Deepak Kademani - Improving Outcomes in Oral Cancer: A Clinical and Translational Update

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Deepak Kademani

Improving Outcomes in Oral Cancer

A Clinical and Translational Update

To my patients who have given me the privilege to care for them and taught me so much about the human spirit

In general histopathology terms, dysplasia is a disordered growth that encompasses an abnormality in the maturation of cells within tissues and the development of cytological atypia within cells. When dysplasia occurs in the epithelium of the oral cavity, the WHO have termed it oral epithelial dysplasia (OED), defining it as a precancerous lesion of stratified squamous epithelium, characterized by cellular atypia and loss of normal maturation and stratification short of carcinoma in situ. It is a histologically proven oral premalignant lesion that is associated with a significant higher risk of malignant transformation. An OED may be part of a clinically apparent lesion, such as leukoplakia, eythroplakia, erytholeukoplakia, lichen planus and submucosal fibrosis, actinic chelitis, and chronic hyperplastic candidiasis. These lesions are termed oral potentially malignant disorders (OPMD) by the 2005 WHO workshop and are referred to a variety of clinical lesions, conditions, or systemic disorders, which result in an increased risk of cancer development in the oral cavity compared to normal mucosa in a healthy patient. Recently, the term, potentially premalignant oral epithelial lesions (PPOEL), has been described in the literature to replace OPMD. For a lesion to be described as an oral epithelial dysplasia, there must be a biopsied and histopathologically reported foci of dysplasia.

OED is a condition comprising of a spectrum of tissue changes, with several grading systems established to classify into arbitrary levels of severity, hence diagnosis is extremely subjective []. These are generally based on the histopathological classification of premalignant lesions of other mucosal sites, which frequently develop SCC.

For example, squamous intraepithelial neoplasia (SIN) is an oral adaptation of a system used for classifying precursor lesions of the uterine cervix and have been used for grading OED in the older literature [].

In the Ljubljana grading system, lesions are categorized into simple hyperplasia, basal/parabasal hyperplasia, atypical hyperplasia, or carcinoma in situ. It is an alternative system based on another anatomical site but adapted for the oral cavity and oropharynx [].

Another grading systems include the Smith and Pindborg, which utilizes 13 histological features that are standardized by a set of photographs. After comparing with the photographic standard, the feature is graded as none, slight, or marked and given a score. The scores are added to achieve the epithelial atypia index (EAI) score (maximum possible is 75), and depending upon the EAI, the dysplasia is graded as no dysplasia, mild, moderate, or severe.