Types of Prostate Biopsies: Your biopsy and Gleason score Part 1

Geoff McLennan, Prostate Cancer Survivor and Advocate

A urologist will usually, but not always, suggest a biopsy of your prostate when there is reason to believe the test is appropriate. Let’s look closer at why a biopsy might be taken, what it can reveal and if you should speak with your urologist about getting one.

Earlier posts in this series have discussed the steps and procedures urologists may follow leading to a biopsy. These include: the digital rectal exam (DRE), the prostate specific antigen blood test (PSA), magnetic resonance imaging (MRI), or a genetic test such as Myriad MyRisk^® Hereditary Cancer Testing which includes a review of your family history of cancer with a certified geneticist. A biopsy, long considered the “gold standard” for diagnosing prostate cancer, may be the next step. There are many ways to evaluate the prostate for cancer (PCa). Will the biopsy prove to be the most accurate indicator? Can this test be subjective and lead to misdiagnosis? And what is the meaning and significance of a Gleason score?

In this first post of two, I’ll discuss prostate biopsy options, and in the next I’ll break down the Gleason score and how it impacts how your doctor will proceed.

What is a prostate biopsy and how does it work?

There are a few different types of biopsies your urologist may recommend.

Transrectal ultrasound biopsy

One test, known as the transrectal ultrasound (TRUS) biopsy, involves insertion of an ultrasound probe into the rectum that uses sound waves to create images of your prostate, allowing biopsy needles (probes) to accurately pierce the rectal wall to reach the prostate. Biopsies are taken in differing quantities, but 12 to 18 probes are common. Some research institutions take 21 or more probes.

A saturation biopsy involves taking 50 or more probes and is not widely used anymore due to poor results and phobia of hat pins. The actual tissue taken per probe is very small (about 11mm) in proportion to a 50cc or larger prostate, and without any active imaging the biopsy procedure inside your body can be described as a “shot in the dark.” However, various biopsies differ considerably in degrees of accuracy. Yes, your biopsy can give you a higher or lower batting average for detection of cancer.

Transperineal biopsy

In another type of biopsy, the transperineal biopsy, probes are inserted between the anus and the scrotum, or through the perineal skin. This method avoids most risks of infection, as the transrectal entry can transfer fecal matter and other biproducts from the digestive tract into urinary tissue. Some urologists believe that probing via the perineum allows better access to regions of the prostate often missed by the transrectal procedure. Once your biopsy is completed, usually in less than 30 minutes, you will be asked to spend a few moments at rest before leaving. You may notice small amounts of blood in your urine and stool for weeks after this procedure and that bragging about the procedure can weaken your friends’ appetites at lunch.

Rarely, but sometimes, the transrectal biopsy can lead to a serious systemic infection called sepsis. However, this is rare and usually prevented by precautions such as taking a prescribed antibiotic and cleaning of the skin surfaces in the rectum via one or more enemas before the biopsy. Assuming your recovery goes well, shortly after the biopsy your urologist will receive an interpretation of your tissue samples from the pathologist and call you in for a consultation. At this time, you will likely be given your formal diagnosis.  Also, don’t be fearful of the biopsy. I have had four over 10 years and was impressed by the procedural care and advancing technology brought to my care by skilled and dedicated clinicians.

What type of prostate biopsy is right for you?

As we know, with time come improvements in science, including prostate biopsies. Recent updates to the standard TRUS biopsy include better imaging to guide the urologist into areas of the prostate and are called guided or combined MRI guided biopsy, inbore and fusion biopsy (combining the image with a target in the prostate), and the newest, the micro-ultrasound biopsy. These newer types of biopsies provide the urologist a better look at prostate tissue, size of the prostate and possible areas that can be missed or lead to a misdiagnosis with the imaging technology. Research has proven that newer imaging technology such as the micro-ultrasound finds significantly more PCa than the older TRUS imaging. Thus it is critically important that you and your urologist thoroughly discuss what type of biopsy if accompanied by what type of imaging is the best for you and why. What urologists ideally want is a bullseye biopsy into the tumor or suspected cancer images that leads to a clearer determination or diagnosis of your PCa.

I hope this helps your understanding of how a prostate biopsy works, the benefits to each and the importance of having a discussion with your urologist about your options. In part two of this blog series, I’ll discuss the Gleason score, how the biopsy tissue is used to determine the score and what it might mean for your future treatment.

If you have questions about genetic testing for prostate cancer, please reach out to [email protected].

Geoff is dedicated to helping families and friends support a prostate cancer patient. He joined the board of Active Surveillance Patients International (ASPI) in 2018 and is an 11-year PCa patient. As a PCa patient advocate, he envisions providing a broad understanding of how patients can collaborate with clinicians for realistic medical care. He enjoys meeting and learning from his clinicians, cancer researchers, providing free online programs for patients, and reminds us that “to live, learn and thrive with PCa” is the motto of ASPI. He is glad he took science courses for understanding a healthy lifestyle that includes exercise and diet.

Geoff also volunteers as a board member and past chairman of the Placer County Mental Health Advisory Board where his interest includes therapy and resources for AS men, and a broad oversight of community mental health programs and innovations. He is married to Constance McLennan, a fine artist, has a grown son, and lives in Northern California.