The conversion window in hepatocellular carcinoma: When resectability alone is not an indication for surgery.

Abstract

Effective systemic therapy has expanded the possibility of resection in hepatocellular carcinoma, while making its timing more uncertain. Technical feasibility alone cannot establish whether surgery adds value to an effective treatment sequence. In this context, the conversion window can be understood as a patient-specific interval in which achievable tumor clearance, preserved hepatic and systemic reserve, and sufficient evidence of disease control are considered together. These factors should be distinguished from the multidisciplinary team's overall determination of whether surgery is likely to provide additional benefit. Evidence from a randomized study supports consolidation in selected patients but does not define an optimal date for surgery. Retrospective associations between treatment duration and pathological response remain vulnerable to selection bias and cannot justify universal timing thresholds. Serial assessment should incorporate remnant liver function, treatment toxicity, drug interruption, uncertainty regarding residual disease, and patient preferences. Future trials and prospective registries should evaluate explicit timing strategies from the point of initial surgical eligibility, including patients who subsequently become ineligible, using survival, safety, and quality-of-life outcomes to inform individualized decisions.