The prognostic and diagnostic value of circulating tumor cells in bladder cancer and upper tract urothelial carcinoma: a meta-analysis of 30 published studies

There are inconsistent conclusions in the association between circulating tumor cells (CTCs) and urothelial cancer (UC). We performed a meta-analysis to assess the prognostic and diagnostic value of CTCs in UC. We search Medline, Embase and Web of science for relevant studies. The study was set up according to the inclusion/exclusion criteria. 30 published studies with a total of 2161 urothelial cancer patients were included. Meta-analysis showed that CTC-positive was significantly associated with tumor stage (≤ II vs III, IV) (OR = 4.60, 95% CI: 2.34–9.03), histological grade (I, II vs III) (OR = 2.91, 95% CI: 1.92–4.40), metastasis (OR = 5.12, 95% CI: 3.47–7.55) and regional lymph node metastasis (OR = 2.47, 95% CI: 1.75–3.49). It was also significantly associated with poor overall survival (OS) (HR = 3.98, 95% CI: 2.20–7.21), progression/disease-free survival (PFS/DFS) (HR = 2.22, 95% CI: 1.80–2.73) and cancer-specific survival (CSS) (HR = 5.18, 95% CI: 2.21–12.13). Overall sensitivity and specificity of CTC detection assays were 0.35 (95% CI: 0.28–0.43) and 0.97 (95% CI: 0.92–0.99) respectively. In summary, our meta-analysis suggests that the presence of CTCs in the peripheral blood is an independent predictive indicator of poor outcomes for urothelial cancer patients. It can also be used as a noninvasive method for the confirmation of cancer diagnosis. More studies are required to further explore the role of this marker in clinical practice.