Table of Contents

Chapter 1: What Does a Diagnosis of Prostate Cancer Mean?

a. Making Sense of the Diagnosis

If you’re like many other men who are diagnosed with prostate cancer, you went to your doctor for a routine check-up and had a PSA and DRE (digital rectal exam) to screen for prostate cancer. Something irregular showed up, and your doctor sent you for a biopsy. Then, a few days after the biopsy, you were told that prostate cancer was found. Or, you might have noticed changes in your urinary or sexual function and asked your doctor about it. Then, after a full work-up, including a biopsy, the diagnosis of prostate cancer was made.

But what exactly did the doctor looking at your biopsy see? Why is it important for you to know what your tumor cells look like? After all, cancer is cancer, right?

In fact, the way your cells look under the microscope can tell a lot about your disease, and will often drive some very important decisions about treatment options.

Under normal conditions, your prostate cells, just like all other cells in your body, are constantly reproducing and dying. And each new prostate cell that grows has the same shape and appearance as all of the other prostate cells. But cancer cells look different, and the degree to which they look different from normal cells is what determines the cancer grade. Low-grade tumor cells tend to look very similar to normal cells, whereas high-grade tumor cells have mutated so much that they often barely resemble the normal cells.

The Gleason grading system accounts for the five distinct patterns that prostate tumor cells tend to go through as they change from normal cells. The scale runs from 1 to 5, where 1 represents cells that are very nearly normal, and 5 represents cells that don’t look much like prostate cells at all.

After examining the cells under a microscope, the pathologist looking at your biopsy sample assigns one Gleason grade to the most common pattern, and a second Gleason grade to the next most common pattern. The two grades are added, and your Gleason score, or sum, is determined.

Generally speaking, the Gleason score tends to predict the aggressiveness of the disease and how it will behave in your body. The higher the Gleason score, the less the cells behave like normal cells, and the more aggressive the tumor tends to be.

Remember, the Gleason score is not just a single number. It’s composed of the two most common Gleason patterns recognized, and the first number, representing the most common pattern, is often more important. So although two scores might be the same, the underlying grades might be different, and, therefore, the tumor characteristics might be different. For example, a Gleason 7 (3+4) cancer would likely prove to be less aggressive than a Gleason 7 (4+3) cancer, even though, technically speaking, both have the same Gleason score.

In some cases, the pathologist might identify a third pattern, which is less common but that has a higher grade than either of the first two patterns that comprised the Gleason score. The presence of this third pattern might indicate that the tumor is more aggressive than the Gleason score would otherwise imply. For example, if a Gleason 4+3 tumor also has some grade 5 cells, the cancer would be considered as being of higher grade disease overall.