Prostate Cancer Screening

  • 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.

Screening for and Detecting Prostate Cancer
The general recommendation is that men start having annual prostate screenings at age 50 but a man who has any of the risk factors described above may want to ask a doctor whether to begin screening for prostate cancer earlier (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 exam -- 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.

If any abnormality is felt or the blood test is abnormal, the doctor may recommend a biopsy. A biopsy is done with guidance from an ultrasound image and several tiny samples are taken at the same time. The procedure is performed under local anethesia. 

National Cancer Institute (NCI) booklet (NIH Publication No. 05-1576)
Posted July