Staging and grading help both patients and doctors understand the severity of prostate cancer.
Grading can be done early in the process and usually involves examining tissue from a needle biopsy to describe how aggressive the cancer is. The higher the grade, the more aggressive the tumor.
Pathologists grade prostate cancer using the Gleason system, which assigns a rating of 1 to 5 to the prostate’s two most cancerous areas, with a 1 meaning the cancer cells resemble normal prostate cells, and a 5 meaning the cells look very abnormal. Those two numbers are added together to get a Gleason score, he explained. The lab report will say, for example, 3+4=7.
In general terms, a Gleason score of 6 or less means that the tumor is well differentiated, resembles more normal prostate cells and is less aggressive. A score of 7 would be moderately differentiated, while 8, 9 and 10 are poorly differentiated and very aggressive.
Staging describes how far the cancer has spread. If it is a higher-stage tumor, it could have spread beyond the prostate gland, de la Roza said.
Staging can be pathological, which involves examining tissue from biopsies or surgery, or clinical, which usually involves imaging, such as a CT or MRI scan, as well as a physical exam and lab tests.
Staging and grading will help determine treatment, which could range from surgical removal of the prostate to radiation therapy to a “wait-and-see” approach of active surveillance.
“In general, the well-differentiated tumors — anything 6 or below — may not need to be treated,” he said. Anything scored above 6 would generally require treatment.
De la Roza urged prostate cancer patients to take an active role in treatment decisions. While grading and staging are important in determining treatment, a patient’s age, desires and lifestyle have to be considered, too. “Patients have to be part of the decision-making with the doctors, because it will depend on many, many factors whether they need to be treated or not, and what kind of treatment they get.”
This article appears in the fall 2015 issue of Cancer Care magazine.