Malignant neoplasms are major causes of fear, morbidity and mortality all over the world. Cancer is one of the five main causes of death in all societies, with its relative position v arying with age and sex. Figure 1.1 shows the main causes of death in England and Wales in 2014, as a typical example of Western industrialized countries (1). In developing countries the proportions will differ, with infectious diseases being a larger component and cardiovascular disease a smaller component. Cancer numbers are important, however. In England and Wales, for example, in the past 65 years infections have declined as a major cause (in spite of the HIV epidemic) so that diseases of the heart and circulatory system now dominate in men, with cancer second; however, cancer dominates in women, especially in the third to sixth decades of life. Globally, “oral cancer” is the sixth most common cause of cancer-related death, although many people are unaware of its existence.