Prostate Screening
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 your gland, you may need more 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 be an indication of prostate infection, inflammation, enlargement, or cancer.
- PSA in combination with DRE. Using both PSA testing and DRE increases the chances of detecting prostate cancer early, when treatment is most effective.
Diagnosing Prostate Cancer
If an abnormality is detected on a DRE or PSA test, your doctor may recommend tests to determine if you have prostate cancer, such as an ultrasound and a prostate biopsy.
- 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. This probe emits sound waves that bounce off the prostate gland. These echoes are collected and used to create a real-time image, helping your doctor assess the size, shape, and any abnormalities.
- 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 performed by inserting a thin needle into the prostate to collect tissue. The tissue sample is analyzed in a lab to determine presence or absence of cancer cells.
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. In a laboratory, a 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. Scoring is based upon the combination of two numbers, with a range from 2 (non-aggressive cancer) to 10 (very aggressive cancer).
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 has spread beyond your prostate, your doctor may recommend the following imaging tests:
- Bone scan
- Ultrasound
- Computerized tomography (CT) scan
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET) scan
Not every person should have every test. Your doctor will help determine which tests are best for your individual case.
Stages
Once testing is complete, your doctor assigns your cancer a stage to determine treatment options. The stages of prostate cancer are listed below:
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Stage I: Cancer is confined to a small area within the prostate. Under the microscope, the cancer cells appear non-aggressive.
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Stage II: Cancer may still be small but looks aggressive under the microscope, or it may be larger and involve both sides of the prostate gland.
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Stage III: Cancer has spread beyond the prostate to the seminal vesicles or nearby tissues.
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Stage IV: Cancer has invaded nearby organs (such as the bladder) or spread to lymph nodes, bones, lungs, or other distant sites.