Less than 2 mm of pattern 4 behaved like favourable intermediate risk

Design

Retrospective cohort

Population

2,499 men with Grade Group 2–4 cancer on targeted and systematic biopsy who had prostatectomy

Primary outcome

Adverse pathology and 5-year biochemical recurrence

Effect

GP4 <2 mm: adverse pathology 5.2% vs 5.0%, BCR 20% vs 21% (favourable intermediate risk)

Active surveillance for Grade Group 2 cancer is usually limited to men with favourable intermediate-risk features. A BJU International study asked whether the actual amount of Gleason pattern 4 on biopsy is a better guide.

Among 2,499 men with Grade Group 2 to 4 cancer on MRI-targeted and systematic biopsy who underwent prostatectomy, 73% of Grade Group 2, 19% of Grade Group 3 and 15% of Grade Group 4 had less than 2 mm of total pattern 4. These men, whatever their grade group, had adverse pathology at prostatectomy (5.2%) and five-year biochemical recurrence (20%) similar to men with favourable intermediate-risk disease (5.0% and 21%). Using under 2 mm as a threshold would make about twice as many men eligible for surveillance.

This challenges the use of grade group alone to decide who can avoid immediate treatment. But it is retrospective surgical-cohort data, and the way pattern 4 length is measured and the right cut-off need standardising. For now, pathologists can usefully report pattern 4 length, and urologists can weigh it in surveillance discussions within current guidelines.

• Ask pathology to report total length of Gleason pattern 4 in millimetres, not only the grade group.
• Men with Grade Group 2 and less than 2 mm of pattern 4 had outcomes similar to favourable intermediate risk.
• Some men with Grade Group 3 or 4 also had low pattern 4 burden; discuss this cautiously within a multidisciplinary team.
• Current guidelines have not adopted a pattern 4 length threshold for surveillance.
• MRI-targeted cores were averaged in this method, which differs from simple summation.

Why it matters

Grade group alone may be pushing men with small amounts of pattern 4 into treatment they do not need.

Don't overread it

This retrospective surgical cohort does not show that surveillance is safe for men selected by pattern 4 length.

The statistics, in plain English

Similar rates of adverse pathology (5.2% vs 5.0%) and recurrence (20% vs 21%) mean the low-pattern-4 group looked as safe as the group already considered for surveillance. These are outcomes after surgery, not after surveillance.

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