Cancer Grading and Stages
Cancer Grading
Tumors with higher grades tend to grow faster than those with lower grades. They are also more likely to spread. Doctors use tumor grade along with your age and other factors to suggest treatment options.
One system of grading is with the Gleason score. Gleason scores range from 2 to 10. To come up with the Gleason score, the pathologist uses a microscope to look at the patterns of cells in the prostate tissue. The most common pattern (most like normal cells) is given a grade of 1 to 5 (almost abnormal). If there is a most common pattern, the pathologist gives it a grade of 1 to 5, and adds the two most common grades together to make the Gleason score. If only one pattern is seen, the pathologist counts it twice. For example, 1 + 1 = 2, a low Gleason score indicates low-grade cancer cells (slow growing, less likely to spread) versus 5 + 5 =10, a high Gleason score means high-grade cancer cells (more likely to grow quickly and spread). Thus, high-grade tumors are more likely than low-grade tumors to grow quickly and spread.
Another system of grading prostate cancer uses grades 1 through 4 (G1 to G4). G4 is more likely to grow quickly and spread than G1, G2 or G3.
Cancer Staging
If the biopsy shows that you have cancer, your doctor needs to learn the extent (stage) of the disease to help you choose the best treatment. Staging is a careful attempt to find out whether the tumor has invaded nearby tissues, whether the cancer has spread and, if so, to what parts of the body.
Stage I: The cancer can’t be felt during a digital rectal exam, and it can’t be seen on a sonogram. It is found by chance when surgery is done for another reason, usually for BPH. The cancer is only in the prostate. The grade is G1, or the Gleason score is no higher than 4 (that is a score of 2 + 2 = 4 or 1 + 3 = 4).
Stage II: The tumor is more advanced or at a higher grade than Stage I, but the tumor doesn’t extend beyond the prostate. It may be felt during a digital rectal exam, or it may be seen on a sonogram.
Stage III: The tumor extends beyond the prostate. The tumor may have invaded the seminal vesicles, but cancer cells haven’t spread to the lymph nodes.
Stage IV: The tumor may have invaded the bladder, rectum, or nearby structures (beyond the seminal vesicles). It may have spread to the lymph nodes, bones or to other parts of the body.
Tests to help determine staging
A bone scan allows the doctor to see if the cancer has spread to your bones.
A CT scan is a kind of x-ray that takes a series of detailed pictures of your pelvis or other parts of your body. This kind of x-ray can show if the cancer has spread to lymph nodes or other areas.
An MRI is a method by which a strong magnet is linked to a computer to make detailed pictures of areas inside your body. These pictures can be viewed on a monitor or printed on film. It is another way to see if the cancer has spread to lymph nodes or other areas of your body.
In order for the physician to see if there is cancer in bones, lymph nodes or in other parts of your body, a special dye is injected into your blood stream or via an enema before an MRI, a bone scan or CT scan is done. The dye creates a contrast in color to help make the abnormal areas easier to see.
