Prevention of oral cancer

Abstract

During the fifteenth century, Desiderius Erasmus, a Dutch scholar and humanist, wisely stated “Prevention is better than cure.” On an intuitive and logical level, it does seem more preferable to avoid rather than repair. If we translate this to the health field, we bring forth the implication that maintaining healthy habits and following basic rules of health can prevent certain diseases from occurring. One such disease which has received a tremendous amount of attention in terms of prevention is cancer and in particular oral cancer. Cancer has been declared as one of the most common causes of mortality and morbidity with more than 10 million new cases and more than 6 million deaths each year worldwide. Oral cancer ranks 12th among all cancers. Data from the Oral Cancer Foundation shows that there are more than 350,000–400,000 new cases of oral cancer each year. In 2004, the World Health Organization (WHO) estimated that 43% of all cancers are a consequence of tobacco use, alcohol consumption, unhealthy diets, unhealthy lifestyles, and infection. Of these, tobacco is the world’s most avoidable cause of cancer. Oral cancer is considered a major constituent in the world’s burden of cancer. Tobacco and alcohol have been proven to be major risk factors for oral cancer. Other risk factors include chewing betel quid (areca nut mixed with Piper betle quid) or gutka, prolonged UV sunlight exposure, long-term irritation of the oral mucous membranes by poor-maintained dentures, immunosuppressive drugs, human papillomavirus 16 (HPV 16) or Epstein-Barr virus (EBV) infection, radiation exposure, and untreated lichen planus. Other 194 uncontrollable risk factors include gender, race, age, genetic syndromes such as Fanconi anemia and dyskeratosis congenita, family history, previous cancer disease, and graft-versus-host disease (GVHD) due to stem cell transplant. Oral cancer, a part of head and neck cancer, is a term used to address the combination of two separate types of cancer: oral cavity cancer and oropharyngeal cancer. The former is comprised of the lips, the inside lining of the lips and cheeks (buccal mucosa), the teeth, the gums, the front two-thirds of the tongue, the floor of the mouth below the tongue, and the bony roof of the mouth (hard palate). The latter includes the part of the throat just behind the mouth. It begins where the oral cavity stops. It includes the base of the tongue (the back third of the tongue), the soft palate (the back part of the roof of the mouth), the tonsils, and the side and back wall of the throat. The most common type of oral cancer is the squamous cell carcinoma which represents more than 90% of oral cancer cases. Other types include the slow-growing verrucous carcinoma (VC) at 5%, salivary gland carcinoma which takes the benign and malignant forms with several subtypes, and lymphomas and melanomas of the mouth and lips. Leukoplakia and erythroplakia are considered benign or precancerous forms of the oropharyngeal tumors but can lead to harmful cancer if left untreated. The increased death rate associated with oral cancer is especially high not because oral cancer is complicated when it comes to detection and diagnosis but rather because it is discovered late in its development. Most times oral cancer is detected at the advanced stage at which point prognosis becomes very poor. Additionally, the 5-year survival rate for oral cancer is low, with only 48–55% surviving 5 years compared with 71% survival following prostate cancer, 62% following cervical cancer, 80% following breast cancer, and 78–91% following malignant melanoma. In light of the above facts, prevention becomes a crucial and central weapon in the challenge of oral cancer. Cancer prevention is defined as action taken to lower the chance of getting cancer, consequently lowering the number of new cases of cancer in a population and hopefully decreasing the number of deaths caused by cancer. However, prevention is not a solid concept but rather a state of priorities and stages, the major of which is primary prevention. Primary prevention aims to decrease the incidence of oral cancer through changing behaviors that may directly contribute to the development of oral cancer. Primary prevention includes but is not limited to cessation of smoking, reduced alcohol consumption, and improved nutrition. While primary prevention is the gold standard to battling oral cancer, behavioral change takes time and is not always easy to achieve, and hence secondary prevention such as detection of malignant or potentially malignant lesions becomes a key player. Secondary prevention also encompasses HPV vaccination, diagnosis, and treatment of erythroplakia and leukoplakia as well as chemoprevention. Tertiary prevention is indicated when the patient has previously had cancer which was treated in its acute clinical phase. Tertiary prevention seeks to soften the impact caused by the disease on the patient’s function, life expectancy, and quality of life.