Screening & Diagnosis For Prostate Cancer

Prostate cancer may not cause any symptoms at first. The first indication of a problem may come during a routine screening test, such as:

• 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 and analyzed for PSA, a substance that's naturally produced by your prostate gland to help liquefy semen. It's normal for a small amount of PSA to enter your bloodstream. However, if a higher than normal level is found, it may be an indication of prostate infection, inflammation, enlargement or cancer. Studies have not been able to show that routine screening decreases the chance that anyone will die of prostate cancer, but screening with PSA and DRE can help identify cancer at an earlier stage.
• Transrectal 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 get a picture of your prostate gland.
• Prostate biopsy. If initial test results suggest prostate cancer, your doctor may recommend biopsy. To do a prostate biopsy, your doctor inserts a small ultrasound probe into your rectum. Guided by images from the probe, your doctor uses a fine, spring-propelled needle to retrieve several very thin sections of tissue from your prostate gland. A pathologist who specializes in diagnosing cancer and other tissue abnormalities evaluates the samples. From those, the pathologist can tell if the tissue removed is cancerous and estimate how aggressive your cancer is.

Determining how far the cancer has spread
Once a cancer diagnosis has been made, you may need further tests to help determine if or how far the cancer has spread. Many men don't require additional studies and can directly proceed with treatment based on the characteristics of their tumors and the results of their pre-biopsy PSA tests.

• Bone scan. A bone scan takes a picture of your skeleton in order to determine whether cancer has spread to the bone. Prostate cancer can spread to any bones in your body, not just those closest to your prostate, such as your pelvis or lower spine.
• Ultrasound. Ultrasound not only can help indicate if cancer is present, but also may reveal whether the disease has spread to nearby tissues.
• Computerized tomography (CT) scan. A CT scan produces cross-sectional images of your body. CT scans can identify enlarged lymph nodes or abnormalities in other organs, but they can't determine whether these problems are due to cancer. Therefore, CT scans are most useful when combined with other tests.
• Magnetic resonance imaging (MRI). This type of imaging produces detailed, cross-sectional images of your body using magnets and radio waves. An MRI can help detect evidence of the possible spread of cancer to lymph nodes and bones.
• Lymph node biopsy. If enlarged lymph nodes are found by a CT scan or an MRI, a lymph node biopsy can determine whether cancer has spread to nearby lymph nodes. During the procedure, some of the nodes near your prostate are removed and examined under a microscope to determine if cancerous cells are present.

Grading
When a biopsy confirms the presence of cancer, the next step, called grading, is to determine how aggressive the cancer is. The tissue samples are studied, and the cancer cells are compared with healthy prostate cells. The more the cancer cells differ from the healthy cells, the more aggressive the cancer and the more likely it is to spread quickly.

Cancer cells may vary in shape and size. Some cells may be aggressive, while others aren't. The pathologist identifies the two most aggressive types of cancer cells when assigning a grade. The most common scale used to evaluate prostate cancer cells is called a Gleason score. Based on the microscopic appearance of cells, individual ratings from 1 to 5 are assigned to the two most common cancer patterns identified. These two numbers are then added together to determine your overall score. Scoring can range from 2 (nonaggressive cancer) to 10 (very aggressive cancer).

Staging
After the level of aggressiveness of your prostate cancer is known, the next step, called staging, determines if or how far the cancer has spread. Your cancer is assigned one of four stages, based on how far it has spread:

• Stage I. Signifies very early cancer that's confined to a microscopic area that your doctor can't feel.
• Stage II. Your cancer can be felt, but it remains confined to your prostate gland.
• Stage III. Your cancer has spread beyond the prostate to the seminal vesicles or other nearby tissues.
• Stage IV. Your cancer has spread to lymph nodes, bones, lungs or other organs.