Mouth cancer is a malignancy of the neck and head that can occur on the lips or surface of the tongue, as well as in the gums, tonsils, inside of the cheek, the floor of the mouth, the roof of the mouth, and in the salivary glands. Those who develop cancer in the mouth are typically older than forty. Men are more than twice as likely to develop mouth cancer than women are. Early stages of oral malignancy do not have any obvious symptoms. Later progression of oral cancer manifests in non-healing mouth ulcers or sores, swallowing pain, loose teeth, hoarse voice, tongue pain, poorly fitting dentures, persistent swelling, red or white patches on the mouth or tongue, a lump in the mouth, jaw pain, and neck pain. Oral cancer is treated with the use of surgery, chemotherapy, or radiation therapy.
An individual who has certain DNA mutations in the cells that make up their oral cavity are at an increased risk of developing oral cancer. The cellular DNA is the set of instructions that tells the cell how to perform its functions. Only mutations of certain regions of the cellular DNA are known to cause the development of malignancy. These sections of cellular DNA include those that influence the processes of cell differentiation, adhesion, senescence, division, and apoptosis. It has been proven that anywhere between three and six mutations are required for a cell to alter into its malignant counterpart. The cell becomes functionally independent from neighboring oral epithelium as it accumulations such alterations. The cell acquires the ability to proliferate, grow, or invade locally, and stimulates neovascularization. Essentially, a cell has to gain function as well as lose function to become malignant. Changes that happen in tumor suppressor genes and proto-oncogenes cause the functional gain, while changes that happen in growth-inhibitory pathway genes and other tumor suppressor genes cause the functional loss. Oral cancer has been strongly associated with deletions that occur in chromosomes 9, 18,13, and Y.
Excessive Sun Exposure
Excessive sun exposure to an individual's face and neck regions can cause them to be at an increased risk of developing mouth cancer. The ultraviolet radiation from the sun comes in two forms that can cause the development of malignancy on an individual's lips. UVA rays are able to penetrate deep into the dermis of an individual's lips. This penetration results in suppression of immune activity, on top of the stimulation of cellular genetic damage and photo-aging process. UVB rays are able to penetrate into the epidermis and severely damage all parts of the epidermal cells, including the individual's DNA. The body first attempts to repair the cellular damage that occurs as the result of UVA and or UVB radiation exposure, but may be unable to do so in some instances.
During the process to repair this damage, occasional mistakes occur. When the body is unable to repair the damage, obstruction of the RNA and DNA synthesizing mechanisms can introduce incorrect portions into the cellular DNA. These mistakes can cause a mistranscription or mutation in the cellular DNA. It is this inappropriate enunciation or complete loss of the affected genes compounded over time that results in the development of malignancy. Cancer on the lips spreads easily into the mouth, while cancer on the neck and throat skin can proliferate into oral tissues.
Weakened Immune System
Individuals with a weakened immune system are at a greater risk of developing cancers of the mouth and throat. Numerous factors and processes can cause an individual to have a weakened immune system. Hereditary and congenital conditions can cause some individuals to be immunosuppressed. Acquired immunodeficiency syndrome (AIDS) is a lifelong disease that causes the breakdown of a patient's immune system. Medications used to treat numerous diseases of the autoimmune nature and utilized for the prevention of transplanted donor organ rejection are designed to pump the breaks on the patient's immune system. The immune system is constantly detecting and destroying pre-cancerous or malignant cells. It is often effective at keeping small amounts of malignant cells from proliferating, but occasionally it may experience a hiccup. The temporary lapse in function may allow cancerous cells to evolve and learn how to outsmart the components of the human immune system. Once the cancer cells have achieved this, they begin to grow and spread. Individuals with a weak immune system tend to experience more of these functional hiccups that increases their risk for developing cancers of the mouth and throat.
Use Of Tobacco And Smoking
A good portion of individuals diagnosed with mouth cancer exhibit behaviors of frequent use of tobacco and smoking. The increased risk is aligned with the duration and amount the individual has smoked or chewed substances containing tobacco. Cancers can develop anywhere in an individual's mouth or throat as a result of inhaling smoke from cigars, pipes, and cigarettes. Individuals who frequently smoke tobacco products from a pipe are at an even greater risk of developing malignancies where their lips that come in contact with the stem of the pipe they are smoking. Individuals treated for oral cancer from smoking who begin smoking again are at an increased risk of oral cancer recurrence. Oral products containing tobacco, such as dip, chew, snuff, spit, or dissolvable tobacco, is strongly associated with a significantly increased risk of developing malignancies in the inner lip surface, cheeks, and gums. Individuals who drink alcohol on top of using tobacco products can be at risk of one hundred times greater than the risk in those who do not use tobacco products or drink beverages containing alcohol.
Certain Strains Of Human Papillomavirus
Individuals affected by certain strains of human papillomavirus are at an increased risk of developing mouth cancer. Human papillomavirus is an umbrella term used to classify a group of over 150 variations of viruses. This group of viruses is further subcategorized with use of a number coding system. Cancers of the cervix, vagina, mouth, vulva, anus, and throat can be caused by infection of the human papillomavirus. The HPV16 variation of the virus is the one strongly linked to the development of cancers in the oropharynx and throat. DNA segments of the human papillomavirus have been identified in two of the three cancers of the oropharynx, and a smaller amount of cancers in the oral cavity. It is thought the recent increase of cancers of the mouth and throat related to human papillomavirus infections are the result of changes in sexual practices that involve the oral cavity. While only a small percentage of individuals infected by human papillomavirus in the mouth will go on to develop oral or throat cancer, the probability of its occurrence is increased in these individuals.