose to see areas that the mirror may not reach such as the nasopharynx and voice box. Another option will be a panendoscopy.
To confirm a suspicious lump or area's make-up, a biopsy may be required where a small part of the tissue is removed and looked under a microscope. Through this procedure, the presence of cancer can be observed and confirmed. Different types of biopsy may be used to detect cancer, depending on the case. These types include exfoliative cytology, incisional biopsy, and fine-needle aspiration biopsy.
Aside from the tests mentioned above, imaging tests, such as chest X-ray, computed tomography or CT scan, magnetic resonance imaging or MRI, positron emission tomography or PET, and barium swallow, may also be done to help look for a tumor, how far cancer has spread, the effectiveness of the treatment, and the possibility of recurrence.
How can Oral Cancer be Treated?
Treatment options for oral cancer are dependent on the location and the extent of how far cancer has spread.
In this stage, cancer has not penetrated the tissue's deep layers and is at the surface level. A surgery like the Mohs surgery is the typical option to remove the top layers of the affected tissue and the healthy tissue's small edge. With treatment, the chance of survival is high. However, signs of recurrence must be carefully monitored. If it happens, radiation therapy might be needed.
Stage I and II
A surgery, together with radiation therapy, is often recommended for patients in these oral cancer stages. Another treatment option is chemotherapy along with chemoradiation. This option is usually done after surgery to ensure that no cancer cells have been left behind.
Stages III, IV, and IVA
Treatment options for oral cavity cancers in these stages are often treated with a combination of surgery and radiation as these cancers found in the mouth floor, front of the tongue, inside the gums, hard palate, and cheeks involve the presence of larger cancers that have spread to nearby lymph nodes and grown into nearby areas.
Meanwhile, oropharyngeal cancers are found in the soft palate, tonsils, and the back of the tongue. These cancers are large and have grown into nearby tissues or have spread to the lymph nodes in the neck. For these cancers, a combination of chemoradiation and cetuximab, man-made version of monoclonal antibody, an immune system protein. Surgery may also be conducted to remove any remaining cancer.
Stages IVB and IVC
In these stages, the cancers have spread into nearby structures, and tissues with the stage IVC cancers have spread to other body parts like the lungs. Oral cancers of these stages are treated with chemo, cetuximab, or a combination of the two. Radiation may also be utilized to help relieve the cancer symptoms and prevent new problems from arising.
Recurrent Oral Cancer
For cancer that has recurred, treatment options are dependent on the location, size, and spread of cancer. Previous treatments used, as well as, the patient's general health status is also considered.
According to cancer.net, the survival rate for oral cancer is dependent on location, relation to HPV, the extent of cancer, and how early it was detected and treated.
- The overall five-year survival rate for people with oral cancer is at 65 percent.
- For people whose cancer was discovered on its early stage, the overall five-year survival rate is at 84 percent.
- For people whose cancer has spread to surrounding organs or tissues or the regional lymph nodes, the overall five-year survival rate is at 64 percent.
- For people whose cancer has spread to distant body parts, the overall five-year survival rate is at 39 percent.
Is Oral Cancer Preventable?
Like other types of cancer, there is no proven way to prevent the occurrence of mouth and oral cancer. Still, there are ways to reduce the chances of acquiring cancer including:
- Quit smoking or chewing tobacco products as they expose the mouth cells to harmful, cancer-causing chemicals
- Limit alcohol intake as excessive alcohol consumption can cause irritation and weaken the immune system that may heighten the risk of oral cancer.
- Eat foods rich in vitamins and antioxidants.
- Protect the lips from excessive sun exposure by applying a sunscreen lip product and wearing a broad-brimmed hat.
- Visit the dentist regularly to detect any abnormalities as early as possible. Through a routine dental exam, the dentist can check for signs of oral cancer and treat dental issues that can increase the risk of oral cancer.
Disclaimer: The oral health information published on this web page is solely intended for educational purposes. Hawaii Family Dental strongly recommends to always consult licensed dentists or other qualified health care professionals for any questions concerning your oral health.