Prostate cancer cells, coloured scanning electron micrograph (SEM). The prostate gland is a walnut sized gland at the base of the bladder and is found only in men. Prostate cancer can develop when the cells in the prostate start to divide and multiply in an uncontrolled manner. Prostate cancer often starts slowly and may never appear to cause serious problems. In these cases there are a number of different treatment options available and survival rates are generally good. Some patients may have prostate cancer that is more likely to spread and is therefore more problematic so different treatment plans may be needed. Magnification: x4000 when printed at 10cm wide.