LAUSR

PURPOSE The clinicopathological features and treatment outcomes of plasmacytoid variant (PV)-urothelial carcinoma of the bladder (UCB) have not been fully understood. We aimed to evaluate the clinicopathologic characteristics and survival outcomes of PV-UCB as compared to conventional UCB (C-UCB). METHODS A systematic review was performed following the PRISMA guideline. PubMed/Medline, Embase, and Cochrane Library were searched up to June 2019. The differences in the clinicopathological features (≥stage pT3, lymph node metastasis, ureteral margin-positive, and perivesical soft tissue margin-positive status) and survival outcomes [overall mortality (OM) and cancer-specific mortality (CSM)] between PV-UCB and C-UCB were compared. The GRADE approach was used for rating the certainty of evidence. RESULTS A total of 8 studies were included. Patients with PV-UCB had a higher frequency of ≥stage pT3 (odds ratio [OR], 3.84; 95% confidence interval [CI], 1.63-9.03; p=0.002) and risk of lymph node metastasis (OR, 2.58; 95% CI, 1.15-5.76; p=0.02), ureteral margin-positive (OR 12.18; 95% CI, 4.62-32.13; p<0.00001), and perivesical soft tissue margin-positive (OR 12.31; 95% CI, 5.15-29.41; p<0.00001) status after radical cystectomy than those with C-UCB. Although there was no difference in CSM (hazard ratio [HR], 1.40; 95% CI, 0.82-2.40; p=0.22) between PV-UCB and C-UCB, PV-UCB had worse survival outcomes (OM) than C-UCB approaching the borderline of significance (HR, 1.62; 95% CI, 0.98-2.68; p=0.06) when adjusted for other clinicopathological characteristics. CONCLUSIONS PV-UCB was strongly associated with adverse clinicopathological features and worse OM compared to C-UCB after adjusting other clinicopathological parameters, and PV histology of UCB is an independent prognostic factor for overall survival.