Nomograms to Predict the Disease-free Survival and Overall Survival after Radiofrequency Ablation for Hepatocellular Carcinoma

Retrospective Analysis of Radiofrequency Ablation in Patients with Small Solitary Hepatocellular Carcinoma: Survival Outcomes and Development of a Machine Learning Prognostic Model

BACKGROUND AND OBJECTIVE

The effectiveness of radiofrequency ablation (RFA) in improving long-term survival outcomes for patients with a solitary hepatocellular carcinoma (HCC) measuring 5 cm or less remains uncertain. This study was designed to elucidate the impact of RFA therapy on the survival outcomes of these patients and to construct a prognostic model for patients following RFA.

METHODS

This study was performed using the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2017, focusing on patients diagnosed with a solitary HCC lesion ≤5 cm in size. We compared the overall survival (OS) and cancer-specific survival (CSS) rates of these patients with those of patients who received hepatectomy, radiotherapy, or chemotherapy or who were part of a blank control group. To enhance the reliability of our findings, we employed stabilized inverse probability treatment weighting (sIPTW) and stratified analyses. Additionally, we conducted a Cox regression analysis to identify prognostic factors. XGBoost models were developed to predict 1-, 3-, and 5-year CSS. The XGBoost models were evaluated via receiver operating characteristic (ROC) curves, calibration plots, decision curve analysis (DCA) curves and so on.

RESULTS

Regardless of whether the data were unadjusted or adjusted for the use of sIPTWs, the 5-year OS (46.7%) and CSS (58.9%) rates were greater in the RFA group than in the radiotherapy (27.1%/35.8%), chemotherapy (32.9%/43.7%), and blank control (18.6%/30.7%) groups, but these rates were lower than those in the hepatectomy group (69.4%/78.9%). Stratified analysis based on age and cirrhosis status revealed that RFA and hepatectomy yielded similar OS and CSS outcomes for patients with cirrhosis aged over 65 years. Age, race, marital status, grade, cirrhosis status, tumor size, and AFP level were selected to construct the XGBoost models based on the training cohort. The areas under the curve (AUCs) for 1, 3, and 5 years in the validation cohort were 0.88, 0.81, and 0.79, respectively. Calibration plots further demonstrated the consistency between the predicted and actual values in both the training and validation cohorts.

CONCLUSION

RFA can improve the survival of patients diagnosed with a solitary HCC lesion ≤5 cm. In certain clinical scenarios, RFA achieves survival outcomes comparable to those of hepatectomy. The XGBoost models developed in this study performed admirably in predicting the CSS of patients with solitary HCC tumors smaller than 5 cm following RFA.

A nomogram incorporating Psoas muscle index for predicting tumor recurrence after liver transplantation: A retrospective study in an Eastern Asian population

Background and aims

Tumor recurrence significantly affects the prognostic outcomes for liver cancer patients following liver transplantation. However, existing predictive models often neglect the inclusion of body composition indicators. Hence, this research aimed to investigate the significance of the psoas muscle index (PMI) in evaluating the post-transplant prognosis of liver cancer.

Methods

A retrospective analysis was conducted on liver cancer patients who underwent liver transplantation surgery. Imaging analysis was performed using CT data to calculate PMI based on the left and right psoas muscle areas. Subsequently, the patients were categorized into PMI-Low and PMI-High groups using the established cut-off values. Univariate and multivariate analyses were performed using Cox proportional hazards regression to assess the correlation between PMI and clinical outcomes, and a nomogram was constructed accordingly.

Results

Among the 225 patients included in the analysis, the PMI-High group exhibited significantly improved overall survival (P < 0.001) and disease-free survival (DFS, P < 0.001) rates compared to the PMI-Low group. PMI exhibited a positive correlation with body mass index (R = 0.25, P < 0.001), but no significant correlations were observed. In the multivariate analysis, PMI (HR = 4.596, P < 0.001), MELD score (HR = 1.591, P = 0.038), and Hangzhou criteria (HR = 2.557, P < 0.001) emerged as significant predictors of DFS. The constructed nomogram, incorporating these predictors, demonstrated outstanding predictive performance. Decision curve analysis revealed the superiority of the nomogram over conventional methods.

Conclusions

PMI serves as a valuable prognostic factor for tumor recurrence in liver cancer patients after liver transplantation. The established nomogram is pivotal in delivering personalized predictions of DFS.

Novel Prognostic Nomogram to Predict Progression-Free Survival of Patients with Hepatocellular Carcinoma After Transarterial Chemoembolization

PURPOSE

A retrospective analysis of hepatocellular carcinoma (HCC) patients treated with transarterial chemoembolization (TACE) to identify risk factors was conducted, and a novel predictive nomogram model was constructed.

PATIENTS AND METHODS

A total of 346 HCC patients who underwent TACE as initial treatment were retrospectively included, of which 208 were randomly allocated to the derivation cohort and 138 were allocated to the validation cohort. Progression-free survival (PFS) was used as the follow-up endpoint according to mRECIST. Kaplan‒Meier analysis and the Cox regression model screened out some indicators associated with short-term prognosis, and R language was further used to construct a nomogram model. The nomogram was compared with the classical BCLC staging system.

RESULTS

The independent predictors affecting PFS in HCC patients undergoing TACE included the following: 1. Baseline indicators: age (P=0.013), albumin-bilirubin (ALBI) grade (grade 2 vs grade 1, P=0.029; grade 3 vs grade 1, P<0.001), and portal vein tumour thrombus (PVTT, P<0.001); 2. Indicators at the 1-month follow-up: Neutrophil To Lymphocyte Ratio (NLR, P=0.032) and changes in alpha-fetoprotein (AFP, P<0.05) and des-γ-carboxy prothrombin (DCP, P<0.001); and 3. Cumulative treatment numbers of TACE in 6 months (P=0.007). In the derivation cohort, the calibration curve of the nomogram showed a high consistency between the predicted and actual PFS probability, and the nomogram outperformed the BCLC staging system (P=0.004). This result was also confirmed in the validation cohort (P=0.012).

CONCLUSION

The constructed nomogram was suggested to have good predictive efficacy and could be used as a complementary assessment to predict the survival and prognosis of HCC patients treated with TACE.

Nomogram to Predict the Long-Term Overall Survival of Early-Stage Hepatocellular Carcinoma after Radiofrequency Ablation

Our objective was to develop a predictive nomogram that could estimate the long-term survival of patients with very early/early-stage hepatocellular carcinoma (HCC) undergoing radiofrequency ablation (RFA). For this retrospective study, we enrolled 950 patients who initially received curative RFA for HCC at Barcelona Clinic Liver Cancer (BCLC) stages 0 and A between 2002 and 2016. Factors predicting poor survival after RFA were investigated through a Cox proportional hazard model. The nomogram was constructed using the investigated variables influencing overall survival (OS). After a median follow-up time of 6.25 years, 400 patients had died, and 17 patients had received liver transplantation. The 1-,3-,5-,7-, and 10-year OS rates were 94.5%, 73.5%, 57.9%, 45.7%, and 35.8%, respectively. Multivariate analysis showed that age greater than 65 years, albumin-bilirubin (ALBI) grades 2 and 3, AST-to-platelet ratio index (APRI) greater than 1, tumor size larger than 3 cm, diabetes mellitus, end-stage renal disease, and tumor number greater than 1 were significantly associated with poor OS. The nomogram was constructed using these seven variables. The validation results showed a good concordance index of 0.683. When comparing discriminative ability to tumor, node, and metastasis (TNM), BCLC, and Cancer of the Liver Italian Program (CLIP) staging systems, our nomogram had the highest C-index for predicting mortality. This nomogram provides useful information on prognosis post-RFA as a primary treatment and aids physicians in decision-making.

Radiofrequency ablation of hepatocellular carcinoma: Prognostic factors and recent advances

With the improvement of technology and diagnostic level, radiofrequency ablation (RFA) has made rapid progress in the treatment of primary hepatocellular carcinoma (HCC) in the past two decades. Especially, the overall survival after the treatment of small HCCs by RFA can be comparable to that achieved by hepatic resection. The 10-year survival rates of RFA for HCC were 27.3%-46.1%, and for solitary HCC less than 3 cm, the 10-year survival rate is about 74.0%. RFA combined with other therapies can expand the indications of RFA treatment and benefit the survival of patients with HCC. The prognostic model of RFA for HCC provides a powerful tool for individualized clinical diagnosis and treatment.

Nomograms to predict survival outcomes after microwave ablation in elderly patients (>65 years old) with early-stage hepatocellular carcinoma

Objectives: To develop and validate the nomograms to predict survival outcomes after microwave ablation (MWA) in elderly patients(>65 years old) with early-stage hepatocellular carcinoma (EHCC).Methods: This retrospective study was approved by the institutional review board. A total of 265 EHCC patients (76 females, 189 males; average age 71.4 years ± 5.4 [standard deviation]) with 345 nodules subsequently underwent MWA from April 2006 to October 2019. Baseline characteristics were collected to identify the risk factors for the determination of survival outcomes after MWA. The nomograms were based on prognostic factors for overall survival (OS) and recurrence-free survival (RFS) from the multivariate Cox proportional hazards model and validated in external cohorts from another two institutions (n = 130). The nomograms were assessed for their predictive accuracy using Harrell's concordance index (C-index).Results: After a median follow-up time of 28.6 months, 29.8% (79/265) of the patients died, and 54.3% (144/265) of the patients experienced recurrence in the training set. The OS nomogram was developed based on the hepatitis B virus (HBV) presence, α-fetoprotein (AFP), and albumin, with a C-index of 0.757 (95% confidence interval [CI]: 0.645, 0.789).The scores of the nomogram ranged from 0 to 24. The RFS nomogram was developed based on tumor number, abutting major vessels and platelets, with a C-index of 0.733 (CI: 0.672, 0.774). The likelihood of 3- and 5-year OS and RFS were consistent between clinical observations and nomogram predictions in external cohorts.Conclusions: The nomogram models can be useful in determining the risk of OS and RFS in elderly patients with EHCC after MWA, which can guide individual patient management.Key pointsMWA is an effective and feasible treatment for elderly patients with EHCC and can improve survival outcomes.A calibrated and objective nomogram model for the prediction of survival outcomes in elderly patients (>65 years old) may guide patient selection and MWA treatment.Older age was not deemed to be a risk factor for survival outcomes when the elderly patients with EHCC underwent MWA.

Uni-, Bi- or Trifocal Hepatocellular Carcinoma in Western Patients: Recurrence and Survival after Percutaneous Thermal Ablation

Multifocality is usually reported as a pejorative factor after percutaneous thermal ablation (PTA) of HCC but little is known in Western series. Recurrence and survival were extracted from a prospective database of all patients who underwent PTA for ≤3 cm HCC. From January 2015 to April 2020, we analyzed 281 patients with unifocal (n = 216), bifocal (n = 46) and trifocal (n = 16) HCC. PTA of bi- and trifocal HCC resulted in a high risk of very early (<6 months) distant recurrence (38.8% and 50%, respectively). Median RFS was 23.3 months (95% CI:18.6-30.4), 7.7 months (95% CI:5.1-11.43, p = 0.002) and 5.2 months (95% CI:3-12.3, p = 0.015), respectively, for uni-, bi- and trifocal HCC groups. In a multivariate analysis, both bifocal (HR = 2.46, p < 0.001) and trifocal (HR = 2.70, p = 0.021) vs. unifocal HCC independently predicted shorter RFS. Median OS in trifocal HCC group was 30.3 months (95 CI:19.3-not reached). Trifocal vs. unifocal HCC independently predicted shorter OS (HR = 3.30, p = 0.008), whereas bifocal vs. unifocal HCC did not (p = 0.27). Naïve patient (HR = 0.42, p = 0.007), AFP > 100 ng/mL (HR = 3.03, p = 0.008), MELD > 9 (HR = 2.84, p = 0.001) and steatotic HCC (HR = 0.12, p = 0.038) were also independent predictors of OS. In conclusion, multifocal HCCs in a Western population have a dramatically increased risk of distant recurrence. OS after PTA of trifocal HCC is significantly below what was expected after a curative treatment.

Nomogram Based on Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio to Predict Recurrence in Patients with Hepatocellular Carcinoma after Radiofrequency Ablation

OBJECTIVES

To investigate the prognostic value of pre-procedure neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) and construct a nomogram to predict disease-free survival (DFS) in patients receiving radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) within Milan criteria.

METHODS

The data of 515 patients of HCC within Milan criteria receiving RFA were retrospectively collected. The patients were divided into two groups: the training group (n = 382) and the validation group (n = 133). Several preprocedural variables were analyzed in the two groups to determine the prognostic factors.

RESULTS

The median DFS time of the training and validation group was 28.4 months and 24.5 months, respectively. Multivariate analyses showed that number of lesions, alpha-feto protein levels, NLR and PLR were independent risk factors of DFS. According to the time-dependent receiver operating characteristic curve (t-ROC), the optimal cutoff value of the NLR and PLR was 1.55 and 75.30, respectively, with sensitivity of 0.737 and 0.648 and specificity of 0.541 and 0.508, respectively. The area under curve (AUC) of the t-ROC curves for the NLR was 0.662 and PLR was 0.597. The DFS was significantly higher in the NLR ≤ 1.55 group compared to NLR > 1.55 group and the PLR ≤ 75.30 group compared to PLR > 75.30 group in both training and validation datasets. Nomogram was developed based on the prognostic factors indicated by the Cox regression to predict 1-, 2-, 3- and 5-year DFS probabilities.

CONCLUSIONS

The cutoff value of the NLR and PLR was 1.55 and 75.30. This new nomogram based on NLR and PLR may provide good and individualized prediction of recurrence for HCC patients within Milan criteria after RFA.

An excellent nomogram predicts microvascular invasion that cannot independently stratify outcomes of small hepatocellular carcinoma

Background

Whether microvascular invasion is a prognosis factor for small hepatocellular carcinoma (sHCC) is controversial, and a preoperatively predictive model based on gadoxetate disodium (Gd-EOB-DTPA) MRI is clinically needed for MVI in sHCC.

Methods

Between March 2012 and September 2020, 455 consecutive patients with pathologically confirmed HCC ≤3 cm who underwent hepatectomy and preoperative Gd-EOB-DTPA MRI were retrospectively enrolled. Univariate and multivariate logistic regression combined with cox regression were conducted to find the confounding factors in the cohorts. Propensity score matching (PSM) was employed to balance the biases between MVI and non-MVI groups. Nomogram with C-index visualized the predictive model of MVI.

Results

Multivariate logistic regression identified that 5 characteristics (AFP, tumor size, tumor margin, peritumoral enhancement, radiologic capsule) were markedly associated with MVI of sHCC and incorporated into the nomogram with excellent predictive performance in the training (AUC/C-index: 0.884/0.874, n=288), validation (AUC/C-index: 0.845/0.828, n=123) and test cohorts (AUC/C-index: 0.903/0.954, n=44). Before PSM, histologic MVI independently affected tumor recurrence (hazard ratio: 1.555, 95% CI: 1.055–2.293, P=0.026). However, due to the confounder of tumor size, there was a significant bias between MVI-positive and MVI-negative groups (propensity score: 0.249±0.105 vs. 0.179±0.106, P<0.001). Meanwhile, the frequency of MVI significantly increased as tumor size growing (P<0.001). After PSM, 70 of 79 MVI cases matched with 171 non-MVI (total 332), and no biases were observed between the two groups (propensity score: 0.238±0.104 vs. 0.217±0.109, P=0.186). Although the median recurrence time in non-MVI sHCC was still longer than that in MVI group (74.3 vs. 43.0 months, P=0.063), MVI was not an independent risk factor for RFS in sHCC. Additionally, MVI was not independently vulnerable to mortality in our population.

Conclusions

A preoperative model, mainly based on the peritumoral hallmarks of Gd-EOB-DTPA MRI, showed an excellent performance to predict the occurrence of MVI. Nevertheless, MVI was a potential but not an independent risk factor for recurrence and mortality in sHCC ≤3 cm.

Radiofrequency ablation with four electrodes as a building block for matrix radiofrequency ablation: Ex vivo liver experiments and finite element method modelling. Influence of electric and activation mode on coagulation size and geometry

PURPOSE

Radiofrequency ablation (RFA) is increasingly being used to treat unresectable liver tumors. Complete ablation of the tumor and a safety margin is necessary to prevent local recurrence. With current electrodes, size and shape of the ablation zone are highly variable leading to unsatisfactory local recurrence rates, especially for tumors >3 cm. In order to improve predictability, we recently developed a system with four simple electrodes with complete ablation in between the electrodes. This rather small but reliable ablation zone is considered as a building block for matrix radiofrequency ablation (MRFA). In the current study we explored the influence of the electric mode (monopolar or bipolar) and the activation mode (consecutive, simultaneous or switching) on the size and geometry of the ablation zone.

MATERIALS AND METHODS

The four electrode system was applied in ex vivo bovine liver. The electric and the activation mode were changed one by one, using constant power of 50 W in all experiments. Size and geometry of the ablation zone were measured. Finite element method (FEM) modelling of the experiment was performed.

RESULTS

In ex vivo liver, a complete and predictable coagulation zone of a 3 × 2 × 2 cm block was obtained most efficiently in the bipolar simultaneous mode due to the combination of the higher heating efficacy of the bipolar mode and the lower impedance by the simultaneous activation of four electrodes, as supported by the FEM simulation.

CONCLUSIONS

In ex vivo liver, the four electrode system used in a bipolar simultaneous mode offers the best perspectives as building block for MRFA. These results should be confirmed by in vivo experiments.

Using the Controlling Nutritional Status (CONUT) Score for Evaluating Patients with Early-Stage Hepatocellular Carcinoma After Radiofrequency Ablation: A Two-Center Retrospective Study

PURPOSE

To estimate the prognostic significance of the controlling nutritional status (CONUT) in patients with BCLC stage A hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA).

MATERIALS AND METHODS

From January 2013 to December 2016, 325 patients with BCLC stage A HCC who underwent RFA at the National Cancer Center and First Hospital of Shanxi Medical University were retrospectively studied. The patients were divided into low (≤ 4) and high (≥ 5) CONUT scores for assessment of overall survival (OS) and recurrence-free survival (RFS). Several covariates, including age, sex, the diameter and number of lesions, lesion differentiation, Child-Pugh class, hepatitis B virus infection, along with blood levels of AFP, AST, ALT, γ-GT, and TBIL, were assessed using univariate and multivariate analyses.

RESULTS

The mortality rate was 17.49% (46/263) and 35.48% (22/62) in the low and high CONUT groups, respectively, with the difference being statistically significant (P = 0.033). In addition, disease recurrence was significantly higher in the high CONUT group at 70.97%, as compared to the low CONUT group at 43.35% (P = 0.041). The predictive factors were used to build the nomogram to estimate 1-, 3- and 5-year OS and RFS rates.

CONCLUSIONS

CONUT scores were found to be associated with the prognosis of patients with early-stage HCC who underwent RFA. Higher CONUT scores were associated with poor survival outcomes.

A novel nomogram to predict the local tumor progression after microwave ablation in patients with early-stage hepatocellular carcinoma: A tool in prediction of successful ablation

OBJECTIVES

To develop a nomogram for the local tumor progression (LTP) in patients with early-stage hepatocellular carcinoma (HCC) after computed tomography-guided percutaneous microwave ablation (CT-PMWA) and to assess clinical-pathologic risk factors for individual LTP estimation. Furthermore, we compared the prognostic predictive ability for LTP between the nomogram and the traditional staging systems.

METHODS

This retrospective study was approved by the institutional review board. Five hundred and forty treatment-naïve patients with HCC according to the Milan criteria, who subsequently underwent CT-PMWA were reviewed from 2009 to 2019. Baseline characteristics were collected to identify the risk factors for the determination of LTP after CT-PMWA. The multivariate Cox proportional-hazards model based on significant prognostic factors of LTP was used to construct the nomogram, which was then assessed for its predictive accuracy using mainly the Harrell's C-index and time-dependent area under the curve (tAUC).

RESULTS

After a median follow-up time of 28.7 months, 6.5% (35/540) patients had LTP. The nomogram was developed based on the tumor size, tumor number, Child-Turcotte-Pugh (CTP) grade, platelet, and alanine aminotransferase (ALT). The nomogram had good calibration and discriminatory abilities in the training set, with C-indexes of 0.799 (95% confidence interval (CI): 0.738, 0.860), and tAUCs of 0.844 (CI: 0.728, 0.895), that were greater than those of traditional staging systems. Internal validation with 1000 bootstrap resamples had a good C-index of 0.735 (CI: 0.648, 0.816).

CONCLUSIONS

The nomogram model can be used to predict accurately LTP after CT-PMWA for early-stage HCC, as well as to assist physicians during the therapeutic decision-making process.

Development and validation of a prognostic model for patients with hepatocellular carcinoma undergoing radiofrequency ablation

BACKGROUND

There are large variations in prognosis among hepatocellular carcinoma (HCC) patients undergoing radiofrequency ablation (RFA). However, current staging or scoring systems hardly discriminate the outcome of HCC patients treated with RFA.

METHODS

A total of 757 treatment-naïve HCC patients undergoing RFA (derivation cohort) were analyzed to establish a nomogram for disease-free survival (DFS) based on Cox proportional hazard regression model. Accuracy of the nomogram was assessed and compared with conventional staging or scoring systems. Furthermore, external validation was performed in an independent cohort including 208 patients (validation cohort).

RESULTS

Tumor size, tumor number, alpha-fetoprotein, prothrombin induced by vitamin K absence-II, lymphocyte count, albumin, and presence of ascites were adopted to construct the prognostic nomogram from the derivation cohort. Calibration curves to predict probability of DFS at 3 and 5 years after RFA showed good agreements between the nomogram and actual observations. The concordance index of the present nomogram was 0.759 (95% confidence interval 0.728-0.790), which was superior to those of conventional staging or scoring systems (range 0.505-0.683, all P < .001). These results were also reproduced in the validation cohort.

CONCLUSION

Our simple-to-use nomogram optimized for treatment-naïve HCC patients undergoing RFA provided better prognostic performance than conventional staging or scoring systems.