Usually cells, which are the building blocks that we are made from, grow in a regulated manner to form tissue. Normally cells grow in a controlled way and over time they will die and be replaced by new cells (through a process of cell division) to carry on their specific role for the rest of the body. If these new cells do not receive the correct messages as to what they should do, they can start to grow in an uncontrolled manner and swell to become tumours.
Tumours can be non-cancerous (benign) or cancerous (malignant). When this occurs to cells in the prostate gland which are cancerous, it is called prostate cancer. Non-cancerous cells tend to stick together where they have grown, but when they become cancerous they are less likely to stick together. The cancerous cells can then grow into neighbouring tissues (local invasion) or spread around the body (metastasise). Normally the body can detect unhealthy cells and seeks to repair them. In the case of cancer, the body’s immune system does not always recognise the cancer cells as being unhealthy.
The reasons for this happening in the prostate are still not that well understood and are the subject of much ongoing research. The incidence of prostate cancer is age related, in that the vast majority of prostate cancer occurs almost entirely in men over the age of 40 and particularly over the age of 65, where it is the most common form of male cancer.
We also know that the male sex hormone, testosterone, plays a vital role in promoting the growth of both normal and abnormal prostate cells. Without testosterone (even at normal levels in the male body), prostate cancers do not develop and this factor is used in treating the disease.
A number of other factors can also contribute, such as ethnic origin (men who are of Afro-Caribbean origin have a greater risk) and those with a family history (fathers and brothers with the disease), suggesting that there is a genetic component to prostate cancer. Diet, weight and exercise also seem to play a role, suggesting that the cause of prostate cancer is multi-factorial.
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