taken from Small Gland, Big Problem 4th Edition
by Professor Roger Kirby, Health Press 2011
Prostate cancer develops as a result of a progressive series of faults occurring in the genes that control cell growth in the prostate. These faults can be inherited or develop as a result of damage to the DNA, the material that controls the function of the cell, caused by dietary components, cancer-inducing chemicals or radiation. Normally, cells divide only when the body needs them to, and the process is under strict genetic control. When this genetic control breaks down and the cells begin dividing in an unregulated manner, a lump of excess cells forms (a tumour). A tumour can be benign or malignant, depending on its capacity to invade healthy surrounding tissue (if it can invade, it is cancerous). Because of its capacity to invade surrounding areas, cancer can spread to sites around the prostate, in which case it is said to be ‘locally advanced’. It can also spread to distant sites in a process known as metastasis, which occurs as the cancer becomes more advanced. Cancer cells can break off from the tumour in the prostate and enter the bloodstream and lymphatic system (the latter is a network of tiny vessels that drain fluid from all the organs in the body). In this way, cancer cells can spread to other parts of the body (for example, the lymph nodes or bones) and, like seeds growing in fertile soil, secondary tumours develop.