Letter to the editor for "Evaluation of prognostic efficacy of liver immune status index in predicting postoperative outcomes in hepatocellular carcinoma patients: A multi-institutional retrospective study".
We read the recent article by Imaoka et al., which investigates the prognostic efficacy of the liver immune status index (LISI) in predicting postoperative outcomes in hepatocellular carcinoma (HCC) patients.1 This multi-institutional retrospective study provides valuable insights into LISI as a prognostic tool, yet certain aspects warrant further discussion. The study comprehensively evaluates LISI, combining BMI, serum albumin levels, and the FIB-4 index to predict HCC prognosis. LISI outperformed existing models, especially in HCC with vascular invasion, correlating strongly with overall survival (OS) and recurrence rates (RR). However, relying on the FIB-4 index, originally developed for HIV/HCV coinfected patients,2 raises questions about its applicability in HCC. While the authors briefly address this limitation, they do not explore whether other fibrosis markers could enhance LISI's predictive power. Considering alternative markers such as the AST to platelet ratio index (APRI) or FibroTest might improve LISI's predictive accuracy.3 The reported AUROC values for LISI in predicting 2-year OS and RR (0.67 and 0.59, respectively) indicate moderate predictive accuracy. Although LISI showed superiority in the early postoperative period, its performance diminishes beyond 2 years. This raises concerns about its long-term reliability and suggests the need for a dynamic model. The introduction of the HISCO-HCC score, incorporating LISI, tumor burden score (TBS), and alpha-fetoprotein (AFP) levels, enhances predictive power. However, comparing the HISCO-HCC score with established models like the Barcelona Clinic Liver Cancer (BCLC) staging system or the Cancer of the Liver Italian Program (CLIP) score would clarify its efficacy. The study uses a large sample of 1337 patients, ensuring statistical robustness. The authors should elaborate on the selection criteria for defining the LISI cutoff points (low, moderate, high) and their biological rationale. These cutoff points are derived from a single prior study, limiting their generalizability. Sensitivity analyses or validating these cutoffs in an independent cohort would enhance their applicability. A notable omission is the consideration of potential confounding factors such as liver cirrhosis severity, comorbidities, or the impact of different HCC treatments. Variables like the model for end-stage liver disease (MELD) score, presence of diabetes or cardiovascular disease, and prior treatments like transarterial chemoembolization (TACE) can significantly influence OS and RR.4, 5 Including these factors in the multivariate analysis would provide a more nuanced understanding of LISI's prognostic efficacy. Lastly, while the study emphasizes the importance of natural killer (NK) cell-mediated antitumor activity, the biological mechanisms underlying LISI's predictive capacity remain speculative. Prospective studies measuring NK cell cytotoxicity or TRAIL expression levels alongside LISI scores could substantiate the biological basis of LISI's prognostic capacity. Validating the direct correlation between LISI scores and NK cell activity would reinforce its biological plausibility as a prognostic tool. In conclusion, Imaoka et al. provide a compelling exploration of LISI as a prognostic index for HCC, particularly in predicting early recurrence and OS. However, its moderate predictive accuracy, lack of consideration for confounding factors, and need for long-term validation suggest that LISI should be part of a broader prognostic framework rather than a standalone tool. Future studies addressing these limitations would be invaluable in confirming LISI's utility in clinical practice. Ganesh Bushi: Conceptualization, literature review, writing – original draft. Muhammed Shabil: Data analysis, writing – review and editing. Amogh Verma: Supervision, project administration and correspondence. We thank the authors for their valuable contribution to the field of hepatocellular carcinoma research and for stimulating further discussion on prognostic tools. The authors declare that they have not received any funding for this current study. The authors declare to have no financial and non-financial interests relevant to this study to disclose.
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