Dr. Rupak Sethuraman LEARNING OBJECTIVES Why to screen for oral cancer and what are the advantages of such screening? Potentially malignant disorders Clinical Examination and staging Radiographic examination Diagnostic adjuncts Newer diagnostic techniques Definition Neoplasm is an abnormal mass of tissue the growth of which exceeds and is uncoordinated with that of normal tissues and persists in the same excessive manner after cessation of the stimuli that evoked the change. Oral Cancer is one of the most prevalent cancers with significant mortality responsible for extensive disfigurement, loss of function, behavioural changes and functional and sociologic hardships. 90% is squamous cell carcinoma (SCC) Less common Salivary gland Lymph tissue Bone Connective Tissue Odontogenic Metastatic- Breast, Lung, Prostate, stomach Etiology 5 Ss Smoking Sharp tooth Sepsis- HSV, HPV Spirit- Alcohol Systemic Immune deficiency Oral squamous cell carcinoma overview C. Scully, J. Bagan / Oral Oncology 45 (2009) 301308 Multistep and multifocal process- cancer Normal Cell Acquired (environmental) DNA damaging agents: 1.Chemicals 2.Radiation 3.Viruses Acquired (environmental) DNA damaging agents: 1.Chemicals 2.Radiation 3.Viruses Successful DNA repair DNA Damage Failure of DNA repair Inherited mutation in: 1.Genes affecting DNA repair 2.Genes affecting cell growth or apoptosis Inherited mutation in: 1.Genes affecting DNA repair 2.Genes affecting cell growth or apoptosis Mutations in the genome of somatic cells Mutations in the genome of somatic cells Alterations in genes that regulate apoptosis Rb Alterations in genes that regulate apoptosis Rb Decreased apoptosis Additional mutations Escape from immunity Additional mutations Escape from immunity Angiogenesis Tumor progression Malignant neoplasm Unregulated cell proliferation Activation of growth- promoting oncogenes Activation of growth- promoting oncogenes Inactivation of tumor suppressor genes P 53 Potentially Malignant Disorder Premalignant Lesion: A benign, morphologically altered tissue that has a greater than normal risk of malignant transformation. Premalignant Condition: A disease that does not necessarily alter the clinical appearance of local tissue but is associated with greater than normal risk of precancerous lesion or cancer development in that tissue. Potentially Malignant Disorders World Health Organization (WHO) Workshop, held in 2005, recommend the term Potentially Malignant Disorders, Very high risk 85% Erythroplakia High in some instances 30% Actinic cheilitis Candidal leukoplakia Dyskeratosis congenita Non-homogeneous leukoplakia Proliferative verrucous leukoplakia Sublingual keratosis Submucous fibrosis Syphilitic leukoplakia Low (