A biopsy can be the next step when there are changes in the prostate cancer. During this procedure, we collect small pieces of tissue from your prostate. A urologist removes tissue samples from the prostate using thin needles. Most prostate biopsies at MSK are done on an outpatient basis. You will come in for the procedure during the day and will not have to stay overnight.
First, we will give you medicine to numb the area. Then, we’ll use ultrasound imaging to guide the placement of the needles. Ultrasound is an imaging scan that uses sound waves to make pictures of the inside of your body. We will take tiny pieces of tissue from areas we think may have cancer. After your biopsy, our pathologists will examine the tissue under a microscope to check for abnormal cells.
We can offer the most advanced methods to diagnose prostate cancer. A prostate MRI gives us an excellent view of the prostate. It’s used to see the type, size, and location of tumors, and can guide the biopsy. It can help us see areas that look suspicious. For most biopsies, we remove 12 to 14 tissue samples. We may do more testing to better understand the tumor and choose the best plan of action.
We estimate prostate cancer’s aggressiveness — meaning its potential to grow and metastasize, or spread, to other parts of the body — using the Gleason grading system. The pathologist who examines the sample obtained during your biopsy assigns a Gleason grade, or score.
A Gleason score is actually the sum of two numbers. To get them, the pathologist determines where the cancer is most prominent (or common) and assigns that the primary grade. He or she then determines where the cancer is next most prominent and assigns that region the secondary grade. A score from 1 to 5 is assigned for each area based on how aggressive the tumor appears.
A tumor with cells that appear close to normal is assigned a low Gleason score (6 or below); low-grade tumors are less likely to spread. A tumor with cells that appear clearly different from those of a normal prostate is assigned a high Gleason score (7 or above) and is more likely to spread.
Searching for Signs of Advanced Prostate Cancer
When you are newly diagnosed with prostate cancer, you may be at risk for it spreading beyond the prostate. It may already be in the lymph nodes or bones. Such cancer cells once were very hard to find with standard imaging methods, including MRI, CT scanning, and bone scans.
MSK has been a leader in developing a new kind of imaging called PSMA PET imaging. It can find prostate cancer outside of the prostate with great accuracy and far earlier than older imaging methods. In 2020, the FDA approved PSMA PET imaging for staging prostate cancer when there’s risk of it spreading. (Staging is how we describe the location, size, and other features of a cancer.) This imaging also is approved for cancer that returned after the first treatment, as shown by a rising PSA.