What Do Prostate Cancer Test Results Mean?

A prostate biopsy is used to diagnose prostate cancer. In this procedure, a pathologist will study prostate tissue collected from different samples. About 10 to 12 samples (called cores) are removed and tested during the biopsy procedure. Your pathologist will then create a report that summarizes the results.^1,2

If you are diagnosed with prostate cancer, the report will describe the risk of your cancer progressing. It will use scores to define the grade of the cancer. It may also mention other suspicious or abnormal results. Talk to your doctor about what the results of your tests mean.^1,3

Prostate-specific antigen (PSA) test results

PSA is a protein made by cells in the prostate. A blood test for PSA is often used for routine screening in people without symptoms. It may also be the first test in people who show symptoms.^1,4

Blood PSA levels are measured in nanograms per milliliter (ng/mL). A higher PSA level indicates a higher risk of prostate cancer. Many doctors follow these guidelines:^1,4

• Under 4 ng/mL – lower likelihood of prostate cancer
• Between 4 and 10 ng/mL – approximately 25 percent chance of having prostate cancer
• Above 10 ng/mL – approximately 50 percent or higher chance of having prostate cancer

Many factors other than cancer affect PSA levels. Often, PSA tests may detect small tumors that are not life-threatening. Treating such small tumors can potentially expose you to unnecessary complications and side effects.⁴

Experts recommend PSA testing based on individual situations. For example, people over 70 years old generally should not undergo PSA-based screening.⁴

Biopsy test results

If you have high PSA levels or other results that may indicate prostate cancer, your doctor may suggest a biopsy to be sure. During a biopsy, your doctor will use a needle to remove 10 to 12 samples from different areas of the prostate. A pathologist will then look at the samples under a microscope. They may report the results as negative, positive, or suspicious.^1,3

Negative biopsy results

Negative results mean no cancer cells were seen in the biopsy. In this case, you may not need other tests. But it is possible that a biopsy can miss a cancer. If your doctor still suspects you have prostate cancer, they may suggest other tests.¹

Positive biopsy results: Gleason score and Grade Groups

Positive results mean cancer cells were seen in the biopsy. In this case, your doctor will assign the cancer a grade. Higher grades are more likely to grow and spread quickly. Your doctor may use the Gleason system. In this system, each sample is given a score from 1 to 5. A grade of 1 means that the cells look relatively normal. A grade of 5 means that cells look very abnormal.^1,3,5

Your Gleason score is a combination of the 2 most common grades from your samples. The score may be written as an equation, such as 3+4=7. This score would mean that the most common grade in your samples was 3, with fewer samples being grade 4. They are added together to get a Gleason score of 7.^1-3

The Gleason score ranges from 2 to 10. Scores below 6 are rare. Prostate cancers are divided into 3 groups:^1,3

• Gleason score 2 to 6 – low-grade cancer that is unlikely to spread
• Gleason score 7 – intermediate-grade cancer
• Gleason score 8 to 10 – high-grade cancer

The Gleason score may not be the best way to describe the grade. Many doctors instead use Grade Groups. A higher Grade Group describes cancer as more likely to grow and spread quickly. The higher the grade group, the more likely it is for the cancer to grow and spread quickly:^1,3

• Grade Group 1 = Gleason score 6 or less
• Grade Group 2 = Gleason score 3+4=7
• Grade Group 3 = Gleason score 4+3=7
• Grade Group 4 = Gleason score 8
• Grade Group 5 = Gleason score 9 or 10

Positive biopsy results: TNM staging

The stage of prostate cancer refers to how far it has spread. The most common staging system is the TNM system. This system is based on:^2,5,6

• T – Extent of the tumor
• N – Whether it has spread to nearby lymph nodes
• M – Whether it has metastasized to other body parts
• PSA level at diagnosis
• Grade Group

The stages are numbered with Roman numerals from I (1) to IV (4). A lower number means the cancer has spread less. Knowing the stage helps doctors determine possible outcomes and best treatment options.⁶

Suspicious biopsy results

Biopsy samples may show other abnormal features. Some features predict future cancer or affect treatment. But other features do not. Suspicious or abnormal features may include:^1,3

• Prostatic intraepithelial neoplasia (high-grade) – a precancer
• Atypical small acinar proliferation – suspicious for cancer (also called glandular atypia or atypical glandular proliferation)
• Proliferative inflammatory atrophy – smaller prostate cells and signs of inflammation
• Prostatitis – inflammation of the prostate not linked to prostate cancer
• Intraductal carcinoma – cancer cells growing into prostate ducts, which typically indicates nearby high-grade prostate cancer
• Perineural invasion – cancer cells seen along a nerve fiber, which means a greater risk that cancer has spread

Other test results

If biopsy results are positive for prostate cancer, your doctor may suggest other lab tests. Some of these test the cancer cells for genetic changes. Others look for certain proteins. The results of these additional tests can help your doctor:^1,3

• Understand the risk of the cancer spreading quickly
• Decide the best treatment options
• Know whether certain targeted therapy drugs could help you

Talk to your doctor or care team if you have questions about your prostate cancer test results. They can help you understand what your specific results mean for you and your health.