

How Is Prostate Cancer Diagnosed?

If your prostate specific antigen (PSA) test or digital rectal exam (DRE) is abnormal, doctors may do more tests to find or diagnose prostate cancer.

  • Transrectal ultrasound: A probe the size of a finger is inserted into the rectum, and high-energy sound waves (ultrasound) are bounced off the prostate to create a picture of the prostate called a sonogram. This test may be used during a biopsy.
  • Biopsy: A small piece of tissue is removed from the prostate and looked at under a microscope to see if there are cancer cells.
    • Gleason score: This score is determined when the biopsy is looked at under the microscope. If there is a cancer, the score indicates how likely it is to spread. The score ranges from 2–10. The lower the score, the less likely it is that the cancer will spread. For more information, visit the National Cancer Institute’s (NCI’s) Prostate Cancer.

For more information about diagnosis, visit NCI’s Prostate Cancer Detection and Diagnosis.


If prostate cancer is diagnosed, other tests are done to find out if cancer cells have spread within the prostate or to other parts of the body. This process is called staging. Whether the cancer is only in the prostate, or has spread outside the prostate, determines your stage of prostate cancer. The stage of prostate cancer tells doctors what kind of treatment you need.

For more information about staging, visit NCI’s Stages of Prostate Cancer.