Under 2 mm of Gleason pattern 4 behaved like favourable intermediate risk, whatever the grade group

Design

Retrospective surgical cohort

Population

2,499 men with grade group 2-4 prostate cancer treated by radical prostatectomy

Primary outcome

Adverse pathology and 5-year biochemical recurrence

Effect

<2 mm GP4: adverse pathology 5.2% vs 5.0%; 5-year BCR 20% vs 21% (favourable intermediate risk)

Eligibility for active surveillance in intermediate-risk prostate cancer usually rests on grade group and risk criteria. This study of 2,499 men with grade group 2-4 disease on MRI-targeted and systematic biopsy, all of whom had radical prostatectomy, tested total Gleason pattern 4 length instead.

Men with less than 2 mm of pattern 4 had risks of adverse pathology (5.2%) and five-year biochemical recurrence (20%) similar to those of men with favourable intermediate-risk disease (5.0% and 21%), regardless of grade group. Using a 2 mm threshold would roughly double the number of men eligible for surveillance.

The cohort is surgical, so it excludes men already on surveillance, and pattern 4 length is not measured in a standard way across laboratories. The authors say the method and cut-point need defining before use.

This is a reason to ask the pathologist for pattern 4 extent, not yet a rule for selecting surveillance.

• Less than 2 mm of Gleason pattern 4 carried similar risk to favourable intermediate-risk disease.
• A 2 mm threshold would make about twice as many men eligible for surveillance.
• Ask pathology to report pattern 4 length or percentage in each core.
• Do not yet use the 2 mm threshold alone to select surveillance.
• Measurement methods vary; agree a local approach with the pathologist.

Why it matters

Grade group alone may be pushing some low-burden intermediate-risk men into treatment they could defer.

Don't overread it

This surgical cohort did not follow men on surveillance, so it does not show the threshold is safe in practice.

The statistics, in plain English

Similar adverse pathology rates (5.2% vs 5.0%) and recurrence (20% vs 21%) suggest equivalent risk, but this is observational and not a direct test of surveillance outcomes.

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