Sarcomatoid variant urothelial carcinoma of the bladder: a systematic review and meta-analysis of the clinicopathological features and survival outcomes

Liangyou Gu,Xintao Li,Xin Ma,Xu Zhang,Baojun Wang,Qingbo Huang,Hongzhao Li,Qiang Cheng,Qing Ai,Kan Liu,Xupeng Zhao,Peng Zhang

doi:10.1186/s12935-020-01626-9

Abstract

BackgroundA systematic review and meta-analysis was performed to compare the clinicopathological features and survival outcomes between sarcomatoid variant (SV)-urothelial carcinoma of the bladder (UCB) and conventional UCB (C-UCB).MethodsA comprehensive search of PubMed, Embase, and Cochrane Library was performed. Endpoints included clinicopathological features and survival outcomes (overall survival [OS], cancer-specific survival [CSS], and progression-free survival [PFS]). The survival benefits of neoadjuvant chemotherapy (NAC) or adjuvant chemotherapy (AC) for SV-UCB also have been studied.ResultsA total of 8 observational studies were included. Patients with SV-UCB had a higher rate of ≥ stage pT3 (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.64–2.59; p < 0.001) and a lower rate of concomitant carcinoma in situ (OR, 0.25; 95% CI, 0.09–0.72; p = 0.010). The other clinicopathological variables were similar between SV-UCB and C-UCB. With unadjusted data, patients with SV-UCB had a significant inferior OS (HR, 1.24; 95% CI, 1.07–1.44; p = 0.004) and CSS (HR, 2.08; 95% CI, 1.63–2.66; p < 0.001). However, after adjusted, SV-UCB had worse OS (HR, 1.41; 95% CI, 0.95–2.08; p = 0.090) and CSS (HR, 1.54; 95% CI, 0.95–2.52; p = 0.080) approaching the borderline of significance. For SV-UCB, NAC (HR, 0.73; 95% CI, 0.51–1.05; p = 0.090) and AC (HR, 0.88; 95% CI, 0.66–1.17; p = 0.370) seemed to have no benefit on OS.ConclusionsCompared to C-UCB, SV-UCB was associated with more advanced disease and more inferior OS and CSS. NAC and AC had no survival benefit for SV-UCB.

Highlights

Urothelial carcinoma (UC) is the most common histologic type of bladder cancer
Though former evidences supported that SV-urothelial carcinoma of the bladder (UCB) was aggressive, prone to present at an advanced stage and was associated with poor long-term survival [3, 8, 9], many studies have denied the prognosis significance of sarcomatoid variant in UCB [10–12]
Our findings indicated that Sarcomatoid variant urothelial carcinoma of the bladder (SV-UCB) was associated with more advanced disease, especially for higher pathological T stage

Summary

Introduction

Urothelial carcinoma (UC) is the most common histologic type of bladder cancer. Around 75% of bladder cancers are classified as pure UC, and the remaining 25% are urothelial and nonurothelial histological variants [1]. Sarcomatoid variant (SV) is a rare histologic variant of UC and is estimated to account for 0.1%–0.3% of all urothelial carcinoma of the bladder (UCB) [3]. Sarcomatoid variant urothelial carcinoma of the bladder (SV-UCB) is characterized by the presence of components of two-phase malignancy, there is morphological and/or immunohistochemical evidence of epithelial and mesenchymal differentiation. SV-UCB was first reported as early as 1972, this disease was mainly described by single-center studies in case reports or series. A systematic review and meta-analysis was performed to compare the clinicopathological features and survival outcomes between sarcomatoid variant (SV)-urothelial carcinoma of the bladder (UCB) and conventional UCB (C-UCB)

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