Men who select periodic screening for prostate cancer often have a prostate-specific antigen (PSA) blood test. If the PSA level is abnormally high, men often need a biopsy. A biopsy not only confirms the presence of cancer, but additionally provides details about how it might grow and spread. This is finished by making a Gleason rating from the biopsy samples.
Reaching the middle
The commonest kind of prostate biopsy is a transrectal biopsy. Here, the doctor moves a needle through the rectum and into the prostate to remove a small cylinder of tissue, called the core. Typically, 12 core samples are taken from different areas of the prostate. Your doctor may additionally take tissue samples from questionable areas identified during a DRE or possibly from a prostate MRI, if this was a part of the pre-biopsy evaluation.
Another kind of biopsy that’s increasingly getting used is the transperineal biopsy. This involves taking tissue core samples through the skin between the perineum, rectum and scrotum. Studies have shown that they’ve fewer complications than transrectal. “Another advantage of transperineal biopsies is that samples are more easily obtained from the front of the prostate, where more aggressive cancers may appear,” says Dr. Garnick.
A pathologist then examines the core samples. If the tissue shows prostate cancer, the pathologist grades essentially the most prevalent kind of cancer cell on a scale of three to five. The higher the number, the more aggressive the cancer. The pathologist does the identical for the second most prevalent kind of cancer cell. The sum of the 2 scores is the Gleason rating — for instance, 3+3=6, 3+4=7, 4+3=7, 4+4=8, etc.
- 6 indicates that the cancer will grow more slowly and is less prone to spread.
- 7 indicates intermediate stage cancer.
- 8 to 10 (10 is the very best rating) means advanced, aggressive cancer.
Beyond the Gleason rating
The final Gleason rating doesn’t provide some necessary nuances that influence therapy decisions. For example, a Gleason rating of seven (4+3) is potentially more dangerous than a Gleason rating of seven (3+4). “The first number represents the normal cell pattern,” says Dr. Garnick. “Grade 4 cells are more abnormal and more likely to spread than grade 3 cells, so a score of 4+3 is a higher-risk cancer than 3+4.”
Another problem is that advanced cancers are linked. “Gleason 8, 9, and 10 cancers can make a big difference in their aggressiveness,” says Dr. Garnick. Gleason scores also depend upon where within the prostate the sample comes from. “Cores can come from different areas of the same tumor or from different tumors in the prostate,” says Dr. Garnick. “Because grade can vary within the same tumor or between different tumors, different cores can have different Gleason scores.”
To help address these issues, the International Society of Urological Pathology created a brand new grading system. It divides the Gleason rating into five grade groups:
- Grade group 1 includes Gleason 3+3=6.
- Grade group 2 includes Gleason 3+4=7.
- Grade group 3 includes Gleason 4+3=7.
- Grade group 4 includes Gleason 4+4=8.
- Grade group 5 includes Gleason 4+5=9, 5+4=9, and 5+5=10.
How are Gleason scores used?
Cancers with a Gleason rating of 8, 9, or 10 often require treatment, and your doctor will discuss which options are best for you. However, the necessity and timing of treatment for Gleason scores of 6 and seven is just not all the time clear.
Most men with Gleason 6 or 7 (3+4), which indicate low-risk cancer, can receive treatment or go on energetic surveillance, through which they monitor their PSA levels for changes. . However, some men with low-risk cancers feel uneasy about being so near a more aggressive cancer and need to start out treatment sooner.
Other results from the biopsy are also used to calculate treatment options, akin to the variety of biopsy cores that contain cancer, the proportion of every core that incorporates cancer, and whether cancer was found on either side of the prostate. “The Gleason score is an important marker in the management of prostate cancer, but the number only provides information to help guide therapy decisions,” says Dr. Garnick. “Ultimately, it's up to the doctor and the patient to determine the next steps.”
Photo: © janiecbros/Getty Images