Gleason Score

The Gleason Score is a grading system used by doctors to assess how aggressive prostate cancer cells appear under a microscope. It helps predict how quickly the cancer might grow or spread. This score, along with other test results, guides your doctor in recommending the most suitable treatment options for you.

What is Gleason Score?

The Gleason Score is a system that pathologists (doctors who study diseases) use to grade prostate cancer cells found in a tissue sample. It helps determine how aggressive the cancer is by looking at how much the cancer cells resemble healthy cells. This score is a key factor in planning your treatment.

When a prostate biopsy (a procedure to remove small tissue samples) is performed, a pathologist examines the cells under a microscope. They look for patterns in how the cancer cells are arranged and how abnormal they appear compared to healthy prostate cells. The pathologist assigns a grade from 1 to 5 to the two most common patterns of cancer found in the biopsy sample. A grade of 1 means the cells look very much like healthy cells, while a grade of 5 means the cells look very abnormal and disorganized. The first number represents the most common pattern, and the second number represents the next most common pattern. These two grades are then added together to get the Gleason Score, also called the Gleason sum. For example, if the most common pattern is grade 3 and the next most common is grade 4, the Gleason Score is 3+4=7. The lowest score typically reported for cancer is 6, as scores of 2-5 are rarely found in biopsy samples and are not considered cancerous. Recently, a simplified system called Grade Groups (1-5) has also been adopted. This system groups similar Gleason Scores together to make them easier to understand. For instance, a Gleason Score of 6 is Grade Group 1, while a Gleason Score of 3+4=7 is Grade Group 2, and 4+3=7 is Grade Group 3. Your doctor may use both the Gleason Score and Grade Group to explain your results.

Why it's ordered

Your doctor orders a Gleason Score to understand the aggressiveness of your prostate cancer. This information is crucial for predicting how the cancer might behave over time and for making informed decisions about your treatment plan. It helps tailor care specifically to your cancer's characteristics.

The Gleason Score is a vital tool for your healthcare team. It helps them predict the likelihood of your prostate cancer growing slowly or quickly, and whether it might spread to other parts of your body. A lower score generally means the cancer is less aggressive, while a higher score suggests a more aggressive cancer. This score, along with other factors like your prostate-specific antigen (PSA) blood test results, findings from a digital rectal exam (DRE), and imaging scans, helps your doctor determine the best course of action. Treatment options can range from active surveillance (closely monitoring the cancer) to surgery, radiation therapy, or other treatments. For example, a person with a low Gleason Score might be a candidate for active surveillance, meaning their doctor will monitor the cancer without immediate aggressive treatment. In contrast, someone with a high Gleason Score might need more immediate and intensive treatment to manage the cancer effectively. The score helps your doctor discuss the benefits and risks of each treatment option with you.

How to prepare

Preparation for a Gleason Score involves preparing for the prostate biopsy, which is the procedure that collects the tissue sample needed for grading. Your doctor will provide specific instructions, which usually include discussing your medications, especially blood thinners, and arranging for transportation if sedation is used.

Since the Gleason Score is determined from tissue obtained during a prostate biopsy, your preparation will focus on this procedure. Your doctor or nurse will give you detailed instructions before your biopsy. It is important to follow these instructions carefully to ensure the procedure is safe and effective. You will likely be asked to stop taking certain medications, especially blood thinners (anticoagulants), several days before the biopsy. These medications can increase your risk of bleeding during and after the procedure. Always discuss all your current medications, including over-the-counter drugs, supplements, and herbal remedies, with your doctor. Your doctor may also prescribe antibiotics for you to take before the biopsy to help prevent infection. You might be asked to have an enema at home before the procedure to clear your rectum. If you will receive sedation, you will need to arrange for someone to drive you home afterward, as you will not be able to drive yourself.

What to expect during

During the procedure to obtain a Gleason Score, you will undergo a prostate biopsy. This typically involves lying on your side or back while a doctor uses a thin needle to collect small tissue samples from your prostate gland. The procedure usually takes about 15-30 minutes and is performed with local anesthesia to minimize discomfort.

Before the biopsy begins, you will usually receive a local anesthetic (numbing medicine) to the area around your prostate to help prevent pain. The doctor will typically use an ultrasound probe, inserted into your rectum, to guide the biopsy needle precisely to different areas of your prostate gland. This helps ensure that samples are taken from the most suspicious areas, as well as other parts of the prostate. The doctor will then pass a thin, hollow needle through the wall of your rectum or through the skin between your scrotum and anus (perineum) to take several small tissue samples. You might feel a brief, sharp sting or pressure each time a sample is taken. Most biopsies collect 10 to 12 samples to get a comprehensive view of the prostate. After the samples are collected, they are sent to a pathology lab. There, a pathologist examines the tissue under a microscope to identify cancer cells, grade them based on their appearance, and calculate the Gleason Score. This process takes several days, so you will not receive your score immediately after the biopsy.

Understanding your results

Your Gleason Score results describe how aggressive your prostate cancer appears. Scores range from 6 to 10, with lower scores indicating less aggressive cancer and higher scores suggesting more aggressive cancer. Your doctor will interpret your specific score in the context of all your other test results and your overall health.

A Gleason Score of 6 is considered low-grade prostate cancer. This type of cancer is generally slow-growing and less likely to spread. Many people with a Gleason 6 score may be candidates for active surveillance, where the cancer is closely monitored without immediate treatment. A Gleason Score of 7 is considered intermediate-grade. This score is often broken down further into 3+4=7 or 4+3=7. A score of 3+4=7 means the most common pattern of cancer cells is grade 3, and the second most common is grade 4. This is generally less aggressive than a 4+3=7 score, where grade 4 cells are more dominant. Intermediate-grade cancers may require treatment, but the urgency and type can vary. Gleason Scores of 8, 9, or 10 are considered high-grade prostate cancer. These cancers are typically more aggressive, tend to grow and spread more quickly, and usually require more immediate and intensive treatment. Your doctor will explain what your specific score means for your prognosis and treatment options. It is important to remember that the Gleason Score is just one piece of information. Your doctor will combine it with your PSA levels, the findings from your physical exam, any imaging results, and your personal health history to give you a complete picture and recommend the most appropriate next steps.

Risks

The risks associated with obtaining a Gleason Score are primarily those related to the prostate biopsy procedure itself. These can include bleeding, infection, and discomfort or pain. Your doctor will discuss these potential risks with you before the biopsy and explain how they are managed.

Bleeding is a common risk after a prostate biopsy. You might notice blood in your urine, stool, or semen for a few days or weeks after the procedure. While usually mild, significant bleeding is a less common but possible complication. Your doctor will advise you on what to expect and when to seek medical attention. Infection is another potential risk, as the biopsy needle passes through the bowel or skin, which naturally contain bacteria. To reduce this risk, you will typically be given antibiotics to take before and sometimes after the procedure. Symptoms of infection can include fever, chills, or increased pain, and should be reported to your doctor immediately. Discomfort or pain in the biopsy area is also common. You might feel soreness, bruising, or a dull ache in your rectal or perineal area for a few days. Over-the-counter pain relievers can often help manage this discomfort. Rarely, more serious complications, such as urinary retention (difficulty urinating), can occur, requiring medical attention.

Frequently asked questions

What is the lowest possible Gleason Score for prostate cancer?

The lowest Gleason Score typically assigned to prostate cancer is 6. While the grading system technically goes from 2 to 10, scores below 6 are rarely found in biopsy samples and are not considered cancerous. A Gleason Score of 6 indicates a low-grade, less aggressive cancer. Your doctor will explain what this means for your specific situation.

What does a Gleason Score of 7 mean?

A Gleason Score of 7 means you have intermediate-grade prostate cancer. This score is often further specified as either 3+4=7 or 4+3=7. A 3+4=7 score indicates that grade 3 cells are most common, making it generally less aggressive than a 4+3=7 score, where the more aggressive grade 4 cells are dominant. Your doctor will use this detail to guide treatment decisions.

Can my Gleason Score change over time?

No, your initial Gleason Score, based on your biopsy, does not change. It is a snapshot of the cancer's appearance at the time of the biopsy. However, prostate cancer can evolve. If your cancer is monitored over time (active surveillance) or if new biopsies are taken, a subsequent biopsy might show a different Gleason Score if the cancer has changed or if a more aggressive area was found.

What are Gleason Grade Groups, and how do they relate to the Gleason Score?

Gleason Grade Groups are a newer, simplified system that categorizes Gleason Scores into five groups (1-5) to make them easier to understand. Grade Group 1 corresponds to a Gleason Score of 6, Grade Group 2 to a Gleason Score of 3+4=7, and so on, up to Grade Group 5 for Gleason Scores of 9-10. Your doctor may use both systems to explain your cancer's aggressiveness.

Does a higher Gleason Score mean I will have more symptoms?

Not necessarily. The Gleason Score describes how aggressive the cancer cells look, which helps predict how quickly the cancer might grow or spread. However, it does not directly correlate with the presence or severity of symptoms. Many people with prostate cancer, even those with higher Gleason Scores, may not experience noticeable symptoms, especially in the early stages.

Who interprets my Gleason Score, and what other factors are considered?

Your urologist or oncologist (cancer doctor) will interpret your Gleason Score. They will consider it alongside other important information, such as your PSA (prostate-specific antigen) blood test results, findings from your digital rectal exam (DRE), any imaging scans (like MRI), and your overall health, age, and personal preferences. All these factors together help your doctor recommend the best treatment plan for you.

Sources

• MedlinePlus — Gleason Score
• Mayo Clinic — Gleason Score
• Cochrane Library — Gleason Score