Development of a transformer model for predicting the prognosis of patients with hepatocellular carcinoma after radiofrequency ablation.

INTRODUCTION: Radiofrequency ablation (RFA) is a widely accepted, minimally invasive treatment modality for patients with hepatocellular carcinoma (HCC). Accurate prognosis prediction is important to identify patients at high risk for cancer progression/recurrence after RFA. Recently, state-of-the-art transformer models showing improved performance over existing deep learning-based models have been developed in several fields. This study was aimed at developing and validating a transformer model to predict the overall survival in HCC patients with treated by RFA. METHODS: We enrolled a total of 1778 treatment-naïve HCC patients treated by RFA as the first-line treatment. We developed a transformer-based machine learning model to predict the overall survival in the HCC patients treated by RFA and compared its predictive performance with that of a deep learning-based model. Model performance was evaluated by determining the Harrel's c-index and validated externally by the split-sample method. RESULTS: The Harrel's c-index of the transformer-based model was 0.69, indicating its better discrimination performance than that of the deep learning model (Harrel's c-index, 0.60) in the external validation cohort. The transformer model showed a high discriminative ability for stratifying the external validation cohort into two or three different risk groups (p < 0.001 for both risk groupings). The model also enabled output of a personalized cumulative recurrence prediction curve for each patient. CONCLUSIONS: We developed a novel transformer model for personalized prediction of the overall survival in HCC patients after RFA treatment. The current model may offer a personalized survival prediction schema for patients with HCC undergoing RFA treatment.

Proton Beam Therapy versus Radiofrequency Ablation for Patients with Treatment-Naïve Single Hepatocellular Carcinoma: A Propensity Score Analysis.

Introduction: Proton beam therapy (PBT) is known to be an effective locoregional treatment for hepatocellular carcinoma (HCC). However, few comparative studies in treatment-naïve cases have been reported. The aim of this study was to compare the survival outcomes of PBT with those of radiofrequency ablation (RFA) in patients with treatment-naïve solitary HCC. Methods: Ninety-five consecutive patients with treatment-naïve HCC, a single nodule measuring ≤5 cm in diameter, and a Child-Pugh score of ≤8 who were treated with PBT at the University of Tsukuba Hospital between 2001 and 2013 were enrolled in the study. In addition, 836 patients with treatment-naïve HCC treated by RFA at the University of Tokyo Hospital during the same period were analyzed as controls. Recurrence-free survival (RFS) and overall survival (OS) were compared in 83 patient pairs after propensity score matching. Results: The 1-year, 3-year, and 5-year RFS rates were 86.6%, 49.5%, and 35.5%, respectively, in the PBT group and 59.5%, 34.0%, and 20.9% in the RFA group (p = 0.058); the respective OS rates were 97.6%, 77.8%, and 57.1% in the PBT group and 95.1%, 81.7%, and 67.7% in the RFA group (p = 0.16). Regarding adverse effects, no grade 3 or higher adverse events were noted in the PBT; however, two grade 3 adverse events occurred within 30 days of RFA in the RFA group: one hemoperitoneum and one hemothorax. Discussion: After propensity score matching, PBT showed no significant difference in RFS and OS compared to RFA. PBT can be an alternative for patients with solitary treatment-naïve HCC.

Report of the 23rd nationwide follow-up survey of primary liver cancer in Japan (2014-2015).

For the 23rd Nationwide Follow-up Survey of Primary Liver Cancer in Japan, data from 20 889 newly registered patients and 42 274 previously registered follow-up patients were compiled from 516 institutions over a 2-year period from January 1, 2014 to December 31, 2015. Basic statistics compiled for patients newly registered in the 23rd survey were cause of death, past medical history, clinical diagnosis, imaging diagnosis, treatment-related factors, pathological diagnosis, recurrence status, and autopsy findings. Compared with the previous 22nd survey, the population of patients with hepatocellular carcinoma (HCC) was older at the time of clinical diagnosis, had more female patients, had more patients with non-B non-C HCC, had smaller tumor diameter, and was more frequently treated with hepatectomy. Cumulative survival rates were calculated for HCC, intrahepatic cholangiocarcinoma, and combined hepatocellular cholangiocarcinoma (combined HCC and intrahepatic cholangiocarcinoma) by treatment type and background characteristics for patients newly registered between 2004 and 2015 whose final outcome was survival or death. The median overall survival and cumulative survival rates for HCC were calculated by dividing patients by combinations of background factors (number of tumors, tumor diameter, Child-Pugh grade, or albumin-bilirubin grade) and by treatment type (hepatectomy, radiofrequency ablation therapy, transcatheter arterial chemoembolization, hepatic arterial infusion chemotherapy, and systemic therapy). The same values were also calculated according to registration date by dividing patients newly registered between 1978 and 2015 into five time period groups. The data obtained from this nationwide follow-up survey are expected to contribute to advancing clinical research and treatment of primary liver cancer in the world.

The Impact of Partial Splenic Embolization on Portal Hypertensive Gastropathy in Cirrhotic Patients with Portal Hypertension.

This study investigated the impact of partial splenic embolization (PSE) on portal hypertensive gastropathy (PHG). We retrospectively analyzed endoscopic findings and the portal venous system of 31 cirrhotic patients with PHG. The improved group was defined as the amelioration of PHG findings using the McCormack classification. Child-Pugh scores of the improved group (18 of 31 patients) were significantly lower compared with those of the non-improved group (p = 0.018). The changes in the diameters of the portal trunk and those of the spleno-portal junction and spleen hilum in the splenic vein of the improved group were significantly larger than those of the non-improved group (p = 0.007, p = 0.025, and p = 0.003, respectively). The changes in the diameters of the portal vein and splenic hilum of the splenic vein showed significant correlations with Child-Pugh score (r = 0.386, p = 0.039; r = 0.510, p = 0.004). In a multivariate analysis of baseline factors related to the improved group, Child-Pugh grade A was significantly associated with the improvement of PHG (odds ratio 6.875, p = 0.033). PSE could be useful for PHG, especially in patients with Child-Pugh grade A, at least in the short term.

Steroid administration for ischemic complications after radiofrequency ablation: A retrospective study.

AIM: The aim of this study was to evaluate the effects of steroids on ischemic complications after radiofrequency ablation. METHODS: A total of 58 patients with ischemic complications were divided into two groups according to corticosteroid use or non-use. RESULTS: A total of 13 patients who were administered steroids had a shorter duration of fever than those who were not administered steroids (median 6.0 vs. 2.0 days; p < 0.001). Linear regression analysis showed that steroid administration was associated with a reduction of 3.9 days in the duration of fever (p = 0.008). CONCLUSIONS: Steroid administration for ischemic complications after radiofrequency ablation may reduce the risk of fatal outcomes by blocking systemic inflammatory reactions.

Endobronchial Watanabe Spigot Placement for Hepatic Abscess and Bronchobiliary Fistula Following Radiofrequency Ablation for Hepatocellular Carcinoma.

A bronchobiliary fistula (BBF) is an uncommon but severe complication after radiofrequency ablation (RFA). However, the definitive salvage methods are controversial. We herein report a patient with hepatocellular carcinoma with hepatic abscess and BBF following RFA. We also review previous reports of BBF after RFA. The patient was a man in his 70s who underwent RFA for recurrent hepatocellular carcinoma in the subphrenic area. Despite percutaneous transhepatic abscess drainage, bilioptysis persisted. Finally, the BBF was occluded with an endobronchial Watanabe spigot under fiber-optic bronchoscopy. Placing an endobronchial Watanabe spigot should be considered as a salvage therapy for refractory BBF following RFA.

Ablation for Benign Liver Tumors: Current Concepts and Limitations.

Percutaneous ablation under imaging guidance is a curative treatment that can induce complete tumor necrosis with advantages of minimal invasiveness and a low risk of complications. Thermal ablation, which includes radiofrequency ablation and microwave ablation, is a representative technique that has sufficient antitumor effects in cases of hepatocellular carcinoma with ≤3 lesions measuring ≤3 cm and preserved liver function. The short- and long-term outcomes of patients are comparable with those achieved with surgical resection. Despite their nonmalignant nature, some benign liver tumors require treatment for symptoms caused by the presence of the tumor and/or continuous enlargement. Ablation may be the treatment of choice because it has lower burden on patients than surgical treatment. This review describes the recent concepts, progress, and limitations of ablation-based treatment for benign liver tumors.

Reevaluation of Makuuchi's criteria for resecting hepatocellular carcinoma: A Japanese nationwide survey.

AIM: Although Makuuchi's criteria are widely used to determine the cut-off for safe liver resection, there have been few reports of concrete data supporting their validity. Here, we verified the utility of Makuuchi's criteria by comparing the operative mortality rates associated with liver resection between hepatocellular carcinoma (HCC) patients meeting or exceeding the criteria. METHODS: A database was built using data from 15 597 patients treated between 2000 and 2007 for whom values for all three variables included in Makuuchi's criteria for liver resection (clinical ascites, serum bilirubin, and indocyanine green clearance) were available. The patients were divided into those fulfilling (n = 12 175) or exceeding (n = 3422) the criteria. The postoperative mortality (death for any reason within 30 days) and long-term survival were compared between the two groups. RESULTS: The operative mortality rate was significantly lower in patients meeting the criteria than in those exceeding the criteria (1.07% vs. 2.01%, respectively; p < 0.001). On multivariate analysis, exceeded the criteria was significantly associated with the risk for operative mortality (relative risk 2.08; 95% confidence interval (CI), 1.23-3.52; p = 0.007). Surgical indication meeting or exceeding the criteria was an independent factor for overall survival (hazard ratio 1.27; 95% CI, 1.18-1.36; p < 0.001). CONCLUSION: Makuuchi's criteria are suitable for determining the indication for resection of HCC due to the reduction in risk of operative mortality.

Impact of Cabozantinib Exposure on Proteinuria and Muscle Toxicity in Patients with Unresectable Hepatocellular Carcinoma.

This prospective study investigated the impact of cabozantinib exposure on proteinuria and muscle toxicity, in a cohort of 14 Japanese patients with unresectable hepatocellular carcinoma (uHCC). We measured the trough concentration of cabozantinib (Ctrough) weekly for 6 weeks after starting treatment. Although the initial dose was less than 60 mg in most cases, dose interruption occurred in 79%, primarily because of proteinuria and/or malaise. The median and coefficient of variation of maximum Ctrough at 7−42 d were 929.0 ng/mL and 59.2%, respectively. The urinary protein-to-creatinine ratio (UPCR), serum creatine kinase, and serum aldolase values were all significantly elevated following treatment. Moreover, maximum changes in serum creatine kinase and aldolase were significantly associated with maximum Ctrough (r = 0.736, p < 0.01; r = 0.798, p < 0.001; respectively). Receiver operating characteristic (ROC) curve analysis showed that changes in serum creatine kinase ≥70.5 U/L and aldolase ≥6.1 U/L from baseline relatively accurately predicted inclusion in the high-maximum Ctrough (≥929.0 ng/mL) group, with an area under the ROC of 0.929 and 0.833, respectively. Measurement of serum creatine kinase and aldolase may increase the clinical usefulness of cabozantinib treatment for uHCC and help alleviate difficulties with dose adjustments.

Surgery versus Radiofrequency Ablation for Small Hepatocellular Carcinoma: A Randomized Controlled Trial (SURF Trial).

Introduction: It remains unclear which surgery or radiofrequency ablation (RFA) is the more effective treatment for small hepatocellular carcinoma (HCC). We aimed to compare survival between patients undergoing surgery (surgery group) and patients undergoing RFA (RFA group). Methods: We conducted a randomized controlled trial involving 49 institutions in Japan. Patients with Child-Pugh scores ≤7, largest HCC diameter ≤3 cm, and ≤3 HCC nodules were considered eligible. The co-primary endpoints were recurrence-free survival (RFS) and overall survival (OS). The current study reports the final result of RFS, and the follow-up of OS is still ongoing. Results: During 2009-2015, 308 patients were registered. After excluding ineligible patients, the surgery and RFA groups included 150 and 151 patients, respectively. Baseline factors did not differ significantly between the groups. In both groups, 90% of patients had solitary HCC. The median largest HCC diameter was 1.8 cm (interquartile range [IQR], 1.5-2.2 cm) in the surgery group and 1.8 cm (IQR, 1.5-2.3 cm) in the RFA group. The median procedure duration (274 vs. 40 min, p < 0.01) and the median duration of hospital stay (17 days vs. 10 days, p < 0.01) were longer in the surgery group than in the RFA group. RFS did not differ significantly between the groups as the median RFS was 3.5 (95% confidence interval [CI], 2.6-5.1) years in the surgery group and 3.0 (95% CI, 2.4-5.6) years in the RFA group (hazard ratio, 0.92; 95% CI, 0.67-1.25; p = 0.58). Discussion/Conclusion: Our study did not show which surgery or RFA is the better treatment option for small HCC.

Improved prognosis of hepatitis C-related hepatocellular carcinoma in the era of direct-acting antivirals.

The prognostic impact of direct-acting antivirals (DAAs) on patients with hepatitis C-related hepatocellular carcinoma (C-HCC) is still unclear. This study aimed to evaluate the prognosis of C-HCC in the DAA era. We enrolled 1237 consecutive patients with treatment-naive C-HCC who underwent radical radiofrequency ablation between 1999 and 2019. We also enrolled 350 patients with nonviral HCC as controls. We divided these patients into three groups according to the year of initial treatment: 1999-2005 (cohort 1), 2006-2013 (cohort 2), and 2014-2019 (cohort 3). The use of antiviral agents and their effect in patients with C-HCC was investigated. Overall survival was evaluated for each cohort using the Kaplan-Meier method and a multivariable Cox proportional hazards regression model. Sustained virologic response (SVR) was achieved in 52 (10%), 157 (26%), and 102 (74%) patients with C-HCC in cohorts 1-3, respectively. The 3- and 5-year survival rates of patients with C-HCC were 82% and 59% in cohort 1; 80% and 64% in cohort 2; and 86% and 78% in cohort 3, respectively (p = 0.003). Multivariable analysis adjusted for age, liver function, and tumor extension showed that the prognosis of C-HCC improved in cohort 3 compared to cohort 1 (adjusted hazard ratio [aHR], 0.49; 95% confidence interval [CI], 0.32-0.73; p < 0.001), whereas the prognosis of nonviral HCC did not improve significantly (aHR, 0.96; 95% CI, 0.59-1.57; p = 0.88). The prognosis of C-HCC drastically improved with the advent of DAAs.

Endoscopic Ultrasound-guided Hepaticogastrostomy in a Seven-year-old Girl.

Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is an effective biliary drainage procedure in adult cases with difficult biliary access. However, there have been no reports on this procedure being used in pediatric cases. We successfully performed EUS-HGS in a pediatric case with a surgically altered anatomy. A standard convex-type echoendoscope and standard devices were used, and there were no device-related complications. The benefit of EUS-HGS for pediatric patients was avoidance of a percutaneous tube, which is difficult to maintain in active children. The accumulation of further cases and performance of a prospective study are warranted to standardize and expand the experience with this procedure.

Response Evaluation Criteria in Cancer of the liver version 6 (Response Evaluation Criteria in Cancer of the Liver 2021 revised version).

Response Evaluation Criteria in Solid Tumors (RECIST) is inappropriate to assess the direct effects of treatment on hepatocellular carcinoma (HCC) by locoregional therapies, such as radiofrequency ablation or transarterial chemoembolization. Therefore, establishment of response evaluation criteria solely devoted to HCC is needed in clinical practice, as well as in clinical trials of HCC treatment, such as systemic therapies, which cause necrosis of the tumor. Response Evaluation Criteria in Cancer of the Liver (RECICL) was revised in 2021 by the Liver Cancer Study Group of Japan based on the 2019 version of RECICL, which was commonly used in Japan. The major revised points of the RECICL 2021 is inclusion of RECIST version 1.1 and modified RECIST as response evaluation criteria in systemic therapy for HCC. We hope this new treatment response criteria, RECICL, proposed by the Liver Cancer Study Group of Japan will benefit the HCC treatment response evaluation in the setting of daily clinical practice and clinical trials as well, not only in Japan, but also internationally.

Report of the 22nd nationwide follow-up Survey of Primary Liver Cancer in Japan (2012-2013).

In the 22nd Nationwide Follow-up Survey of Primary Liver Cancer in Japan, data from 21 155 newly registered patients and 43 041 previously registered follow-up patients were compiled from 538 institutions over a 2-year period from January 1, 2012 to December 31, 2013. Basic statistics compiled for patients newly registered in the 22nd survey were cause of death, past medical history, clinical diagnosis, imaging diagnosis, treatment-related factors, pathologic diagnosis, recurrence status and autopsy findings. Compared with the previous 21st survey, the population of patients with hepatocellular carcinoma (HCC) was older at the time of clinical diagnosis, had more female patients, more patients with non-B non-C HCC, smaller tumor diameter and was more frequently treated with hepatectomy. Cumulative survival rates were calculated for HCC, intrahepatic cholangiocarcinoma, and combined hepatocellular cholangiocarcinoma (combined HCC and intrahepatic cholangiocarcinoma) by treatment type and background characteristics for patients newly registered between 2002 and 2013 whose final outcome was survival or death. Median overall survival and cumulative survival rates for HCC were calculated by dividing patients by combinations of background factors (number of tumors, tumor diameter or Child-Pugh grade) and by treatment type (hepatectomy, radiofrequency ablation therapy, transcatheter arterial chemoembolization, hepatic arterial infusion chemotherapy and systemic therapy). The same values were also calculated according to registration date by dividing patients newly registered between 1978 and 2013 into five time period groups. The data obtained from this nationwide follow-up survey are expected to contribute to advancing clinical research and treatment of primary liver cancer worldwide.

Downregulation of METTL6 mitigates cell progression, migration, invasion and adhesion in hepatocellular carcinoma by inhibiting cell adhesion molecules.

RNA modifications have attracted increasing interest in recent years because they have been frequently implicated in various human diseases, including cancer, highlighting the importance of dynamic post­transcriptional modifications. Methyltransferase­like 6 (METTL6) is a member of the RNA methyltransferase family that has been identified in many cancers; however, little is known about its specific role or mechanism of action. In the present study, we aimed to study the expression levels and functional role of METTL6 in hepatocellular carcinoma (HCC), and further investigate the relevant pathways. To this end, we systematically conducted bioinformatics analysis of METTL6 in HCC using gene expression data and clinical information from a publicly available dataset. The mRNA expression levels of METTL6 were significantly upregulated in HCC tumor tissues compared to that in adjacent non­tumor tissues and strongly associated with poorer survival outcomes in patients with HCC. CRISPR/Cas9­mediated knockout of METTL6 in HCC cell lines remarkably inhibited colony formation, cell proliferation, cell migration, cell invasion and cell attachment ability. RNA sequencing analysis demonstrated that knockout of METTL6 significantly suppressed the expression of cell adhesion­related genes. However, chromatin immunoprecipitation sequencing results revealed no significant differences in enhancer activities between cells, which suggests that METTL6 may regulate genes of interest post­transcriptionally. In addition, it was demonstrated for the first time that METTL6 was localized in the cytosol as detected by immunofluorescence analysis, which indicates the plausible location of RNA modification mediated by METTL6. Our findings provide further insight into the function of RNA modifications in cancer and suggest a possible role of METTL6 as a therapeutic target in HCC.

Impact of genetic polymorphisms on the pharmacokinetics and pharmacodynamics of lenvatinib in patients with hepatocellular carcinoma.

This prospective study examined the impact of genetic polymorphisms on the pharmacokinetics and clinical efficacy and safety of lenvatinib, a substrate of ATP-binding transporters, in a cohort of 48 Japanese patients with hepatocellular carcinoma (HCC). Pharmacokinetic studies were performed at the start of lenvatinib therapy (day 1) and on day 15. The coefficients of variation in AUC0-24h of lenvatinib on days 1 and 15 were 44.0% and 52.4%, respectively. Although the ABCB1 3435C > A, 1236C > T, and 2677G>T/A polymorphisms did not influence pharmacokinetic parameters, the AUC0-24h values on days 1 and 15 of the ABCG2 C/A or A/A group were approximately 1.1-fold and 1.4-fold that in the ABCG2 C/C group (P = 0.164 and 0.024). There were no significant differences in AUC0-24h on days 1 and 15 between the responders (complete or partial response) and non-responders (stable or progressive disease). The AUC0-24h on day 15 in those developing anorexia of any grade was significantly higher than that without such development (P = 0.017). In multivariate analysis, ABCG2 421C > A C/A or A/A was significantly associated with the development of anorexia (odds ratio 9.009, P = 0.009). ABCG2 421C > A polymorphism could affect exposure to lenvatinib and the development of anorexia.

Levocarnitine Supplementation Suppresses Lenvatinib-Related Sarcopenia in Hepatocellular Carcinoma Patients: Results of a Propensity Score Analysis.

This study investigated the inhibitory effect of levocarnitine supplementation on sarcopenia progression in hepatocellular carcinoma (HCC) patients treated with lenvatinib. We evaluated the skeletal muscle index (SMI). After propensity score matching for age, sex, modified albumin-bilirubin grade, baseline presence of sarcopenia, and branched-chain amino acid administration, we selected 17 patients who received levocarnitine supplementation after starting lenvatinib therapy and 17 propensity-score-matched patients who did not receive levocarnitine. Sarcopenia was present in 76% of the patients at baseline. Changes in baseline SMI at 6 and 12 weeks of treatment were significantly suppressed in the group with levocarnitine supplementation compared with those without (p = 0.009 and p = 0.018, respectively). While there were no significant differences in serum free carnitine levels in cases without levocarnitine supplementation between baseline and after 6 weeks of treatment (p = 0.193), free carnitine levels were significantly higher after 6 weeks of treatment compared with baseline in cases with levocarnitine supplementation (p < 0.001). Baseline SMI and changes in baseline SMI after 6 weeks of treatment were significantly correlated with free carnitine levels (r = 0.359, p = 0.037; and r = 0.345, p = 0.045, respectively). Levocarnitine supplementation can suppress sarcopenia progression during lenvatinib therapy.

Infectious complications related to radiofrequency ablation of liver tumors: The role of antibiotics.

BACKGROUND AND AIM: Prophylactic administration of antibiotics within 24 hours of surgery is recommended to reduce the risk of infection. We conducted a prospective study to compare the efficacy of single administration of antibiotics with a historical control of continuous administration of antibiotics for radiofrequency ablation (RFA) of malignant liver tumors. METHODS: Between February 1, 1999 and November 30, 2010, a total of 6,763 RFA treatments were performed in 2,355 patients, using a protocol with continuous administration of prophylactic antibiotics. On December 1, 2010, we began using a revised protocol with a single administration of prophylactic antibiotics, while continuing to use the old continuous administration protocol for patients who declined the new protocol. Interim analysis was performed to assess the safety of the single administration protocol. Thereafter, from April 1, 2012, all patients were treated using the new protocol. Risk factors for infectious complications of RFA were assessed using logistic regression. RESULTS: From December 2010 to March 2012, 766 RFA treatments were performed in 663 patients using the new antibiotic protocol. Infectious complications were observed following 4 of these treatments (0.52%). As the upper limit of the confidence interval (CI) resulting from a one-sided binomial test was exactly the prespecified limit of 1.0%, from April 2012 onwards, we treated all patients using the new protocol with single administration of prophylactic antibiotics. A total of 3,547 RFA treatments were performed using the single administration protocol. Univariable logistic regression indicated that prior transcatheter arterial chemoembolization (TACE) and maximal tumor diameter were significant risk factors for infectious complications (P = 0.04 and P < 0.001, respectively). Multivariable analysis indicated that the adjusted hazard ratio of single vs. continuous administration of antibiotics was 1.20 (95% CI: 0.53-2.75; P = 0.66). CONCLUSIONS: The rate of infectious complications related to RFA was acceptably low. Single administration of prophylactic antibiotics did not significantly increase the rate of infectious complications related to RFA, compared with a more intensive antibiotic protocol.