Introduction
Oral cancer is cancer, tumor, or lesion that arises either from the oral structures within the mouth, lining, or oral mucosal membranes of the oral cavity. The oral cavity compromises, basically, the mucosal lining of the lips, the cheeks, the teeth, the gingiva or gum, the tongue, the floor of the mouth, the buccal mucosa, hard palate, soft palate, jaw bone, alveolar ridge, the retromolar trigone posterior to the wisdom teeth, etc. Most forms of oral cancer are observed within the older age groups between the 5th to 7th decade of life; however, cases of individuals affected by oral cancer are reported in even the younger age groups with a predilection for more males as compared to females. However, factors like gender, age, exposure to ultraviolet light, poor health, or malnutrition in individuals are also implicated in developing oral cancer.
What Are the Risk Factors for Developing Oral Cancer?
The most common risk factors for developing oral cancer are listed below as follows-
Tobacco: Smoking, Chewing, and Smokeless Forms
Tobacco smoking is definitely considered the most widespread or a great risk factor for developing oral cancer. This is due to the presence of carcinogenic chemical components, mainly nitrosamines, benzopyrenes, and aromatic amine compounds. According to medical research and data collection, the risk of an individual developing oral cancer is three times higher in smoking individuals as compared to the non-smoking population. Also, current research shows that individuals are at higher risk from passive smoking environments as well. Studies also have indicated a potential or synergistic link between the smoking populations and those who are also associated with alcohol consumption, thus resulting in a higher risk or predisposition to developing oral cancerous or malignant lesions. Globally, tobacco is used either in chewing form or placed within the mouth for passive reasons rather than being smoked by most of the population. Nicotine that is held within the mouth not only gets released and subsequently absorbed within the mucous membranes but also invokes a detrimental immune response within the oral cavity. Thus, tobacco smoking is almost always linked to oral cavity cancers because of the direct contact or involvement of nicotine release into oral tissues. Research also indicates an association of oropharyngeal malignancies in individuals with a history of tobacco smoking or chewing.
In the chewable forms, betel quid, also known as ‘pan’ or ‘paan,’ refers to a combination of betel leaf, areca nut, slaked lime, and tobacco. Snuff is a moist form of smokeless tobacco that is usually placed under the upper lip for extended periods of time. This chewing of paan or snuff usage is a widespread practice in Asia, especially within the Indian subcontinent, which has shown a higher risk of developing premalignant and malignant lesions compared to smoking tobacco alone. This is because the chewing form of tobacco causes prolonged exposure to the carcinogens inside the oral cavity.
Alcoholism
Alcohol consumption in regular amounts or users with a chronic intake of alcohol is definitely prone to increased risk or predisposition for oral cancerous lesions.
Consumption of alcohol, whether in conjunction with smoking (especially in chronic alcoholism cases or alcohol abuse) or without, not only increases the risk of oral cancer but also significantly impacts the systemic and immune health of the individual. Although medical research has not evidentially proven that clear carcinogenic properties exist in ethanol yet alcohol is known to increase the permeability of oral mucosa by interfering with oral immune defense and breaching the host immunity enabling carcinogenic-induced damage inside the mouth.
Ill-Fitting Dentures
Long-term irritation is a common risk factor studied by dentists as the lining of the mouth can get easily inflamed and irritated by poorly fitting dentures. However, inflammatory responses cannot be a risk factor alone for developing oral cancer. Trauma or chronic irritation may aggravate or interfere with the oral immune response, especially in immunocompromised patients leading to an increased possibility of developing premalignant or malignant lesions.
Poorly fitting dentures also can trap agents that impact the possibility of developing oral cancer. For example, individuals with a history of tobacco smoking or alcoholism can either have alcohol or tobacco particles entrapped easily. Lack of proper oral hygiene or regular dental visits can further worsen the inflammatory process or increase the presence of proinflammatory mediators. An ill-fitting denture should be corrected by the dental surgeon, and all denture wearers are recommended to ideally remove their dentures at night. Cleaning and rinsing the dentures in water or cleansing using denture tablets thoroughly can also help maintain denture hygiene and reduce local inflammatory responses alongside practicing good oral hygiene.
Poor Oral Hygiene and Lack of Dental Health Checkups
Various studies in recent decades have suggested the pivotal importance of dental and oral health in the forms of regular dental checkups or visits, yearly oral prophylaxis, and the use of chemical or mechanical plaque control measures for maintaining appropriate oral hygiene. This is because the overall health of the mouth impacts the possibility of oral or oropharyngeal cancer risks caused due to the changes in oral microbial flora and host immune response.
HPV Infections
Human Papillomavirus (HPV), specifically HPV 16 and 18, has been associated with oral malignancies. Individuals with HPV infections are shown to be more prone to cervical, tonsillar, or any form of oropharyngeal or tongue cancer. Individuals affected by HPV within the oral cavity are four times more likely to develop squamous cell carcinomas in the mouth in contrast to HPV individuals with healthy oral mucous membranes. The spread of infection occurs mainly through oral and sexual contact. HPV-related oropharyngeal cancers are more often seen in men as compared to women.
History of Stem Cell Transplants
Patients with a history of hemopoietic stem cell transplants are shown to be four to seven times more prone to developing oral cancers in contrast to the average population. Clinical symptoms after a stem cell transplant may include mucositis, oral mucous membrane changes, xerostomia or dry mouth, and other lichenoid reactions or changes. Case reports of transplant patients developing tongue or salivary gland cancers after a few years make stem cell transplant patients potentially predisposed to oral cancers.
Genetic Syndromes
People with certain genetic syndromes that are caused by mutations within certain genes follow a molecular pathway or pathogenesis that ends up predisposing these individuals to develop oral cancers. Individuals with high-risk genetic syndromes or conditions like Fanconi anemia, leukemias myelodysplastic syndrome, dyskeratosis congenital, etc., have a very high risk of developing head and neck cancer, especially of the mouth and throat, more so at a younger age.
Oral Infections
Syphilis: Although the data on actual association or linkage between syphilis and oral cancers is weak, case reports of serological positivity for syphilis in patients suffering from tongue cancer indicate a predisposition or a mutual probability of developing malignant lesions.
Candida: Clinical studies have implicated the role of candida infections in the development of oral cancers. In certain conditions, like in the cases of nodular leukoplakia (which is a premalignant lesion), the lesions infected with Candida have a higher potential for undergoing dysplastic changes or may show a malignant transformation. Candida and syphilis, though implicated in recent research, still need further evidence to be proven as mainline risk factors for developing oral cancers.
Conclusion
Thus to conclude, cessation of major risk factors like tobacco and alcoholism, regular dental checkups, prevention of oral infections, management of potential oral lesions by the dental surgeon, lifestyle modification by the practice of good oral hygiene, and maintenance of systemic health is crucial in preventing an individual from the risks of developing oral cancer.
