Prostate Cancer Risks, Causes and Cures

 Prostate Cancer Risks, Causes and Cures

Prostate Cancer



Prostate cancer is the most common type of cancer in men in the United States other than skin cancer. Of all the men who are diagnosed with cancer each year, more than one-fourth have prostate cancer. Research is increasing our understanding of prostate cancer. Scientists are learning more about the possible causes of prostate cancer and are looking for new ways to prevent, detect, diagnose, and treat this disease. Because of this research, men with prostate cancer now have a lower chance of dying from the disease.


The prostate


The prostate is a gland in a man's reproductive system. It makes and stores seminal fluid, a milky fluid that nourishes sperm. This fluid is released to form part of semen. The prostate is about the size of a walnut. It is located below the bladder and in front of the rectum. It surrounds the upper part of the urethra, the tube that empties urine from the bladder. If the prostate grows too large, the flow of urine can be slowed or stopped. To work properly, the prostate needs male hormones (androgens). Male hormones are responsible for male sex characteristics. The main male hormone is testosterone, which is made mainly by the testicles. Some male hormones are produced in small amounts by the adrenal glands.


Prostate cancer: who's at risk


The causes of prostate cancer are not well understood. Doctors cannot explain why one man gets prostate cancer and another does not. Researchers are studying factors that may increase the risk of this disease. Studies have found that the following risk factors are associated with prostate cancer:


Age. In the United States, prostate cancer is found mainly in men over age 55. The average age of patients at the time of diagnosis is 70.


Family history of prostate cancer. A man's risk for developing prostate cancer is higher if his father or brother has had the disease.


Race. This disease is much more common in African American men than in white men. It is less common in Asian and American Indian men.


Diet and dietary factors. Some evidence suggests that a diet high in animal fat may increase the risk of prostate cancer and a diet high in fruits and vegetables may decrease the risk. Studies are in progress to learn whether men can reduce their risk of prostate cancer by taking certain dietary supplements.


Although a few studies suggested that having a vasectomy might increase a man's risk for prostate cancer, most studies do not support this finding. Scientists have studied whether benign prostatic hyperplasia, obesity, lack of exercise, smoking, radiation exposure, or a sexually transmitted virus might increase the risk for prostate cancer. At this time, there is little evidence that these factors contribute to an increased risk.


Detecting prostate cancer


A man who has any of the risk factors described in the "Prostate Cancer: Who's at Risk" section may want to ask a doctor whether to begin screening for prostate cancer (even though he does not have any symptoms), what tests to have, and how often to have them. The doctor may suggest either of the tests described below. These tests are used to detect prostate abnormalities, but they cannot show whether abnormalities are cancer or another, less serious condition. The doctor will take the results into account in deciding whether to check the patient further for signs of cancer. The doctor can explain more about each test.


Digital rectal examination -- the doctor inserts a lubricated, gloved finger into the rectum and feels the prostate through the rectal wall to check for hard or lumpy areas.


Blood test for prostate-specific antigen (PSA) -- a lab measures the levels of PSA in a blood sample. The level of PSA may rise in men who have prostate cancer, BPH, or infection in the prostate.


Methods of treatment


Treatment for prostate cancer may involve watchful waiting, surgery, radiation therapy, or hormonal therapy. Some patients receive a combination of therapies. In addition, doctors are studying other methods of treatment to find out whether they are effective against this disease. (The "Promise of Cancer Research" section has information about research studies.)


Watchful waiting may be suggested for some men who have prostate cancer that is found at an early stage and appears to be slow growing. Also, watchful waiting may be advised for older men or men with other serious medical problems. For these men, the risks and possible side effects of surgery, radiation therapy, or hormonal therapy may outweigh the possible benefits. Men with early stage prostate cancer are taking part in a study to determine when or whether treatment may be necessary and effective. (See "The Promise of Prostate Cancer Research" section for information about this study.)