What is the optimal surgical treatment for hepatocellular carcinoma beyond the debate between anatomical versus non-anatomical resection?

The optimal type of hepatectomy for hepatocellular carcinoma (HCC)-anatomical or non-anatomical resection-remains controversial despite numerous comparative studies. There are common fundamental issues in published studies comparing anatomical resection with non-anatomical resection: (1) confounding by indication, (2) setting primary outcomes, and (3) a lack of a clear definition of non-anatomical resection. This degrades the quality of the comparison of the two types of surgery. To measure the therapeutic effect of hepatectomy, it is essential to understand the accumulated knowledge underlying these issues, such as the mechanism of hepatocellular carcinoma spread, tumor blood flow drainage theory, and the three patterns of hepatocellular carcinoma recurrence: (1) local intrahepatic metastasis, (2) systemic metastasis, and (3) multicentric carcinogenesis recurrence. Based on evidence that the incidence of local intrahepatic metastasis was so low it was almost negligible, the therapeutic effect of anatomical resection on the oncological survival was determined to be similar to that of non-anatomical resection. Recent research progress demonstrating the clinical impact of subclinical dissemination of HCC after surgery may stimulate new debate on the optimal surgical treatment for HCC beyond the comparison of anatomical and non-anatomical resection.