High Expression of Karyopherin-α2 Defines Poor Prognosis in Non–Muscle-Invasive Bladder Cancer and in Patients with Invasive Bladder Cancer Undergoing Radical Cystectomy

BackgroundConventional clinicopathologic risk factors have failed to accurately predict the prognosis of patients with bladder cancer (BC).ObjectiveTo evaluate karyopherin-α2 (KPNA2) expression as a progression marker in patients with non–muscle-invasive BC (NMIBC) treated by conservative methods and as a prognostic marker in patients with invasive BC undergoing radical cystectomy (RC).Design, setting, and participantsTwo different tissue microarrays were constructed, one with 234 primary Ta/T1 tumours from patients treated by transurethral resection of the bladder and one with 377 tumours from RC patients.InterventionKPNA2 expression based on immunohistochemistry.MeasurementsRisk of progression of Ta/T1 patients to muscle-invasive BC was estimated in clinical follow-up to progression or a minimum of 53 mo. Risk of recurrent disease and death following RC was estimated in clinical follow-up of a minimum of 24 mo in patients alive.Results and limitationsA high KPNA2 expression in Ta/T1 patients was significantly correlated with a higher risk of progression that was independent of conventional risk factors in multivariate analysis. In patients undergoing RC, a high KPNA2 expression was an independent predictor of poor prognosis. A high KPNA2 expression was correlated with a higher risk of visceral metastasis rather than lymphatic spread.ConclusionsKPNA2 expression is a marker for progression of NMIBC and a prognostic marker in patients undergoing RC.