Gleason Score 3+3

The Gleason grading system is used to assign a score that describes the aggressiveness of prostate cancer. The Gleason score is based on the evaluation of prostate tissue samples obtained through a biopsy. The score is based on the microscopic appearance of the prostate cancer cells and is determined by a pathologist who examines biopsy samples of the prostate gland.

Gleason Score and International Society of Urological Pathology (ISUP) Grade Groups

The new, ISUP prostate grading system expands on the Gleason grading system and provides a more simplified grouping. In the Gleason system, a grade of 2-10 can be assigned, with 6 being the lowest grade that defines cancer. The ISUP grading system includes only 5-grade groups, all describing cancer, and starts with Grade Group 1. Starting the grading system at 1 instead of 6 can reduce the overtreatment of less aggressive diseases.
Here is the correspondence between Gleason score and ISUP Grade Group:

  • Gleason 3+3 = 6 – Grade Group 1
  • Gleason 3+4 = 7 – Grade Group 2
  • Gleason 4+3 = 7 – Grade Group 3
  • Gleason 4+4, 3+5, 5+3 = 8 – Grade Group 4
  • Gleason 4+5, 5+4, 5+5 = 9/10 – Grade Group 5

Read more details about the ISUP Grade Groups here (refer to Epstein et al 2016 Am J Surg Path.)

A Detailed Look into Gleason Score 3+3

Cancer with a Gleason Score of 3+3 is considered to below-grade. The Gleason score is determined by adding up the top two most frequently occurring patterns of cancer cells that are seen in the biopsy sample. Gleason 3+3 cancer is also known as a ISUP Grade Group 1 cancer.

When a Gleason Score of 3+3 is assigned, both the primary and secondary patterns of tumour cells are Gleason pattern 3, which indicates that the cancer cells are moderately differentiated. Prostate cancer with a Gleason Score of 3+3 is considered to be low-risk cancer.

This means that the cancer is unlikely to grow or spread quickly and may not require immediate treatment. However, it is important to note that every individual case of prostate cancer is different, and the Gleason Score (or ISUP Grade Group) is just one factor that is used to determine the best course of treatment.

Next Steps After Receiving a Diagnosis of Gleason 3+3 Disease

Prostate cancer classified as low-risk frequently exhibits slow growth or may not grow at all or spread to other organs. A management strategy called “active surveillance” is the preferred approach, instead of opting for active treatments like radiotherapy or surgery. With active surveillance, the tumour is closely monitored on a regular basis using information from prostate-specific antigen (PSA) blood tests and magnetic resonance imaging (MRI) scans. Active treatment is started only if there is evidence of tumour progression.

Blog posts from Profound Medical are for general information only. The content should not be considered medical advice. If you are in need of professional medical advice or assistance, please reach out to your local doctor or clinic.

Jul 19, 2023 | TULSA Procedure

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