Cancer: science and society

[From introduction] The first question which needs to be answered is “What is Cancer?” This is in fact a very difficult question as, in many respects, cancer is a group of diverse diseases since it can affect every tissue in the body with different manifestations depending on the type of cancer. Can we therefore define this disease? I have synthesised a definition which I think covers the salient points. “Cancer is the uncontrolled or asynchronous growth of abnormal cells arising from a change in the cells DNA”. Let me explain this. Normal cells grow in a very controlled and synchronous manner. In going from a child to an adult hormones and other factors control the rate of growth of bones, muscles, etc.. They do this in a very controlled way by influencing the genetic material in the cell, viz. DNA. In adults there is also constant cell growth in, for example, skin and blood cells where new cells are replacing dead or old cells, again in a very controlled fashion. Many factors, which I will be discussing shortly, can disrupt this controlled cell growth and can further cause cells which normally are static or grow very slowly to enter into a state of high rates of cell growth. These cells which arc now growing in an uncontrolled fashion have been changed by these factors so that they no longer resemble the normal cells in the tissue in which they are found. They can therefore be regarded as abnormal cells