Diagnosing prostate cancer starts with a biopsy. When abnormal cells are found in the prostate tissue samples removed during the biopsy, a pathologist will assign a score to the two most predominant cell patterns to create a Gleason score. Based on the Gleason score, the prostate cancer’s grade is determined. This will direct the next steps in the treatment process.
The Gleason score is a grading system for prostate cancer, named after the doctor who established this scoring system. As cancer cells grow and divide, they look different from healthy cells. The more advanced the cancer, the less the cells look like healthy cells.
The pathologist reviewing the tissue samples will assign a number between 1 and 5 to the first and second most common patterns. A one means the cells look healthy, while a score of five means the cells are highly different from healthy cells. The two numbers are then added together to establish the patient's Gleason score. This information is included in the pathology report.
The Gleason score determines the aggressiveness of prostate cancer and the likelihood of it spreading. Below is a more detailed explanation of what your Gleason score means. Note that any score less than a six is not considered cancer.
The grade group system is a newer, more straightforward system than the Gleason score. Under this system, cancer cells are classified into grade groups 1 through 5. A grade group of 1 means the cancerous cells look almost normal and are growing slowly, if at all. A grade group of 5 means the cells look very abnormal and are growing quickly.
Here is how grade groups correlate with the Gleason score:
The grade group system can be more precise than the Gleason score. For example, Grades 2 and 3 have the same Gleason score, but the aggressiveness of the cancer is different. Using the Gleason score and grades together can help the urologist make their best recommendation on what should happen next.
The Gleason score, along with the grade of cancer, will help the doctor assess how quickly the cancer is growing. For intermediate or high-grade cancers, additional tests are needed to see if the cancer has spread outside the prostate. Treatment may begin quickly, and an oncologist should lead it. They will finalize the stage of cancer and determine the timing of each treatment, including surgery, if necessary.
Less aggressive cancers are likely to follow the active surveillance procedure of follow-up PSA blood tests and digital exams every six months. If the PSA numbers continue to go up, a repeated biopsy may also be needed. These patients have some time to review treatment options and discuss them with one or more cancer specialists in addition to the urologist.
Remember that there are more options than surgery if prostate cancer is found. For those whose cancer is found at a later stage, surgery is more likely. Talk to an oncologist about what’s best for you. They will work with your urologist to create a treatment plan that can be started when the time is right.