For most men, a biopsy is a logical next step if there appear to be cancerous changes developing in the prostate. In this procedure, a urologist removes tissue samples from the prostate using thin needles. At Memorial Sloan Kettering, you’ll likely have your biopsy as an outpatient, which means you’ll come for the procedure during the day and won’t have to stay overnight.
First, you’ll receive medicine to numb the area. Then we’ll use ultrasound to guide the placement of the needles and ensure that we take a tiny piece of tissue from areas we suspect are abnormal for our pathologists to examine.
We are committed to offering our patients the most-advanced techniques used to diagnose prostate cancer. Therefore, we use a prostate MRI to plan and guide your biopsy using novel targeting technology. For most biopsies, we remove 12 to 14 tissue samples. If the results indicate that you have prostate cancer, we may perform more tests to better understand the tumor and come up with your 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 one to five 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 (six 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 (seven or above) and is more likely to spread.
If the pathologist determines that cancerous cells are present in your biopsy tissue, we’ll likely recommend imaging tests to identify exactly where the tumor is located and determine the extent of the disease. We usually perform a test called an MRI with a device called an endorectal coil to examine the inside of the prostate and determine the tumor’s volume, location, and stage (the extent to which the cancer has spread to other parts of the body, if at all).
Other tests we may recommend before formulating a treatment plan for you include:
- MRI to help us stage the cancer and see whether it has spread to lymph nodes, other organs, or bones
- radionuclide bone scan to see whether the cancer has spread to the bones
- PET scan to see whether the cancer has spread to other organs in the body
Our researchers are also investigating new imaging techniques so that we have even better ways to characterize prostate cancer. These tools could help us predict how each man might respond to various treatments and evaluate a treatment’s effectiveness while it’s under way.