Making Sense of the Gleason Prostate Cancer Grading System

Andrew Siegel MD  6/15/19

Each case of prostate cancer is unique and has a distinctive biological behavior.  One of the best predictors of the future behavior of any prostate cancer is the  cancer grade, a microscopic determination made by the examining pathologist.  Dr. Donald Gleason, a former chief of pathology at the Minneapolis Veterans Administration Center, devised a prostate cancer grading system many years ago that is still used today. His legacy, the system that bears his name—the Gleason score—provides one of the best and most reliable predictors for prostate cancer growth and spread.  Gleason score remains one of the most important factors guiding the individualized and nuanced treatment of the prostate cancer.

Gleason grade, Gleason score, Gleason grade group

Gleason GRADE

Gleason grade is determined by the pathologist who studies the biopsied prostate cancer with a microscope. Grade is indicative of the extent of difference in the cellular architecture of cancer cells as compared with normal cells. Low grade cancers appear almost like normal cells whereas high grade cancers bear little resemblance to normal cells. Gleason grades range from 3 (just over the threshold for cancer) to 5 (the cells that have the most cancerous appearance). Grade 3 is considered a low grade and grade 5 a high grade cancer.


Gleason grades based upon cellular architecture: note that grades 1 and 2 are not considered to be cancer.  Thank you

Gleason SCORE

The cancer from any individual biopsy site is often heterogeneous as opposed to homogeneous. In other words, cancer cells often have a variety of architectural patterns,  a predominant pattern as well as secondary and tertiary patterns. To determine Gleason score, the pathologist assigns a separate numerical grade to the two most predominant architectural patterns of the cancer cells, the first number representing the grade of the primary (most predominant) pattern and the second number representing the grade of the secondary pattern. The sum of the two grades is the Gleason score. The lowest possible score is 6; the highest is 10.

Gleason score predicts the aggressiveness and behavior of the cancer. Higher scores indicate a worse prognosis than lower scores because the more mutated cells typically grow faster than the more normal-appearing ones. Prognosis also depends on further refinements. For example, a Gleason score of 7 can occur two ways: “4+3” or “3+4”. With “4+3,” cancer cells in the most predominant category appear more aggressive than those in the secondary pattern, suggesting a more serious threat than a “3+4” score, in which cells in the most predominant group appear less aggressive.


There are 5 Gleason grade groups based upon Gleason score:

Grade Group 1 (Gleason score 3+3=6)

Grade Group 2 (Gleason score 3+4=7)

Grade Group 3 (Gleason score 4+3=7)

Grade Group 4 (Gleason score 4+4=8 or 3+5=8 or 5+3= 8)

Grade Group 5 (Gleason score 4+5=9 or 5+4= 9 or 5+5=10)

The lower the Gleason grade group, the less aggressive the cancer; conversely, the higher the Gleason grade group, the more aggressive the prostate cancer.

Bottom Line: The Gleason grading system is an effective, reliable and time-tested means of determining the biological potential of any given prostate cancer to grow and spread, of vital importance in helping guide the appropriate treatment. 

Coming next week…Prostate Cancer Risk Assessment: A Sensible Guide to Appropriate Treatment.

Wishing you the best of health,

2014-04-23 20:16:29

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Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery.  He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro Area, Inside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community. He is a urologist at New Jersey Urology, the largest urology practice in the United States.

The content of this entry is excerpted from his new book, PROSTATE CANCER 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families

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Video trailer for Prostate Cancer 20/20

Preview of Prostate Cancer 20/20

Andrew Siegel MD Amazon author page

Prostate Cancer 20/20 on Apple iBooks

Dr. Siegel’s other books:

FINDING YOUR OWN FOUNTAIN OF YOUTH: The Essential Guide to Maximizing Health, Wellness, Fitness and Longevity

PROMISCUOUS EATING— Understanding and Ending Our Self-Destructive Relationship with Food

MALE PELVIC FITNESS: Optimizing Sexual and Urinary Health

THE KEGEL FIX: Recharging Female Pelvic, Sexual, and Urinary Health

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2 Responses to “Making Sense of the Gleason Prostate Cancer Grading System”

  1. Biomarkers to Predict Progression on Active Surveillance or Recurrence After Prostate Cancer Surgery | Our Greatest Wealth Is Health Says:

    […] potential of any given cancer. For example, 15% or so of low risk prostate cancers based upon Gleason score may have high risk features from the perspective of cancer […]

  2. Prostate Cancer With a Normal PSA: A Digital Rectal Exam Can Be Life-Saving | Our Greatest Wealth Is Health Says:

    […] Gleason prostate cancer grading system […]

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