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 used because they have been shown to find cancer in some people; however, it has not been proven in clinical trials that use of these tests will decrease the risk of dying from cancer.

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 (finding cancer before it causes symptoms) 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.

There is no standard or routine screening test for prostate cancer.

Screening for prostate cancer is under study and there are screening clinical trials taking place in many parts of the country.

Tests that may detect (find) prostate cancer are being studied:

Digital rectal exam

Digital rectal exam (DRE) is an exam of the rectum. 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 test

A prostate-specific antigen (PSA) test is a test that 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. PSA levels may also be high in men who have an infection or inflammation of the prostate or benign prostatic hyperplasia (BPH; an enlarged, but noncancerous, prostate).

Scientists at the National Cancer Institute are studying the combination of PSA testing and digital rectal exam as a way to get more accurate results from the screening tests.