The effects of several postoperative adjuvant therapies for hepatocellular carcinoma patients with microvascular invasion after curative resection: a systematic review and meta-analysis

BACKGROUND: For patients with hepatocellular carcinoma (HCC) with microvascular invasion (MVI) after curative resection, the effects of various postoperative adjuvant therapies are not summarized in detail, and the comparison between the effects of various adjuvant therapies is still unclear. Thus, we collected existing studies on postoperative adjuvant therapies for patients with HCC with MVI after curative resection and analyzed the effects of various adjuvant therapies. METHOD: We collected all studies on postoperative adjuvant therapy for patients with HCC with MVI after curative resection from PubMed, EMBASE, Cochrane Library and SinoMed ending on May 1, 2019. Overall survival (OS) and disease-free/recurrence-free survival (RFS) between each group were compared in these studies by calculating the pooled hazard ratio (HR) and 95% confidence interval (CI). All statistical analyses were assessed by two authors independently. RESULT: A total of 13 studies were included in this study, including 824 postoperative adjuvant transarterial chemoembolization (pa-TACE) patients, 90 postoperative radiotherapy patients, 57 radiofrequency ablation (RFA)/re-resection patients, 16 sorafenib patients and 886 postoperative conservative treatment patients. The results showed that pa-TACE significantly improved OS and RFS compared with postoperative conservative treatment in patients with HCC with MVI after curative resection (HR: 0.64, 95% CI: 0.55–0.74, p < 0.001; HR: 0.70, 95% CI: 0.62–0.78, p < 0.001, respectively). There was no significant difference in OS between pa-TACE and radiotherapy in patients with HCC with MVI (HR: 1.75, 95% CI: 0.92–3.32, p = 0.087). RFS in patients with HCC with MVI after pa-TACE was worse than that after postoperative adjuvant radiotherapy (HR: 2.29, 95% CI: 1.43–3.65, p < 0.001). The prognosis of pa-TACE and RFA/re-resection in patients with MVI with recurrent HCC had no significant differences (HR: 0.65, 95% CI: 0.09–4.89, p = 0.671). Adjuvant treatments significantly improved the OS and RFS of patients compared with the postoperative conservative group (HR: 0.580, 95% CI: 0.480–0.710, p < 0.001; HR: 0.630, 95% CI: 0.540–0.740, p < 0.001, respectively). CONCLUSION: Compared with postoperative conservative treatment, pa-TACE, postoperative radiotherapy and sorafenib can improve the prognosis of patients with hepatocellular carcinoma with microvascular invasion after curative resection. Postoperative radiotherapy can reduce the recurrence of patients with HCC with MVI after curative resection compared with pa-TACE.