What are the limitations of the PSA test?
A few percent of prostate cancers do not produce detectable increases in the blood PSA, even with advanced disease. Many early cancers will also not produce enough PSA to cause a significantly abnormal blood level. It is therefore important not to rely only on blood PSA testing. The most useful additional test is a physical prostate examination by a doctor known as the digital rectal exam (DRE). During this examination a doctor inserts a finger into the rectum to feel the prostate for lumps, size, shape, tenderness, and hardness.
