Gleason grade 5 prostate cancer: sub-patterns and prognosis

Area of Science:

• Uropathology
• Prostate Cancer Grading
• Oncologic Pathology

Background:

• The Gleason grading system for prostate cancer has undergone modifications, particularly regarding Gleason pattern 5 (GP5) and its sub-patterns.
• Comedonecrosis's classification as a GP5 pattern has been debated and revised by the International Society of Urological Pathology (ISUP).
• Gleason pattern 5 is associated with an unfavorable prognosis, including increased risk of metastasis and disease-specific death.

Purpose of the Study:

• To review the evolving definitions and reporting of Gleason pattern 5 (GP5) and its sub-patterns in prostate cancer.
• To investigate the potential reasons for an observed increase in GP5 diagnoses over time.
• To highlight the need for further research into the prognostic impact of individual GP5 sub-patterns.

Main Methods:

• Review of historical definitions and ISUP guidelines for Gleason pattern 5 (GP5).
• Analysis of biopsy and prostatectomy specimen reporting trends.
• Institutional biopsy review study to assess changes in GP5 diagnosis over time.

Main Results:

• Gleason pattern 5 (GP5) definitions and sub-patterns, including comedonecrosis, have evolved.
• An institutional review showed an increase in GP5 diagnosis, not linked to new sub-patterns or overdiagnosis.
• The most common GP5 sub-patterns in biopsies are single files and single cells; frequency is 1-5% in most series.

Conclusions:

• The reporting and definition of Gleason pattern 5 (GP5) in prostate cancer have changed over time.
• An increase in GP5 diagnosis may be related to evolving biopsy indications rather than diagnostic changes.
• Further research is crucial to understand the prognostic significance of individual GP5 sub-patterns and their molecular basis.