Cancer
Essay title: Cancer
Prostate cancer is cancer of the prostate gland. The prostate is part of the male reproductive system. This gland is locates inside the body at the base of the penis, just below the bladder and in front of the rectum. It is composed of the glandular and fibrous tissue enclosed in a capsule of connective tissue. The prostate is in the shape of a donut and about the size of a walnut. It surrounds the first inch or so of the urethra, the tube that carries urine from the bladder. Normal functions of the prostate depend on the presence of the male hormone testosterone, which is produced by the testes. The prostate produces semen, the thick, whitish fluid that carries sperm.
Cancer of the prostate has become the number one cancer in American men. In the United States, approximately 1 in every 11 men will develop prostate cancer during his lifetime. Prostate cancer becomes increasingly common with each decade of life. Over 80 percent of all cases are diagnosed in men over 65.
The incidence of prostate cancer increased 47 percent from 1973 to 1987, about a 2.6 percent increase each year. It is estimated that 106,00 new cases of prostate cancer were diagnosed in the US during the 1990. Black men in the US have the highest incidence of prostate cancer in the world.
Little is known about the cause of prostate cancer, and it is seldom possible to explain why a man has developed this disease. Scientists believe that cancer of the prostate develops over a period of many years as a result of gradual changes in the cells. No single theory explains the development of this disease, but a number of possible causes have been suggested. Investigations have focused on four general areas: genetic predisposition (heredity), hormonal influences, environmental and lifestyle factors, and sexually transmitted agents, including viruses. Data from population studies have produced opposite results. Some studies suggest a genetic predisposition to prostate cancer and an increased risk for blood relatives of men with the disease. However, other studies have not confirmed a genetic link.
Data from studies of people migrating from one geographic area to another point to the importance of the environment as a factor, including diet, in the development of prostate cancer. Some doctors suggest that a diet rich in fat increases the risk of prostate cancer.
Scientists have suspected that hormones contribute to the development of prostate cancer. Men who’s testicles were removed before puberty have little risk of developing this disease, apparently because the primary source of male hormones was removed. Currently, scientists are comparing testosterone production and metabolism in prostate cancer patients and their brothers as well as in men from families who do not have prostate cancer. Many studies have also been done with cancer causing agents. The results have not been very conclusive.
The possible role of sexually transmitted viral diseases in the development of prostate cancer has been examined by many researchers. Currently there are no conclusive results, but scientists are working hard.
To detect prostate cancer a person has to go to his doctor and get examined. Because the cause of prostate cancer remain unknown, pretension of the disease is not yet possible. However, when the disease is detected early , treatment is usually successful.
The only treatment for