What Is the Gleason Score?
If cancer cells are found during a biopsy, the pathologist will use a method known as the Gleason system to describe (or grade) the two types of tissue that make up most of the tumor. Differentiation describes how different the prostate cancer cells look when compared with normal prostate cells. A number ranging from 1 (well-differentiated) to 5 (very poorly differentiated) is assigned to each of the two patterns the pathologist sees. The two numbers are then added together to produce a total Gleason score between 2 and 10. The higher the number, the more aggressive the cancer is likely to be.
After prostate cancer has been diagnosed and a Gleason score has been determined, additional tests are performed to find out if cancer cells have spread to other parts of the body.
- Lymph Node Biopsy: The purpose of this test is to find out if cancer has spread from your prostate to nearby lymph nodes. If your lymph nodes appear enlarged in medical images, your doctor may want you to have a biopsy before surgery. However, most biopsies are done during surgery.
- CT Scan: A CT (Computed Tomography) scan, also called a CAT (Computed Axial Tomography) scan, makes several cross-sectional images of your body using special x-rays and computer enhancement, creating an image many times more precise than a simple x-ray. A CT scan can be used in several ways: to detect tumors and determine the stage and location of the cancer; after treatment, to find out how effective the treatment was; and during a biopsy, to guide the doctor to the exact location of the tumor.
- MRI: MRI (Magnetic Resonance Imaging) is an imaging machine that uses a large magnet, a computer and radio waves to look inside and evaluate parts of your body. This test helps determine if cancer has spread beyond the prostate.
- Radionuclide Bone Scan: This test is often done as part of a checkup to be sure that your bones are free of cancer and also to determine the effects of cancer treatment on your bones. A medication that contains a small amount of radioactive material is injected into a vein in your arm. Radiation rays from the medication make an image on photographic film.