There is no standard or routine screening test for prostate cancer. Some screening tests are used because they have been shown to be helpful both in finding cancers early and decreasing the chance of dying from these cancers. Other tests are effective in detecting cancer in some cases, though their efficacy in actually decreasing the risk of death from cancer has yet to be proven.
Scientists study screening tests to find those with the fewest risks and most benefits. Cancer screening trials also are meant to show whether early detection decreases a person's chance of dying from the disease. For some types of cancer, finding and treating the disease at an early stage may result in a better chance of recovery.
Digital Rectal Exam (DRE)
During a DRE, the doctor or nurse inserts a lubricated, gloved finger into the lower part of the rectum to feel the prostate for lumps or anything else that seems unusual.
Prostate-Specific Antigen (PSA) Test
This test measures the level of PSA in the blood. PSA is a substance made mostly by the prostate that may be found in an increased amount in the blood of men who have prostate cancer. The level of PSA may also be high in men who have an infection or inflammation of the prostate or benign prostatic hyperplasia (enlargement of the prostate gland).
Scientists are studying the combination of PSA testing and using a digital rectal exam as a way to get more accurate results from screening tests. Some cancers never cause symptoms or become life-threatening, but if found by a screening test, the cancer may be treated. It is not known if treatment of these cancers would extend life longer than if no treatment were given, and treatments for cancer may have serious side effects. Follow-up tests, such as a biopsy, may also be done to diagnose cancer.
Transrectal Ultrasound (TRUS)
Transrectal ultrasound uses sound waves to make an image of the prostate on a video screen. For this test, a small probe is placed in the rectum. It gives off sound waves, which enter the prostate and create echoes that are picked up by the probe. A computer turns the pattern of echoes into a black and white image of the prostate. The procedure takes only a few minutes and is done in a doctor's office or outpatient clinic. You will feel some pressure when the TRUS probe is placed in your rectum, but it is usually not painful.
A biopsy is a procedure in which a sample of tissue is removed and then examined under a microscope. The doctor will use transrectal ultrasound (TRUS) for guidance and insert a narrow needle through the wall of your rectum into several areas of your prostate gland. The needle then removes a cylinder of tissue, usually about 1/2-inch long and 1/16-inch across, that is sent to the laboratory to see if cancer is present.
Healthy prostate cells are uniform in size and shape, neatly arranged in the patterns of a normal gland. As cancer spreads, cells lose their uniform appearance. They change from normal, well-differentiated tissues to more disorganized, poorly differentiated tissue. Eventually, a tumor develops. If your biopsy shows the presence of prostate cancer, the pathologist assigns each tissue sample a grade, indicating how far the cells have traveled along the path from normal to abnormal.
The process used to find out if cancer has spread within the prostate or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment.