Understanding Prostate Cancer Grades and the Gleason Score, with Adam B. Weiner, M.D.

Prostate cancer grading plays a key role in how doctors decide on the best treatment plan, and Adam B. Weiner, M.D., a urologic oncologist at Cedars-Sinai Medical Center focused on prostate cancer, is helping patients make sense of it. The Gleason scoring system, while widely used, can be confusing. Traditionally, scores ranged from 6 to 10, even though 6 was actually considered a low-grade cancer — which often puzzled patients. Today, doctors use a simplified “Grade Group” system that ranks cancer from 1 to 5, with 1 being the least aggressive and 5 the most.

Grading is based on how much the cancer cells resemble normal prostate cells under a microscope. The more abnormal they appear, the higher the grade—and the more likely the cancer is to grow and spread.

• Grade Group 1 (Gleason 6): Low risk, often monitored with active surveillance.
• Grade Group 2-3 (Gleason 7): Intermediate risk, likely requiring treatment.
• Grade Group 4-5 (Gleason 8-10): High risk, often requiring imaging and aggressive treatment.

Weiner emphasizes that patients with high-grade cancers — such as former President Joe Biden’s recently reported Gleason 9 (Grade Group 5) diagnosis — need imaging and may be candidates for systemic treatments like hormone therapy, chemotherapy, or a combination of surgery and radiation. Genetic counseling is also recommended for patients with aggressive or metastatic cancer.

When it comes to treatment decisions, age and overall health matter. For example:

• A 72-year-old in good health might still benefit from surgery to avoid long-term side effects of radiation.
• A younger man in his 50s is more likely to be offered surgery early, since radiation can cause side effects that worsen over time.
• For some older adults, especially those with lower-grade cancer, active surveillance (monitoring without immediate treatment) may be the best option.

Finally, Weiner underscores the importance of screening and having open discussions with primary care doctors about whether and when to start. An elevated prostate-specific antigen doesn’t always mean cancer — it might prompt further testing, like MRI or blood work, before a biopsy is done.