Platelet count as a predictor of vascular invasion and extrahepatic metastasis in hepatocellular carcinoma: A systematic review and meta-analysis

Background Vascular invasion (VI) indicates highly invasive tumor biological behavior and is a major determining factor of poor survival and high risk of metastasis in hepatocellular carcinoma (HCC). Epidemiological evidence of the association between pretherapeutic platelet count (PLT) and the risk of VI and extrahepatic metastasis in HCC remains controversial. Methods A systematic retrieval was executed in databases of PubMed, Embase, and Web of Science until Dec 2022. Effect size and 95% confidence interval (CI) were extracted or estimated to synthetically investigate the effects of pretherapeutic PLT on VI and extrahepatic metastasis. Meta-analyses were performed by using a random or a fixed effects model. Results Finally, the current meta-analysis included 15 studies with a total of 12,378 HCC patients. It was shown that, patients with a higher pretherapeutic level of PLT had a significantly increased risk of VI (11 studies,8,759 patients; OR = 1.44, 95%CI: 1.02–2.02) and extrahepatic metastasis (6 studies,8, 951 patients; OR = 2.51, 95% CI: 2.19–2.88) in comparison with patients with a lower PLT. Funnel plots and Begg's tests indicated that there were no significant publication biases. Conclusion This meta-analysis shows that pretherapeutic elevated PLT is associated with an increased risk of VI and extrahepatic metastasis in HCC.