Prostate cancer occurs when cells in the prostate gland become altered and multiply at an uncontrollable rate. Whilst the tumour starts initially in the prostate gland, it may potentially spread outside the prostate via the lymphatic system or through the blood stream.
Prostate cancer is the most common cancer (apart from skin cancer) in Australian men, and effects ~ one in six Australian men in their life time.
The cause of prostate cancer is mostly unknown. The biggest risk factor though is a family history of prostate cancer. The chance of being diagnosed with prostate cancer increases with the number of affected first degree relatives within a family. The risk is doubled if there is one first degree relative with prostate cancer, and if two first degree relatives have been diagnosed with prostate cancer, then the risk is increased five times. The risk is also higher if a first degree relative is diagnosed with prostate cancer at an earlier age. The prostate cancer risk is also age-dependent. Prostate cancer is very uncommon in men under the age of fifty but the risk increases as a man gets older. Up to 80% of men aged eighty or more years old have evidence of prostate cancer in autopsy studies. Other risk factors for prostate cancer include ethic origin. African-American men have a higher rate of prostate cancer compared with Asian men.
There may also be some dietary factors which affect the prostate cancer risk. Diets high in animal fats, or low in selenium, lycopene and soy products may have a role in the development of prostate cancer.