Liver stiffness measured by acoustic radiation force impulse elastography predicted prognoses of hepatocellular carcinoma after radiofrequency ablation

Conventional and machine learning-based risk scores for patients with early-stage hepatocellular carcinoma

BACKGROUND/AIMS

The performance of machine learning (ML) in predicting the outcomes of patients with hepatocellular carcinoma (HCC) remains uncertain. We aimed to develop risk scores using conventional methods and ML to categorize early-stage HCC patients into distinct prognostic groups.

METHODS

The study retrospectively enrolled 1,411 consecutive treatment-naïve patients with the Barcelona Clinic Liver Cancer (BCLC) stage 0 to A HCC from 2012 to 2021. The patients were randomly divided into a training cohort (n=988) and validation cohort (n=423). Two risk scores (CATS-IF and CATS-INF) were developed to predict overall survival (OS) in the training cohort using the conventional methods (Cox proportional hazards model) and ML-based methods (LASSO Cox regression), respectively. They were then validated and compared in the validation cohort.

RESULTS

In the training cohort, factors for the CATS-IF score were selected by the conventional method, including age, curative treatment, single large HCC, serum creatinine and alpha-fetoprotein levels, fibrosis-4 score, lymphocyte-tomonocyte ratio, and albumin-bilirubin grade. The CATS-INF score, determined by ML-based methods, included the above factors and two additional ones (aspartate aminotransferase and prognostic nutritional index). In the validation cohort, both CATS-IF score and CATS-INF score outperformed other modern prognostic scores in predicting OS, with the CATSINF score having the lowest Akaike information criterion value. A calibration plot exhibited good correlation between predicted and observed outcomes for both scores.

CONCLUSION

Both the conventional Cox-based CATS-IF score and ML-based CATS-INF score effectively stratified patients with early-stage HCC into distinct prognostic groups, with the CATS-INF score showing slightly superior performance.

Stiffness on shear wave elastography as a potential microenvironment biomarker for predicting tumor recurrence in HBV-related hepatocellular carcinoma

BACKGROUND

To explore the pathologic basis and prognostic value of tumor and liver stiffness measured pre-operatively by two-dimensional shear wave elastography (2D-SWE) in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) patients who undergo hepatic resection.

METHODS

A total of 191 HBV-infected patients with solitary resectable HCC were prospectively enrolled. The stiffness of intratumoral tissue, peritumoral tissue, adjacent liver tissue, and distant liver tissue was evaluated by 2D-SWE. The correlations between stiffness and pathological characteristics were analyzed in 114 patients. The predictive value of stiffness for recurrence-free survival (RFS) was evaluated, and Cutoff Finder was used for determining optimal cut-off stiffness values. Cox proportional hazards analysis was used to identify independent predictors of RFS.

RESULTS

Pathologically, intratumoral stiffness was associated with stroma proportion and microvascular invasion (MVI) while peritumoral stiffness was associated with tumor size, capsule, and MVI. Adjacent liver stiffness was correlated with capsule and liver fibrosis stage while distant liver stiffness was correlated with liver fibrosis stage. Peritumoral stiffness, adjacent liver stiffness, and distant liver stiffness were all correlated to RFS (all p < 0.05). Higher peritumoral stiffness (> 49.4 kPa) (HR = 1.822, p = 0.023) and higher adjacent liver stiffness (> 24.1 kPa) (HR = 1.792, p = 0.048) were significant independent predictors of worse RFS, along with tumor size and MVI. The nomogram based on these variables showed a C-index of 0.77 for RFS prediction.

CONCLUSIONS

Stiffness measured by 2D-SWE could be a tumor microenvironment and tumor invasiveness biomarker. Peritumoral stiffness and adjacent liver stiffness showed important values in predicting tumor recurrence after curative resection in HBV-related HCC.

CLINICAL RELEVANCE STATEMENT

Tumor and liver stiffness measured by two-dimensional shear wave elastography serve as imaging biomarkers for predicting hepatocellular carcinoma recurrence, reflecting biological behavior and tumor microenvironment.

KEY POINTS

• Stiffness measured by two-dimensional shear wave elastography is a useful biomarker of tumor microenvironment and invasiveness. • Higher stiffness indicated more aggressive behavior of hepatocellular carcinoma. • The study showed the prognostic value of peritumoral stiffness and adjacent liver stiffness for recurrence-free survival. • The nomogram integrating peritumoral stiffness, adjacent liver stiffness, tumor size, and microvascular invasion showed a C-index of 0.77.

Can Liver Ultrasound Elastography Predict the Risk of Hepatocellular Carcinoma Recurrence After Radiofrequency Ablation? A Systematic Review and Meta-Analysis

PURPOSE

The role of liver stiffness (LS) on ultrasound elastography in the prediction of hepatocellular carcinoma (HCC) recurrence after treatment with radiofrequency ablation (RFA) is still unclear. Our aim was to perform a systematic review and meta-analysis to assess whether LS can predict the recurrence of HCC after RFA.

MATERIALS AND METHODS

Medline via PubMed, Embase, Scopus, and Cochrane Library databases, and abstracts of international conference proceedings were searched up to June 30, 2020. Cohort studies were included if they assessed the association between LS values measured by ultrasound elastography before RFA and HCC recurrence.

RESULTS

9 studies including 1373 patients with HCC treated by RFA, 643 of whom developed HCC recurrence, were identified. The mean value of LS before RFA was significantly higher in patients who developed HCC recurrence than in those who did not (weighted mean difference=11.98 kPa, 95%CI: 7.60-16.35, I2=63.8%). There was a significant positive association between LS value and HCC recurrence both at univariate (unadjusted HR=1.03, 95%CI: 1.00-1.07, I2=72.7%) and multivariate analysis (adjusted HR=1.03, 95%CI: 1.02-1.04, I2=0). Patients with LS value ≥13-14 kPa or >1.5 m/s have a higher risk of both HCC recurrence (unadjusted HR=2.18, 95%CI: 1.46-3.25, I2=49.7%; adjusted HR=2.41, 95%CI: 1.53-3.79, I2=0) and overall mortality (adjusted HR=4.38; 95%CI: 2.33-8.25, I2=0) in comparison with those with LS below these cutoffs.

CONCLUSION

Liver ultrasound elastography appears to be a reliable tool to predict HCC recurrence and overall survival after RFA. This technique may be useful for the management of patients with HCC treated by RFA.

Prognostic value of liver stiffness measurement in patients with hepatocellular carcinoma (HCC) treated by radiofrequency ablation: a meta-analysis

BACKGROUND

In patients with stage 0-A (as per Milan criteria) hepatocellular carcinoma (HCC) image-guided ablation is less invasive and requires shorter hospitalization than resection, but long-term prognosis is poorer. This meta-analysis was conducted to investigate whether liver stiffness measurement (LSM) could be used to predict prognosis in HCC patients after tumor ablation.

METHODS

A literature search was conducted for all studies published till July 2020 in PubMed, Web of Science, Cochrane Library and EMBASE. Studies were included if they investigated the association between pretreatment LSM and prognosis in HCC patients treated with ablation. Subgroup analysis, meta-regression, publication bias assessment and sensitivity were conducted.

RESULTS

Eight studies (with a total of 1276 HCC patients) were included in this meta-analysis. All patients were treated with radiofrequency ablation. Pooled results showed that high pretreatment LSM were associated with poor overall survival (OS) (hazard ratio [HR] = 4.31, 95% confidence interval [CI]: 2.27-8.20, p < .001) and recurrence-free survival (RFS), regardless of whether LSM was considered as a categorical variable (HR = 2.63, 95% CI = 1.63-4.22, p < .001) or as a continuous variable (HR = 1.02, 95% CI = 1.01-1.04, p = .003). Among studies treating LSM value as a categorical variable, liver stiffness measured using acoustic radio force impulse (ARFI) or transient elastography (TE) was significantly associated with RFS, but not liver stiffness measured using two-dimensional shear wave elastography (SWE).

CONCLUSIONS

High baseline LSM value appears to be associated with poor prognosis in HCC patients treated with radiofrequency ablation.

The role of liver and spleen elastography in advanced chronic liver disease

Portal hypertension is the main driver of complications in patients with advanced chronic liver disease (ACLD). In the last decade, many non-invasive tests, such us liver and spleen elastography, have been proposed and validated for the identification of patients with clinically significant portal hypertension (CSPH) and its complications, mainly hepatic decompensation and liver-related morbidity and mortality. Moreover, elastography accurately stratifies for the risk of HCC development, HCC recurrence and decompensation after liver surgery. Recent studies suggest a role of SSM in monitoring response to treatments and interventions in ACLD, such as viral eradication, non-selective beta-blockers and transjugular intrahepatic portosystemic shunt placement. However, one of the most indications to perform elastography in ACLD still remains the screening for esophageal varices. In fact, according to the Baveno VI consensus, liver stiffness measurement (LSM) <20 kPa and platelet count >150,000/mm³ can safely identify patients at low risk of varices requiring treatment (VNT) and could therefore avoid invasive upper invasive endoscopy; LSM>20-25 kPa can accurately rule-in CSPH in patients with viral etiology. Spleen stiffness measurement (SSM) is a direct surrogate of portal hypertension and has been demonstrated more accurate in predicting portal hypertension severity and VNT. A combined model including Baveno VI Criteria and SSM (≤46 kPa) can significantly increase the number of spared endoscopies (>40-50%), maintaining a low (<5%) of missed VNT.

The role of albumin-bilirubin grade in determining the outcomes of patients with very early-stage hepatocellular carcinoma

BACKGROUND

Patients with hepatocellular carcinoma (HCC) and with a single tumor <2 cm in size are classified as having Barcelona Clinic Liver Cancer (BCLC) stage 0 HCC. We aimed to investigate the role of the albumin-bilirubin (ALBI) grade in predicting outcomes in patients with BCLC stage 0 HCC.

METHODS

We retrospectively enrolled patients with BCLC stage 0 HCC in Taipei Veterans General Hospital from 2007 to 2015. Prognostic factors were analyzed using a Cox proportional hazards model and propensity score matching (PSM) analysis.

RESULTS

There were 420 patients enrolled, including 207 with ALBI grade 1, and 213 with ALBI grade 2 or 3. After a median follow-up of 60.0 months (interquartile range, 37.2-84.6 months), 179 patients died. The cumulative 5-year overall survival (OS) rates were 80.6% in patients with ALBI grade 1 and 53.7% in those with ALBI grade 2 or 3, respectively (p < 0.001). Multivariate analysis showed that age >65 years, negative hepatitis B surface in serum, creatinine >1.0 mg/dL, platelet count ≤105/mm3, tumor size >1.5 cm, nonsurgical resection (SR) therapy, and higher ALBI grade were independent risk factors related to poor OS. Patients who underwent SR had a better OS and recurrence-free survival than those who received radiofrequency ablation, which was confirmed by a multivariate analysis and PSM analysis.

CONCLUSION

The ALBI grade can determine OS for patients with BCLC stage 0 HCC. SR can also provide a better outcome than nonsurgical treatment.