The prostate, a gland found only in men, is part of the reproductive system. Prostate cancer is a disease in which the cells of the prostate become abnormal and start to grow uncontrollably, forming tumors. Tumors that can spread to other parts of the body are called malignant tumors or cancers. Tumors that are not capable of spreading are said to be benign.
The prostate is a gland that produces the semen, the fluid that contains sperm. The prostate is about the size of a walnut and lies just beneath the urinary bladder. Usually prostate cancer is slow growing, but it can grow faster in some instances. As the prostate cancer grows, some of the cells break off and spread to other parts of the body through the lymphatic or the blood systems. This is known as metastasis. The most common sites of spreading are the lymph nodes and various bones in the spine and pelvic region.
The cause of prostate cancer is not clear; however, several risk factors are known. The average age at diagnosis of prostate cancer is around 72. In fact, 80% of prostate cancer cases occur in men over the age of 65. As men grow older, the likelihood of getting prostate cancer increases. Hence, age appears to be a risk factor for prostate cancer. Race may be another contributing factor. African-Americans have the highest rate of prostate cancer in the world, while the rate in Asians is one of the lowest. However, although the rate of prostate cancer in native Japanese is low, the rate in Japanese-Americans is closer to that of white American men. This suggests that environmental factors also play a role in prostate cancer.
There is some evidence to suggest that a diet high in fat increases the risk of prostate cancer. Studies also suggest that nutrients such as soy isoflavones, vitamin E, selenium, vitamin D and carotenoids (including lycopene, the red color agent in tomatoes and beets) may decrease prostate cancer risk. Vasectomy may be linked to increased prostate cancer rates as well. Workers in industries, such as welding, with exposure to the metal cadmium appear to have a higher than average risk of prostate cancer. Male sex hormone levels also may be linked to the rate of prostate cancer. In addition, some studies have linked increased prostate cancer risk to smoking.
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Author Info: Kristin Baker Niendorf MS, CGC, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Genetic Disorders Part I, 2002 |