Tumor protrusion assessment and clinical integration for enhanced mortality risk prediction in spontaneously ruptured hepatocellular carcinoma

Abstract

BACKGROUND

Spontaneously ruptured hepatocellular carcinoma (rHCC) carries high early mortality following emergency hemostatic procedures like transarterial embolization (TAE) or transarterial chemoembolization (TACE). Existing prognostic models lack accuracy, particularly by omitting morphological risk factors such as tumor protrusion.

AIM

To develop and validate a novel scoring system that integrates quantitative tumor protrusion with clinical parameters to improve 30-day mortality prediction.

METHODS

This retrospective cohort study included consecutive patients with rHCC treated with emergency TAE/TACE between January 2007 and December 2024. Three quantitative protrusion metrics (percentage, maximum diameter, and area) were compared for predictive performance. Inter-observer reliability was assessed using intraclass correlation coefficients. Multivariable logistic regression was used to identify independent predictors of 30-day mortality. A weighted scoring system was derived from regression coefficients and internally validated using bootstrap resampling (1000 iterations). The model’s discriminative ability was compared to the model for end-stage liver disease and Child-Pugh scores using the area under the receiver operating characteristic curve (AUC) and DeLong’s test.

RESULTS

Eighty-nine patients were included. Protrusion area (PA) exhibited the highest discriminative power for 30-day mortality (AUC = 0.618) and excellent inter-observer reliability (intraclass correlation coefficients = 0.981). Multivariable analysis identified three independent predictors: PA ≥ 8.7 cm², total bilirubin ≥ 2.5 mg/dL, and albumin ≤ 3.0 g/dL. The derived PA-bilirubin-albumin (PBA) score stratified patients into low-, intermediate-, and high-risk groups with 30-day mortality rates of 8.6%, 40.0%, and 81.8%, respectively (P < 0.001). The PBA score demonstrated excellent and robust discrimination, confirmed by bootstrap validation (optimism-corrected AUC = 0.814). The PBA score significantly outperformed both the model for end-stage liver disease score (AUC = 0.672, P = 0.005) and Child-Pugh score (AUC = 0.594, P = 0.001).

CONCLUSION

By integrating PA with bilirubin and albumin, the PBA score is a novel, validated prognostic tool specifically for rHCC. It provides superior risk stratification over existing scores and identifies high-risk patients for whom emergency TAE/TACE is unlikely to provide clinical benefit.

Keywords: Hepatocellular carcinoma; Tumor rupture; Transarterial chemoembolization; Prognosis; Risk score

Core Tip: Spontaneously ruptured hepatocellular carcinoma carries a high 30-day mortality risk. Current assessment of tumor protrusion remains largely subjective, and existing prognostic models often lack precision in acute settings. This study identifies “protrusion area” (PA) as a superior predictor of early mortality compared to other metrics. We developed the PA-bilirubin-albumin score, which significantly outperforms conventional scoring systems (area under the receiver operating characteristic curve = 0.813). By stratifying patients into three distinct risk groups, the PA-bilirubin-albumin score provides clinicians with a robust, objective tool for rapid bedside decision-making, helping to identify patients who may benefit more from palliative care than from futile aggressive interventions.