Incomplete radiofrequency ablation enhances invasiveness and metastasis of residual cancer of hepatocellular carcinoma cell HCCLM3 via activating β-catenin signaling

Indolent cancer and pattern of progression: Two missing parameters in trial design for hepatology

The indolent and aggressive behaviors of HCC might have a role in clinical trial (CT) results; however, the indolent HCC is less analyzed compared to others cancer. Indolent profile could be characterized as follows: (1) patients with low risk of progression itself due to the HCC molecular profile and/or due to the interaction between cancer cell their microenvironment; (2) patients who achieve objective response or present spontaneous regression; and (3) patients who develop radiological progression with no consequence on either the liver function or general status, and without trigger a change in the tumor stage. Patients with "indolent HCC" generally never develop cancer-related symptoms neither die for HCC-related causes. Thus, we hypothesize that the imbalance in the proportion of "indolent" versus "aggressive HCC" between arms or the underestimation/overestimation of HCC behavior at baseline in single-arm CT could be associated with CT failure or under-overestimation of trial results. The "indolent progression" may also explain the discrepancy between radiological progression-based end points and survival. Moreover, we discuss the related causes that explain the indolent profile of HCC and propose (1) refining the progression-related end point by the pattern of progression to minimize the limitations of the current end points; (2) considering alternative statistical tools for survival analysis such as milestone survival, or restricted mean survival time to capture the value of indolent HCC. According to these considerations, we propose incorporating novel end points into the single arm of phase I/II CT as exploratory analysis or as a secondary end point in phase III CT.

Radiofrequency hyperthermia enhances the effect of OK-432 for Hepatocellular carcinoma by activating of TLR4-cGAS-STING pathway

Radiofrequency ablation (RFA) has been used as an alternative to surgical management of early-stage hepatocellular carcinoma (HCC). However, when large and irregular HCCs are subjected to RFA, a safety margin is usually difficult to obtain, thus causing a sublethal radiofrequency hyperthermia (RFH) at the ablated tumor margin. This study investigated the feasibility of using RFH to enhance the effect of OK-432 on HCC, with the aim to generate a tumor-free margin during RFA of HCC. Our results showed OK-432 could activate the cGAS-STING pathway, and RFH could further enhance the activation. Meanwhile, RFH could induce a high expression of TLR4, and TLR4 might be an upstream molecular of the cGAS-STING pathway. The combined therapy of RFH with OK-432 resulted in a better tumor response, and a prolonged survival compared to the other three treatments. In conclusion, RFH in combination with OK-432 might reduce the residual and recurrent tumor after RFA of large and irregular HCCs, and serve as a new option for other solid malignancies treated by RFA.

Aberrantly expressed HIF-1α enhances HCC stem cell-like traits via Wnt/β-catenin signaling activation after insufficient radiofrequency ablation

BACKGROUND

Radiofrequency ablation has become a favorable treatment modality for small hepatocellular carcinoma (HCC) recently; however, insufficient radiofrequency ablation (RFA) was shown to lead to enhanced invasiveness and metastasis of HCC in our previous study, while the underlying molecular mechanism has not been understood.

MATERIALS AND METHODS

In order to explore the influence of the hypoxic microenvironment on residual cancer and cancer stem cell (CSC)-like characteristics of HCC cells in this process, an in vitro hypoxic model and an insufficient RFA mouse model were established with HCC cancer cell lines. Immunochemistry staining and western blot were used to examine the expression of hypoxia-inducible factor (HIF)-1α and liver CSC markers. The 3D colon formation assay, tumor cell invasion assay, and gene transfection assays were applied to test the change in liver CSC stemness and HCC cell invasion.

RESULTS

After insufficient RFA treatment, the upregulated HIF-1α expression was associated with an increase in the CSC-like population in residual cancer. In vitro, hypoxic tumor cells showed aggressive CSC-like properties and phenotypes. Wnt/β-catenin signaling activation was shown to be necessary for the acquisition of liver CSC-like characteristics under hypoxic conditions.

CONCLUSION

Overall, the aberrantly enhanced HIF-1α expression enhanced the liver CSC-like traits via abnormal Wnt/β-catenin signaling activation after insufficient RFA, and the overexpressed HIF-1α would be a vital factor and useful biomarker during the HCC recurrence and metastasis.

Mechanisms and therapeutic strategies to combat the recurrence and progression of hepatocellular carcinoma after thermal ablation

Thermal ablation (TA), including radiofrequency ablation (RFA) and microwave ablation (MWA), has become the main treatment for early-stage hepatocellular carcinoma (HCC) due to advantages such as safety and minimal invasiveness. However, HCC is prone to local recurrence, with more aggressive malignancies after TA closely related to TA-induced changes in epithelial-mesenchymal transition (EMT) and remodeling of the tumor microenvironment (TME). According to many studies, various components of the TME undergo complex changes after TA, such as the recruitment of innate and adaptive immune cells, the release of tumor-associated antigens (TAAs) and various cytokines, the formation of a hypoxic microenvironment, and tumor angiogenesis. Changes in the TME after TA can partly enhance the anti-tumor immune response; however, this response is weak to kill the tumor completely. Certain components of the TME can induce an immunosuppressive microenvironment through complex interactions, leading to tumor recurrence and progression. How the TME is remodeled after TA and the mechanism by which the TME promotes HCC recurrence and progression are unclear. Thus, in this review, we focused on these issues to highlight potentially effective strategies for reducing and preventing the recurrence and progression of HCC after TA.

Salvage Hepatectomy for Recurrent Hepatocellular Carcinoma after Radiofrequency Ablation: A Retrospective Cohort Study with Propensity Score-Matched Analysis

BACKGROUND AND OBJECTIVES

Although radiofrequency ablation (RFA) is a well-established locoregional treatment modality for hepatocellular carcinoma (HCC), the optimal strategy to handle local recurrence after ablation is still debated. This study aims to investigate the role of salvage hepatectomy (SH) as a rescue therapy for recurrent HCC after RFA.

MATERIALS AND METHODS

Between January 2004 and December 2020, 1161 patients were subject to surgical resection for HCC. Among them, 47 patients who underwent SH for local recurrence after ablation were retrospectively analyzed and compared to a propensity score-matched group of controls (n = 47) who received primary hepatectomy (PH). Short-term and long-term outcomes were analyzed between the two groups.

RESULTS

After matching, operation time, intraoperative blood loss, postoperative hospital stay, and postoperative morbidity rates showed no statistically significant difference. Tumors in the SH group were associated with poor differentiation (SH 9 (19.1%) vs. PH 1 (2.1%), p < 0.001). The 5-year disease-free survival rates (31.6% vs. 73.4%, p < 0.001) and overall survival rates (80.3% vs. 94.2%, p = 0.047) were significantly lower in the SH group. In multivariable analysis, less extensive resection compared to the initial plan (hazard ratio (HR) 4.68, p = 0.024), higher grade (HR 5.38, P < 0.001), negative but close (<0.1 cm) resection margin (HR 22.14, p = 0.007), and R1 resection (HR 3.13, p = 0.006) were significant predictors for recurrence.

CONCLUSIONS

SH for recurrent tumors after ablation showed safety and effectiveness equivalent to primary resection. As recurrent tumors show a higher grade and more aggressive behavior, more extensive resections with wide surgical margins are necessary to prevent recurrence.

Feasibility of the chick chorioallantoic membrane model for preclinical studies on tumor radiofrequency ablation

BACKGROUND

We evaluated the feasibility of a chick chorioallantoic membrane (CAM) tumor model for preclinical research on tumor radiofrequency ablation (RFA).

METHODS

Fertilized chicken eggs were incubated and divided into five cohorts: RFA for 30 s (n = 5), RFA for 60 s (n = 5), RFA for 120 s (n = 4), sham (n = 8), and controls (n = 6). Xenografting using pancreatic neuroendocrine tumor cells of the BON-1 cell line was performed on embryonic day (ED) 8. The RFA was performed on ED 12. Survival, stereomicroscopic observations, and histological observations using hematoxylin-eosin (H&E) and Ki67 staining were evaluated.

RESULTS

The survival rates in the 30-s, 60-s, and 120-s, sham and control cohort were 60%, 60%, 0%, 100%, and 50%, respectively. Signs of bleeding and heat damage were common findings in the evaluation of stereomicroscopic observations. Histological examination could be performed in all but one embryo. Heat damage, bleeding, thrombosis, and leukocyte infiltration and hyperemia were regular findings in H&E-stained cuts. A complete absence of Ki67 staining was recorded in 33.3% and 50% of embryos in the 30-s and 60-s cohorts that survived until ED 14, respectively.

CONCLUSIONS

The CAM model is a feasible and suiting research model for tumor RFA with many advantages over other animal models. It offers the opportunity to conduct in vivo research under standardized conditions. Further studies are needed to optimize this model for tumor ablations in order to explore promising but unrefined strategies like the combination of RFA and immunotherapy.

RELEVANCE STATEMENT

The chick chorioallantoic membrane model allows in vivo research on tumor radiofrequency ablation under standardized conditions that may enable enhanced understanding on combined therapies while ensuring animal welfare in concordance with the "Three Rs."

KEY POINTS

• The chorioallantoic membrane model is feasible and suiting for tumor radiofrequency ablation. • Radiofrequency ablation regularly achieved reduction but not eradication of Ki67 staining. • Histological evaluation showed findings comparable to changes in humans after RFA. • The chorioallantoic membrane model can enable studies on combined therapies after optimization.

Multiple Pretransplant Treatments for Patients Without Pathological Complete Response may Worsen Posttransplant Outcomes in Patients with Hepatocellular Carcinoma

BACKGROUND

Liver transplant (LT) candidates with hepatocellular carcinoma (HCC) often receive cancer treatment before transplant. We investigated the impact of pre-transplant treatment for HCC on the risk of posttransplant recurrence.

METHODS

Adult HCC patients with LT at our institution between 2013 and 2020 were included. The impact of pre-LT cancer treatments on the cumulative recurrence was evaluated, using the Gray and Fine-Gray methods adjusted for confounding factors. Outcomes were considered in two ways: 1) by pathologically complete response (pCR) status within patients received pre-LT treatment; and 2) within patients without pCR, grouped by pre-LT treatment as A) none; B) one treatment; C) multiple treatments.

RESULTS

The sample included 179 patients, of whom 151 (84%) received pretreatment and 42 (28% of treated) demonstrated pCR. Overall, 22 (12%) patients experienced recurrence. The 5-year cumulative post-LT recurrence rate was significantly lower in patients with pCR than those without pCR (4.8% vs. 19.2%, P = 0.03). In bivariable analyses, pCR significantly decreased risk of recurrence. Among the 137 patients without pCR (viable HCC in the explant), 28 (20%) had no pretreatment (A), 70 (52%) had one treatment (B), and 39 (20%) had multiple treatments (C). Patients in Group C had higher 5-year recurrence rates than those in A or B (39.6% vs. 8.2%, 6.5%, P = 0.004 and P < 0.001, respectively). In bivariable analyses, multiple treatments was significantly associated with recurrence.

CONCLUSIONS

pCR is a favorable prognostic factor after LT. When pCR was not achieved by pre-LT treatment, the number of treatments might be associated with post-LT oncological prognosis.

Radiomics-Based Prediction of Future Portal Vein Tumor Infiltration in Patients with HCC-A Proof-of-Concept Study

Portal vein infiltration (PVI) is a typical complication of HCC. Once diagnosed, it leads to classification as BCLC C with an enormous impact on patient management, as systemic therapies are henceforth recommended. Our aim was to investigate whether radiomics analysis using imaging at initial diagnosis can predict the occurrence of PVI in the course of disease. Between 2008 and 2018, we retrospectively identified 44 patients with HCC and an in-house, multiphase CT scan at initial diagnosis who presented without CT-detectable PVI but developed it in the course of disease. Accounting for size and number of lesions, growth type, arterial enhancement pattern, Child-Pugh stage, AFP levels, and subsequent therapy, we matched 44 patients with HCC who did not develop PVI to those developing PVI in the course of disease (follow-up ended December 2021). After segmentation of the tumor at initial diagnosis and texture analysis, we used LASSO regression to find radiomics features suitable for PVI detection in this matched set. Using an 80:20 split between training and holdout validation dataset, 17 radiomics features remained in the fitted model. Applying the model to the holdout validation dataset, sensitivity to detect occurrence of PVI was 0.78 and specificity was 0.78. Radiomics feature extraction had the ability to detect aggressive HCC morphology likely to result in future PVI. An additional radiomics evaluation at initial diagnosis might be a useful tool to identify patients with HCC at risk for PVI during follow-up benefiting from a closer surveillance.

Combinatory local ablation and immunotherapies for hepatocellular carcinoma: Rationale, efficacy, and perspective

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Local ablation, such as radiofrequency ablation, microwave ablation, cryoablation and irreversible electroporation, etc., are well established in elimination and control of HCC. However, high recurrence rate after local ablation remains the biggest challenge for HCC management. Novel and effective therapeutic strategies to improve long-term survival are urgently needed. Accumulating studies have reported the role of ablation in modulating the tumor signaling pathway and the immune microenvironment to both eliminate residual/metastatic tumor and promote tumor progression. Ablation has been shown to elicit tumor-specific immune responses by inducing massive cell death and releasing tumor antigen. Immunotherapies that unleash the immune system have the potential to enhance the anti-tumor immunity induced by ablation. Multiple combinatory strategies have been explored in preclinical and clinical studies. In this review, we comprehensively summarize the latest progress on different mechanisms underlying the effects of ablation on tumor cells and tumor microenvironment. We further analyze the clinical trials testing the combination of ablation and immunotherapies, and discuss the possible role of immunomodulation to boost the anti-tumor effects of ablation and prevent HCC recurrence.

Progression of hepatocellular carcinoma after radiofrequency ablation: Current status of research

Hepatocellular carcinoma (HCC) remains an important disease for health care systems in view of its high morbidity, mortality, and increasing incidence worldwide. Radiofrequency ablation (RFA) is preferred to surgery as a local treatment for HCC because it is safer, less traumatic, less painful, better tolerated, causes fewer adverse reactions, and allows more rapid postoperative recovery. The biggest shortcoming of RFA when used to treat HCC is the high incidence of residual tumor, which is often attributed to the vascular thermal deposition effect, the wide infiltration zone of peripheral venules, and the distance between satellite foci and the main focus of the cancer. Recurrence and progression of the residual tumor is the most important determinant of the prognosis. Therefore, it is important to be aware of the risk of recurrence and to improve the efficacy of RFA. This review summarizes the relevant literature and the possible mechanisms involved in progression of HCC after RFA. Current studies have demonstrated that multimodal treatments which RFA combined with other anti-cancer approaches can prevent progression of HCC after RFA.

Recent Perspectives on the Mechanism of Recurrence After Ablation of Hepatocellular Carcinoma: A Mini-Review

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Hepatectomy, liver transplantation, and ablation are the three radical treatments for early-stage hepatocellular carcinoma (ESHCC), but not all patients are fit for or can tolerate surgery; moreover, liver donors are limited. Therefore, ablation plays an important role in the treatment of ESHCC. However, some studies have shown that ablation has a higher local recurrence (LR) rate than hepatectomy and liver transplantation. The specific mechanism is unknown. The latest perspectives on the mechanism of recurrence after ablation of HCC were described and summarized. In this review, we discussed the possible mechanisms of recurrence after ablation of HCC, including epithelial–mesenchymal transition (EMT), activating autophagy, changes in non-coding RNA, and changes in the tumor microenvironment. A systematic and comprehensive understanding of the mechanism will contribute to the research and development of related treatment, combined with ablation to improve the therapeutic effect in patients with ESHCC.

Clinical Outcome of CT-Guided Iodine-125 Radioactive Seed Implantation for Intrahepatic Recurrent Hepatocellular Carcinoma: A Retrospective, Multicenter Study

The efficacy and safety of CT-Guided Iodine-125 Radioactive Seed Implantation (RSI) for the treatment of intrahepatic recurrent hepatocellular carcinoma (rHCC) were analyzed in this multicenter retrospective study. We reviewed the medical records of patients with rHCC treated with I-125 seed implantation at four different hospitals in China from December 2011 and January 2021. The local progression-free survival (LPFS),liver PFS, and overall survival (OS) were calculated, and the short-term efficacy and treatment-related toxicities were evaluated. A total of 82 patients were enrolled; the median follow-up time was 46 months (range, 3–80 months). The 1-, 3- and 5-year LPFS rates were 63.8%, 27.1%, and 7.9%, respectively, and the corresponding OS rates were 74.8%, 32.9%, and 12.6%, respectively. Univariate analysis showed that factors influencing LPFS included the maximum lesion diameter, Barcelona Clinic Liver Cancer (BCLC) stage, interval between treatment and recurrence, and D90. Multivariate analyses revealed that the BCLC stage, interval between treatment and recurrence, and D90 were independent factors influencing LPFS, whereas BCLC stage, D90, and short-term efficacy were independent factors influencing OS. In summary, I-125 seed implantation is a safe and effective treatment for rHCC. The BCLC stage, interval, and D90 were found to influence the local control. A larger, prospective study is required to confirm the dose-response curve for Iodine-125 RSI of rHCC.

An Overview of Hepatocellular Carcinoma After Insufficient Radiofrequency Ablation

Radiofrequency ablation (RFA) is a commonly used treatment for hepatocellular carcinoma (HCC), however, various complex conditions in clinical practice may lead to insufficient radiofrequency ablation (IRFA), allowing residual HCC to survive. In clinical practice and laboratory models, IRFA plays an important role in rapid tumor progression. Therefore, targeting the residual HCC and avoiding IRFA were worthwhile methods. A deeper understanding of IRFA is required; IRFA contributes to the improvement of proliferative activity, migration rates, and invasive capacity, and this may be due to the involvement of multiple complex processes or proteins, including epithelial mesenchymal transitions (EMTs), cancer stem cells (CSCs), autophagy, heat shock proteins (HSPs), changes of non-tumor cells and extracellular matrix, altered immune microenvironment, hypoxia-inducible factors (HIFs), growth factors, epigenetic alterations, and metabolic reprogramming. We focus on the processes of the above mechanisms and possible therapeutic approach, with a review of the literature. Additionally, we recapitulated the construction methods of various experimental models of IRFA (in vivo and in vitro).

A Review of Clinical Applications for Super-resolution Ultrasound Localization Microscopy

Microvascular structure and hemodynamics are important indicators for the diagnosis and assessment of many diseases and pathologies. The structural and functional imaging of tissue microvasculature in vivo is a clinically significant objective for the development of many imaging modalities. Contrast-enhanced ultrasound (CEUS) is a popular clinical tool for characterizing tissue microvasculature, due to the moderate cost, wide accessibility, and absence of ionizing radiation of ultrasound. However, in practice, it remains challenging to demonstrate microvasculature using CEUS, due to the resolution limit of conventional ultrasound imaging. In addition, the quantification of tissue perfusion by CEUS remains hindered by high operator-dependency and poor reproducibility. Inspired by super-resolution optical microscopy, super-resolution ultrasound localization microscopy (ULM) was recently developed. ULM uses the same ultrasound contrast agent (i.e. microbubbles) in CEUS. However, different from CEUS, ULM uses the location of the microbubbles to construct images, instead of using the backscattering intensity of microbubbles. Hence, ULM overcomes the classic compromise between imaging resolution and penetration, allowing for the visualization of capillary-scale microvasculature deep within tissues. To date, many in vivo ULM results have been reported, including both animal (kidney, brain, spinal cord, xenografted tumor, and ear) and human studies (prostate, tibialis anterior muscle, and breast cancer tumors). Furthermore, a variety of useful biomarkers have been derived from using ULM for different preclinical and clinical applications. Due to the high spatial resolution and accurate blood flow speed estimation (approximately 1 mm/s to several cm/s), ULM presents as an enticing alternative to CEUS for characterizing tissue microvasculature in vivo. This review summarizes the principles and present applications of CEUS and ULM, and discusses areas where ULM can potentially provide a better alternative to CEUS in clinical practice and areas where ULM may not be a better alternative. The objective of the study is to provide clinicians with an up-to-date review of ULM technology, and a practical guide for implementing ULM in clinical research and practice.

Combination of Ablation and Immunotherapy for Hepatocellular Carcinoma: Where We Are and Where to Go

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide and is increasing in incidence. Local ablative therapy plays a leading role in HCC treatment. Radiofrequency (RFA) is one of the first-line therapies for early local ablation. Other local ablation techniques (e.g., microwave ablation, cryoablation, irreversible electroporation, phototherapy.) have been extensively explored in clinical trials or cell/animal studies but have not yet been established as a standard treatment or applied clinically. On the one hand, single treatment may not meet the needs. On the other hand, ablative therapy can stimulate local and systemic immune effects. The combination strategy of immunotherapy and ablation is reasonable. In this review, we briefly summarized the current status and progress of ablation and immunotherapy for HCC. The immune effects of local ablation and the strategies of combination therapy, especially synergistic strategies based on biomedical materials, were discussed. This review is hoped to provide references for future researches on ablative immunotherapy to arrive to a promising new era of HCC treatment.

Meta-analysis and systematic review of contrast-enhanced ultrasound in evaluating the treatment response after locoregional therapy of hepatocellular carcinoma

PURPOSE

Contrast-enhanced ultrasound (CEUS) is a useful tool to assess treatment response after percutaneous ablation or transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Here, we performed a systematic review and meta-analysis to evaluate the usefulness of CEUS in identifying residual tumor after locoregional therapy.

METHODS

PubMed, Scopus, and Cochrane library databases were searched from their inception until March 8, 2021, for diagnostic test accuracy studies comparing CEUS to a reference standard for identifying residual tumors after locoregional therapy of HCC. The pooled sensitivity, specificity, accuracy, and diagnostic odds ratio (DOR) were obtained using a bivariate random effects model. Subgroup analyses were performed by stratifying the studies based on study design, type of locoregional therapy, CEUS criteria for residual tumor, timing of CEUS follow up, and type of standard reference.

RESULTS

Two reviewers independently evaluated 1479 publications. After full-text review, 142 studies were found to be relevant, and 43 publications (50 cohorts) were finally included. The overall sensitivity of CEUS in detection of residual disease estimated from the bivariate random effects model was 0.85 (95% CI 0.80-0.89). Similarly, the overall specificity was 0.94 (95% CI 0.91-0.96). The diagnostic accuracy was 93.5%. The DOR was 70.1 (95% CI 62.2-148), and the AUROC was 0.95. Importantly, subgroup analysis showed no apparent differences in the diagnostic performance between locoregional therapy (TACE vs. ablation) and criteria used to define residual enhancement, timing of performing CEUS, study design, or type of reference standard.

CONCLUSION

CEUS is a highly accurate method to identify HCC residual tumor after TACE or percutaneous ablation.

Wnt Signaling Pathway Is among the Drivers of Liver Metastasis

Liver metastasis, originating either from a primary liver or other cancer types, represent a large cancer-related burden. Therefore, studies that add to better understanding of its molecular basis are needed. Herein, the role of the Wnt signaling pathway in liver metastasis is outlined. Its role in hepatocellular carcinoma (HCC) epithelial-mesenchymal transition (EMT), motility, migration, metastasis formation, and other steps of the metastatic cascade are presented. Additionally, the roles of the Wnt signaling pathway in the liver metastasis formation of colorectal, breast, gastric, lung, melanoma, pancreatic, and prostate cancer are explored. The special emphasis is given to the role of the Wnt signaling pathway in the communication between the many of the components of the primary and secondary cancer microenvironment that contribute to the metastatic outgrowth in the liver. The data presented herein are a review of the most recent publications and advances in the field that add to the idea that the Wnt pathway is among the drivers of liver metastasis and that its targeting could potentially relieve liver metastasis–related complications.

The 10-year Survival Analysis of Radiofrequency Ablation for Solitary Hepatocellular Carcinoma 5 cm or Smaller: Primary versus Recurrent HCC

Background Although favorable outcomes have been reported with radiofrequency ablation (RFA) for limited hepatocellular carcinoma (HCC), the efficacy of this treatment for recurrent HCC has not been thoroughly investigated. Purpose To compare the long-term outcomes and analyze the prognostic factors for outcomes after RFA for initial HCC versus as a second-line treatment for recurrent HCC. Materials and Methods This retrospective study included 560 patients with solitary tumors 5 cm or smaller (263 initial HCCs, 297 -recurrent HCCs) who underwent percutaneous US-guided RFA from January 2005 to December 2016. Of 297 patients with -recurrent HCC, 134 had previously undergone hepatectomy, 128 had undergone transarterial chemoembolization (TACE), and 35 had undergone local ablation therapy. Overall survival (OS) between initial HCC and recurrent HCC was compared before and after propensity score matching. Prognostic factors for all patients were analyzed with the log-rank test and Cox proportional hazards model. Results A total of 560 patients (mean age, 60 years ± 12 [standard deviation]; 441 men) were evaluated. Before matching, the OS rates at 1, 3, 5, and 10 years were 92.6%, 73.9%, 59.3%, and 39.6%, respectively, in patients with recurrent HCC and 92.8%, 75.4%, 63.3%, and 44.7% in patients with initial HCC (P = .27). After matching, the OS rates at 1, 3, 5, and 10 years were 94.8%, 75.7%, 61.6%, and 47.3% in the initial HCC group and 91.9%, 71.2%, 58.7%, and 45.2% in the recurrent HCC group (P = .32). Among patients with recurrent HCC, no significant difference in mean OS was noted for local recurrence versus distant recurrence (81.6 months ± 5.1 vs 83.8 months ± 6.6, P = .82) or previous treatment modality (82.0 months ± 7.3 in the resection group, 82.7 months ± 5.3 in the TACE group, and 79.3 months ± 10.8 in the local ablation group; P = .83). Local tumor progression after previous local ablation (10 of 35 [28.6%]) was higher than that after previous hepatectomy (15 of 134 [11.2%], P = .04). Multivariable analysis demonstrated that tumor size (hazard ratio, 1.58; 95% CI: 1.06, 2.36; P = .02), portal hypertension (hazard ratio, 1.52; 95% CI: 1.03, 2.26; P = .04), Child-Pugh class (hazard ratio, 2.01; 95% CI: 1.02, 3.96; P = .045), and serum α-fetoprotein level (hazard ratio, 1.62; 95% CI: 1.10, 2.39; P = .01) were independent predictive factors for recurrent HCC outcomes. Conclusion Radiofrequency ablation provides similar long-term survival for solitary hepatocellular carcinoma of 5 cm or less, regardless of whether treatment is initial or salvage therapy. © RSNA, 2021 Online supplemental material is available for this article.

Molecularly targeted photothermal ablation improves tumor specificity and immune modulation in a rat model of hepatocellular carcinoma

Thermal ablation is a standard therapy for patients with hepatocellular carcinoma (HCC). Contemporary ablation devices are imperfect, as they lack tumor specificity. An ideal ablation modality would generate thermal energy only within tumoral tissue. Furthermore, as hyperthermia is known to influence tumor immunity, such a tumor-specific ablation modality may have the ability to favorably modulate the tumor immune landscape. Here we show a clinically relevant thermal ablation modality that generates tumor-specific hyperthermia, termed molecularly targeted photothermal ablation (MTPA), that is based upon the excellent localization of indocyanine green to HCC. In a syngeneic rat model, we demonstrate the tumor-specific hyperthermia generated by MTPA. We also show through spatial and transcriptomic profiling techniques that MTPA favorably modulates the intratumoral myeloid population towards tumor immunogenicity and diminishes the systemic release of oncogenic cytokines relative to conventional ablation modalities.

Nina Muñoz et al. present a novel thermal ablation technique, termed molecularly targeted photothermal ablation (MTPA) that generates hyperthermia specifically within tumor tissue in a clinically-relevant rat model of liver cancer. They further show that MTPA modulates the intratumoral immune profile toward stronger tumor immunogenicity while reducing the release of oncogenic cytokines relative to conventional ablation techniques.

Tract ablation after radiofrequency ablation to prevent viable tumor cell adhesion to the needle electrode

PURPOSE

To evaluate whether the additive needle tract ablation (TA) can reduce adherent cells on the needle tract after radiofrequency ablation (RFA) in a preclinical HCC mouse model.

METHODS

Hep3B-Luc cells were engrafted in the Balb/c-nude mice. Nineteen mice were randomly assigned into three groups: the needle only group (needle placement only without performing RFA), the RFA only group (needle placement with active RFA treatment), and the RFA-TA group (needle placement with active RFA treatment and additive tract ablation). The 17-gauge needle with a 10-mm active tip was used. After RFA and TA, the viability of adherent tumor cells on the RFA needle was evaluated with bioluminescence imaging (BLI) and live-cell counting.

RESULTS

We observed that RFA-TA group had the lowest BLI values compared with other groups (needle only group, 11.2 ± 6.4 million; RFA only group, 13.6 ± 9.1 million; RFA-TA group, 1.11 ± 0.8 million, p = 0.001). Live cell counting with acridine orange/propidium iodide staining also confirmed that the counted viable cell numbers in RFA-TA group were lowest compared to the other groups (needle only group, 14.8 ± 4.5; RFA only group, 643.8 ± 131.9; RFA-TA group, 1.5 ± 0.9, p < 0.001).

CONCLUSIONS

The additive tract ablation can significantly reduce the number of viable tumor cells adherent to the RFA needle, which can prevent needle tract seeding after RFA procedure.

Specific Inhibitor of Matrix Metalloproteinase Decreases Tumor Invasiveness After Radiofrequency Ablation in Liver Tumor Animal Model

Objective

To determine whether the specific inhibitor of matrix metalloproteinase (MMP)-batimastat (BB-94)-could decrease the progression of liver tumor after radiofrequency ablation (RFA) and achieve better therapeutic efficacy in an animal model.

Methods

In vitro experiments, the proliferation of H22 liver tumor cells was detected by CCK 8 assay and cell migration was detected by Transwell method. In vivo experiments, H22 murine liver tumors were used. First, 32 mice with one tumor were randomized into four groups (n = 8 each group): control (PBS only), RFA alone (65°C, 5 min), BB-94 (30 mg/kg), RFA+BB-94. The growth rate of the residual tumor and the end point survival were calculated and the pathologic changes were evaluated. Secondly, a total of 48 tumors in 24 animals (paired tumors) were randomized into three groups (n = 8 each group): control, RFA alone, RFA+BB-94. Each mouse was implanted with two tumors subcutaneously, one tumor was treated by RFA and the other was evaluated for distant metastasis after applying BB-94.

Results

In vitro, the proliferation assay demonstrated higher proliferation ability after heat treatment (0.82 ± 0.07 vs 1.27 ± 0.08, P = 0.008), and it could be inhibited by BB-94 (1.27 ± 0.08 vs 0.67 ± 0.06, P = 0.001). In the cell migration assay, the H22 cells demonstrated enhanced tumor invasiveness in the heat group than the control group (33.7 ± 2.1 vs 19.7 ± 4.9, P = 0.011). And it could be significantly suppressed after BB-94 incubation (33.7 ± 2.1 vs 23.0 ± 4.6, P = 0.009). With one tumor animal, the growth rate of the residual tumor in the BB-94+RFA group was slower than that in the RFA alone group (P = 0.003). And combination of BB-94 could significantly prolong the survival of the mice (40.3 ± 1.4d vs 47.1 ± 1.3d, P = 0.002). The expression of CD31 and VEGF at the coagulation margin were decreased after combined with BB-94. With two tumors animal, the growth of metastasis tumor in the BB-94+RFA group was slower than that in the RFA group (P < 0.001).

Conclusion

BB-94 combined with RFA reduced the invasiveness of the liver tumor and improved the end-point survival. Our data suggested that targeting the MMP process with the specific inhibition could help to increase overall ablation efficacy.

Early Identification of Residual Tumors following Microwave Ablation Using Contrast-Enhanced Ultrasonography in a Rabbit VX2 Liver Cancer Model

Objective

It is difficult to evaluate the ablation effect immediately after thermal ablation of liver cancer by clinical imaging methods, due to the immediate formation of an annular inflammatory reaction band (IRB). This study is aimed at exploring the early identification indicators of the IRB and residual tumor postmicrowave ablation (MVA) using contrast-enhanced ultrasonography (CEUS).

Methods

MVA was used to inactivate part of the tumor nodules in rabbit VX2 liver cancer models, leading to the coexistence of the IRB with residual tumors. Quantitative analysis of the perfusion parameters of the tumor and ablation zone was performed using CEUS, followed by liver biopsy and VEGFR-2 immunohistochemical staining.

Results

All rabbits successfully tolerated VX2 tumor inoculation and MVA operation. No statistically significant difference existed between the IRB vs. residual tumors, the IRB vs. junctional areas, and residual tumors postablation vs. VX2 tumors before ablation in regional blood volume, blood velocity, and blood flow estimated by parameters A, k, and A^∗k of CEUS quantitative analysis. There was a statistically significant difference between the IRB and normal liver parenchyma in regional blood velocity and blood flow (p = 0.005 and p = 0.023, respectively). Normal liver parenchyma showed nonspecific VEGFR-2 staining, while VX2 tumor before ablation and residual tumor after ablation both showed positive VEGFR-2 staining; the necrosis zone showed negative staining by VEGFR-2 immunohistochemical staining.

Conclusion

MVA had no significant effect on the residual tumor hemodynamics. The blood flow in the IRB increased significantly as compared to normal liver parenchyma, resembling tumor hemodynamic patterns. CEUS can detect residual tumors immediately postablation only when they protrude from the annular-shaped IRB. In addition, VEGFR-2 targeted CEUS may have a great potential for detecting residual tumor after thermal ablation of hepatocellular carcinoma.

The Perfusion Features of Recurrent Hepatocellular Carcinoma After Radiofrequency Ablation Using Contrast-Enhanced Ultrasound and Pathological Stemness Evaluation: Compared to Initial Tumors

Objective: To investigate the perfusion features of local recurrence in hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) with contrast-enhanced ultrasound (CEUS) and pathological correlation, as well as to compare with those of initial HCC. Methods: From 2010 to 2018, 42 patients with recurrent HCC after RFA were enrolled in this study. The initial HCC patients included 32 males and 10 females with an average age of 58.2 ± 8.1 years. The CEUS images for initial HCC lesions and local recurrence after RFA were compared. The perfusion features were analyzed, including enhancement time, process, boundary, morphology, washout time, washout degree, feeding vessels, and internal necrosis. H&E staining and CD133/EpCAM staining were performed with biopsy samples for the stemness study. Results: According to CEUS, 59.5% of initial HCC lesions had centripetal enhancement, and 61.9% of recurrent HCC lesions had homogeneous enhancement in the arterial phase (p < 0.001). A total of 73.8% of initial HCC lesions had well-defined margins at the peak, and 81.0% of recurrent HCC lesions had poorly defined margins (p < 0.001). A total of 78.6% of initial HCC lesions had regular morphology at the peak, and 83.3% of recurrent HCC lesions were irregular (p < 0.001). Feeding vessels were more frequently found in initial HCC lesion (71.4%) than in recurrent HCCs (38.1%, p = 0.002). In the late phase, 60% of initial HCCs had marked washout while 83.3% of recurrent HCC lesion had marked washout (p = 0.019). A total of 31.3% of the initial HCC lesions had internal necrosis areas while only 7.1% of recurrent HCC lesions had internal necrosis areas (p = 0.035). In tumors 3-5 cm in size, the washout time of recurrent HCCs was shorter than that of initial HCCs (50.3 ± 13.5 s vs. 75.6 ± 45.8 s, p = 0.013). Pathological staining showed that the tumor stem cell markers (CD133 and EpCAM) were both highly expressed in recurrent samples compared with initial tumor samples (CD133+: 19 vs. 5%, p = 0.002; EpCAM+:15 vs. 6%, p = 0.005). Conclusions: Recurrent HCC after RFA had more homogeneous enhancement with a poorly defined border, marked washout, and fewer less feeding vessels and inner necrosis areas compared to initial HCC. The stemness study also found upregulated stemness in recurrent HCC. These specific features might be related to the aggressive biological behavior of recurrent HCC.

ATPase Inhibitory Factor 1 Promotes Hepatocellular Carcinoma Progression After Insufficient Radiofrequency Ablation, and Attenuates Cell Sensitivity to Sorafenib Therapy

Epithelial-mesenchymal transition (EMT) and angiogenesis is involved in tumor progression after radiofrequency ablation (RFA). ATPase inhibitory factor 1 (IF1) is a bad predictor of prognosis. Sorafenib inhibited EMT of hepatocellular carcinoma (HCC) after RFA. Whether IF1 promotes the EMT and angiogenesis of HCC and attenuates the effect of sorafenib after insufficient RFA is investigated. In this study, higher expression of IF1 was found in residual tumor after insufficient RFA. Hep3B or Huh7 cells after insufficient RFA were designated as Hep3B-H or Huh7-H cells in vitro. Hep3B-H or Huh7-H cells exhibited enhanced capacities of colony formation, migration, and increased expression of EMT associated markers and IF1 compared with Hep3B or Huh7 cells. IF1 knockdown in Hep3B-H or Huh7-H cells decreased the colony formation and migratory capacity, and IF1 overexpression in Hep3B or Huh7 cells increased these capacities. IF1 in HCC cells directly and indirectly affected angiogenesis of TAECs after insufficient RFA. IF1 promoted HCC cells growth and metastasis after insufficient RFA. IF1 increased HCC cells resistance after insufficient RFA to sorafenib. Higher IF1 expression indicated poor disease survival in HCC patients after sorafenib therapy. NF-κB activation induced by IF1 attenuated the effect of sorafenib on HCC cells after insufficient RFA. Our results demonstrated that IF1 promotes the EMT and angiogenesis, and attenuates HCC cell sensitivity to sorafenib after insufficient RFA through NF-κB signal pathway.

Iodine-125 Brachytherapy Can Prolong Progression-Free Survival of Patients with Locoregional Recurrence and/or Residual Hepatocellular Carcinoma After Radiofrequency Ablation

Background: Radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC) is limited by locoregional recurrence and/or residual tumors caused by incomplete ablation. Iodine-125 brachytherapy can achieve a high local control rate in solid carcinoma, but few studies have assessed the efficacy of this treatment for locoregional recurrence and/or residual HCC after RFA. Objective: To investigate the effectiveness and safety of iodine-125 brachytherapy for treating locoregional recurrence and/or residual HCC in patients treated with RFA. Methods: Eligible study patients were those with locoregional recurrence and/or residual HCC on abdominal imaging performed 1 month after RFA at this institution between February 2009 and September 2014 retrospectively. Patients were divided into either the control group (no treatment until the tumor progressed) or the treatment group (underwent iodine-125 brachytherapy). Progression-free survival (PFS), overall survival (OS), and complications of iodine-125 brachytherapy were evaluated. Results: A total of 42 patients were included in the final analysis, including 29 in the control group and 13 in the treatment group. A total of 457 iodine-125 particles were used (mean 32.8 ± 21.3 mCi per case). The median follow-up time was 25 months. Median PFS was 9 months in the control group and 18 months in the treatment group (p = 0.026). The median OS was 28 months in the control group and 33 months in the treatment group (p = 0.441). There were no major complications observed in patients treated with iodine-125 brachytherapy. Conclusion: Iodine-125 brachytherapy can prolong PFS in patients with locoregional recurrence and/or residual HCC after RFA.

Potential therapies for residual hepatoblastoma following incomplete ablation treatment in a nude mouse subcutaneous xenograft model based on lncRNA and mRNA expression profiles

Tumor recurrence following radiofrequency ablation (RFA) treatment in liver cancer is an important factor affecting patient prognosis. Furthermore, the biological role of long non‑coding RNAs (lncRNAs) in residual hepatoblastoma (HB) tissues after RFA remains largely unknown. By using microarray technology, this study investigated the expression of lncRNAs and mRNAs among four pairs of HB tissues (incomplete ablation treatment and no treatment) in a nude mouse subcutaneous xenograft model. Subsequently, bioinformatics analysis was used to understand the functions and pathways of the identified mRNAs. Finally, a connectivity map (CMap) analysis was conducted to identify potential therapeutic strategies for residual HB tissues. Compared with the untreated nude mouse subcutaneous xenograft model, in the experimental group, a significant difference in the expression of 740 lncRNAs and 663 mRNAs was detected. Subsequently, bioinformatics analysis revealed that the differentially expressed mRNAs were significantly enriched in pathways associated with antigen processing, the presentation of endogenous antigens, the regulation of cellular metabolic processes, MAPK signaling and cell cycle regulation. Additionally, six compounds (valproic acid, metformin, tanespimycin, wortmannin, fulvestrant and MK‑886) were identified by CMap analysis as potential therapeutic agents for the treatment of residual HB tissues. These findings provide a novel insight into the pathogenesis of residual HB and potential therapeutic strategies for aggressive tumor recurrence following RFA treatment in patients with HB.

Comparative safety and effectiveness of ultrasound-guided radiofrequency ablation combined with preoperative three-dimensional reconstruction versus surgical resection for solitary hepatocellular carcinoma of 3-5 cm

OBJECTIVE

To investigate the safety and effectiveness of ultrasound-guided radiofrequency ablation (RFA) combined with preoperative three-dimensional (3D) reconstruction versus surgical resection for solitary hepatocellular carcinoma of 3-5 cm.

METHODS

The cohort of this retrospective study included 66 consecutive patients who underwent open hepatectomy (Surgery group) between January 2009 and December 2014, as well as 54 consecutive patients who underwent ultrasound-guided RFA combined with preoperative 3D reconstruction (RFA group) during the same period. Preoperative 3D reconstruction was performed using Myrian-XP-Liver software. The image fusion system was used to evaluate the RFA safety margin at 1 month after surgery. Kaplan-Meier analysis and the log-rank test were used to compare the recurrence and overall survival (OS) rates between the two treatment groups.

RESULTS

There were no significant differences in the baseline characteristics of the two groups. The complete ablation rate was 94.4% (51/53). As compared with surgical resection for solitary HCC of 3-5 cm, ultrasound-guided RFA combined with preoperative 3D reconstruction significantly reduced the morbidity of excessive pain, total complications, and infections (p < 0.001). A significant decrease in the duration of the hospital stay after treatment was also observed in the RFA group (t = 10.017, p < 0.001). There was no significant difference in the cumulative recurrence rate between the two groups. Kaplan-Meier analysis and the log-rank test revealed no significant difference in the OS rate between the two groups over a 3-year follow-up period.

CONCLUSION

Ultrasound-guided RFA combined with preoperative 3D reconstruction appears to be a safe and effective therapeutic option for patients with solitary HCC of 3-5 cm.

Survival Benefit for Patients With Metastatic Urothelial Carcinoma Receiving Continuous Maintenance Chemotherapy

BACKGROUND/AIM

Urothelial carcinoma is a chemo-sensitive cancer. We investigated the contributory factors to survival benefit of metastatic urothelial carcinoma (MUC) patients receiving continuous maintenance chemotherapy.

PATIENTS AND METHODS

Inclusion criteria were: i) pathology-confirmed urothelial carcinoma, ii) metastatic lesions identified mainly on pre-therapy computed tomography (CT) scans, and iii) inpatient-administered chemotherapy of at least three cycles. Chemotherapy regimens included 5-fluorouracil, leucovorin, cisplatin, and gemcitabine.

RESULTS

A total of 139 cases were enrolled in this study. The overall objective response rate was 60% and the median survival time was 17 months. Eight-two (59%) patients had inflammation-related symptoms following the course of chemotherapy. Fifty-five (41%) patients survived more than two years. All patients exhibited various fibrosis formations. No patient experienced unfavorable metastatic conditions. Inflammation-related symptoms remained in 28 (51%) patients. We found that surgery, invasive procedures, and infection likely led to a rapid tumor progression.

CONCLUSION

Continuous maintenance chemotherapy targeting chemo-sensitive tumors, administered at metronomic intervals and focus on tumor microenvironment, can increase MUC survival benefits.

Ultrasonic Cavitation Ameliorates Antitumor Efficacy of Residual Cancer After Incomplete Radiofrequency Ablation in Rabbit VX2 Liver Tumor Model

Residual cancer after incomplete ablation remains a major problem for radiofrequency ablation (RFA). We aimed to investigate the synergetic treatment efficacy of RFA combined with ultrasonic cavitation for liver tumor. Sixty rabbits with VX2 liver tumor were randomly divided into three groups. Group A was control group without any treatment. Combined ultrasonic cavitation with RFA was performed for group B1. Group B2 underwent RFA alone. The histopathological results were compared at the 5th, 11th, and 18th day of experiment, and the survival time and metastasis were assessed. The tumor volume growth rate, percentage of necrosis area, microvessel density, and apoptosis index showed significant differences among these groups at the 5th day, 11th day, and 18th day of experiment (P < .05). In contrast, the difference of metastatic score was not significant at the 5th and 11th day (P > .05). At the 18th day, the metastatic score of group A was significant higher than that of group B1 (P < .05), whereas the differences between group A and group B2, or group B1 and group B2 were not significant (P > .05). The median/range interquartile of survival time in groups A, B1, and B2 were 25/8 days, 50/19 days, and 48/20 days, respectively, and there was significant difference between groups A and B1 or B2 (P < .05). The difference between groups B1 and B2 was not significant (P > .05). Ultrasonic cavitation after incomplete RFA for liver tumor improved the antitumor effect, which could be considered as a potentially useful combined therapeutic strategy for liver malignancy.

Insufficient radiofrequency ablation promotes the metastasis of residual hepatocellular carcinoma cells via upregulating flotillin proteins

Purpose

Radiofrequency ablation (RFA) therapy has proven to be effective and feasible for early-stage hepatocellular carcinoma (HCC); however, rapid progression of residual tumor cells after RFA has been confirmed, but the molecular mechanisms of this phenomenon are poorly understood. This study evaluated the effect of the lipid raft proteins known as flotillins on the invasive and metastatic potential of residual HCC.

Methods

The human HCC cell line HCCLM3 was used to establish insufficient RFA models in vivo and in vitro. Changes in cellular morphology, soft agar colony formation, motility, metastasis, and epithelial–mesenchymal transition (EMT) markers after insufficient RFA intervention in vitro and in vivo were detected by real-time PCR, western blotting, immunohistochemistry and transwell assays.

Results

The results showed that flotillin-1 and flotillin-2 expression were upregulated in HCCLM3 cells following 45 °C heat treatment and in residual HCCLM3 xenografts cells after insufficient RFA. Knocking down flotillin-1 or flotillin-2 in HCCLM3 cells by shRNA significantly lowered insufficient RFA-induced tumor growth, EMT changes, and metastasis in vitro and in vivo. Furthermore, mechanism studies indicated that flotillins altered the EMT status and metastatic potential of heat-treated HCCLM3 cells by activating the Akt/Wnt/β-catenin signaling pathway.

Conclusions

Our findings present new evidence that flotillins play a key role in the aggressive behaviors of residual cancer cells after insufficient RFA and provide new insights into the regulatory mechanism of Wnt/β-catenin signaling.

Electronic supplementary material

The online version of this article (10.1007/s00432-019-02852-z) contains supplementary material, which is available to authorized users.

Sub-lethal hyperthermia promotes epithelial-to-mesenchymal-like transition of breast cancer cells: implication of the synergy between hyperthermia and chemotherapy

Thermotherapy has demonstrated a potential to be an effective non-surgical technique to treat breast cancer.

Periostin involved in the activated hepatic stellate cells-induced progression of residual hepatocellular carcinoma after sublethal heat treatment: its role and potential for therapeutic inhibition

BACKGROUND

Incomplete thermal ablation may induce invasiveness of hepatocellular carcinoma (HCC). Here, we investigated whether activated hepatic stellate cells (HSCs) would accelerate the progression of residual HCC after sublethal heat treatment, and thus sought to identify the potential targets.

METHODS

Hepatocellular carcinoma cells were exposed to sublethal heat treatment and then cultured with the conditioned medium from activated HSCs (HSC-CM). The cell proliferation, migration, invasion and parameters of epithelial-mesenchymal transition (EMT) were analyzed. In vivo tumor progression of heat-treated residual HCC cells inoculated with activated HSCs was studied in nude mice.

RESULTS

HSC-CM significantly enhanced the proliferation, motility, invasion, prominent EMT activation and decreased apoptosis of heat-exposed residual HCC cells. These increased malignant phenotypes were markedly attenuated by neutralizing periostin (POSTN) in HSC-CM. Furthermore, exogenous POSTN administration exerted the similar effects of HSC-CM on heat-treated residual HCC cells. POSTN induced the prominent activation of p52Shc and ERK1/2 via integrin β1 in heat-exposed residual HCC cells. Vitamin D analog calcipotriol blocked POSTN secretion from activated HSCs. Calcipotriol plus cisplatin significantly suppressed the activated HSCs-enhanced tumor progression of heat-treated residual HCC cells via the inhibited POSTN expression and the increased apoptosis.

CONCLUSIONS

Activated HSCs promote the tumor progression of heat-treated residual HCC through the release of POSTN, which could be inhibited by calcipotriol. Calcipotriol plus cisplatin could be used to thwart the accelerated progression of residual HCC after suboptimal heat treatment.

Interferon-α Combined With Herbal Compound "Songyou Yin" Effectively Inhibits the Increased Invasiveness and Metastasis by Insufficient Radiofrequency Ablation of Hepatocellular Carcinoma in an Animal Model

Objective: We had previously proved that insufficient radiofrequency ablation (RFA) could enhance invasiveness and metastasis of hepatocellular carcinoma (HCC) through epithelial-mesenchymal transition (EMT), which is mediated by activating β-catenin signaling. Thus, the aim of the present study was to demonstrate whether the combined treatment of interferon-α (IFN-α) and “Songyou Yin” (SYY) minimizes the pro-metastatic effects of insufficient RFA, as well as to explore its underlying mechanism. Methods: Insufficient RFA was performed in an orthotopic nude mice model of HCCLM3 with high metastatic potential. The effects of IFN-α, SYY, and combined IFN-α and SYY were observed in the animal model. Tumor sizes, lung metastasis, and survival time were assessed. Immunochemistry staining, real-time polymerase chain reaction, and Western blot were used to examine gene expression related to metastasis and angiogenesis in residual cancer after insufficient RFA. Results: For up to 8 weeks of treatment, the combined therapy significantly decreased the residual cancer sizes, minimized the lung metastasis rate, and prolonged the survival time of nude mice, which might be due to suppression of the EMT via β-catenin signal blockade, in addition to attenuating angiogenesis in residual cancer after insufficient RFA. Conclusion: IFN-α combined with SYY significantly weakened the enhanced metastatic potential of residual cancer after insufficient RFA by attenuating EMT, which is mediated through inhibiting activation of β-catenin. In addition, decreasing angiogenesis of residual cancer might also play a certain role.

Percutaneous treatment of hepatocellular carcinoma: State of the art and innovations

Percutaneous treatment of hepatocellular carcinoma (HCC) encompasses a vast range of techniques, including monopolar radiofrequency ablation (RFA), multibipolar RFA, microwave ablation, cryoablation and irreversible electroporation. RFA is considered one of the main curative treatments for HCC of less than 5 cm developing on cirrhotic liver, together with surgical resection and liver transplantation. However, controversies exist concerning the respective roles of ablation and liver resection for HCC of less than 3 to 5 cm on cirrhotic liver. In line with the therapeutic algorithm of early HCC, percutaneous ablation could also be used as a bridge to liver transplantation or in a sequence of upfront percutaneous treatment, followed by transplantation if the patient relapses. Moreover, several innovations in ablation methods may help to efficiently treat early HCC, initially considered as "non-ablatable", and might, in some cases, extend ablation criteria beyond early HCC, enabling treatment of more patients with a curative approach.

Promotion of malignant phenotype after disruption of the three-dimensional structure of cultured spheroids from colorectal cancer

Individual and small clusters of cancer cells may detach from the edges of a main tumor and invade vessels, which can act as the origin of metastasis; however, the mechanism for this phenomenon is not well understood. Using cancer tissue-originated spheroids, we studied whether disturbing the 3D architecture of cancer spheroids can provoke the reformation process and progression of malignancy. We developed a mechanical disruption method to achieve homogenous disruption of the spheroids while maintaining cell–cell contact. After the disruption, 9 spheroid lines from 9 patient samples reformed within a few hours, and 3 of the 9 lines exhibited accelerated spheroid growth. Marker expression, spheroid forming capacity, and tumorigenesis indicated that stemness increased after spheroid disruption. In addition, the spheroid forming capacity increased in 6 of 11 spheroid lines. The disruption signature determined by gene expression profiling supported the incidence of remodeling and predicted the prognosis of patients with colorectal cancer. Furthermore, WNT and HER3 signaling were increased in the reformed spheroids, and suppression of these signaling pathways attenuated the increased proliferation and stemness after the disruption. Overall, the disruption and subsequent reformation of cancer spheroids promoted malignancy-related phenotypes through the activation of the WNT and ERBB pathways.

USP22 drives colorectal cancer invasion and metastasis via epithelial-mesenchymal transition by activating AP4

Ubiquitin specific peptidase 22 (USP22), a putative cancer stem cell marker, is overexpressed in liver metastases of colorectal cancer (CRC). However, the mechanism by which USP22 promotes CRC metastasis remains largely unknown. Here, we report that USP22 and AP4 are simultaneously overexpressed during TGF-β1-induced CRC cell epithelial-mesenchymal transition (EMT). USP22 up-regulation enhances CRC cell migration and invasion and EMT-related marker and AP4 expression, but these effects are partly blocked by AP4 knockdown. In addition, USP22 binds to the promoter region of AP4 to activate its transcription. In vivo, elevated USP22 expression promotes CRC cell metastasis to the lungs in nude mice, as evidenced by the fact that CRC metastatic nodules stain deeply positive for USP22 and AP4. In human CRC tissues, the genes encoding USP22 and AP4 are overexpressed in metastatic liver lesions compared with primary cancer tissues, and their overexpression is significantly associated with poor CRC patient survival. These findings indicate that USP22 and AP4 may serve as prognostic markers for predicting the risk of developing distant metastases in CRC.

Safety and effect on ablation size of hydrochloric acid-perfused radiofrequency ablation in animal livers

PURPOSE

Our objective was to determine the safety and ablation size of hydrochloric acid-perfused radiofrequency ablation (HCl-RFA) in liver tissues, prospectively using in vivo rabbit and ex vivo porcine liver models.

MATERIALS AND METHODS

The livers in 30 rabbits were treated in vivo with perfusions of normal saline (controls) and HCl concentrations of 5%, 10%, 15%, and 20%, during RFA at 103 °C and 30 W for 3 min. For each experimental setting, six ablations were created. Safety was assessed by comparing baseline weight and selected laboratory values with those at 2, 7, and 14 days' post-ablation, and by histopathological analysis. The livers in 25 pigs were treated ex vivo with the same five perfusions during RFA at 103 °C, at both 30 W and 60 W, for 30 min. Ablation diameters and volumes were measured by two examiners.

RESULTS

Rabbit weights and selected laboratory values did not differ significantly from baseline to 7 and 14 days' post-ablation, liver tissues outside the ablation zones were normal histologically, and adjacent organs showed no macroscopic damage. The mean ablation volumes in the porcine livers treated with HCl-RFA were all larger than those treated with normal saline perfusion during RFA (NS-RFA), at both 30 W and 60 W (p < 0.001). The largest ablation volume and transverse diameter were observed in the porcine livers during 10% HCl-RFA at 60 W, measuring 179.22 (SD = 24.79) cm³ and 6.84 (SD = 0.36) cm, respectively.

CONCLUSIONS

Based on our experiments, HCl-RFA in the liver appears to be as safe as NS-RFA while also resulting in larger ablation zones.

LncRNA FUNDC2P4 down-regulation promotes epithelial-mesenchymal transition by reducing E-cadherin expression in residual hepatocellular carcinoma after insufficient radiofrequency ablation

PURPOSE

Hepatocellular carcinoma (HCC) after insufficient radiofrequency ablation (RFA) could induce epithelial-mesenchymal transition (EMT) in residual tumours, resulting in rapid and aggressive recurrence. However, the role of EMT-related Long noncoding RNAs (lncRNAs) in residual tumour progression remains unclear.

METHODS

Insufficient RFA was simulated in vitro by heating Huh7 cells in water bath at 47 °C, named as Huh7-H. Cell invasion, migration assays and wound healing assay were conducted for functional analysis. Cell proliferation was determined by CCK8 assay. Differential expression profile of EMT-related lncRNAs between Huh7-H and Huh7 was analysed by LncPath human EMT array, and validated by qRT-PCR. Gain/loss-of-function assays of selected lncRNA were conducted by over-expressing or silencing its expression.

RESULTS

Huh7-H presented characteristic EMT morphological changes. WB analysis showed significantly decreased E-cadherin in Huh7-H cells. Transwell assays indicated the abilities of Huh7-H cells in migration and invasion were evidently strengthened. A new lncRNA, FUNDC2P4, was identified by LncPath human EMT array to be significantly down-regulated in Huh7-H cells. In vitro studies showed overexpression of FUNDC2P4 inhibited proliferation, invasion and migration potential and up-regulated E-cadherin expression in SMMC-7721 cells, whereas silencing FUNDC2P4 promoted these potentials and down-regulated E-cadherin expression in Huh7 cells.

CONCLUSIONS

We explored that lncRNA FUNDC2P4 down-regulation promoted EMT leading to tumour proliferation, invasion and migration by reducing E-cadherin expression in residual HCC after insufficient RFA in vitro. These results suggest that FUNDC2P4 may have potentially therapeutic value for prevention and treatment of HCC recurrence after RFA in the future.

Increased matrix stiffness promotes tumor progression of residual hepatocellular carcinoma after insufficient heat treatment

Aggravated behaviors of hepatocellular carcinoma (HCC) will occur after inadequate thermal ablation. However, its underlying mechanisms are not fully understood. Here, we assessed whether the increased matrix stiffness after thermal ablation could promote the progression of residual HCC. Heat‐treated residual HCC cells were cultured on tailorable 3D gel with different matrix stiffness, simulating the changed physical environment after thermal ablation, and then the mechanical alterations of matrix stiffness on cell phenotypes were explored. Increased stiffness was found to significantly promote the proliferation of the heat‐treated residual HCC cells when the cells were cultured on stiffer versus soft supports, which was associated with stiffness‐dependent regulation of ERK phosphorylation. Heat‐exposed HCC cells cultured on stiffer supports showed enhanced motility. More importantly, vitamin K1 reduced stiffness‐dependent residual HCC cell proliferation by inhibiting ERK phosphorylation and suppressed the in vivo tumor growth, which was further enhanced by combining with sorafenib. Increased matrix stiffness promotes the progression of heat‐treated residual HCC cells, proposing a new mechanism of an altered biomechanical environment after thermal ablation accelerates HCC development. Vitamin K1 plus sorafenib can reverse this protumor effect.

Long noncoding RNA expression profiles in sub-lethal heat-treated hepatoma carcinoma cells

Background

Sub-lethal heat treatment characterizes a transition zone of radiofrequency ablation (RFA) which explains hepatocellular carcinoma (HCC) residual cancer occurrence in this area after RFA treatment. The biochemistry of residual cancer cell recurrence is poorly understood, but long noncoding RNAs (lncRNAs) may have aberrant expression that is associated with diverse cancers. Thus, we measured lncRNA gene expression in sub-lethally heat-treated HCC cells using microarray.

Method

Differentially expressed lncRNA and mRNA were measured with an Agilent Human lncRNA + mRNA Array V4.0 (4 × 180 K format) containing 41,000 lncRNAs and 34,000 mRNAs. Bioinformatics analysis was used to assess differentially expressed lncRNA and mRNA. Seven lncRNA and seven mRNA were validated by qRT-PCR analysis in HCC cells.

Results

Genome-wide lncRNA and mRNA expression data in sub-lethal heat-treated SMMC-7721 HCC cells 558 lncRNA and 250 mRNA were significantly up-regulated and 224 lncRNA and 1031 mRNA down-regulated compared to normal cultured SMMC-7721 cells. We demonstrated for the first time that ENST00000570843.1, ENST00000567668.1, ENST00000582249.1, ENST00000450304.1, TCONS_00015544, ENST00000602478.1, TCONS_00001266 and ARC, IL12RB1, HSPA6 were upregulated, whereas STAT3, PRPSAP1, MCU, URB2 were down-regulated in sub-lethally heat-treated HCC cells.

Conclusions

lncRNA expression data in sub-lethally heat-treated HCC cells will provide important insights about lncRNAs’ contribution to HCC recurrence after RFA treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-017-1194-4) contains supplementary material, which is available to authorized users.

Epidermal growth factor receptor transactivation is involved in the induction of human hepatoma SMMC7721 cell proliferation by insufficient radiofrequency ablation

Our previous study revealed that insufficient radiofrequency ablation (RFA) promotes the malignancy of human hepatocellular carcinoma (HCC) SMMC7721 cells via the Ca²⁺/calmodulin-dependent protein kinase II (CaMKII)/extracellular signal-regulated kinase (ERK)-induced overexpression of vascular endothelial growth factor (VEGF). The aims of the present study were to address the involvement of epidermal growth factor receptor (EGFR) transactivation in the enhanced SMMC7721 cell proliferation induced by insufficient RFA, in addition to its association with the CaMKII/ERK/VEGF signaling cascade. SMMC7721 cells were subjected to a 47°C treatment regimen to simulate insufficient RFA. Cell proliferation was determined using MTT and colony formation assays. The expression levels of VEGF, CaMKII, phosphorylated (phospho)-CaMKII, ERK, phospho-ERK, EGFR and phospho-EGFR were analyzed using western blotting. The results demonstrated that the enhancement of SMMC7721 cell proliferation by the 47°C treatment regimen was significantly inhibited by exposure of the cells to AG178 (a specific inhibitor of EGFR). Furthermore, AG1478 exposure prevented the overexpression of VEGF and phosphorylation of ERK, but had no significant effects on CaMKII phosphorylation. By contrast, 47°C treatment-induced EGFR phosphorylation was inhibited by treatment with KN93 (a specific inhibitor of CaMKII). Overall, the results of the present study have suggested a role for EGFR transactivation in the RFA-promoted growth of residual HCC. Thus, targeting EGFR may represent a useful preventive and therapeutic strategy for RFA-induced HCC progression and recurrence.

Iodine-125 Brachytherapy Prophylaxis after Radiofrequency Ablation Cannot Benefit Patients in High Risk of Locoregional Hepatocellular Carcinoma Recurrence

This study evaluated if iodine-125 brachytherapy prophylaxis after radiofrequency ablation (RFA) prolongs time to recurrence (TTR) and overall survival (OS) of patients in high risk of locoregional hepatocellular carcinoma (HCC) recurrence. 116 patients with total tumor necrosis after RFA were divided into iodine-125 brachytherapy prophylaxis treatment group and control group. The primary endpoint was TTR, and secondary endpoints were OS and treatment-related adverse events. There were no significant differences among the baseline characteristics of two subgroups patients. The mean iodine-125 particles were 29.8 (26.59 ± 12.51 mCi) per patient. The mean follow-up was 25 months, and mean TTR of treatment and control groups were 21.7 and 15.9 months (P = 0.733); mean OS of two subgroups were 41.7 and 40.9 months (P = 0.316). There were no significant differences of 1-, 2-, 3-, 4-and 5-years TTR and OS and patients’ immunity pre- and 1 month post-treatment. Extrahepatic metastasis was found to have a statistically significant influence on TTR, and AFP, extrahepatic metastasis were found to have a statistically significant influence on OS by multivariate analysis. There was no major complications and procedure related death. Iodine-125 brachytherapy prophylaxis after RFA can’t improve TTR and OS of HCC patients who were in high risk of locoregional tumor recurrence.

Local tumor progression patterns after radiofrequency ablation of colorectal cancer liver metastases

PURPOSE

We aimed to evaluate patterns of local tumor progression (LTP) after radiofrequency ablation (RF ablation) of colorectal cancer liver metastases (CRCLM) and to highlight the percentage of LTP not attributable to lesion size or RF ablation procedure-related factors (heat sink or insufficient ablation margin).

METHODS

CRCLM treated by RF ablation at a single tertiary care center from 2004-2012, with a minimum of six months of postprocedure follow-up, were included in this retrospective study. LTP morphology was classified as focal nodular (<90° of ablation margin), circumferential (>270°), or crescentic (90°-270°). Initial metastasis size, minimum ablation margin size, morphology of LTP, presence of a heat sink, and time to progression were recorded independently by two radiologists.

RESULTS

Thirty-two of 127 RF ablation treated metastases (25%) with a mean size of 23 mm (standard deviation 12 mm) exhibited LTP. Fifteen of 32 LTPs (47%) were classified as focal nodular, with seven having no procedure-related factor to explain recurrence. Ten of 32 LTPs (31%) were circumferential, with four having no procedure-related factor to explain recurrence. Seven of 32 LTPs (22%) were crescentic, with two having no procedure-related factor to explain recurrence. Of the 13 lesions without any obvious procedure-related reason for LTP, six (46%) were <3 cm in size.

CONCLUSION

Although LTP in RF ablation treated CRCLM can often be explained by procedure-related factors or size of the lesion, in this study up to six (5%) of the CRCLM we treated showed LTP without any reasonable cause.

Radio-frequency ablation-based studies on VX2rabbit models for HCC treatment

Hepatocellular carcinoma (HCC) is the fifth most frequent cancer worldwide with high morbidity, mortality and increasing incidence. It is of note that the main curative therapies for HCC are hepatic resection and transplantation although the majority of patients at the time of presentation are not eligible for resection or orthotopic liver transplantation (OLT) due to the underlying cirrhosis. Currently, a variety of loco-regional therapies, including radiofrequency ablation (RFA), percutaneous ethanol injection (PEI), microwave coagulation therapy (MCT), transarterial chemoembolization (TACE) and others, have been developed as alternative treatment options for HCC. Among these techniques, RFA is currently the most widely used treatment, due to its several advantages, such as safety and efficacy. To date, the effectiveness of RFA for HCC is reduced by the presence of residual tumor as a consequence of insufficient treatment. In order to ameliorate the effects of RFA on HCC, several in vivo studies, have been performed on its application as single or in combination treatment with drugs or others loco-regional therapies, by using rabbit VX2 liver model. This represents an ideal model of liver cancers and is widely used for imaging and other experimental studies due to the rapid growth of these tumors and their similarity to human hepatocellular carcinoma. In order to elucidate the therapeutic potential of RFA with adjuvant treatments for HCC, we reviewed the latest findings on the RFA-based studies in rabbit VX2 hepatocarcinoma models.

Elevated MTSS1 expression associated with metastasis and poor prognosis of residual hepatitis B-related hepatocellular carcinoma

Background

Hepatectomy generally offers the best chance of long-term survival for patients with hepatocellular carcinoma (HCC). Many studies have shown that hepatectomy accelerates tumor metastasis, but the mechanism remains unclear.

Methods

An orthotopic nude mice model with palliative HCC hepatectomy was performed in this study. Metastasis-related genes in tumor following resection were screened; HCC invasion, metastasis, and some molecular alterations were examined in vivo and in vitro. Clinical significance of key gene mRNA expression was also analyzed.

Results

Metastasis suppressor 1 (MTSS1) located in the central position of gene function net of residual HCC. MTSS1 was up-regulated in residual tumor after palliative resection. In hepatitis B-related HCC patients undergone palliative hepatectomy, those with higher MTSS1 mRNA expression accompanied by activation of matrix metalloproteinase 2 (MMP2) in residual HCC, had earlier residual HCC detection after hepatectomy and poorer survival when compared to those with lower MTSS1. In different cell lines, the levels of MTSS1 mRNA increased in parallel with metastatic potential. MTSS1 down regulation via siRNA decreased MMP2 activity, reduced invasive potentials of HCC by 28.9 % in vitro, and averted the deteriorated lung metastatic extent in vivo.

Conclusions

The poor prognosis of hepatitis B-related HCC patients following palliative hepatectomy associates with elevated MTSS1 mRNA expression; therefore, MTSS1 may provide a new research field for HCC diagnosis and treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0361-8) contains supplementary material, which is available to authorized users.