Understanding Prostate Cancer: Diagnosing, Grading, and Staging
(Read time: 5 minutes)
This article is not intended to replace professional medical care or advice. If you have any questions or need additional information, please talk with your doctor.
A prostate cancer diagnosis can be a life-changing event. This article provides more information on how prostate cancer is diagnosed, graded, and staged.
How prostate cancer is diagnosed
Prostate cancer may be found through early detection and screening.
A digital rectal exam (DRE) and a prostate-specific antigen (PSA) blood test may be performed by your physician. PSA levels are often monitored over time, and for some, over the course of several years. Changes in PSA levels may warrant further testing for cancerous cells. Depending on results of these exams, your physician may conduct a prostate biopsy.1
A prostate biopsy is the only way to confirm the presence and severity of prostate cancer. If prostate cancer is suspected, a biopsy is performed to remove a small amount of prostate tissue to be tested. The pathology report will advise your doctor whether any cancerous cells were found.2
After prostate cancer has been confirmed, doctors may want to perform further image testing to see if it has spread, including additional MRIs, CT or CAT scans, and bone scans.2Download a prostate cancer treatment discussion guide
How is prostate cancer graded? What is a Gleason score?
If the pathologist who reviews your biopsy finds prostate cancer, they will assign grades to the cancer. Prostate cancer is commonly graded by the Gleason score, which assesses abnormal cell growth in the tumor.2
Typically, there are two grades assigned to the biopsy: the first grade assigned is to the cells most common in the tumor, and the second grade is the next most common. The grade ranges from 1, which looks like very normal tissue, to grade 5, which looks like very abnormal tissue, and grades 2 to 4 have features in between this range.2
These two scores are added together to provide the Gleason score. A Gleason score of 6 or less is low grade, 7 is intermediate grade, and a score of 8 to 10 is high grade cancer.2
The Gleason score can be confusing, so to simplify grading, doctors have developed Grade Groups. Grade Groups range from 1 to 5 in order from least to most likely to grow and spread quickly. Currently, you might see either a Gleason score or a Grade Group (or both) on a biopsy pathology report.2
What are the stages of prostate cancer?
The TNM Staging System is the most commonly used staging by medical professionals around the world and stages different types of cancer based on certain, standard criteria.3
The TNM staging system for prostate cancer is based on five key pieces of information:4
The extent of the main tumor
The extent of spread to the lymph nodes
Whether the cancer has spread (metastasized) to other parts of the body
The PSA level
The Grade Group (based on the Gleason score)
The “T category” measures the original tumor:3
TX: Primary tumor cannot be evaluated
T0: No evidence as primary tumor
Tis: Early cancer that hasn’t spread to neighboring tissue
T1–T4: Size and extent of tumor
The “N category” is whether the cancer has spread to nearby lymph nodes:3
NX: Nearby lymph nodes can’t be evaluated
N0: No cancer found in lymph nodes
N1–N3: Number and extent of spread to lymph nodes
The “M category” tells whether the cancer metastasized, or spread to other parts of the body:3
M0: No metastasis
M1: Distant metastasis (cancer has spread to distant parts of the body)
Once the T, N and M are determined, they’re combined to assign a cancer stage of 0, I, II, III, or IV. The next step is to determine your treatment options.3
Talk to your doctor to learn more
If you or a loved one suspects they may have prostate cancer, ask your physician for a checkup and discuss your concerns with them.
If you don’t have a physician or would like to speak with a specialist, use the Physician Finder tool to schedule an appointment today:
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*Please note, there may be other doctors in your area who treat prostate cancer not listed here.