The effect of bile duct tumor thrombus on the long-term prognosis of hepatocellular carcinoma patients after liver resection: a systematic review and meta-analysis

Background The effect of bile duct tumor thrombus (BDTT) on the postoperative long-term prognosis of hepatocellular carcinoma (HCC) patients is still under debate. Methods The PubMed, Embase, Cochrane Library, Web of Science databases were systematically searched to collect the clinicopathologic characteristics, perioperative indices, and postoperative survival outcomes in the BDTT and non-BDTT groups of HCC patients from inception to February 1, 2020. The study outcomes were extracted by two independent investigators. Results A total of 15 studies involving 6,484 patients were included. The meta-analysis revealed that the levels of serum total bilirubin and alkaline phosphatase were notably higher in patients with HCC and BDTT than those without BDTT. Meanwhile, HCC patients with BDTT had more aggressive biological characteristics, such as poor tumor differentiation, macrovascular invasion, and lymph node metastasis, as compared to patients without BDTT. The 1-year [odds ratio (OR) 0.39, 95% confidence interval (CI): 0.31-0.48, P<0.01], 3-year (OR 0.33, 95% CI: 0.22-0.51, P<0.01) and 5-year overall survival (OS) rates (OR 0.31, 95% CI: 0.20-0.49, P<0.01) of the BDTT group were significantly worse than those of the non-BDTT group. The hazard ratio of HCC with BDTT was 4.27 (95% CI: 3.47-5.26, P<0.01) within 5 years after hepatectomy. Conclusions HCC patients with BDTT had worse OS compared to patients free of BDTT after surgery. BDTT may be a potential prognostic factor for HCC patients.