What is cancer?
Cancer affects people of all ages, regardless of gender and ethnicity, with the risk for most types increasing with age. It is responsible for approximately 7.6 million human deaths in 2007. It is a class of diseases in which a cell or a group of cells display uncontrollable growth, invasion to adjacent tissues and sometimes metastasize (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumours, which are self-limiting, and do not invade or metastasize. Most of them form a tumour but some, like leukaemia, do not. Classification of cancer Cancers are classified by the type of cells that resemble the tumour and the tissues presumed to be the origin of the tumour. The general categories of include: • Carcinomas: These malignant tumours originate from epithelial cells. This group represents the most common of cancers, including breast, prostate, lungs and colon cancer. •...