Letter to the editor: Treatment options for 3–5‐cm solitary HCC—Need a closer look!

To the editor, We read with great interest the retrospective study by Wang et al. comparing the efficacy and safety of patients undergoing laparoscopic liver resection (LLR) versus microwave ablation (MWA) for solitary 3–5‐cm HCC.[1] Despite better disease‐free survival with LLR, the overall survival and severe adverse effect profiles were similar. The authors also suggested that MWA might be considered as a first‐line alternative to LLR, with technical advances especially for patients unsuitable for LLR. Some of the issues need further consideration. First, over ~80% patients in the study cohort had no portal hypertension. For these patients, LLR prevails over local ablation for 3–5‐cm HCC with lower rates of tumor recurrence and 5‐year mortality.[2] Denying LLR as first‐line treatment in these "ideal" candidates is not justified. The study should have carefully compared LLR and MWA for high‐risk individuals alone. These include patients with deep‐seated HCC, high albumin‐bilirubin score, presence of portal hypertension, and possibly poor tumor biology.[3] In these cases, up‐front liver transplantation is desirable but not always available, and both LLR and MWA have suboptimal safety and/or efficacy. It is hard to believe that despite the presence of portal hypertension in ~15% patients undergoing LLR, only one had liver failure. Furthermore, the comparison of LLR outcomes based on tumor locations and resection approach is desirable. Second, complete tumor ablation for 3–5‐cm HCC is essential as overall patient survival based on tumor response after MWA is an important prognostic factor. With technical advances, different MWA devices seem to produce substantial differential ablation volumes and shapes; however, complete ablation using single antenna may be produced mostly for 3‐cm lesions, and larger lesions do require placement of multiple antennas in a specified fashion for achieving complete ablation (having a 5‐mm margin of adjoining normal liver parenchyma and simultaneously preserving normal parenchyma), which may be challenging at times. To overcome this issue, MWA is increasingly being combined with transarterial chemoembolization (TACE) to achieve complete ablation in tumors > 3 cm.[4] The study should have elaborated on the overall and disease‐free survival outcomes in patients requiring repeat MWA for incomplete ablation and/or residual lesions and for those requiring the next suitable option such as TACE after tumor recurrence. Third, almost 80% of patients had HCC related to chronic hepatitis B infection, but only 40% were on antiviral therapy at enrollment. Whether these clinical outcomes could be generalized to HCC from other emerging causes such as alcohol use and metabolic‐associated fatty liver disease remains to be determined. Over 10% patients had missing long‐term prognostic data on tumor recurrence. Biases due to the retrospective study nature and data loss after propensity matching remain inevitable. CONFLICT OF INTEREST Nothing to report.