Oral lesions of premalignant nature are recognize clinically as leukoplakia or erythroplakia are risk factors for the development of oral cancer.
Oral premalignant lesions or a manifestation of field cancerization.
Premalignant Conditions of the Oral Cavity
Oral cavity cancer accounts for approximately 3% of all malignancies and is a significant worldwide health problem.
Most oral malignancies occur as squamous cell carcinomas.
5-year survival rate of oral malignancies has not significantly improved over the past several decades and still hovers at about 50-60%.
Many oral SCCs develop from premalignant conditions of the oral cavity.
Conditions have been implicated in the development of oral cancer include: leukoplakia, erythroplakia, palatal lesion of reverse cigar smoking, oral lichen planus, oral submucous fibrosis, discoid lupus erythematosus, and hereditary disorders such as dyskeratosis congenital and epidermolysis bullosa.
Many malignancies are not diagnosed until late stages of disease.
Survival rates markedly improve when the oral lesion is identified at an early stage.
An accepted prevalence rate of premalignant oral disease ranges between 1% and 5%.
Most affected patients are middle-aged or elderly men.
Potentially malignant disorders are discovered most commonly on the buccal mucosa, lower gingiva, tongue and floor of mouth.
Oral cancer accounts for approximately 3% of all malignancies.
Approximately 25,000-30,000 cases of oral cancer are diagnosed each year.
Oral cancer is one of the most common malignancies in Southeast Asia, accounting for up to 30-40% of all malignancies in India.
Oral cancer occurs most commonly in middle-aged and elderly individuals, but recent evidence suggests these demographics may be changing.
Surveillance Epidemiology and End Results data demonstrated an increase in the incidence of tongue cancer in young individuals.
The traditional male predominance is less overt in young individuals with oral SCC, a reflection of the general acceptance of social habits such as smoking and drinking by both sexes.
Up to 80% of patients with oral SCC have used tobacco products,
The risk of developing oral malignancy is 5-9 times greater for smokers than nonsmokers.
Alcohol use has also been implicated as a risk factor for the development of oral SCC and premalignant lesions, with moderate to heavy drinkers having a 3-9 times greater risk of developing cancer.
The heavy use of alcohol and tobacco combined may convey a risk greater than 100 times the general population for oral cancer.
HPV types 16 and 18 may be found in approximately 22% and 14% of oropharyngeal tumors.
HPV DNA has been demonstrated in 17.6% of oral leukoplakic lesions and 19.7% of oral lichen planus samples.
Evidence substantiates the role of HPV in oropharyngeal tumors is more definitive, the implication of the presence and integration of HPV in oral cavity lesions requires further clarification.
Despite the association between tobacco and alcohol and the development of persistent oral lesions, a definitive etiology is seldom identified in many of these lesions.
A precancerous lesion refers to altered tissue in which oral cancer is more likely to occur than its apparently normal counterpart.
These precancerous lesions include leukoplakia, erythroplakia, and the palatal lesions of smokers.
Erythroplakia describes a red patch that cannot be clinically or pathologically distinguished as any other definable disease.
Erythroplakia appears of erythroplakia as a red macule or patch with a soft, velvety texture most often occurring on the floor of mouth, lateral tongue, retromolar pad, and soft palate.
Erythroplakia is far less common than leukoplakia.
Erythroplakia often harbors dysplasia.
Upon histological analysis, 51% of erythroplakic lesions have been shown to demonstrate invasive squamous cell carcinoma (SCC), with 40% demonstrating carcinoma in situ, and 9% exhibiting mild-moderate dysplasia.
Proliferative v2242ucous leukoplakia (PVL) is a unique form of aggressive disease.
Most patients with PVL are women, and many do not have a history of tobacco use.
PVL generally appears on the oral mucosa as an irregular white patch or plaque with a varying surface.
The disease is often characterized by resistance to treatment, recurrence, multifocal proliferation, and a progression to carcinoma in up to 87% of patients.
The palatal lesion of reverse smokers, who place the lit end of a cigarette inside the mouth may appear clinically as a red, white, melanotic patch or papule.
Up to 84% of such palatal lesions have been harbor dysplastic changes.
Oral submucous fibrosis (OSF) is a chronic progressive condition found predominantly in people of Asian decent, and is considered to be the result of the use of the Areca nut product with resultant disruption of the extracellular matrix.
The disease often manifests with diffuse involvement of the oral cavity, down to the upper esophagus that appears clinically as whitish mucosa lacking elasticity.
Studies suggest a malignant transformation rate in approximately 7% of these lesions.
The diagnosis of oral squamous cell carcinoma at an early stage of disease allows for less aggressive treatment, improves quality of life, and improves the overall 5-year survival rate.
For diagnosis and identification of oral lesions histopathologic analysis by surgical biopsy is required.
Oral cavity examination has traditionally been the pref2242ed approach for the detection of oral mucosal abnormalities.
Evidence to support the use of oral examination as a general screening program is insufficient.
The efficacy of an oral cancer screening program in a high-risk population has been demonstrated.
Toluidine blue (TB) is an acidophilic dye designed to stain acidic cellular components such as DNA and RNA.
It can be used in the detection of precancerous/cancerous as dysplastic tissue contains quantitatively more DNA and RNA than nondysplastic tissue.
Toluidine blue may provide better demarcation of lesion margins, may guide biopsy site selection, and may be valuable in the identification and visualization of lesions in high-risk patients, and has a sensitivity ranging from 0.78 to 1.00, and the specificity ranges from 0.31 to 1.00.
Oral cytology describes a diagnostic technique used to sample oral tissue for histomorphological analysis.
Chemiluminescent light source can visualize abnormal oral mucosa not visible under normal incandescent light.