Could Gleason pattern 4 length widen active surveillance? A prostatectomy cohort suggests so

Design

Retrospective cohort of men with grade group 2 to 4 cancer who had radical prostatectomy

Population

2,499 men (1,691 GG2, 694 GG3, 114 GG4) with MRI-targeted and systematic biopsy

Primary outcome

Adverse pathology and 5-year biochemical recurrence by Gleason pattern 4 length

Effect

Under 2 mm pattern 4: adverse pathology 5.2% vs 5.0%; 5-year recurrence 20% vs 21% (favourable intermediate risk)

Investigators studied 2,499 men with grade group 2 to 4 prostate cancer on MRI-targeted and systematic biopsy who went on to radical prostatectomy. Total Gleason pattern 4 length was the sum of millimetres in systematic cores plus the average across targeted cores. They compared it with risk groups for adverse pathology and 5-year biochemical recurrence.

Of the cohort, 1,691 had grade group 2, 694 grade group 3 and 114 grade group 4; 73%, 19% and 15% respectively had under 2 mm of pattern 4. Men with under 2 mm, whatever their grade group, had similar adverse pathology (5.2% against 5.0%) and 5-year biochemical recurrence (20% against 21%) to men with favourable intermediate-risk disease. Using this threshold for surveillance would classify about twice as many men as eligible.

All men had surgery, so the cohort is selected, and recurrence after prostatectomy is not the same as outcome under surveillance. The authors say the best way to measure pattern 4 and the cut-point must be settled before use. Current guideline criteria stand.

• Report total Gleason pattern 4 length in millimetres across cores where your pathologists can do so consistently.
• Do not change surveillance eligibility on this study; the authors call for a defined cut-point first.
• Discuss grade group 2 disease with low pattern 4 volume as a case for individualised surveillance within current guidelines.
• Confirm MRI-targeted and systematic sampling are both reported.

Why it matters

Surveillance eligibility depends on coarse risk groups, and a continuous measure might sort men more precisely.

Don't overread it

Retrospective surgical data on surrogate outcomes do not prove outcomes on surveillance, and no guideline has adopted this threshold.

The statistics, in plain English

Equal risks in two groups (5.2% against 5.0%) mean pattern 4 under 2 mm behaves like the already accepted favourable group; it does not show that surveillance is safe for either. A 20% 5-year biochemical recurrence rate after surgery is itself not trivial.

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