Mouth cancer can be defined as a type of malignant disease that occurs in the tissues of the mouth or oral cavity. The areas that are included are the lips, tongue, gums, inner lining of the cheeks, floor of the mouth, hard and soft palate, and the area of the throat at the back of the mouth, considered the oropharynx. Like many other cancers, oral cancer can be classified under the larger group of head and neck cancers. Cancer occurs when some type of abnormal change is made in one's cells, causing the cells to grow uncontrollably and resulting in the formation of a mass or tumor that may be benign, but in some cases can also be malignant. A malignant, mouth-based tumor has the potential to invade other parts of adjacent tissues, causing serious health complications and can also metastasize to other tumors in addition to benign tumors, which are considered non-invasive. Oral cancer usually begins in the squamous cells lining the inside of the oral cavity and throat; However, other types of cancer such as adenocarcinoma, lymphoma, or melanoma may also occur.
Oral disease is caused by genetic mutations in the cells of the oral tissues due to various risk factors such as the use of tobacco in any form; alcohol abuse; excessive exposure to ultraviolet rays from sunlight (especially the lips); infection with one or other forms of the human papilloma virus (HPV); immunodeficiency; poor oral hygiene conditions; and chronic irritation or trauma to the mouth. Together or individually, these risk factors interfere with the normal process of cell growth and repair within the body, resulting in uncontrolled and unhindered proliferation of cells, and they acquire characteristics of escaping the mechanisms that usually eliminate damaged or abnormal cells. In addition to these external risk factors, there will also be genetic and environmental risks such as carcinogenic exposure at the workplace that will ultimately play an important role in the development of oral cancer, as well as family history of cancer and certain genetic predispositions.
The general appearance of oral cancer varies according to the site of origin and the specific type of cells involved. A mouth sore that will not heal or an ulcer, or a thickened area or lump in the tissues of the mouth, or a red or white spot inside the mouth that cannot be wiped away are some of the most common presentations of oral cancer. Such symptoms may include difficulty chewing, swallowing or speaking; numbness or pain in the mouth or lips; unexplained bleeding; loose teeth for no apparent reason; and a persistent sore throat or feeling like something is stuck in the throat. Symptoms may also indicate oral cancer. The initial symptomatology is often vague at the beginning, and therefore diagnosis and treatment are usually delayed, significantly affecting the outcome.
The diagnosis of oral cancer generally relies on a combination of physical examination, imaging studies such as X-rays, CX scans, MRI or PET scans, and a sample of suspicious tissue for analysis under a microscope on a biopsy to confirm the presence of cancer. After confirmation, the next step is staging—the process of determining the extent of cancer—to help decide treatment. Staging is done with respect to the size or volume of the tumor, involvement of local lymph nodes, and the presence or absence of metastasis to other body organs.
Typically, oral cancer is treated using a multidisciplinary approach that may include surgery, radiation, chemotherapy, targeted therapy or immunotherapy, depending on the stage, type and location of the cancer, as well as the patient's overall health. Surgery involves removing the tumor and some of the tissue around it to ensure complete resection, and in some cases reconstruction may be needed to restore shape and function after this surgery. Radiation therapy uses high-energy rays to kill cancer cells or prevent them from growing. These may be used in conjunction with chemotherapy for later-stage cancers or independently for early-stage cancers. Chemotherapy is where drugs are used to kill cancer cells, especially those that have spread outside the mouth or is combined with radiation to increase its effectiveness. Newer treatments are targeted therapies, which specifically target molecules used in the growth of cancer cells. Immunotherapy, on the other hand, aims to improve the body's natural defenses to fight cancer.
In general, the prognosis of oral cancer depends on the stage at which it is diagnosed. Therefore, the earlier the diagnosis, the higher the chances of the patient being successfully treated and surviving. Preventive measures such as abstinence from tobacco and excessive alcohol, protecting the lips from the sun, good oral hygiene and dental check-ups can significantly reduce the incidence of oral cancer. Public awareness campaigns and educational efforts should be emphasized to move the society towards early detection and to encourage the convenience of seeking medical help for any confusing oral symptom. New and advanced tools of diagnosis, treatment modalities and preventive strategies are going to improve the outlook for oral cancer over time along with the advancement of research.
