The only way for a physician to truly diagnose prostate cancer is through a biopsy. This involves collecting a small sample of prostate tissue and examining it under a microscope for cancerous cells. Research has found, however, that many patients with high PSA levels don’t actually need biopsies.

As a Siteman patient, know that you will only be tested when absolutely necessary. Washington University urologists use a range of techniques and tools to identify at-risk patients who require biopsies. Our experts perform all testing as precisely as possible.

What tests are used to diagnose prostate cancer at Siteman?

At Siteman, Washington University prostate cancer specialists perform a range of urine, blood, and imaging tests to determine whether high PSA scores indicate a real risk of aggressive prostate cancer.

When our experts do recommend a biopsy, they often use advanced imaging methods to make sure they target the correct area of the prostate.

Urine and blood-based biomarkers

These tests evaluate a patient’s blood and urine for signs of potential prostate cancer. Depending on the results, doctors may decide that a patient’s high PSA score does not indicate cancer.

There are many urine and blood-based biomarker tests. Washington University prostate cancer specialists at Siteman are leaders in identifying and assessing the accuracy of biomarkers to correctly diagnose prostate cancer, and to correctly differentiate aggressive from slow-growing disease.


This helps the urologist identify which part of the prostate to biopsy and check for signs of cancer in the surrounding tissue.

Clinicians and researchers at Siteman are researching ways to combine biomarkers and MRI scans to predict which patients with high PSA scores have cancer, and which of those patients have a more serious form of the condition.

Transrectal ultrasound

During this test, the urologist inserts a finger-sized probe into the rectum to check the prostate. The probe bounces high-energy sound waves (ultrasound) off internal structures to create a picture. Washington University prostate cancer experts at Siteman have begun to explore the use of newer ultrasound technology that allows for higher resolution imaging of the prostate, which is only available at a few locations in the world.

MRI-fusion biopsy

During an MRI-fusion biopsy, the urologist will combine a patient’s MRI scan and ultrasound imaging to pinpoint the suspicious area of the prostate. This means that the biopsy will catch any cancerous cells in the prostate. In addition, the detail of the imaging can help physicians to recognize when cancers can be treated with non-surgical methods.

Transrectal biopsy

The urologist inserts a thin needle into the rectum through a small ultrasound probe and collects cells from the prostate for examination.

Transperineal biopsy

Although transrectal biopsy is available at many locations, Siteman urologists conduct a high number of transperineal biopsies that go through the skin rather than the rectum.  This dramatically reduces the risk of infection and improves the quality of the biopsy.

What happens after prostate cancer diagnosis?

Once prostate cancer is diagnosed, it is given a grade on a scale of 2 to 10. The scale indicates how aggressive the cancer is, with 10 being the highest. The grade, called a Gleason score, is based on the tissue samples collected from the prostate during the biopsy.

Depending on the patient’s PSA level and Gleason score, additional tests may be needed to determine if the cancer has spread to other parts of the body. Conventional staging imaging includes a bone scan and a CT scan:

  • Bone scan: demonstrates abnormal bone activity, which could indicate prostate cancer that has spread into the bone (metastatic prostate cancer)
  • CT scan: takes detailed pictures of organs to determine if the cancer has spread outside the prostate

What is the average prognosis of patients with prostate cancer?

Overall, the prognosis of prostate cancer is very good. Most patients who get a prostate cancer diagnosis as a result of PSA screening are found to have early disease. The majority of prostate cancers that are detected this way can be either observed with active surveillance or cured with a prostatectomy.  For patients with more aggressive disease, prognosis depends on a number of factors:

  • The stage of the cancer
  • Gleason score
  • PSA level
  • The patient’s age
  • The treatment approach – surveillance, surgery, radiation, etc.

Treatment options also may depend on the patient’s general health, expected side effects of treatment, past treatment for prostate cancer and the wishes of the patient.