Plasmacytoid Variant Urothelial Carcinoma of the Bladder: A Systematic Review and Meta-Analysis of Clinicopathological Features and Survival Outcomes

Purpose: The clinicopathological features and treatment outcomes of plasmacytoid variant-urothelial carcinoma of the bladder have not been fully understood. We evaluated the clinicopathological characteristics and survival outcomes of plasmacytoid variant-urothelial carcinoma of the bladder compared to conventional urothelial carcinoma of the bladder. Materials and 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 or greater, lymph node metastasis, ureteral margin positive and perivesical soft tissue margin positive status) and survival outcomes (overall mortality and cancer specific mortality) between plasmacytoid variant-urothelial carcinoma of the bladder and conventional urothelial carcinoma of the bladder were compared. The GRADE approach was used for rating the certainty of evidence. Results: Eight studies were included. Patients with plasmacytoid variant-urothelial carcinoma of the bladder had a higher frequency of stage pT3 or greater (OR 3.84, 95% 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