Cribriform growth pattern in prostate cancer

The International Society of Urological Pathology defines the cribriform pattern as a confluent sheet of contiguous malignant epithelial cells with multiple glandular lumina easily visible at low power, with no intervening stroma or mucin separating the individual or fused glands. It is one of the morphologies inside Gleason pattern 4, and the ISUP 2014 consensus settled that any cribriform gland is assigned pattern 4 rather than pattern 3. Since then a run of studies has shown that it is the pattern that carries the risk: cribriform carcinoma in a prostatectomy specimen is associated with worse biochemical-recurrence-free, metastasis-free and disease-specific survival, and its presence in a pre-treatment biopsy predicts a higher pathological stage, upgrading at surgery and poorer outcomes after both surgery and radiotherapy. Most of that evidence is in Gleason score 7 tumours, grade groups 2 and 3, which is exactly where the decision between surveillance and treatment is made.

The Royal College of Pathologists made the presence of invasive cribriform carcinoma a core reporting item in the 2024 UK dataset, and both ISUP and the Genitourinary Pathology Society recommend excluding men whose biopsy shows it from active surveillance. Whether the size of the cribriform glands matters is unsettled: some series find no difference between large and small, one found large glands worse, and the definitions of large differ between studies, from more than twelve luminal spaces to twice the diameter of the neighbouring benign glands. The pattern is also hard to tell from intraductal carcinoma without an immunohistochemical stain for basal cells, and most of the outcome studies did not separate the two, so part of the risk attributed to cribriform growth may belong to intraductal carcinoma instead.