Immunomodulation after radiofrequency ablation of locally advanced pancreatic cancer by monitoring the immune response in 10 patients

Role of Endoscopic Ultrasound-Guided Radiofrequency Ablation in Pancreatic Lesions: Where Are We Now and What Does the Future Hold?

Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has emerged as an effective and minimally invasive treatment for pancreatic lesions, particularly in patients at high surgical risk. Utilizing thermal energy, RFA induces the coagulative necrosis of the tissue and potentially triggers immunomodulation by releasing intracellular antigens. Numerous studies have confirmed the technical feasibility, safety, and efficacy of EUS-RFA in pancreatic neuroendocrine tumors and premalignant cystic lesions, with an acceptable profile of adverse events. The technique's potential immunomodulatory effects offer intriguing implications for the treatment of advanced pancreatic malignancies, encouraging further evaluation. This review paper aims to highlight the EUS-RFA principles, technology, and clinical applications in various pancreatic lesions and safety, and the future research directions.

EUS-Guided Radiofrequency Ablation Therapy for Pancreatic Neoplasia

Radiofrequency ablation (RFA) under endoscopic ultrasound (EUS) guidance has been developed and utilized over the last decade to provide the loco-regional treatment of solid and cystic pancreatic neoplastic lesions. The advantage of this approach relies on the close proximity of the EUS transducer to the target pancreatic lesion, which, coupled with the development of specifically designed RFA ablation devices, has made the procedure minimally invasive, with a clear reduction in adverse events as compared to the high morbidity of the surgical approach. EUS-RFA has been applied so far to pancreatic functional and non-functional neuroendocrine neoplasms, pancreatic ductal adenocarcinoma or metastases to the pancreas, and pancreatic neoplastic cysts. Excluding neuroendocrine tumors, for other indications, most of these procedures have been performed in patients who refused surgery or were at high surgical risk. More studies evaluating EUS-RFA in selected patients, not at surgical risk, are gradually becoming available and will pave the road to extend the indications for this therapeutic approach, also in association with other oncological therapies. The present manuscript will critically review the available evidence in the field of the EUS-guided RFA of solid and cystic pancreatic neoplasms.

Adjuvant endobiliary radio-frequency ablation combined with self-expandable biliary metal stents for unresectable malignant hilar strictures: A pragmatic comparative study

INTRODUCTION

The role of endo-biliary radio-frequency ablation (EB-RFA) in treating malignant biliary strictures remains a subject of controversy. This study aims to assess the efficacy and safety of EB-RFA in conjunction with self-expandable metal stents (SEMS) compared to SEMS alone.

METHODS

This single-center prospective pragmatic comparative study, conducted between June 2021 and November 2022, involved 23 patients undergoing EB-RFA plus SEMS and 48 patients undergoing SEMS for unresectable malignant hilar obstruction. The study evaluated overall survival, stent patency and adverse events.

RESULTS

Seventy-one patients (mean age [SD], 57.8 [11.2] years; 73.2% men) were enrolled. The clinical success rates did not significantly differ between the two groups (78.3% in EB-RFA and 66.6% in SEMS; p 0.316). The median (95% CI) overall survival was 155 (79.87-230.13) days in the EB-RFA group, contrasting with 86.0 (78.06-123.94) days in the SEMS group (p 0.020). The presence of carcinoma gallbladder (p 0.035; HR 0.55; 95% CI 0.32-0.96) and EB-RFA (p 0.047; HR 1.88; 95% CI 1.01-3.49) independently predicted overall survival. Median (95% CI) stent patency was 143.0 (95% CI, 61.61-224.39) days in the EB-RFA group compared to 78.0 (95% CI, 32.74-123.26) days in the SEMS group (p 0.019). The presence of carcinoma gallbladder (p 0.046, HR 0.60; 95% CI, 0.36-0.99), EB-RFA (p 0.023; HR 1.92; 95% CI, 1.10-3.36) and chemotherapy (p 0.017, HR 1.91; 95% CI, 1.12-3.26) independently predicted longer stent patency. There was no difference in procedure-related adverse events in both groups.

CONCLUSION

EB-RFA with SEMS placement proves to be a safe and effective technique for palliative biliary decompression in patients with malignant biliary strictures, demonstrating superior overall survival and stent patency compared to SEMS alone. Further confirmation through multi-center trials is warranted.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (ID: NCT05320328).

Impact of temperature-controlled endobiliary radiofrequency ablation for inoperable hilar cholangiocarcinoma: A propensity score-matched analysis

Background and study aims Endobiliary radiofrequency ablation (RFA) can be an effective palliative treatment, but few studies have evaluated its outcomes for malignant obstruction in the hilar bile duct, which has a thin wall and complex duct-vascular contacts. We evaluated the efficacy and safety of temperature-controlled endobiliary RFA, which can reduce the risk of unintentional thermal injury by maintaining the temperature of the ablation segment, in the treatment of inoperable hilar cholangiocarcinoma (CCA). Patients and methods After propensity score matching, 64 patients with inoperable hilar CCA were categorized to the RFA + stent group (endobiliary RFA with stenting; n=32) or stent-only group (stenting only; n=32). The evaluated outcomes were the median time to recurrent biliary obstruction (RBO), overall survival (OS), and adverse events (AEs). Results Technical success was achieved in all patients. The clinical success rate was 93.8% in the RFA + stent group and 87.5% in the stent-only group ( P =0.672). The median time to RBO was 242 days in the RFA + stent group and 168 days in the stent-only group ( P =0.031). The median OS showed a non-significant tendency to be higher in the RFA + stent group (337 versus 296 days; P =0.260). Overall AE rates were comparable between the two groups (12.5% vs 9.4%, P =1.000). Conclusions Temperature-controlled endobiliary RFA resulted in favorable stent patency without increasing the rate of AEs but it did not significantly increase OS in patients with inoperable hilar CCA (Clinical trial registration number: KCT0008576).

Endoscopic Ultrasound-Guided Ablation of Premalignant Pancreatic Cysts and Pancreatic Cancer

Pancreatic cancer is on the rise and expected to become the second leading cause of cancer-related death by 2030. Up to a one-fifth of pancreatic cancers may arise from mucinous pancreatic cysts, which are frequently present in the general population. Currently, surgical resection is the only curative approach for pancreatic cancer and its cystic precursors. However, only a dismal proportion of patients are eligible for surgery. Therefore, novel treatment approaches to treat pancreatic cancer and precancerous pancreatic cysts are needed. Endoscopic ultrasound (EUS)-guided ablation is an emerging minimally invasive method to treat pancreatic cancer and premalignant pancreatic cysts. Different ablative modalities have been used including alcohol, chemotherapy agents, and radiofrequency ablation. Cumulative data over the past two decades have shown that endoscopic ablation of mucinous pancreatic cysts can lead to cyst resolution in a significant proportion of the treated cysts. Furthermore, novel data are emerging about the ability to endoscopically ablate early and locally advanced pancreatic cancer. In this review, we aim to summarize the available data on the efficacy and safety of the different EUS-ablation modalities for the management of premalignant pancreatic cysts and pancreatic cancer.

Local ablative therapies and the effect on antitumor immune responses in pancreatic cancer - A review

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease, projected to rank as the second most prevalent cause of cancer-related mortality by 2030. Despite significant progress in advances in surgical techniques and chemotherapy protocols, the overall survival (OS) remains to be less than 10 % for all stages combined. In recent years, local ablative techniques have been introduced and utilized as additional therapeutic approaches for locally advanced pancreatic cancer (LAPC), with promising results with respect to local tumor control and OS. In addition to successful cytoreduction, there is emerging evidence that local ablation induces antitumor immune activity that could prevent or even treat distant metastatic tumors. The enhancement of antitumor immune responses could potentially make ablative therapy a therapeutic option for the treatment of metastatic PDAC. In this review, we summarize current ablative techniques used in the management of LAPC and their impact on systemic immune responses.

Consensus statements on endoscopic radiofrequency ablation for malignant biliary strictures

Endoscopy-guided endobiliary radiofrequency ablation has emerged as a novel treatment for malignant biliary strictures in recent years. When combined with biliary stenting and systemic chemotherapy, it can effectively postpone local tumor progression, improve patient's quality of life, and prolong their survival, which is mainly indicated for patients with inoperable extrahepatic cholangiocarcinoma and ampullary cancer. Based on the existing clinical evidence, the Digestive Endoscopology Branch of Chinese Medical Association, the Digestive Endoscopy Professional Committee, Endoscopic Physicians Branch of Chinese Medical Doctor Association, and the National Clinical Research Center for Digestive Diseases (Shanghai) organized relevant experts to discuss the indications, contraindications, technical operation specifications, and prevention and treatment of the complications during endoscopy-guided endobiliary radiofrequency ablation. Consensus statements were established, trying to provide references for standard treatment of malignant biliary tumors in clinical practice.

Endoscopic ultrasound-guided radiofrequency ablation of pancreatic insulinoma: a state of the art review

INTRODUCTION

Insulinomas are the most common functional pancreatic neuroendocrine tumors (PNETs) that lead to incapacitating hypoglycemia. Guidelines recommend surgical resection as the mainstay of management. However, surgery is fraught with complications, causing significant peri/post-operative morbidity. Since insulinomas are usually benign, solitary, small (<2 cm), and do not need lymphadenectomy, hence, in this regard, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is now being increasingly performed, to circumvent these adverse events and impairment of pancreatic function.

AREAS COVERED

A comprehensive literature search was undertaken across various databases (PubMed/MEDLINE, Embase, Scopus), with no language restriction, for relevant articles (case series, reviews, case reports) pertaining to EUS-RFA for insulinoma and PNETs, till October 2023. In this review, we have explicated the role of EUS-RFA for insulinoma management, detailing thoroughly its mechanism of action, EUS-RFA devices with data on its safety and efficacy, and an algorithmic approach for its management.

EXPERT OPINION

EUS-RFA is being advocated as a 'mini-invasive' option with the potential to replace surgery as a first-line approach for benign, sporadic, solitary, and small (<2 cm) insulinomas. Under real-time guidance, EUS-RFA has immense precision, is safe, predictable, with acceptable safety profile. Presently, it is being frequently performed for high-risk or inoperable candidates. Current need-of-the-hour is a randomized controlled trial to substantiate its role in the therapeutic algorithm for insulinoma management.

Successful In Situ Targeting of Pancreatic Tumors in a Novel Orthotopic Porcine Model Using Histotripsy

OBJECTIVE

New therapeutic strategies and paradigms are direly needed to treat pancreatic cancer. The absence of a suitable pre-clinical animal model of pancreatic cancer is a major limitation to biomedical device and therapeutic development. Traditionally, pigs have proven to be ideal models, especially in the context of designing human-sized instruments, perfecting surgical techniques and optimizing clinical procedures for use in humans. However, pig studies have typically focused on healthy tissue assessments and are limited to general safety evaluations because of the inability to effectively model human tumors.

METHODS

Here, we establish an orthotopic porcine model of human pancreatic cancer using RAG2/IL2RG double-knockout immunocompromised pigs and treat the tumors ex vivo and in vivo with histotripsy.

RESULTS

Using these animals, we describe the successful engraftment of Panc-1 human pancreatic cancer cell line tumors and characterize their development. To illustrate the utility of these animals for therapeutic development, we determine for the first time, the successful targeting of in situ pancreatic tumors using histotripsy. Treatment with histotripsy resulted in partial ablation in vivo and reduction in collagen content in both in vivo tumor in pig pancreas and ex vivo patient tumor.

CONCLUSION

This study presents a first step toward establishing histotripsy as a non-invasive treatment method for pancreatic cancer and exposes some of the challenges of ultrasound guidance for histotripsy ablation in the pancreas. Simultaneously, we introduce a highly robust model of pancreatic cancer in a large mammal model that could be used to evaluate a variety biomedical devices and therapeutic strategies.

The Role of Immune Checkpoint Inhibitors in Metastatic Pancreatic Cancer: Current State and Outlook

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest tumors, characterized by its aggressive tumor biology and poor prognosis. While immune checkpoint inhibitors (ICIs) play a major part in the treatment algorithm of various solid tumors, there is still no evidence of clinical benefit from ICI in patients with metastatic PDAC (mPDAC). This might be due to several reasons, such as the inherent low immunogenicity of pancreatic cancer, the dense stroma-rich tumor microenvironment that precludes an efficient migration of antitumoral effector T cells to the cancer cells, and the increased proportion of immunosuppressive immune cells, such as regulatory T cells (Tregs), cancer-associated fibroblasts (CAFs), and myeloid-derived suppressor cells (MDSCs), facilitating tumor growth and invasion. In this review, we provide an overview of the current state of ICIs in mPDAC, report on the biological rationale to implement ICIs into the treatment strategy of pancreatic cancer, and discuss preclinical studies and clinical trials in this field. Additionally, we shed light on the challenges of implementing ICIs into the treatment strategy of PDAC and discuss potential future directions.

State-of-the-Art and Upcoming Innovations in Pancreatic Cancer Care: A Step Forward to Precision Medicine

Pancreatic cancer remains a social and medical burden despite the tremendous advances that medicine has made in the last two decades. The incidence of pancreatic cancer is increasing, and it continues to be associated with high mortality and morbidity rates. The difficulty of early diagnosis (the lack of specific symptoms and biomarkers at early stages), the aggressiveness of the disease, and its resistance to systemic therapies are the main factors for the poor prognosis of pancreatic cancer. The only curative treatment for pancreatic cancer is surgery, but the vast majority of patients with pancreatic cancer have advanced disease at the time of diagnosis. Pancreatic surgery is among the most challenging surgical procedures, but recent improvements in surgical techniques, careful patient selection, and the availability of minimally invasive techniques (e.g., robotic surgery) have dramatically reduced the morbidity and mortality associated with pancreatic surgery. Patients who are not candidates for surgery may benefit from locoregional and systemic therapy. In some cases (e.g., patients for whom marginal resection is feasible), systemic therapy may be considered a bridge to surgery to allow downstaging of the cancer; in other cases (e.g., metastatic disease), systemic therapy is considered the standard approach with the goal of prolonging patient survival. The complexity of patients with pancreatic cancer requires a personalized and multidisciplinary approach to choose the best treatment for each clinical situation. The aim of this article is to provide a literature review of the available treatments for the different stages of pancreatic cancer.

Endoscopic intraductal radiofrequency ablation for extrahepatic cholangiocarcinoma: An update (2023)

Recently, endoscopic intraductal radiofrequency ablation (ID-RFA) has attracted attention as a local treatment method for malignant biliary obstruction (MBO). ID-RFA causes coagulative necrosis of the tumor tissue in the stricture and induces exfoliation. Its effects are expected to extend the patency period of biliary stents and prolong the survival period. Evidence for extrahepatic cholangiocarcinoma (eCCA) is gradually accumulating, and some reports show significant therapeutic effects in eCCA patients without distant metastasis. However, it is still far from an established treatment technique, and many unsolved problems remain. Therefore, when performing ID-RFA in clinical practice, it is necessary to understand and grasp the current evidence well and to operate appropriately for the true benefit of the patients. This paper reviews the current status, issues, and prospects of endoscopic ID-RFA for MBO, especially for eCCA.

Radiofrequency ablation for the management of pancreatic mass lesions

PURPOSE OF REVIEW

Patients with pancreatic tumors may have limited treatment options. Pancreatic tumor ablation is a novel and emerging treatment modality which can now be performed using endoscopic ultrasound (EUS) guidance. This modality is well suited to guide energy delivery for radiofrequency ablation (RFA) and microwave ablation. These approaches provide minimally invasive, nonsurgical methods for delivering energy to ablate pancreatic tumors in situ. This review summarizes the current data and safety profile for ablation in managing pancreatic cancer and pancreatic neuroendocrine tumors.

RECENT FINDINGS

RFA uses thermal energy to induce cell death by coagulative necrosis and protein denaturation. Studies have reported increased overall survival in patients with pancreatic tumors treated with EUS-guided RFA in a multimodality systemic approach and when used in palliative surgeries. Radiofrequency ablation may have corollary benefits in inducing an immune-modulatory effect. Tumor marker carbohydrate antigen 19-9 has been reported to decrease in response to RFA. Microwave ablation is an emerging modality.

SUMMARY

RFA utilizes focal thermal energy to induce cell death. RFA has been applied through open, laparoscopic, and radiographic modalities. EUS-guided approaches are now allowing RFA and microwave ablation to be performed for pancreatic tumors in situ.

Recent Updates on Local Ablative Therapy Combined with Chemotherapy for Extrahepatic Cholangiocarcinoma: Photodynamic Therapy and Radiofrequency Ablation

Although chemotherapy constitutes of the first-line standard therapy for unresectable extrahepatic cholangiocarcinoma, the treatment outcomes are unsatisfactory. In recent years, local ablative therapy, which is delivered to the cholangiocarcinoma lesion via the percutaneous or endoscopic approach, has garnered attention for the treatment of unresectable, extrahepatic cholangiocarcinoma. Local ablative therapy, such as photodynamic therapy and radiofrequency ablation, can achieve local tumor control. A synergistic effect may also be expected when local ablative therapy is combined with chemotherapy. However, it is a long way from being entrenched as an established therapeutic technique, and several unresolved problems persist, including the paucity of evidence comparing photodynamic therapy and radiofrequency ablation. Clinical application of photodynamic therapy and radiofrequency ablation requires sound comprehension and assimilation of the available evidence to truly benefit each individual patient. In this study, we reviewed the current status, issues, and future prospects of photodynamic therapy and radiofrequency ablation for extrahepatic cholangiocarcinoma, with a special focus on their combination with chemotherapy.

A Review on Endoscopic Ultrasound-Guided Radiofrequency Ablation (EUS-RFA) of Pancreatic Lesions

The morbidity associated with pancreatectomies limits surgical options for high-risk patients with pancreatic neoplasms that warrant resection. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) offers a minimally invasive and potentially definitive means to treat pancreatic neuroendocrine tumors and precancerous pancreatic cystic lesions. In addition, EUS-RFA may play a role in the treatment and palliation of non-surgical cases of pancreatic adenocarcinoma. The efficacy of RFA appears to be further enhanced by systemic immunomodulatory effects. Here, we review current studies on the developing role of EUS-RFA in these pancreatic pathologies.

Dynamic Changes of Cytokine Profiles and Their Correlation With Tumor Recurrence Following Thermal Ablation in Hepatocellular Carcinoma

The 5-year recurrence rate of thermal ablation for hepatocellular carcinoma (HCC) is high, and whether this treatment strategy induces systemic immune response remains elusive. This study aimed to investigate the effects of thermal ablation on HCC patients' cytokine profiles and to explore the correlation of cytokine profiles with tumor recurrence after ablation. A total of 22 HCC patients were included in this prospective study. The levels of 27 cytokines in the peripheral blood of HCC patients were measured before ablation (baseline), week 1, and week 4 after ablation using a Bio-Plex Pro Human Cytokine 27-plex Assay kit. Cytokines showed different dynamic changing trends after ablation treatment. It was found that the level of IL-6 was significantly elevated at week 1 and returned to the baseline level at week 4 after ablation. The level of IL-10 was slightly reduced at week 1 and significantly decreased at week 4. The levels of MCP-1, macrophage inflammatory protein-1β (MIP-1β), and TNF-α were similarly reduced at week 1 and increased at week 4. The levels of IL-17, platelet-derived growth factor-BB (PDGF-BB), and regulated upon activation, normal T cell expressed and secreted (RANTES) showed little to no change at week 1 while an observable increase at week 4. Patients with a high IL-10 level (2.99 pg/ml) at baseline and low levels of TNF-α (20.4 pg/ml), PDGF-BB (107.78 pg/ml), and RANTES (2303.94 pg/ml) at week 4 were at risk of tumor recurrence during 1-year follow-up. The results suggested that thermal ablation activated systemic immune responses by changing the levels of cytokines. The results also demonstrated that measurement of IL-10 at baseline, TNF-α, PDGF-BB, and RANTES at week 4 after ablation might predict the risk of tumor recurrence.

Characteristics and postoperative dynamic changes in circulating CD4+ helper T lymphocytes in patients with breast cancer

Introduction

Circulating CD4⁺ helper T cell (Th) subsets provide potentially important information on disease progression in several cancers. In this study, we explored the characteristics and postoperative dynamic changes in circulating CD4⁺Th subsets in patients with breast cancer.

Methods

Circulating CD4⁺Th subsets, including CD4⁺ naive T cells (Tn), CD4⁺ central memory T cells (Tcm), CD4⁺ effector memory T cells (Tem), CD4⁺CD57⁺T, and CD4⁺PD-1⁺T, were detected with multiparameter flow cytometry. T-test and Wilcoxon rank-sum test were used to compare differences between groups for normally and non-normally distributed continuous variables, respectively. Postoperative dynamic changes in CD4⁺Th subsets were assessed using the paired-sample rank-sum test.

Results

Seventy-five patients with invasive breast cancer and fifty-three patients with benign breast tumors were enrolled. Compared with that in patients with benign tumors, the proportion of CD4⁺Tn in patients with breast cancer patients decreased, whereas the proportion and absolute number of CD4⁺CD57⁺T and CD4⁺PD-1⁺T increased. Moreover, the proportion of CD4⁺PD-1⁺T was correlated with the clinicopathology of breast cancer. After tumor resection, the proportion and absolute number of CD4⁺Tcm significantly decreased, while those of CD4⁺Tem significantly increased, compared with preoperative values. Tumor resection caused significant changes in the proportion and absolute number of CD4⁺CD57⁺T and CD4⁺PD-1⁺ T, both of which showed significant decreases.

Discussion

We found significant changes in circulating CD4⁺Th subsets in patients with breast cancer. Additionally, complete tumor resection can benefit the patient as it balances the patient's immunosuppression and immune stress and improves the immune exhaustion and immunosenescence states.

Thermal ablation in pancreatic cancer: A scoping review of clinical studies

BACKGROUND

Pancreatic cancer is a deadly cancer with a 5-year survival rate less than 10%. Only 20% of patients are eligible to receive surgery at diagnosis. Hence, new therapies are needed to improve outcomes for non-surgical candidates. Thermal ablation techniques can offer a non-invasive alternative to surgery.

AIM

The aim of this review is to map the literature for the use of thermal ablative techniques: Radiofrequency ablation (RFA), High-intensity focused ultrasound (HIFU), Microwave ablation (MWA), and Laser ablation (LA) in the management of patients with PC.

METHODS

A search strategy was applied to PUBMED and EMBASE using keywords concerning pancreatic cancer, radiofrequency ablation, ultrasound ablation, laser ablation, and microwave ablation. The studies that fit this inclusion criteria were summarized in table format and results reviewed for interpretation.

RESULTS

72 clinical studies were included. Most of the included studies related to RFA (n=35) and HIFU (n=27). The most common study design was retrospective (n=33). Only 3 randomized control trials (RCT) were included, all of which related to RFA. Safety outcomes were reported in 53 of the 72 studies, and survival outcomes were reported in 39. Statistically significant survival benefits were demonstrated in 11 studies.

CONCLUSION

The evidence for the benefit of MWA and LA in PC patients is limited. RFA and HIFU are safe and feasible therapies to be used in PC patients. Further RCTs where thermal techniques are standardized and reported are necessary in the future to elucidate thermal ablation's clinical utility, and before an evidence-based decision on its routine use in PC management can be considered.

Endobiliary Radiofrequency Ablation Using a Short-Type Balloon Enteroscope in Patients with Surgically Altered Anatomy

BACKGROUND

Endoscopic radiofrequency ablation (RFA) is expected to prolong stent patency for malignant biliary obstruction (MBO). However, its feasibility when used in conjunction with a balloon enteroscope (BE) in patients with surgically altered anatomy (SAA) remains unknown.

AIMS

This study aimed to investigate the feasibility of RFA combined with metal stent insertion under BE guidance for MBO in patients with SAA.

METHODS

Thirty-seven patients who underwent treatment between October 2016 and January 2021 and met the eligibility criteria were investigated retrospectively. Study outcomes included technical and clinical success, recurrent biliary obstruction (RBO), and other adverse events besides RBO associated with RFA with metal stent placement using BE.

RESULTS

Technical and clinical success rates were 100% (37/37) each. The rates of early and late adverse events were 8.1% (3/37) and 8.1% (3/37), respectively. RBO occurred in 32.4% (12/37) of the patients, and the median time to RBO was 296 days. The cause of RBO was ingrowth in eight patients, overgrowth in three patients, and indeterminate in one patient. All reinterventions for RBO were successful using the BE approach; all ingrowths, except one, were recanalized using additional RFA without additional stent placement. The frequency of reintervention-related adverse events was 9.1% (1/11). The median time to RBO after reintervention was 166 days.

CONCLUSIONS

This study demonstrated the technical safety and feasibility as well as good long-term outcomes of endobiliary RFA combined with metal stent placement under BE guidance. This approach may be a useful option for treating MBO in patients with SAA.

Impact of Endoluminal Radiofrequency Ablation on Immunity in Pancreatic Cancer and Cholangiocarcinoma

Radiofrequency ablation (RFA) is a mini-invasive loco-regional ablation technique that is increasingly being used as a palliative treatment for pancreatic cancer and cholangiocarcinoma. Ablation-triggered immune system stimulation has been proposed as a mechanism behind the systemic effects of RFA. The aim of our study was to investigate the immune response to endoluminal biliary RFA. Peripheral blood samples were collected from patients with pancreatic cancer and cholangiocarcinoma randomised to receive endoluminal biliary radiofrequency ablation + stent (19 patients) or stent only (21 patients). We observed an early increase in IL-6 levels and a delayed increase in CXCL1, CXCL5, and CXCL11 levels as well as an increase in CD8+ and NK cells. However, these changes were not specific to RFA treatment. Explicitly in response to RFA, we observed a delayed increase in serum CXCL1 levels and an early decrease in the number of anti-inflammatory CD206+ blood monocytes. Our study provides the first evidence of endoluminal biliary RFA-based regulation of the systemic immune response in patients with pancreatic cancer and cholangiocarcinoma. These changes were characterised by a general inflammatory response. RFA-specific activation of the adaptive immune system was not confirmed.

Comparison of Intraductal RFA Plus Stent versus Stent-Only Treatment for Unresectable Perihilar Cholangiocarcinoma—A Systematic Review and Meta-Analysis

Simple Summary

In patients with unresectable perihilar cholangiocarcinoma, adequate biliary drainage is essential. Stent patency remains a challenge in these complex patients, as both plastic and metal stent occlusion may occur, necessitating additional drainage procedures. Radiofrequency ablation (RFA) is a promising local treatment that has already proven its usefulness in other malignancies, such as hepatocellular carcinoma. In this meta-analysis and systematic review, we aimed to compare intraductal RFA with stent placement to stent placement alone in patients with unresectable perihilar cholangiocarcinoma. We found that RFA + stent treatment showed a significantly longer overall survival, in comparison to stent-only treatment. Further research is necessary in order to validate these findings to support the implementation of this promising strategy in clinical practice.

Abstract

Background: One of the cornerstones of palliative treatment for unresectable perihilar cholangiocarcinoma is biliary stent placement in order to restore biliary drainage. In this review, the potential added value of RFA with stent placement in comparison to stent placement alone in patients with unresectable perihilar cholangiocarcinoma is analyzed. Methods: We performed a comprehensive online search for relevant articles in November 2021 (PROSPERO ID: CRD42021288180). The primary endpoint was difference in overall survival. Secondary endpoints included overall survival, stent patency and complications. Only studies comparing survival after RFA + stent placement with stent placement alone were included in the meta-analysis. Non-comparative studies or comparative studies describing stent patency only were included in the systematic review. Results: A total of nine studies, including 217 patients with pCCA who underwent RFA + stent placement and 294 patients who underwent stent-only treatment, met the inclusion criteria for the primary endpoint analysis. Direct comparison between the two treatment groups showed a significantly longer overall survival for RFA + stent treatment, with a pooled HR of 0.65 [95% CI, 0.50–0.84, I² = 38%]. When all eligible studies were included, RFA + stent treatment revealed an overall survival of 9.5 months [95% CI, 6.3–12.6], whereas survival for stent-only treatment was 7.0 months [95% CI, 5.7–8.2]. Due to the heterogeneity of the data, no pooled data analysis could be performed on stent patency or complications. Conclusions: RFA + stent placement displays promising potential to prolong survival. However, further research incorporating confounding factors like use of palliative chemotherapy is necessary in order to validate these findings.

Locoregional therapies and their effects on the tumoral microenvironment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second leading cause of death from cancer by 2030. Despite intensive research in the field of therapeutics, the 5-year overall survival is approximately 8%, with only 20% of patients eligible for surgery at the time of diagnosis. The tumoral microenvironment (TME) of the PDAC is one of the main causes for resistance to antitumoral treatments due to the presence of tumor vasculature, stroma, and a modified immune response. The TME of PDAC is characterized by high stiffness due to fibrosis, with hypo microvascular perfusion, along with an immunosuppressive environment that constitutes a barrier to effective antitumoral treatment. While systemic therapies often produce severe side effects that can alter patients' quality of life, locoregional therapies have gained attention since their action is localized to the pancreas and can thus alleviate some of the barriers to effective antitumoral treatment due to their physical effects. Local hyperthermia using radiofrequency ablation and radiation therapy - most commonly using a local high single dose - are the two main modalities holding promise for clinical efficacy. Recently, irreversible electroporation and focused ultrasound-derived cavitation have gained increasing attention. To date, most of the data are limited to preclinical studies, but ongoing clinical trials may help better define the role of these locoregional therapies in the management of PDAC patients.

Local Ablative Therapy Associated with Immunotherapy in Locally Advanced Pancreatic Cancer: A Solution to Overcome the Double Trouble?-A Comprehensive Review

Pancreatic ductal adenocarcinoma (PDAC) remains a major killer and is a challenging clinical research issue with abysmal survival due to unsatisfactory therapeutic efficacy. Two major issues thwart the treatment of locally advanced nonresectable pancreatic cancer (LAPC): high micrometastasis rate and surgical inaccessibility. Local ablative therapies induce a systemic antitumor response (i.e., abscopal effect) in addition to local effects. Thus, the incorporation of additional therapies could be key to improving immunotherapy's clinical efficacy. In this systematic review, we explore recent applications of local ablative therapies combined with immunotherapy to overcome immune resistance in PDAC and discuss future perspectives and challenges. Particularly, we describe four chemoradiation studies and nine reports on irreversible electroporation (IRE). Clinically, IRE is the ablative therapy of choice, utilized in all but two clinical trials, and may create a favorable microenvironment for immunotherapy. Various immunotherapies have been used in combination with IRE, such as NK cell- or γδ T cell-based therapy, as well as immune checkpoint inhibitors. The results of the clinical trials presented in this review and the advancement potential of these therapies to phase II/III trials remain unknown. A multiple treatment approach involving chemotherapy, local ablation, and immunotherapy holds promise in overcoming the double trouble of LAPC.

Endobiliary Radiofrequency Ablation Combined with Gemcitabine and Cisplatin in Patients with Unresectable Extrahepatic Cholangiocarcinoma

Background: Endobiliary radiofrequency ablation (RFA) is a promising treatment modality for patients with extrahepatic cholangiocarcinoma (eCCA). However, no study has investigated the combined use of endobiliary RFA and gemcitabine plus cisplatin (GC) chemotherapy. This study aimed to examine the feasibility and efficacy of endobiliary RFA with GC therapy for patients with unresectable eCCA. Methods: The study outcomes included overall survival (OS), progression-free survival (PFS), time to recurrent biliary obstruction (RBO), and adverse events associated with the treatment. These parameters were retrospectively compared between 25 patients who underwent RFA with self-expandable metal stent (SEMS) placement followed by GC therapy (with-RFA group) and a control cohort of 25 patients who underwent SEMS placement alone and GC therapy (without-RFA group). Results: The median time to RBO was significantly longer in the with-RFA group (10.7 versus 5.2 months, p = 0.048). The median OS was significantly higher in patients with locally advanced tumors in the with-RFA group (23.1 versus 16.6 months, p = 0.032), but did not differ significantly in patients with metastasis (11.4 versus 8.5 months, p = 0.180). Similarly, the median PFS was significantly higher in the with-RFA group in patients with locally advanced disease (10.1 versus 7.3 months, p = 0.015), while there was no significant difference in patients with metastasis (5.4 versus 4.4 months, p = 0.529). The rates of various toxicities did not differ significantly between the groups. Conclusions: Endobiliary RFA prolonged the patency period of uncovered SEMS combined with GC therapy in patients with eCCA. Although RFA also yielded survival benefits, its effect was restricted to locally advanced tumors.

An update on EUS-guided ablative techniques for pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are increasingly being recognized due to improvements and widespread use of cross-sectional imaging. With an estimated prevalence of 15% in general population, incidentally discovered PCLs represent a dilemma in management. While pancreatectomies offer a chance of cure, the morbidity is considerable in patients with high surgical risks. More recently, EUS-guided approaches for cyst ablation are being offered in clinical trials for the management of PCLs. EUS-chemoablation studies have progressed from first investigating safety and efficacy of EUS-guided alcohol lavage to single-agent paclitaxel ablation. Recent studies have shown that alcohol lavage may not be required, and long-term resolution can be achieved by chemoablation alone. EUS-guided lauromacrogol ablation and EUS-guided radiofrequency ablation (RFA) are new techniques that have shown promising results in a few small studies. Overall, the current literature suggests that EUS-guided paclitaxel ablation has better cyst resolution rates compared to other existing minimally invasive techniques including ethanol injection, lauromacrogol ablation, or RFA. This article will review EUS-guided PCL ablation approaches and future directions the field is headed into.

Updated evidence on the clinical impact of endoscopic radiofrequency ablation in the treatment of malignant biliary obstruction

Endoscopic biliary radiofrequency ablation (RFA) was recently developed as a novel adjunctive procedure and a promising therapeutic option in patients with malignant biliary obstruction (MBO). RFA can achieve local tumor control, resulting in improved biliary stent patency and a potential survival benefit. However, the efficacy of biliary RFA remains controversial, and previous studies have shown conflicting results. At present, extrahepatic cholangiocarcinoma is considered the condition most effectively treated by biliary RFA, but there is limited research even on this point. Further, limitations of RFA associated with the devices used during the procedure are an important subject of discussion. In addition to further well-designed clinical trials, development of innovative devices is warranted to investigate and conclusively establish the usefulness of biliary RFA. In this review we summarize the updated evidence regarding the use of endoscopic biliary RFA for MBO and discuss issues that should be addressed in future studies.

Role of endoscopic ultrasound in anticancer therapy: Current evidence and future perspectives

The digestive system is one of the most common sites of malignancies in humans. Since gastrointestinal tumors represent a massive global health burden both in terms of morbidity and health care expenditures, scientists continuously develop novel diagnostic and therapeutic methods to ameliorate the detrimental effects of this group of diseases. Apart from the well-established role of the endoscopic ultrasound (EUS) in the diagnostic course of gastrointestinal and hepatobiliary malignancies, we have recently become acquainted with a vast array of its therapeutic possibilities. A multitude of previously established, evidence-based methods that might now be guided by the EUS emerged: Radiofrequency ablation, brachytherapy, fine needle injection, celiac plexus neurolysis, and endoscopic submucosal dissection. In this review we endeavored to provide a comprehensive overview of the role of these methods in different malignancies of the digestive system, primarily in the treatment and symptom control in pancreatic cancer, and additionally in the management of hepatic, gastrointestinal tumors, and pancreatic cysts.

Modulation of the Human Pancreatic Ductal Adenocarcinoma Immune Microenvironment by Stereotactic Body Radiotherapy

PURPOSE

Stereotactic body radiotherapy (SBRT) is an emerging treatment modality for pancreatic ductal adenocarcinoma (PDAC), which can effectively prime cytotoxic T cells by inducing immunogenic tumor cell death in preclinical models. SBRT effects on human PDAC have yet to be thoroughly investigated; therefore, this study aimed to characterize immunomodulation in the human PDAC tumor microenvironment following therapy.

EXPERIMENTAL DESIGN

Tumor samples were obtained from patients with resectable PDAC. Radiotherapy was delivered a median of 7 days prior to surgical resection, and sections were analyzed by multiplex IHC (mIHC), RNA sequencing, and T-cell receptor sequencing (TCR-seq).

RESULTS

Analysis of SBRT-treated tumor tissue indicated reduced tumor cell density and increased immunogenic cell death relative to untreated controls. Radiotherapy promoted collagen deposition; however, vasculature was unaffected and spatial analyses lacked evidence of T-cell sequestration. Conversely, SBRT resulted in fewer tertiary lymphoid structures and failed to lessen or reprogram abundant immune suppressor populations. Higher percentages of PD-1⁺ T cells were observed following SBRT, and a subset of tumors displayed more clonal T-cell repertoires.

CONCLUSIONS

These findings suggest that SBRT augmentation of antitumor immunogenicity may be dampened by an overabundance of refractory immunosuppressive populations, and support the continued development of SBRT/immunotherapy combination for human PDAC.

Open radiofrequency ablation as upfront treatment for locally advanced pancreatic cancer: Requiem from a randomized controlled trial

BACKGROUND

Local ablation of pancreatic cancer has been suggested as an option to manage locally advanced pancreatic cancer (LAPC) although no robust evidence has been published to date to support its application. The aim of this study is to compare overall survival (OS) and progression-free survival (PFS) in patients receiving both radiofrequency ablation (RFA) and conventional chemoradiotherapy (CHRT) with patients receiving CHRT only.

METHODS

This is a multicentre prospective randomized controlled trial (RCT). Patients with LAPC diagnosed by the Pancreas-Ablation-Team-Verona were randomly assigned to open RFA (Group A) or CHRT (Group B). Survival analyses were performed using the Kaplan-Meier method and compared using the log-rank test. Statistical significance was set at p < 0.05.

RESULTS

One hundred LAPC patients were enrolled from January 2014 to August 2016. 33% of patients in Group A did not receive the designated procedure because of intraoperative findings of liver (18.7%) or peritoneal metastases (43.8%), or technical contraindications (37.5%). We did not observe any statistically significant survival benefit from RFA compared to CHRT, neither in terms of OS (medians of 14.2 months and 18.1 months, respectively, p = 0.639) nor PFS (medians of 8 months and 6 months respectively, p = 0.570). Mortality was nil and RFA-related morbidity was 15.6%. In 13% of subjects, conversion to surgery occurred (2 after RFA and 11 after CHRT).

CONCLUSIONS

This is the first RCT evaluating the impact of upfront RFA in the multimodal treatment of LAPC. Compared to CHRT, RFA alone did not provide any advantage in terms of OS or PFS. It could be considered as a therapeutic option for LAPC within a multimodal context and after neoadjuvant therapies.

Minimally invasive image-guided therapy of primary and metastatic pancreatic cancer

Pancreatic cancer is a challenging malignancy with limited treatment options and poor life expectancy. The only curative option is surgical resection, but only 15%-20% of patients are resectable at presentation because more than 50% of patients has distant metastasis at diagnosis and the rest of them has locally advanced pancreatic cancer (LAPC). The standard of care first line treatment for LAPC patients is chemotherapy with or without radiation therapy. Recent developments in minimally invasive ablative techniques may add to the treatment armamentarium of LAPC. There are increasing number of studies evaluating these novel ablative techniques, including radiofrequency ablation, microwave ablation, cryoablation and irreversible electroporation. Most studies which included pancreatic tumor ablation, demonstrated improved overall survival in LAPC patients. However, the exact protocols are yet to set up to which stage of the treatment algorithm ablative techniques can be added and in what kind of treatment combinations. Patients with metastatic pancreatic cancer has dismal prognosis with 5-year survival is only 3%. The most common metastatic site is the liver as 90% of pancreatic cancer patients develop liver metastasis. Chemotherapy is the primary treatment option for patients with metastatic pancreatic cancer. However, when the tumor is not responding to chemotherapy or severe drug toxicity develops, locoregional liver-directed therapies can provide an opportunity to control intrahepatic disease progression and improve survival in selected patients. During the last decade new therapeutic options arose with the advancement of minimally invasive technologies to treat pancreatic cancer patients. These new therapies have been a topic of increasing interest due to the severe prognostic implications of locally advanced and metastatic pancreatic cancer and the low comorbid risk of these procedures. This review summarizes new ablative options for patients with LAPC and percutaneous liver-directed therapies for patients with liver-dominant metastatic disease.

Endoscopic radiofrequency ablation plus plastic stent placement versus stent placement alone for unresectable extrahepatic biliary cancer: a multicenter randomized controlled trial

BACKGROUND AND AIMS

We sought to compare the efficacy and safety between endoscopic radiofrequency ablation (RFA) and stent placement alone in patients with unresectable extrahepatic biliary cancer (EBC).

METHODS

In this randomized controlled trial, patients with locally advanced or metastatic cholangiocarcinoma (CCA) or ampullary cancer who were unsuitable for surgery were recruited from 3 tertiary centers. Eligible patients were randomly assigned to RFA plus plastic stent placement (RFA group) or plastic stent placement alone (stent placement alone group) in a 1:1 ratio. Both groups underwent 2 scheduled interventions with an interval of approximately 3 months. The primary outcome was overall survival (OS).

RESULTS

Altogether, 174 participants completed the 2 index endoscopic interventions. No significant differences in baseline characteristics were noted between the 2 groups. The median OS was significantly higher in the RFA group (14.3 vs 9.2 months; hazard ratio, .488; 95% confidence interval, .351-.678; P < .001). A survival benefit was also shown in patients with CCA (13.3 vs 9.2 months; hazard ratio, .546; 95% confidence interval, .386-.771; P < .001). However, no significant between-group differences were found in jaundice control or stent patency duration. The postprocedural Karnofsky performance scores were significantly higher in the RFA group until 9 months (all P < .001). Adverse events were comparable between the 2 groups (27.6% vs 19.5%, P = .211), except for acute cholecystitis, which was more frequently observed in the RFA group (9 vs 0, P = .003).

CONCLUSIONS

Compared with stent placement alone, additional RFA may improve OS and quality of life of patients with inoperable primary EBC who do not undergo systemic treatments. (Clinical trial registration number: NCT01844245.).

Local ablation of pancreatic tumors: State of the art and future perspectives

BACKGROUND

Currently, the technologies most commonly used to treat locally advanced pancreatic cancer are radiofrequency ablation (RFA), microwave ablation, and irreversible (IRE) or reversible electroporation combined with low doses of chemotherapeutic drugs.

AIM

To report an overview and updates on ablative techniques in pancreatic cancer.

METHODS

Several electronic databases were searched. The search covered the years from January 2000 to January 2021. Moreover, the reference lists of the found papers were analysed for papers not indexed in the electronic databases. All titles and abstracts were analysed.

RESULTS

We found 30 studies (14 studies for RFA, 3 for microwave therapy, 10 for IRE, and 3 for electrochemotherapy), comprising 1047 patients, which were analysed further. Two randomized trials were found for IRE. Percutaneous and laparotomy approaches were performed. In the assessed patients, the median maximal diameter of the lesions was in the range of 2.8 to 4.5 cm. All series included patients unfit for surgical treatment, but Martin et al assessed a subgroup of patients with borderline resectable tumours who underwent resection with margin attenuation with IRE. Most studies administered chemotherapy prior to ablative therapies. However, several studies suggest that the key determinant of improved survival is attributable to ablative treatment alone. Nevertheless, the authors suggested chemotherapy before local therapies for several reasons. This strategy may not only downstage a subgroup of patients to curative-intent surgery but also support to recognize patients with biologically unfavourable tumours who would likely not benefit from ablation treatments. Ablation therapies seem safe based on the 1047 patients assessed in this review. The mortality rate ranged from 1.8% to 2%. However, despite the low mortality, the reported rates of severe post procedural complications ranged from 0%-42%. Most reported complications have been self-limiting and manageable. Median overall survival varied between 6.0 and 33 mo. Regarding the technical success rate, assessed papers reported an estimated rate in the range of 85% to 100%. However, the authors reported early recurrence after treatment. A distinct consideration should be made on whether local treatments induce an immune response in the ablated area. Preclinical and clinical studies have shown that RFA is a promising mechanism for inducing antigen-presenting cell infiltration and enhancing the systemic antitumour T-cell immune response and tumour regression.

CONCLUSION

In the management of patients with pancreatic cancer, the possibility of a multimodal approach should be considered, and conceptually, the combination of RFA with immunotherapy represents a novel angle of attack against this tumour.

Locally Advanced Pancreatic Cancer: Percutaneous Management Using Ablation, Brachytherapy, Intra-arterial Chemotherapy, and Intra-tumoral Immunotherapy

PURPOSE OF REVIEW

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplasms, bearing a terrible prognosis. Stage III tumors, also known as locally advanced pancreatic cancer (LAPC), are unresectable, and current palliative chemotherapy regimens have only modestly improved survival in these patients. At this stage of disease, interventional techniques may be of value and further prolong life. The aim of this review was to explore current literature on locoregional percutaneous management for LAPC.

RECENT FINDINGS

Locoregional percutaneous interventional techniques such as ablation, brachytherapy, and intra-arterial chemotherapy possess cytoreductive abilities and have the potential to increase survival. In addition, recent research demonstrates the immunomodulatory capacities of these treatments. This immune response may be leveraged by combining the interventional techniques with intra-tumoral immunotherapy, possibly creating a durable anti-tumor effect. This multimodality treatment approach is currently being examined in several ongoing clinical trials. The use of certain interventional techniques appears to improve survival in LAPC patients and may work synergistically when combined with immunotherapy. However, definitive conclusions can only be made when large prospective (randomized controlled) trials confirm these results.

Multiple Endocrine Neoplasia Type 1: Latest Insights

Multiple endocrine neoplasia type 1 (MEN1), a rare tumor syndrome that is inherited in an autosomal dominant pattern, is continuing to raise great interest for endocrinology, gastroenterology, surgery, radiology, genetics, and molecular biology specialists. There have been 2 major clinical practice guidance papers published in the past 2 decades, with the most recent published 8 years ago. Since then, several new insights on the basic biology and clinical features of MEN1 have appeared in the literature, and those data are discussed in this review. The genetic and molecular interactions of the MEN1-encoded protein menin with transcription factors and chromatin-modifying proteins in cell signaling pathways mediated by transforming growth factor β/bone morphogenetic protein, a few nuclear receptors, Wnt/β-catenin, and Hedgehog, and preclinical studies in mouse models have facilitated the understanding of the pathogenesis of MEN1-associated tumors and potential pharmacological interventions. The advancements in genetic diagnosis have offered a chance to recognize MEN1-related conditions in germline MEN1 mutation-negative patients. There is rapidly accumulating knowledge about clinical presentation in children, adolescents, and pregnancy that is translatable into the management of these very fragile patients. The discoveries about the genetic and molecular signatures of sporadic neuroendocrine tumors support the development of clinical trials with novel targeted therapies, along with advancements in diagnostic tools and surgical approaches. Finally, quality of life studies in patients affected by MEN1 and related conditions represent an effort necessary to develop a pharmacoeconomic interpretation of the problem. Because advances are being made both broadly and in focused areas, this timely review presents and discusses those studies collectively.

Potential Mechanisms of Triptolide against Diabetic Cardiomyopathy Based on Network Pharmacology Analysis and Molecular Docking

The incidence of heart failure was significantly increased in patients with diabetic cardiomyopathy (DCM). The therapeutic effect of triptolide on DCM has been reported, but the underlying mechanisms remain to be elucidated. This study is aimed at investigating the potential targets of triptolide as a therapeutic strategy for DCM using a network pharmacology approach. Triptolide and its targets were identified by the Traditional Chinese Medicine Systems Pharmacology database. DCM-associated protein targets were identified using the comparative toxicogenomics database and the GeneCards database. The networks of triptolide-target genes and DCM-associated target genes were created by Cytoscape. The common targets and enriched pathways were identified by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The gene-gene interaction network was analyzed by the GeneMANIA database. The drug-target-pathway network was constructed by Cytoscape. Six candidate protein targets were identified in both triptolide target network and DCM-associated network: STAT3, VEGFA, FOS, TNF, TP53, and TGFB1. The gene-gene interaction based on the targets of triptolide in DCM revealed the interaction of these targets. Additionally, five key targets that were linked to more than three genes were determined as crucial genes. The GO analysis identified 10 biological processes, 2 cellular components, and 10 molecular functions. The KEGG analysis identified 10 signaling pathways. The docking analysis showed that triptolide fits in the binding pockets of all six candidate targets. In conclusion, the present study explored the potential targets and signaling pathways of triptolide as a treatment for DCM. These results illustrate the mechanism of action of triptolide as an anti-DCM agent and contribute to a better understanding of triptolide as a transcriptional regulator of cytokine mRNA expression.

Assessment of Ablation Therapy in Pancreatic Cancer: The Radiologist's Challenge

This article provides an overview of imaging assessment of ablated pancreatic cancer. Only studies reporting radiological assessment on pancreatic ablated cancer were retained. We found 16 clinical studies that satisfied the inclusion criteria. Radiofrequency ablation and irreversible electroporation have become established treatment modalities because of their efficacy, low complication rates, and availability. Microwave Ablation (MWA) has several advantages over radiofrequency ablation (RFA), which may make it more attractive to treat pancreatic cancer. Electrochemotherapy (ECT) is a very interesting emerging technique, characterized by low complication rate and safety profile. According to the literature, the assessment of the effectiveness of ablative therapies is difficult by means of the Response Evaluation Criteria in Solid Tumors (RECIST) criteria that are not suitable to evaluate the treatment response considering that are related to technique used, the timing of reassessment, and the imaging procedure being used to evaluate the efficacy. RFA causes various appearances on imaging in the ablated zone, correlating to the different effects, such as interstitial edema, hemorrhage, carbonization, necrosis, and fibrosis. Irreversible electroporation (IRE) causes the creation of pores within the cell membrane causing cell death. Experimental studies showed that Diffusion Weigthed Imaging (DWI) extracted parameters could be used to detect therapy effects. No data about functional assessment post MWA is available in literature. Morphologic data extracted by Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) do not allow to differentiate partial, complete, or incomplete response after ECT conversely to functional parameters, obtained with Position Emission Tomography (PET), MRI, and CT.

Immunological combination treatment holds the key to improving survival in pancreatic cancer

Advances in surgery, peri-operative care and systemic chemotherapy have not significantly improved the prognosis of pancreatic cancer for several decades. Early clinical trials of immunotherapy have yielded disappointing results proposing other means by which the tumour microenvironment serves to decrease the immune response. Additionally, the emergence of various subtypes of pancreatic cancer has emerged as a factor for treatment responses with immunogenic subtypes carrying a better prognosis. Herein we discuss the reasons for the poor response to checkpoint inhibitors and outline a rationale why combination treatments are likely to be most effective. We review the therapies which could provide optimal synergistic effects to immunotherapy including chemotherapy, agents targeting the stroma, co-stimulatory molecules, vaccinations and methods of immunogenic tumour priming including radiofrequency ablation. Finally, we discuss reasons why peri-operative and in particular neoadjuvant combination treatments are likely to be most effective and should be considered for early clinical trials.

Standardization of a Radiofrequency Ablation Tool in an Ex-Vivo Porcine Liver Model

(1) Background: Preclinical and clinical data about a novel radiofrequency ablation (RFA) system (STARmed Co, Ltd.; Koyang, Korea) designed to be used under endoscopic ultrasound (EUS) control for pancreatic lesion ablation, are limited, obtained with non-standardized procedures and heterogeneous results. The aim of this study is to standardize the RFA procedure of this system in order to define the optimal ablation power and time. (2) Methods: RFA was performed on an ex-vivo porcine liver at different powers (40, 30, 20, 10 Watts (W)) and times (1, 3, 5, 7, 15 min) with a 1-centimeter monopolar electrode (perfused by chilled solution) positioned on the distal tip of a 19-Gauge needle. A blinded expert pathologist histologically analyzed each ablation area. (3) Results: The size of the total macroscopic ablated area was negatively correlated with ablation power (R −0.74): the largest was obtained at 10 W (p = 4.7 × 10−4) for longer times (R 0.92; p = 8.9 × 10−8). Central histologic coagulative necrosis did not differ among ablation settings (mean size 3.25 mm). External “parenchymal hypochromia” or “diaphanization” resulted the widest at 10 W, for longer times (R 0.8, p = 3.6 × 10−4). (4) Conclusions: The RFA system can produce small sizes of coagulative necrosis, regardless of the setting. Larger areas of diaphanization surrounding the necrosis can be produced at lower powers for longer times.

Endosonography-guided Radiofrequency Ablation in Pancreatic Diseases: Time to Fill the Gap Between Evidence and Enthusiasm

Over the past 20 years, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has generated interest as a novel minimally invasive tool in the multimodal treatment of pancreatic malignant and premalignant lesions. However, although optimization of probes and settings has made EUS-RFA relatively safe, questions on the ideal positioning of this treatment in a multimodal strategy remain unanswered. This review will summarize the technical aspects of EUS-RFA and available clinical experiences for each pancreatic indication (pancreatic cancer, neuroendocrine neoplasms, cystic lesions, and celiac ganglia neurolysis). Established indications will be discussed along those requiring additional clinical data or even proof-of-concept studies. A dedicated session will further discuss evidence expected to emerge from ongoing registered trials, together with issues that must be addressed in future research, including the possible combination with immunotherapy, and the personalization of this treatment on the basis of genetic profiling. Despite the great clinical enthusiasm and scientific fervor, while evidence-based answers are produced, EUS-RFA must be centralized in high-volume centers of recognized expertise, where multidisciplinary discussions of indications and actively recruiting research protocols are available.

Immune response activation following hyperthermic intraperitoneal chemotherapy for peritoneal metastases: A pilot study

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal metastases (PM) is considered to be feasible, safe and to improve survival.

AIM

To investigate whether an immune response is activated following HIPEC for PM.

METHODS

Six patients were enrolled in this study. Peripheral blood samples were obtained from each patient prior to (day 0) and post-procedure (day 30), and used to evaluate the number of CD3⁺ total, CD3⁺/CD4⁺ T-Helper, CD3⁺/CD8⁺ cytotoxic T, CD3⁺/CD56⁺ natural killer and CD19⁺ B lymphocyte numbers, and CD4⁺: CD8⁺ T lymphocyte ratios.

RESULTS

The total numbers of CD3⁺, CD3⁺/CD4⁺ T-Helper, CD3⁺/CD8⁺ cytotoxic T, CD3⁺/CD56⁺ natural killer and CD19⁺ B lymphocytes, and CD4⁺: CD8⁺ lymphocyte ratios were increased in all but one patient 30 d following the cytoreductive surgery-HIPEC procedure, and these increases were significant (P ≤ 0.05) for CD3⁺/CD4⁺ T Helper and CD3⁺/CD8⁺ cytotoxic T lymphocyte numbers.

CONCLUSION

This report provides the first evidence that HIPEC exhibits immunomodulating activity in PM patients, resulting in generalized activation of the adaptive immune response. Moreover, the majority of lymphocyte populations increased following HIPEC and continued to be elevated several weeks following the procedure, consistent with a potential authentic immunomodulating effect rather than a normal inflammatory response, to be fully characterised in future studies.

Efficacy and safety of palliative endobiliary radiofrequency ablation using a novel temperature-controlled catheter for malignant biliary stricture: a single-center prospective randomized phase II TRIAL

BACKGROUND

Endobiliary radiofrequency ablation (EB-RFA) has emerged as a palliative treatment for malignant biliary strictures (MBSs); however, concerns about complications related to thermal injury remain. In this study, we evaluated the efficacy and safety of EB-RFA with a novel catheter for MBS.

METHODS

Patients with inoperable cancer causing MBS were randomly assigned to either the radiofrequency ablation (RFA) group or the non-RFA group. The RFA group underwent EB-RFA at the stricture site with a temperature-controlled catheter (ELRA™; STARmed Co., Goyang, Korea) followed by deployment of a self-expanding metal stent (SEMS). For the non-RFA group, only SEMS placement was performed. The duration of stent patency, overall survival (OS), and 30-day complication rate were evaluated. This trial was registered at ClinicalTrials.gov (number NCT02646514).

RESULTS

A total of 48 patients were enrolled (24 in each group). During a median follow-up period of 135.0 days (RFA group) and 119.5 days (non-RFA group), the 90-day stent patency rate, median duration of stent patency, and median OS were not different between the groups (58.3% vs. 45.8% [P = 0.386], 132.0 days vs. 116.0 days [P = 0.440], and 244.0 days vs. 180.0 days [P = 0.281], respectively). In the RFA group, procedure-related complications including thermal injury-related complications, such as bile duct perforation or hemobilia, were not reported. The early complication (< 7 days) rates were not different between the groups (4.2% vs. 12.5%, P = 0.609), and there were no late complications (7-30 days) in both groups.

CONCLUSION

EB-RFA with a temperature-controlled catheter followed by SEMS placement for patients with inoperable MBS can be safe and feasible with acceptable biliary patency.

Endoscopic Ultrasound-Guided Treatment of Pancreatic Cancer

PURPOSE OF REVIEW

The aim of this review is to evaluate the emerging role of endoscopic ultrasound (EUS) in the guidance of tumor-targeted therapies for patients with pancreatic cancer (PC).

RECENT FINDINGS

EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described to date. EUS-guided fiducial placement for SBRT in pancreatic cancer has entered the clinical practice and is performed at many centers clinically without a research protocol. EUS-guided brachytherapy and RFA have been shown to be feasible and safe procedures, and potentially offer local disease control. Other potential techniques of EUS-guided treatment of pancreatic cancer are still considered experimental, with many of them appearing to be safe and reasonably well tolerated. However, their effectiveness and exact role in oncological treatment have yet to be established. Clinical trials with many of the techniques/agents described are underway and multicentric randomized trials with prospective design are eagerly awaited.

Safety of radiofrequency ablation in patients with locally advanced, unresectable pancreatic cancer: A phase II study

INTRODUCTION

Radiofrequency ablation (RFA) has been proposed as a new treatment option for locally advanced, unresectable pancreatic cancer (LAPC). In preparation of a randomized controlled trial (RCT), the aim of this phase II study was to assess the safety of RFA for patients with LAPC.

MATERIALS AND METHODS

Patients diagnosed with LAPC confirmed during surgical exploration between November 2012 and April 2014 were eligible for inclusion. RFA probes were placed under ultrasound guidance with a safety margin of at least 10 mm from the duodenum and 15 mm from the portomesenteric vessels. During RFA, the duodenum was continuously perfused with cold saline to reduce risk for thermal damage. Primary outcome was defined as the amount of major complications (Clavien-Dindo grade ≥III). RFA-related complications were predefined as: pancreatic fistula, pancreatitis, thermal damage to the portomesenteric vessels and duodenal perforation.

RESULTS

In total, 17 patients underwent RFA. Delayed gastric emptying (DGE) requiring endoscopic feeding tube placement occurred in 4 patients (24%) as only major complication. Five patients (29%) had a major complication other than DGE. One (6%) RFA-related major complications occurred. One patient (6%) died due to complications from a biliary leak following hepaticojejunostomy. After evaluation of the first 5 patients, gastrojejunostomy was no longer performed routinely. Since then severe DGE seemed to occur less (3/5 vs. 3/12 grade C DGE).

CONCLUSION

RFA is a major, but safe procedure for patients with LAPC if performed with strict predefined safety criteria. A RCT is currently investigating the true effectiveness of RFA in patients with LAPC.

Hepatic progenitor cell activation is induced by the depletion of the gut microbiome in mice

The homeostasis of the gut microbiome is crucial for human health and for liver function. However, it has not been established whether the gut microbiome influence hepatic progenitor cells (HPCs). HPCs are capable of self‐renewal and differentiate into hepatocytes and cholangiocytes; however, HPCs are normally quiescent and are rare in adults. After sustained liver damage, a ductular reaction occurs, and the number of HPCs is substantially increased. Here, we administered five broad‐spectrum antibiotics for 14 days to deplete the gut microbiomes of male C57BL/6 mice, and we measured the plasma aminotransferases and other biochemical indices. The expression levels of two HPC markers, SRY‐related high mobility group‐box gene 9 (Sox9) and cytokeratin (CK), were also measured. The plasma aminotransferase activities were not affected, but the triglyceride, lactate dehydrogenase, low‐density lipoprotein, and high‐density lipoprotein concentrations were significantly altered; this suggests that liver function is affected by the composition of the gut microbiome. The mRNA expression of Sox9 was significantly higher in the treated mice than it was in the control mice (p < 0.0001), and a substantial expression of Sox9 and CK was observed around the bile ducts. The mRNA expression levels of proinflammatory factors (interleukin [IL]‐1β, IL‐6, tumor necrosis factor [TNF]‐α, and TNF‐like weak inducer of apoptosis [Tweak]) were also significantly higher in the antibiotic‐treated mice than the levels in the control mice. These data imply that the depletion of the gut microbiome leads to liver damage, negatively impacts the hepatic metabolism and function, and activates HPCs. However, the underlying mechanisms remain to be determined.

Immunomodulatory Effect after Irreversible Electroporation in Patients with Locally Advanced Pancreatic Cancer

Purpose

Irreversible electroporation (IRE) has been demonstrated to be a safe and effective method for locally advanced pancreatic cancer (LAPC). The aim of this study was to evaluate the immunomodulatory effect after IRE and to evaluate the prognostic value of variations of the immune parameters in LAPC patients after IRE.

Methods

Peripheral blood samples of 34 patients were obtained preoperatively and on the third day (D3) and seventh day (D7) after IRE, respectively. The phenotypes of lymphocytes were analyzed by flow cytometry, and dynamic changes of serum levels of cytokines, complement, and immunoglobulin were assayed by enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curve and concordance index (C-index) were used to compare the survival predictive ability.

Results

There was a transitory decrease followed by a steady increase for CD4⁺ T cell, CD8⁺ T cell, NK cell, IL-2, C3, C4, and IgG while a reverse trend was detected for Treg cell, IL-6, and IL10 after IRE. The alteration of CD8⁺ T cell between D3 and D7 was identified as a prognostic factor for both overall survival (OS) and progression-free survival (PFS). The values of ROC curve (AUC) and C-indexes of the alteration of CD8⁺ T cell for OS and PFS were 0.816 and 0.773 and 0.816 and 0.639, respectively, which were larger than those of other immune or inflammation-based indexes.

Conclusions

This study presented the first evidence of IRE-based immunomodulatory in patients with LAPC. The alteration of CD8⁺ T cell between D3 and D7 showed relatively good performance and could be used as an effective tool for prognostic evaluation for LAPC patients after IRE.

Ablation treatments in unresectable pancreatic cancer

Ablation treatments have been increasingly applied as an alternative treatment for unresectable locally advanced pancreatic cancer (LAPC). The goal of LAPC therapy is surgical resection with negative margins (R0); however, that can be achieved only in a minority of patients and only following neoadjuvant treatment. Ablation might be useful for those patients with unresectable LAPC that do not progress towards metastatic stage and do not experience a true downstaging. Indeed, some LAPC that tend to grow locally, might be the subgroup of tumors that could benefit from ablation. Experience is necessary to select patients and the technique to adopt, since serious or fatal complications can occur. This review aims to discuss the role of ablation treatments in LAPC, with a unique focus on radiofrequency ablation and irreversible electroporation.

Immunotherapy and pancreatic cancer: unique challenges and potential opportunities

Despite decades of research, pancreatic ductal adenocarcinoma (PDAC) continues to have the worst 5-year survival of any malignancy. With 338,000 new cases diagnosed and over 300,000 deaths per year globally there is an urgent unmet need to improve the therapeutic options available.

Novel immunotherapies have shown promising results across multiple solid tumours, in a number of cases surpassing chemotherapy as a first-line therapeutic option. However, to date, trials of single-agent immunotherapies in PDAC have been disappointing and PDAC has been labelled as a nonimmunogenic cancer. This lack of response may in part be attributed to PDAC’s unique tumour microenvironment (TME), consisting of a dense fibrotic stroma and a scarcity of tumour infiltrating lymphocytes. However, as our understanding of the PDAC TME evolves, it is becoming apparent that the problem is not simply the immune system failing to recognize the cancer. There is a highly complex interplay between stromal signals, the immune system and tumour cells, at times possibly restraining tumour growth and at others supporting growth and metastasis.

Understanding this complexity will enable the development of rational combinations with immunotherapy, priming the TME to offer immunotherapy the best chance of success. This review seeks to describe the unique challenges of the PDAC TME, the potential opportunities it may afford and the trials in progress capitalizing on recent insights in this area.