What is the best way to explain the Gleason score to a patient with prostate cancer?

Explaining the Gleason Score to a Patient with Prostate Cancer

The Gleason score is a grading system that helps determine how aggressive your prostate cancer is by examining the cancer cells under a microscope, with scores ranging from 6 (least aggressive) to 10 (most aggressive). 1

What is the Gleason Score?

• The Gleason score is determined by a pathologist who examines tissue samples from your prostate biopsy under a microscope 1
• It evaluates how much the cancer cells differ from normal prostate cells (their degree of differentiation) 1
• The score is calculated by adding the grades of the two most common cancer patterns seen in your biopsy 1
• Each pattern is scored from 1 to 5, with 5 being the most abnormal or aggressive 1
• For example, if your most common pattern is grade 3 and your second most common is grade 4, your Gleason score would be 7 (3+4) 1

Understanding the Numbers

• The Gleason system assigns grades from 1 to 5 for each pattern, but in practice, grades 1 and 2 are rarely used today 2
• Gleason scores range from 6 to 10 in clinical practice 2
• Gleason score 6 (3+3): Well-differentiated cancer cells that look similar to normal cells and tend to grow slowly 1
• Gleason score 7: Moderately differentiated cancer cells with intermediate aggressiveness 1
  • Important distinction: Gleason 3+4=7 has a better prognosis than Gleason 4+3=7 2, 3
• Gleason scores 8-10: Poorly differentiated cancer cells that look very different from normal cells and tend to grow more rapidly 1

What Your Gleason Score Means for Prognosis

• With each increase in Gleason score, there is an increase in cancer aggressiveness 1
• Lower Gleason scores (6) generally indicate a better prognosis 3
• Higher Gleason scores (8-10) are associated with more aggressive disease and potentially worse outcomes 1, 4
• The Gleason score is one of several factors used to determine your risk category (low, intermediate, or high risk) 1

The New Grade Group System

• A newer grading system has been developed to address limitations of the traditional Gleason system 2, 3
• This system uses Grade Groups 1-5:
  • Grade Group 1 (Gleason 6): Lowest risk
  • Grade Group 2 (Gleason 3+4=7): Intermediate risk, better prognosis
  • Grade Group 3 (Gleason 4+3=7): Intermediate risk, worse prognosis
  • Grade Group 4 (Gleason 8): High risk
  • Grade Group 5 (Gleason 9-10): Highest risk 3, 5
• This system helps clarify that Gleason 6 is actually the lowest grade assigned, not a mid-range score 2

How the Gleason Score Affects Treatment Decisions

• Your Gleason score, along with your PSA level and clinical stage, helps determine your risk category 1
• Risk categories guide treatment recommendations:
  • Low risk (Gleason ≤6, PSA ≤10 ng/mL, stage T1c or T2a): May be candidates for active surveillance, surgery, or radiation 1
  • Intermediate risk (Gleason 7 or PSA 10-20 ng/mL): May need more aggressive treatment options 1
  • High risk (Gleason 8-10 or PSA >20 ng/mL): Often requires multimodal therapy 1

Common Misunderstandings to Avoid

• A Gleason score of 6 is not a "middle" score - it's actually the lowest score assigned in clinical practice 2, 3
• Not all Gleason 7 cancers are the same - a 3+4 has a better prognosis than a 4+3 2, 3
• The Gleason score is just one factor in determining your overall risk and treatment plan - PSA levels and clinical stage are also important 1
• The interpretation of Gleason scores has evolved over time, so information from older sources may not reflect current understanding 5