The only way for a physician to truly diagnose a patient with prostate cancer is to perform a biopsy: to collect a small sample of prostate tissue and examine 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, you can be confident that you will not be tested unnecessarily. Our Washington University urologists use a range of techniques and tools to identify at-risk patients who should be given biopsies, and to guarantee that all biopsies and other tests are performed as precisely as possible.

What tests are used to diagnose prostate cancer at Siteman?

Patients at Siteman are given a range of urine, blood, and imaging tests to determine whether their high PSA scores indicate a real risk of aggressive prostate cancer.

When physicians at Siteman do recommend a biopsy, they often employ 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.

Many tests are included in this group.  Siteman physicians are among national 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 testing biomarkers and MRI scans in combination 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, a probe that is about the size of a finger is inserted into the rectum to check the prostate. The probe is used to bounce high-energy sound waves (ultrasound) off internal structures to create a picture. Siteman physicians 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 if there are any cancerous cells in the prostate, they will be captured in the biopsy. In addition, the detail of the imaging can help physicians to recognize when cancers can be treated with non-surgical methods.

Transrectal biopsy

A thin needle is inserted into the rectum through a small ultrasound probe and collects cells from the prostate for examination.

Transperineal biopsy

Although transrectal biopsy is performed 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 cores removed.

What happens after prostate cancer is diagnosed?

Once prostate cancer is diagnosed, it is given a grade: a number from 2 to 10 that indicates how aggressive it is, with 10 being the highest. The grade is called a Gleason score, and it’s 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 done to determine if the cancer has spread to other parts of the body. Conventional staging imaging includes a bone scan and a CT scan.  A bone scan can demonstrate abnormal bone activity, which could signify metastatic prostate cancer into the bone. A 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 diagnosed with it 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 those patients with more aggressive disease, prognosis is depended on a number of factors, including:

  • The stage of the cancer — whether the cancer has spread to other places in the body
  • Gleason score
  • The level of PSA elevation
  • The patient’s age
  • The treatment approach – surveillance, surgery, radiation, etc.

Treatment options also may depend on whether the patient has other health problems, expected side effects of treatment, past treatment for prostate cancer, and the wishes of the patient.