Effect of KI-67 positive cellular index on prognosis after hepatectomy in Barcelona Clinic Liver Cancer stage A and B hepatocellular carcinoma with microvascular invasion

OBJECTIVE: This study aimed to explore the relationship between KI-67 positive cellular index and recurrence-free survival (RFS) in Barcelona Clinic Liver Cancer (BCLC) stage A and B hepatocellular carcinoma (HCC) patients, particularly those with microvascular invasion (MVI). METHODS: A total of 333 patients who underwent curative hepatectomy had their immunohistochemistry analyzed retrospectively for KI-67 positive cellular index. RESULTS: In total, 41.1% (137/333) of HCC patients displayed high KI-67 positive cellular index (>35%). Patients with high KI-67 positive cellular index had poorer RFS than those with low index (P<0.0001). Patients were then subdivided into an MVI positivity group (n=192) and an MVI negativity group (n=141). In the MVI positivity group, patients with high KI-67 positive cellular index had a shorter RFS after operation as compared to those with low index (P<0.0001). However, there was no significant difference in RFS between high- and low-index subgroups within the MVI negativity group (P>0.05). Additionally, patients with high KI-67 positive cellular index combined with MVI positivity had the shortest RFS of all those with MVI negativity, regardless of KI-67 cellular index level (P<0.0001). Multivariate analysis showed that node number >1, capsule absence, high KI-67 positive cellular index, and alpha-fetoprotein >400 ng/mL were independent risk factors for a recurrence of HCC with MVI. CONCLUSION: Our results suggested that high KI-67 positive cellular index may represent a poor prognostic factor in BCLC stage A and B HCC patients, especially those with MVI.