POTENTIALLY MALIGNANT DISORDERS AFFECTING ORAL CAVITY

About The Book

***INTRODUCTION*** Cancer, Latinized from the Greek word *Karkinos* (meaning crab), is a leading cause of mortality globally, ranking as the second most leading cause in economically developed countries and the third in developing countries (following heart and diarrhoeal diseases). Worldwide, an estimated 12 million new cancer cases were expected in 2007, with 6.7 million occurring in developing countries. Oral cancer specifically is highly prevalent in the Indian subcontinent, where it is the most common cancer among men, even though it is only the sixth most common worldwide. Oral squamous cell carcinomas constitute 92–95% of all oral malignancies, with over one million new cases estimated to be detected annually in the Indian subcontinent. Five-year survival for cancer is directly linked to the stage at which the initial diagnosis is made. Researchers have established a "two-step process" of cancer development, noting that virtually all oral cancers are preceded by visible clinical changes in the oral mucosa, typically appearing as a white or red patch. These clinical changes are collectively categorized as **Potentially Malignant Disorders (PMDs)**. The World Health Organization (WHO) defined PMDs in 2005 as the risk of malignancy being present in a lesion or condition either at the time of initial diagnosis or at a future date. Prior to this, confusion existed between the historical terms *Precancerous Lesion* ('A morphologically altered tissue in which oral cancer is more likely to occur...') and *Precancerous Condition* ('A generalized state associated with a significantly increased risk of cancer'), both defined by the WHO in 1978. The WHO workshop of 2005 recommended abandoning this distinction in favor of the encompassing term "potentially malignant disorders". The early detection and prevention of PMDs are crucial for decreasing the incidence of oral cancer and improving the survival rate for those who develop the disease. However, diagnostic delay remains a challenge, primarily attributed to a lack of public awareness regarding signs, symptoms, and risk factors, coupled with insufficient knowledge about early detection among healthcare providers. Epidemiologically, the risk of developing cancer increases with age and exposure to risk factors. The average age of the population affected by PMDs is 50–69 years, typically occurring about five years earlier than oral cancer. While potentially malignant disorders traditionally showed a predilection for males, recent studies indicate a 1:1 male to female ratio, possibly due to increased habitual tobacco and alcohol use among women. In India, the most common sites for PMDs are the buccal mucosa, followed by the tongue, palate, and floor of the mouth.