Bladder cancer is a heterogeneous disease classified into two broad molecular subtype categories, basal and luminal, with critical treatment and prognostic implications. Recent studies have shown the utility of immunohistochemistry in predicting bladder cancer molecular subtypes, with a two-marker approach using GATA3 and CK5/6 showing over 80% reliability. In the current study, we calculated the accuracy of uroplakin II (UPII), a marker of urothelial differentiation, with different scores (0: <1%, 1+: 1-10%, 2+: 10-50%, 3+: >50%) to predict RNA-based luminal versus basal subtypes in a cohort of muscle-invasive bladder cancer-received neoadjuvant chemotherapy followed by radical cystectomy. The 1% cutoff of the UPII stain predicts the luminal subtype with the sensitivity and specificity of 95% and 56%, respectively. With a UPII cutoff of 10%, the sensitivity and specificity were 93% and 81%, respectively, and with a UPII cutoff of 50%, the sensitivity and specificity were 91% and 96%, respectively. The prediction performance of UPII was better than either GATA3 or CK5/6. There was no significant difference in prognoses between UPII 0-2+ and UPII 3+ patients in this cohort. The current study shows that evaluating the staining proportion score of UPII can accurately predict basal and luminal subtypes of muscle-invasive bladder cancer.
Virchows Archiv : an international journal of pathology. 2022 May 25 [Epub ahead of print]
Collin Pryma, Carlos Villamil, Ewan A Gibb, Htoo Zarni Oo, Roland Seiler, Alberto Contreras-Sanz, James Douglas, Peter C Black, Gang Wang
Department of Pathology, University of British Columbia, Vancouver, BC, Canada., Decipher Urological Cancers, Veracyte, Inc., Vancouver, BC, Canada., Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada., Department of Urology, University Hospital Bern, Bern, Switzerland., Department of Urology, University Hospital of Southampton, Hampshire, UK., Department of Pathology, University of British Columbia, Vancouver, BC, Canada. .