LAUSR

We read with interest the article of Aoki et al.1. The authors evaluated the impact of surgical margin (SM) on outcomes in patients undergoing anatomical and non-anatomical resection for solitary hepatocellular carcinoma (HCC). They revealed poorer outcomes in the SM0(−) group compared with the SM more than 0 mm group for patients who had undergone non-anatomical hepatic resection. In comparison, the outcomes were similar in these two groups for patients who had undergone anatomical resection. However, we disagree with the conclusions. Microvascular invasion (MVI) is a marker of aggressive tumour behaviour that impairs surgical outcome in patients with HCC2,3, and postoperative adjuvant transcatheter arterial chemoembolization (TACE) has been certified to improve outcome in patients with MVI4. Moreover, better therapeutic response to preoperative TACE was associated with preferable overall and tumour-free survival according to Lei et al3. Arguably, paramount factors such as MVI status and perioperative adjuvant treatment that have an arresting impact on surgical outcomes were not included in the background adjustment, in either the anatomical or non-anatomical resection group, reducing the potency of the conclusions. Notably, disease-free survival (DFS) was defined as the time interval between primary treatment and the first detection of tumour recurrence, which varied depending on diagnostic criteria such as elevated α-fetoprotein level, radiological evidence of de novo neoplasm after tumour liquidation, development of symptoms, pathological findings or death. However, DFS was not defined in Aoki et al.’s work. In addition, the second sentence of the third paragraph of the Discussion draws an opposite conclusion about the impact of surgical margin width for anatomical and