Diagnosis

Screening for prostate cancer

Whether to test healthy men with no symptoms for prostate cancer is controversial. Medical organizations don't agree on the issue of screening and whether it delivers benefits.

Some medical organizations recommend men consider prostate cancer screening in their 50s, or sooner for men who have risk factors for prostate cancer.

Discuss your particular situation and the benefits and risks of screening with your doctor. Together, you can decide whether prostate cancer screening is right for you.

Prostate screening tests might include:

  • Digital rectal exam (DRE). During a DRE, your doctor inserts a gloved, lubricated finger into your rectum to examine your prostate, which is adjacent to the rectum. If your doctor finds any abnormalities in the texture, shape or size of the gland, you may need further tests.
  • Prostate-specific antigen (PSA) test.A blood sample is drawn from a vein in your arm and analyzed for PSA, a substance that's naturally produced by your prostate gland. It's normal for a small amount of PSA to be in your bloodstream. However, if a higher than normal level is found, it may indicate prostate infection, inflammation, enlargement or cancer.

PSA testing combined with DRE helps identify prostate cancers at their earliest stages. Hence, debate continues surrounding prostate cancer screening.

Diagnosing prostate cancer

If a DRE or PSA test detects an abnormality, your doctor may recommend further tests to determine whether you have prostate cancer, such as:

  • Ultrasound. If other tests raise concerns, your doctor may use transrectal ultrasound to further evaluate your prostate. A small probe, about the size and shape of a cigar, is inserted into your rectum. The probe uses sound waves to create a picture of your prostate gland.
  • Collecting a sample of prostate tissue. If initial test results suggest prostate cancer, your doctor may recommend a procedure to collect a sample of cells from your prostate (prostate biopsy). Prostate biopsy is often done using a thin needle that's inserted into the prostate to collect tissue. The tissue sample is analyzed in a lab to determine whether cancer cells are present.
  • MRI fusion. While still being developed worldwide, MRI fusion to assist in prostate biopsy and diagnosis is being used more and more.

At Mayo Clinic, urologists and radiologists collaborate to leverage MRI fusion biopsy technology, yielding the best fusion imaging available for prostate cancer care.

Mayo Clinic also leverages MRI-TRUS fusion technology, which blends (fuses) images from an MRI scan and transrectal ultrasound (TRUS) to create a more-precise 360-degree prostate map, which in turn can improve prostate biopsy accuracy.

Mayo Clinic is also the first medical center in the United States approved by the Food and Drug Administration to prepare and administer C-11 choline PET scanning to help detect recurrent prostate cancer at its earliest stages — before it can be detected by other imaging tests — and enable more-precise targeting for follow-up treatment.

Determining whether prostate cancer is aggressive

When a biopsy confirms the presence of cancer, the next step is to determine the level of aggressiveness (grade) of the cancer cells. A laboratory pathologist examines a sample of your cancer to determine how much cancer cells differ from the healthy cells. A higher grade indicates a more aggressive cancer that is more likely to spread quickly.

The most common scale used to evaluate the grade of prostate cancer cells is called a Gleason score. Gleason scoring combines two numbers and can range from 2 (nonaggressive cancer) to 10 (very aggressive cancer).

In addition, genomic testing in increasingly being used to more accurately assess risk and detect aggressive prostate cancer.

Mayo Clinic physicians and researchers are leaders in the development of biomarkers for prostate cancer. Doctors in Mayo Clinic's Center for Individualized Medicine are advancing research on the use of biomarkers in blood and in prostate tissue to better individualize and optimize treatment for men with prostate cancer. The technology helps caregivers distinguish between insignificant and significant prostate cancer, as well as identify particularly aggressive prostate cancer in men undergoing surgery.

Determining how far the cancer has spread

Once a prostate cancer diagnosis has been made, your doctor works to determine the extent (stage) of the cancer. If your doctor suspects your cancer may have spread beyond your prostate, one or more of the following imaging tests may be recommended:

  • Bone scan
  • Ultrasound
  • Computerized tomography (CT) scan
  • Magnetic resonance imaging (MRI)
  • Positron emission tomography (PET) scan

At Mayo Clinic, caregivers can also turn to prostate-specific membrane antigen (PSMA) studies to help detect the extent of newly diagnosed prostate cancer and whether the disease has spread to nearby lymph nodes.

Mayo clinicians also use recent 7 Tesla (7T) magnet imaging technology advancements to differentiate between prostate cancer that does or doesn't require immediate intervention.

Not every person should have every test. Your doctor will help determine which tests are best for your individual case.

Once testing is complete, your doctor assigns your cancer a stage. This helps determine your treatment options. The prostate cancer stages are:

  • Stage I. This stage signifies very early cancer that's confined to a small area of the prostate. When viewed under a microscope, the cancer cells aren't considered aggressive.
  • Stage II. Cancer at this stage may still be small but may be considered aggressive when cancer cells are viewed under the microscope. Alternatively, cancer that is stage II may be larger and may have grown to involve both sides of the prostate gland.
  • Stage III. The cancer has spread beyond the prostate to the seminal vesicles or other nearby tissues.
  • Stage IV. The cancer has grown to invade nearby organs, such as the bladder, or spread to lymph nodes, bones, lungs or other organs.