TUMOURS IN PRECANCEROUS CONDITION
INTRODUCTION
One of the most common precancerous tumours found is in the oral cavity. Cancers of the oral cavity and oropharynx represent 2/3rds of all malignancies in INDIA.
A wide array of precancerous tumours have been implicated in the development of oral cancer including leukoplakia, erythroplakia, oral lichen planus, oral submucous fibrosis, and actinic cheilitis.
RISK FACTORS
The risk of developing oral cancer is 5-9 times greater for smokers than for non-smokers and this may increase to as much as 17 times greater for extremely heavy smokers. Chewing tobacco has also been associated with an increased risk of oral cancer. The chronic use of betel quid(Paan) which consists of a betel leaf that is wrapped around a mixture of areca nut and slaked lime, usually with tobacco has a strong association with oral cancer.
The prototypic viruses implicated in oral cancer development are human herpes virus, human papillomavirus, and herpes simplex virus. HPV-16 has been associated with 22% of oral cancers.
The clinician should always have a high degree of suspicion especially if the use of tobacco and alcohol is present. These lesions often present as either white or red patches, known as leukoplakia and erythroplakia. It may present early on as a non-healing ulcer. The later stage includes bleeding, loosening of teeth, difficulty wearing dentures, and development of a neck mass.
LEUKOPLAKIA
First described by Schwimmer in 1877 as a white lesion of the tongue. According to WHO “leucoplakia is a white patch or plaque that cannot be characterized clinically or pathologically as any other disease”. It is a diagnosis of exclusion. The common sites are the buccal mucosa, alveolar mucosa, and lower lip. Early on leukoplakia appears as a slightly elevated greyish-white plaque that may be well defined or may gradually blend into the surrounding mucosa. As the lesion progresses, it becomes thicker and whiter sometimes developing a leathery texture. One of the best treatments for the above is surgical excision.
ERYTHROPLAKIA
Erythroplakia is defined as “A fiery red patch that cannot be characterized clinically or pathologically as any other definable disease”. The clinical appearance is characterized by flat or even depressed erythematous changes of the mucous. Both red and white changes in the same lesion are referred to as “erythroleukoplakia”. Most commonly seen in males and among the middle-aged and elderly. The most common affected areas reported are soft palate, the floor of the mouth, and buccal mucosa.
Chewing tobacco and drinking alcohol are the possible etiological factors for the development of erythroplakia. Clinically, the typical lesion of oral erythroplakia is less than 1.5 cm in diameter. Malignant transformation rate is high(14-50%), so it needs to be treated expeditiously.
Treatment options include surgery either by cold knife or by laser.
ORAL LICHEN PLANUS
Lichen planus is a chronic, autoimmune, inflammatory disease that may affect the skin, oral mucosa, genital mucosa, scalp, and nails. Involves female gender between the 5th-6th decade. The most commonly affected areas are dorsum of the tongue, buccal mucosa, and gingiva. Clinically, OLP is of 6 types including papular, reticular, plaque-like, atrophic, erosive, and bullous type.
The most common type is the reticular pattern which is present as a fine white striae known as “Wickham’s striae”. Patients with reticular and other asymptomatic OLP can be followed without treatment. But if there are any symptoms lesions should be surgically removed.
ORAL SUBMUCOUS FIBROSIS
Oral submucous fibrosis is a chronic and potentially malignant disorder characterized by fibroelastic change of the lamina propria(intermediate cell layer) and epithelial atrophy leading to stiffness of oral mucosa and inability to eat. Usually seen in the Asian population, occurring in the 2nd-3rd decade and both sexes may be equally affected. The strongest risk factor is the chewing of betel quid containing areca nut. Symptoms such as burning sensation and intolerance to spicy food are the most common symptoms of the initial phase. Over time, it gradually progresses and fibrosis develops that can affect the mouth opening. Three current treatment options include surgical, physical, and medical. Physical treatment includes exercise regimen, splint, and microwave diathermy. Medical therapies include steroids, interferon-gamma, beta-carotene.
ACTINIC CHEILITIS
Actinic cheilitis is a potentially malignant disease of the lip caused by exposure to solar radiation. In addition tobacco use, poor oral hygiene, and ill-fitting dentures may play a role. Initial stages show erythema and edema though later on can present as leukoplakia and erythroplakia. Malignant transformation is seen in 2-36% of cases.
In treatment 5-fluorouracil, scalpel vermillionectomy, electrosurgery, and cryosurgery can be used.
CONCLUSION
The ability to control precancerous oral tumours will depend on two cornerstones: prevention and early diagnosis. Continuing educational campaigns to educate the public about the early signs/symptoms, individuals encouraged to seek professional oral examinations, and health care workers asked to perform oral examinations as part of their patient care regime.