Systematic Review of Irreversible Electroporation Role in Management of Locally Advanced Pancreatic Cancer

Irreversible electroporation to bring initially unresectable locally advanced pancreatic adenocarcinoma to surgery: the IRECAP phase II study

OBJECTIVES

The aim of the IRECAP study was to evaluate the rate of locally advanced pancreas cancer patients (LAPC) who could undergo R0 or R1 surgery after irreversible electroporation (IRE).

MATERIALS AND METHODS

IRECAP study is a phase II, single-center, open-label, prospective, non-randomized trial registered at clinicaltrials.gov (NCT03105921). Patients with LAPC were first treated by 3-month neo-adjuvant chemotherapy in order to avoid inclusion of either patients with LAPC having become resectable after chemotherapy or patients with rapid disease progression. In cases of stable disease, IRE was performed percutaneously under CT guidance. Surgery was planned between 28 and 90 days after IRE. Tumor specimens were studied to evaluate the resection margins (R0/R1/R2).

RESULTS

Six men and 11 women were included (median age 61 years, range 37-77 years). No IRE-related death was observed. Ten patients (58%, 10/17) experienced 25 serious adverse events related to IRE. Four patients progressed between IRE and surgery and were excluded from surgery. Thirteen patients were finally operated, six withheld for pancreas resection, three for diffuse peritoneal carcinosis, two for massive vascular entrapment, and one for hepato-cellular carcinoma not diagnosed before surgery. Rate of R1-R0 was 35% (n = 6/17). Median overall survival was 31 months (95% CI; 4-undefined) for the six patients with R0/R1 resection and 21 months (95% CI; 4-25) for the 11 patients without resection or R2 resection (logrank p = 0.044).

CONCLUSION

After neoadjuvant chemotherapy, IRE could provide R0 or R1 resection in 35% of LAPC, which seems to be associated with higher OS.

CLINICAL RELEVANCE STATEMENT

After induction chemotherapy, stable locally advanced pancreatic cancers can be treated by irreversible electroporation, which could lead to a secondary 35% rate of R0 or R1 surgical resection which may be associated with a significantly higher overall survival.

KEY POINTS

• In cases of unresectable LAPC (locally advanced pancreatic cancer), percutaneous irreversible electroporation (pIRE) is feasible (100% success rate of the procedure), but is associated with a 58% rate of grade 3-4 adverse events. • In patients with unresectable LAPC, pIRE could lead 35% of patients to R0-R1 surgical resection. • From IRE, median overall survival was 31 months (95% CI; 4-undefined) for the patients with R0/R1 resection and 21 months (95% CI; 4-25) for the patients without resection or R2 resection (logrank p = 0.044).

Clinical efficacy and safety of irreversible electroporation combined with chemotherapy in stage IV pancreatic cancer treatment

PURPOSE

This study evaluates the clinical efficacy and safety of irreversible electroporation (IRE) therapy combined with chemotherapy in patients with stage IV pancreatic cancer.

METHODS

Between September 2021 and November 2023, we enrolled 38 patients with stage IV pancreatic cancer, with 20 receiving IRE plus chemotherapy and 18 receiving only chemotherapy. We recorded the general information of the patients and regularly followed up postoperative IRE-related adverse reactions. Progression-free survival (PFS) and overall survival (OS) were evaluated during follow-up.

RESULTS

Median OS was longer in the IRE group than in the chemotherapy group. Median PFS was slightly extended with IRE compared to chemotherapy alone. The mean hospital stay for the IRE group was 5.90 ± 0.75 days. Four serious adverse events occurred after IRE. Postoperative pain scores were significantly lower than preoperative scores.

CONCLUSION

IRE combined with chemotherapy showed clinical effectiveness in stage IV pancreatic cancer treatment, offering potential pain reduction benefits with fewer adverse effects and shorter hospital stays.

Efficacy and safety of irreversible electroporation in unresectable perihilar cholangiocarcinoma: a systematic review and meta-analysis

OBJECTIVES

The prognosis of patients with perihilar-cholangiocarcinoma (PHC) is poor, with the majority presenting with unresectable disease at diagnosis. Palliative chemotherapy (CHT) is the standard treatment for unresectable PHC. Irreversible electroporation (IRE) has been introduced as a novel ablation technique, working predominantly nonthermal. This review aims to analyse the efficacy and safety of IRE in treating unresectable PHC.

METHODS

This systematic review and meta-analysis was performed according to a specific protocol designed a priori, and reported according to the PRISMA. PubMed/MEDLINE, Scopus, and Cochrane CENTRAL were searched up to December 2023. Primary Outcome of interest of our meta-analysis was the mean Overall Survival (OS). Secondary outcomes were progression-free survival (PFS) and adverse event rate (AE).

RESULTS

The mean OS was estimated at 25.49 months (CI, 21.47-38.72, I2 81.37%), PFS 17.86 (CI, 13.00-22.72, I2 11.42%), with an AE incidence of 12% (CI, 7%-31%, I2 83.57%). High heterogeneity was found among studies, with no single study fully responsible for it, suggesting high variability among facilities/populations.

CONCLUSION

IRE is effective and relatively safe for unresectable PHC. However, the lack of prospective studies and randomized trials comparing chemotherapy or locoregional treatment with IRE prevents drawing sufficiently robust conclusions.

ADVANCES IN KNOWLEDGE

IRE appears a safe and effective technique for treating unresectable perihilar cholangiocarcinoma.

Successful immunotherapy with PD-1 Iinhibitor for advanced pancreatic cancer: report of two cases and review of literature

Pancreatic cancer is a highly malignant tumor, and most patients are diagnosed at an advanced stage. Unfortunately, due to the immunosuppressive tumor microenvironment of pancreatic cancer, the benefits of immunotherapy for patients with advanced pancreatic cancer are still unclear. Here, we present two cases of advanced pancreatic cancer being controlled by immunotherapy, with pathological diagnoses of ductal adenocarcinoma and acinar cell carcinoma, respectively. Next-generation sequencing (NGS) of both patients is high tumor mutation burden (tumor mutation burden-High) and microsatellite stable. The patient with pancreatic ductal adenocarcinoma was diagnosed as a locally advanced disease (stage III). She received irreversible electroporation, used the programmed death receptor-1 (PD-1) inhibitor (pembrolizumab) combined with chemotherapy (S-1), and then used only the PD-1 inhibitor as a maintenance treatment. As a result, the patient's lesion was significantly reduced, with a partial response time of up to 31 months. The patient with acinar cell carcinoma was diagnosed as a metastatic disease (stage IV), next-generation sequencing revealed mutations in SMAD4 and KMT2D, and two chemotherapy regimens were used unsuccessfully. Then, the combination of chemotherapy with PD-1 (tislelizumab) and vascular endothelial growth factor/vascular endothelial growth factor receptor (anlotinib) inhibitors were used, and the lesions of the patient were significantly reduced, and the progression-free survival after immunotherapy was 19 months. In advanced pancreatic cancer, a prognosis of this magnitude is rare. Our cases reveal the potential of immunotherapy as a cornerstone treatment in the management of advanced pancreatic cancer.

Sequential Irreversible Electroporation for Locally Advanced Pancreatic Cancer

Pancreatic cancer is a lethal disease, with locally advanced pancreatic cancer (LAPC) having a dismal prognosis. For patients with LAPC, gemcitabine-based regimens, with or without radiation, have long been the standard of care. Irreversible electroporation (IRE), a non-thermal ablative technique, may potentially prolong the survival of patients with LAPC. In this article, the authors present a case of LAPC of the uncinate process (biopsy proven pancreatic neuroendocrine carcinoma) with duodenal invasion. The patient had a combination of chemotherapy and radiation therapy but was found to have stable disease. He then underwent intra-operative IRE with cholecystectomy, Roux-en-Y gastrojejunostomy and hepaticojejunostomy. He subsequently underwent percutaneous IRE 13 months post open IRE. The patient also completed peptide receptor radionuclide therapy and has been started on Lanreotide. Following combination therapy, the pancreatic tumor showed significant reduction in size, with patient survival at 53 months post-diagnosis at the time of writing.

Percutaneous cryoablation of follicular thyroid carcinoma metastasis to the pancreas

The following is a technical report of the successful cryoablation of pancreatic metastasis originating from follicular thyroid carcinoma. The patient was a 72-year-old female who underwent total thyroidectomy and radioiodine ablation for follicular carcinoma. One year after surgery, a positron emission tomography-computed tomography (PET-CT) examination, performed to demonstrate the source of the increased thyroglobulin, showed a fluorodeoxyglucose (FDG) avid mass located in the body of the pancreas. A percutaneous tru-cut biopsy was performed that revealed follicular thyroid carcinoma metastasis to the pancreas. Because of the patient's comorbidities, the patient underwent percutaneous cryoablation and made a successful recovery over the following 13 months. At the most recent follow-up, the thyroglobulin level was undetectable, and a PET-CT scan showed no FDG avid mass in the pancreas. To our knowledge, follicular carcinoma metastasis of the pancreas is extremely rare, and this is the first report of successful cryoablation of a metastatic tumor in the pancreas.

Irreversible electroporation for the management of pancreatic cancer: Current data and future directions

Pancreatic cancer is currently the seventh leading cause of cancer death (4.5% of all cancer deaths) while 80%-90% of the patients suffer from unresectable disease at the time of diagnosis. Prognosis remains poor, with a mean survival up to 15 mo following systemic chemotherapy. Loco-regional thermal ablative techniques are rarely implemented due to the increased risk of thermal injury to the adjacent structures, which can lead to severe adverse events. Irreversible electroporation, a promising novel non-thermal ablative modality, has been recently introduced in clinical practice for the management of inoperable pancreatic cancer as a safer and more effective loco-regional treatment option. Experimental and initial clinical data are optimistic. This review will focus on the basic principles of IRE technology, currently available data, and future directions.

Advanced triboelectric nanogenerator-driven drug delivery systems for targeted therapies

In the current decade, remarkable efforts have been made to develop a self-regulated, on-demand and controlled release drug delivery system driven by triboelectric nanogenerators (TENGs). TENGs have great potential to convert biomechanical energy into electricity and are suitable candidates for self-powered drug delivery systems (DDSs) with exciting features such as small size, easy fabrication, biocompatible, high power output and economical. This review exclusively explains the development and implementation process of TENG-mediated, self-regulated, on-demand and targeted DDSs. It also highlights the recently used TENG-driven DDSs for cancer therapy, infected wounds healing, tissue regeneration and many other chronic disorders. Moreover, it summarises the crucial challenges that are needed to be addressed for their universal applications. Finally, a roadmap to advance the TENG-based drug delivery system developments is depicted for the targeted therapies and personalised healthcare.

[Irreversible electroporation in locally advanced pancreatic cancer]

OBJECTIVE

To determine the feasibility of irreversible electroporation (IRE) for locally advanced pancreatic adenocarcinoma.

MATERIAL AND METHODS

Twenty-three patients underwent IRE after chemotherapy for locally advanced pancreatic cancer between 2015 and 2022. IRE was performed during laparotomy as a rule (n=22). In one case, IRE was combined with palliative pancretoduodenectomy. Nineteen (86.3%) patients received adjuvant chemotherapy after the procedure. The follow-up examination included contrast-enhanced CT/MRI of the abdomen, chest X-ray or CT, analysis of CA 19-9 marker one month after surgery and then every three months.

RESULTS

Complications after IRE developed in 5 (21.7%) patients. Three patients (13.0%) had arrhythmia, two (8.7%) ones had pancreatic necrosis. A 90-day mortality after the procedure was 4.3% (n=1), the cause was pancreatic necrosis. According to intraoperative data and the first examination (CT/MRI), the entire tumor infiltrate was treated in 21 (91.3%) cases. Median follow-up was 19 months. Median period until local recurrence was 15 months. Isolated local recurrence was observed in 7 patients. Of these, 3 ones underwent radiotherapy, one patient underwent repeated IRE. Distant metastases were found in 11 patients; systemic therapy was restarted. Median time to progression was 7 months after IRE and 14 months after initiation of chemotherapy. The median overall survival was 16 months after electroporation and 25 months after chemotherapy.

CONCLUSION

Irreversible electroporation may be useful in carefully selected patients with unresectable locally advanced pancreatic adenocarcinoma after successful induction chemotherapy. This procedure provides local control, but the impact on long-term outcomes and feasibility of routine use should be analyzed in randomized trials.

Interventional oncology: new techniques and new devices

Interventional oncology is a rapidly emerging field in the treatment of cancer. Minimally invasive techniques such as transarterial embolization with chemotherapeutic and radioactive agents are established therapies and are found in multiple guidelines for the management of primary and metastatic liver lesions. Percutaneous ablation is also an alternative to surgery for small liver, renal, and pancreatic tumors. Recent research in the niche of interventional oncology has focused on improving outcomes of established techniques in addition to the development of novel therapies. In this review, we address the recent and current advancements in devices, technologies, and techniques of chemoembolization and ablation: thermal ablation, histotripsy, high-intensity focused ultrasound, embolization strategies, liquid embolic agents, and local immunotherapy/antiviral therapies.

Simultaneous Gemcitabine and Percutaneous CT-Guided Irreversible Electroporation for Locally Advanced Pancreatic Cancer

Background

Irreversible electroporation (IRE) is a new local ablation technique for pancreatic cancer. The aim of this study is to analyse the safety and effectiveness of simultaneous gemcitabine and percutaneous CT-guided IRE for locally advanced pancreatic cancer (LAPC).

Materials and Methods

From October 2016 to January 2018, 61 patients with LAPC who received simultaneous gemcitabine and IRE therapy (GEM-IRE group, n = 31) or IRE alone therapy (IRE group, n = 30). Routine intravenous gemcitabine chemotherapy was performed 2 weeks after IRE in both groups.

Results

Technical success rates were 90.0% (27/30) and 93.3% (28/30) in the GEM-IRE and IRE groups. Compared with the IRE group, the GEM-IRE group exhibited longer overall survival (OS), local tumor progression free survival (LTPFS), and distant disease free survival (DDFS) from IRE (OS, 17.1 vs. 14.2 months, p=0.031; LTPFS, 14.6 vs. 10.2 months, p=0.045; DDFS, 15.4 vs. 11.7 months, p=0.071). Multivariate Cox regression analysis results suggested that tumor volume ≤37 cm³ and simultaneous gemcitabine with IRE were significant independent prognostic factors of OS, LTPFS, and DDFS. Four major adverse reactions occurred; all of them were resolved after symptomatic treatment.

Conclusions

Simultaneous gemcitabine and percutaneous CT-guided IRE therapy model was effective and well-tolerated therapeutic strategy in LAPC patients.

The Synergistic Role of Irreversible Electroporation and Chemotherapy for Locally Advanced Pancreatic Cancer

Irreversible electroporation (IRE) is a local ablative technique used in conjunction with chemotherapy to treat locally advanced pancreatic cancer (LAPC). The combination of IRE and chemotherapy has showed increased overall survival when compared to chemotherapy alone, pointing towards a possible facilitating effect of IRE on chemotherapeutic drug action and delivery. This review aims to present current chemotherapeutic regimens for LAPC and their co-implementation with IRE, with an emphasis on possible molecular augmentative mechanisms of drug delivery and action. Moreover, the potentiating mechanism of IRE on immunotherapy, M1 oncolytic virus and dendritic cell (DC)-based treatments is briefly explored. Investigating the synergistic effect of IRE on currently established treatment regimens as well as newer ones, may present exciting new possibilities for future studies seeking to improve current LAPC treatment algorithms.

Treatment of unresectable locally advanced pancreatic cancer with percutaneous irreversible electroporation (IRE) following initial systemic chemotherapy (LAP-PIE) trial: study protocol for a feasibility randomised controlled trial

BACKGROUND

Approximately 30% of patients with pancreas cancer have unresectable locally advanced disease, which is currently treated with systemic chemotherapy. A new treatment option of irreversible electroporation (IRE) has been investigated for these patients since 2005. Cohort studies suggest that IRE confers a survival advantage, but with associated, procedure-related complications. Selection bias may account for improved survival and there have been no prospective randomised trials evaluating the harms and benefits of therapy. The aim of this trial is to evaluate the feasibility of a randomised comparison of IRE therapy with chemotherapy versus chemotherapy alone in patients with locally advanced pancreatic cancer (LAPC).

METHODS AND ANALYSIS

Eligible patients with LAPC who have undergone first-line 5-FluoroUracil, Leucovorin, Irinotecan and Oxaliplatin chemotherapy will be randomised to receive either a single session of IRE followed by (if indicated) further chemotherapy or to chemotherapy alone (standard of care). Fifty patients from up to seven specialist pancreas centres in the UK will be recruited over a period of 15 months. Trial follow-up will be 12 months. The primary outcome measure is ability to recruit. Secondary objectives include practicality and technical success of treatment, acceptability of treatment to patients and clinicians and safety of treatment. A qualitative study has been incorporated to evaluate the patient and clinician perspective of the locally advanced pancreatic cancer with percutaneous irreversible electroporation trial. It is likely that the data obtained will guide the structure, the primary outcome measure, the power and the duration of a subsequent multicentre randomised controlled trial aimed at establishing the clinical efficiency of pancreas IRE therapy. Indicative procedure-related costings will be collected in this feasibility trial, which will inform the cost evaluation in the subsequent study on efficiency.

ETHICS AND DISSEMINATION

The protocol has received approval by London-Brent Research Ethics Committee reference number 21/LO/0077.Results will be analysed following completion of trial recruitment and follow-up. Results will be presented to international conferences with an interest in oncology, hepatopancreaticobiliary surgery and interventional radiology and be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRCTN14986389.

Current status of non-surgical treatment of locally advanced pancreatic cancer

Pancreatic cancer is the 7th leading cause of death due to cancer in industrialized countries and the 11th most common cancer globally, with 458918 new cases (2.5% of all cancers) and 432242 deaths (4.5% of all cancer deaths) in 2018. Unfortunately, 80% to 90% of the patients present with unresectable disease, and the reported 5-year survival rate range between 10% and 25%, even after successful resection with tumor-free margins. Systemic chemotherapy, radiotherapy, and minimally invasive image-guided procedures that have emerged over the past years, are used for the management of non-operable PC. This review focuses on currently available non-surgical options of locally advanced pancreatic cancer.

Can local ablative techniques replace surgery for locally advanced pancreatic cancer?

In the treatment of pancreatic ductal adenocarcinoma (PDAC) the best chance at long term survival or cure has to date always included the complete surgical removal of the tumor. However, locally advanced pancreatic cancer (LAPC), about 25% of all newly diagnosed PDAC, is defined by its primary technical unresectability due to infiltration of visceral arteries and absence of metastasis. Induction therapies, especially FOLFIRINOX treatment, together with technical surgical advancement have increased the numbers for conversion to secondary resectability. Recent data on resections after induction therapy show promising, almost doubled survival compared to palliative treatment. Yet, around 70% of LAPC remain unresectable after induction therapy, often due to persistent local invasion. As locally ablative techniques are becoming more widely available this review examines their possible applicability to substitute for surgery in these cases which we propose to group under the new term "Inconvertible LAPC". The need for defining this novel subgroup who might benefit from ablative treatment is based on the findings in our review that high-level evidence on ablative techniques for PDAC is largely lacking and the latest effective, harmonized treatment guidelines for LAPC are not often incorporated in these studies. The "inconvertible LAPC" label requires persistent unresectability after staging and induction therapy of LAPC according to current guidelines followed by liberal indication for aggressive surgical exploration at a center equipped for extended pancreatic resections. Ideally, this specification of a new, distinct patient group will also put it in the spotlight more, hopefully prompt more trials designed to generate robust evidence and optimize transferability of study results.

Evolving Concepts Regarding Radiation Therapy for Pancreatic Cancer

In todays practice most institutions individualize the use of adjuvant, neoadjuvant, and definitive RT based on their interpretation of the available data. This review highlights novel concepts and approaches to the use of RT that should be considered by the surgical oncologist.

Immunomodulatory Effect of Irreversible Electroporation Alone and Its Cooperating With Immunotherapy in Pancreatic Cancer

Emerging studies have showed irreversible electroporation (IRE) focused on pancreatic cancer (PC). However, the effects of IRE treatment on the immune response of PC remain unknown. Moreover, there are few studies on the therapeutic effect of IRE combining with immunotherapy on PC. Thus, we review recent advances in our understanding of IRE alone and its working with immunotherapy towards the immune response of PC, discussing potential opportunities for exploring future treatment strategies.

Multicenter randomized controlled trial and registry study to assess the safety and efficacy of the NanoKnife® system for the ablation of stage 3 pancreatic adenocarcinoma: overview of study protocols

BACKGROUND

Irreversible electroporation (IRE) is a local ablation technique utilizing high voltage, low energy direct current to create nanopores in cell membrane which disrupt homeostasis and leads to cell death. Previous reports have suggested IRE may have a role in treating borderline resectable and unresectable Stage 3 pancreatic tumors.

METHODS

Patients with Stage 3 pancreatic ductal adenocarcinoma (PDAC) will be enrolled in either a randomized, controlled, multicenter trial (RCT) or a multicenter registry study. Subjects enrolled in the RCT must have no evidence of disease progression after 3 months of modified FOLFIRINOX (mFOLFIRINOX) treatment prior to being randomization to either a control or IRE arm. Post-induction and post-IRE treatment for the control and IRE arms, respectively, will be left to the discretion of the treating physician. The RCT will enroll 528 subjects with 264 per arm and include up to 15 sites. All subjects will be followed for at least 24 months or until death. The registry study will include two cohorts of patients with Stage 3 PDAC, patients who received institutional standard of care (SOC) alone and those treated with IRE in addition to SOC. Both cohorts will be required to have undergone at least 3 months of SOC without progression prior to enrollment. The registry study will enroll 532 patients with 266 patients in each arm. All patients will be followed for at least 24 months or until death. The primary efficacy endpoint for both studies will be overall survival (OS). Co-primary safety endpoints will be 1) time from randomization or enrollment in the registry to death or new onset of Grade 4 adverse event (AE), and (2 high-grade complications defined as any AE or serious AE (SAE) with a CTCAE v5.0 grade of 3 or higher. Secondary endpoints will include progression-free survival, cancer-related pain, quality of life, and procedure-related pain for the IRE arm only.

DISCUSSION

These studies are intended to provide Level 1 clinical evidence and real-world data demonstrating the clinical utility and safety of the use of IRE in combination with chemotherapy in patients with Stage 3 PDAC.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03899636 and NCT03899649. Registered April 2, 2019. Food and Drug Administration (FDA) Investigational Device Exemption (IDE) trial G180278 approved on May 3, 2019.

Margin Accentuation Irreversible Electroporation in Stage III Pancreatic Cancer: A Systematic Review

Simple Summary

This literature review shows preliminary evidence to suggest that electroporation, the use of electricity to cause the death of cells around the tumour, may be associated with an improved survival and complete resection rates following pancreatic surgery for higher stage pancreatic cancer. However, one in five patients have a complication from the procedure that alters their normal course in hospital. Moreover, the number of patients who underwent this technique is small and further data is needed to support the preliminary evidence. The results therefore should be interpreted with caution.

Abstract

The present systematic review aimed to summarise the available evidence on indications and oncological outcomes after MA IRE for stage III pancreatic cancer (PC). A literature search was performed in the Pubmed, MEDLINE, EMBASE, SCOPUS databases using the PRISMA framework to identify all MA IRE studies. Nine studies with 235 locally advanced (LA) (82%, 192/235) or Borderline resectable (BR) PC (18%, 43/235) patients undergoing MA IRE pancreatic resection were included. Patients were mostly male (56%) with a weighted-mean age of 61 years (95% CI: 58–64). Pancreatoduodenectomy was performed in 51% (120/235) and distal pancreatectomy in 49% (115/235). R0 resection rate was 73% (77/105). Clavien Dindo grade 3–5 postoperative complications occurred in 19% (36/187). Follow-up intervals ranged from 3 to 29 months. Local and systematic recurrences were noted in 8 and 43 patients, respectively. The weighted-mean progression free survival was 11 months (95% CI: 7–15). The weighted-mean overall survival was 22 months (95% CI 20–23 months) and 8 months (95% CI 1–32 months) for MA IRE and IRE alone, respectively. Early non-randomised data suggest MA IRE during pancreatic surgery for stage III pancreatic cancer may result in increased R0 resection rates and improved OS with acceptable postoperative morbidity. Further, larger studies are warranted to corroborate this evidence.

Margin ACcentuation for resectable Pancreatic cancer using Irreversible Electroporation - Results from the MACPIE-I study

INTRODUCTION

Margin accentuation (MA) using Irreversible electroporation (IRE) offers an unique opportunity to reduce the R1 resections in resectable pancreatic cancer (RPC). This study aims to assess the rate of margin positivity using IRE for MA during pancreaticoduodenectomy (PD) for resectable pancreatic head tumours.

MATERIALS AND METHODS

Following ethical approval, MA using IRE was carried out in 20 consecutive patients to posterior and superior mesenteric vein (SMV) margin, and the pancreatic neck, prior to the PD resection. The control group (non-IRE; n = 91) underwent PD without MA over the study period, March 2018 to March 2020.

RESULTS

There was no difference between the two groups in terms of patients' age, gender, pre-op biliary drainage, site of malignancy or pre-operative TNM stage. The overall margin positive rate for IRE group was lesser (35.0%) when compared to non-IRE group (51.6%; p = 0.177), with significantly less posterior pancreatic margin positivity (5.0% vs. 25.3%; p = 0.046). When only treated margins (SMA margin excluded) were compared, the IRE group had significantly lower margin positive rates (20.0% vs. 51.6%; p = 0.013). There was no difference between the two groups in terms of intra- or post-operative complications. With a median follow-up of 15.6 months, the median DFS and OS for IRE and non-IRE groups were 17 and 18 months (p = 0.306) and 19 and 22 months (p = 0.227) respectively.

CONCLUSION

Our pilot study confirms the safety of MA using IRE for RPC, with reduction in margin positivity. These results as a proof of concept are promising and need further validation with a randomised controlled trial.

Irreversible Electroporation (IRE) in Locally Advanced Pancreatic Cancer: A Review of Current Clinical Outcomes, Mechanism of Action and Opportunities for Synergistic Therapy

Locally advanced pancreatic cancer (LAPC) accounts for 30% of patients with pancreatic cancer. Irreversible electroporation (IRE) is a novel cancer treatment that may improve survival and quality of life in LAPC. This narrative review will provide a perspective on the clinical experience of pancreas IRE therapy, explore the evidence for the mode of action, assess treatment complications, and propose strategies for augmenting IRE response. A systematic search was performed using PubMed regarding the clinical use and safety profile of IRE on pancreatic cancer, post-IRE sequential histological changes, associated immune response, and synergistic therapies. Animal data demonstrate that IRE induces both apoptosis and necrosis followed by fibrosis. Major complications may result from IRE; procedure related mortality is up to 2%, with an average morbidity as high as 36%. Nevertheless, prospective and retrospective studies suggest that IRE treatment may increase median overall survival of LAPC to as much as 30 months and provide preliminary data justifying the well-designed trials currently underway, comparing IRE to the standard of care treatment. The mechanism of action of IRE remains unknown, and there is a lack of data on treatment variables and efficiency in humans. There is emerging data suggesting that IRE can be augmented with synergistic therapies such as immunotherapy.

Achieving 'Marginal Gains' to Optimise Outcomes in Resectable Pancreatic Cancer

Simple Summary

Improving outcomes in pancreatic cancer is achievable through the accumulation of marginal gains. There exists evidence of variation and undertreatment in many areas of the care pathway. By fully realising the existing opportunities, there is the potential for immediate improvements in outcomes and quality of life.

Abstract

Improving outcomes among patients with resectable pancreatic cancer is one of the greatest challenges of modern medicine. Major improvements in survival will result from the development of novel therapies. However, optimising existing pathways, so that patients realise benefits of already proven treatments, presents a clear opportunity to improve outcomes in the short term. This narrative review will focus on treatments and interventions where there is a clear evidence base to improve outcomes in pancreatic cancer, and where there is also evidence of variation and under-treatment. Avoidance of preoperative biliary drainage, treatment of pancreatic exocrine insufficiency, prehabiliation and enhanced recovery after surgery, reducing perioperative complications, optimising opportunities for elderly patients to receive therapy, optimising adjuvant chemotherapy and regular surveillance after surgery are some of the strategies discussed. Each treatment or pathway change represents an opportunity for marginal gain. Accumulation of marginal gains can result in considerable benefit to patients. Given that these interventions already have evidence base, they can be realised quickly and economically.

The role of irreversible electroporation in promoting M1 macrophage polarization via regulating the HMGB1-RAGE-MAPK axis in pancreatic cancer

Irreversible electroporation (IRE) is an effective method for treating pancreatic ductal adenocarcinoma (PDAC). It remains unclear whether IRE can induce a specific immune response by stimulating macrophages. Here, the associated markers of macrophages were analyzed after exposure to tumor culture supernatant (TSN) of tumor cells treated with electroporation. Subcutaneous and orthotopic PDAC models were also used to evaluate the effect of macrophage polarization induced by IRE. Aside from its direct killing effect, IRE could induce the immunogenic cell death of tumor cells by increasing the synthesis and secretion of damage associated molecular patterns. Moreover, IRE could increase the release of HMGB1, which activates the MAPK-p38 pathway and leads to the increased expression of M1 markers in macrophages, through binding to the receptor of the advanced glycation end-product (RAGE) receptor. M1 polarization was inhibited by the inhibitors of HMGB1 release, the RAGE receptor, and the MAPK-p38 signaling pathway, but it was activated by rHMGB1 or the stimulator of MAPK-p38. In addition, the promotion of M1 macrophage polarization was enhanced by the positive-feedback release or expression of HMGB1 and RAGE through the MAPK-ERK pathway in macrophages. The promotion of M1 macrophage polarization induced by IRE provided a specific rationale for the combination of IRE and immune therapy in treating PDAC.

Antitumor Effect and Immune Response of Nanosecond Pulsed Electric Fields in Pancreatic Cancer

Nanosecond pulsed electric fields (nsPEFs) have emerged as a novel and effective strategy for the non-surgical and minimally invasive removal of tumors. However, the effects of nsPEFs treatment on the tumor immune microenvironment remain unknown. In this study, the changes in the morphology and function of pancreatic cancer cells after nsPEFs were assessed and the modifications in the immune profile in pancreatic cancer models were investigated. To this end, electrodes were inserted with different parameters applied to ablate the targeted tumor tissues. Tumor development was found to be inhibited, with decreased volumes post-nsPEFs treatment compared with control tumors (P < 0.05). Hematoxylin and eosin staining showed morphological changes in pancreatic cancer cells, Ki-67 staining confirmed the effects of nsPEFs on tumor growth, and caspase-3 staining indicated that nsPEFs caused apoptosis in the early stages after treatment. Three days after nsPEFs, positron emission tomography demonstrated little residual metabolic activity compared with the control group. Gene expression profiling identified significant changes in immune-related pathways. After treatment with nsPEFs, CD8⁺ T lymphocytes increased. We showed that nsPEFs led to a significant decrease in immune suppressive cells, including myeloid derived suppressor cells, T regulatory cells, and tumor-associated macrophages. In addition, the levels of TNF-α and IL-1β increased (P < 0.05), while the level of IL-6 was decreased (P < 0.05). NsPEFs alleviated the immunosuppressive components in pancreatic cancer stroma, including hyaluronic acid and fibroblast activation protein-α. Our data demonstrate that tumor growth can be effectively inhibited by nsPEFs in vivo. NsPEFs significantly altered the infiltration of immune cells and triggered immune response.

Laser Treatment of Pancreatic Cancer with Immunostimulating Interstitial Laser Thermotherapy Protocol: Safety and Feasibility Results From Two Phase 2a Studies

PURPOSE

Ablative techniques have emerged as new potential therapeutic options for patients with locally advanced pancreatic cancer (LAPC). We explored the safety and feasibility of using TRANBERG|Thermal Therapy System (Clinical Laserthermia Systems AB, Lund, Sweden) in feedback mode for immunostimulating Interstitial Laser Thermotherapy (imILT) protocol, the newest ablative technique introduced for the treatment of LAPC.

METHODS

The safety and feasibility results after the use of imILT protocol treatment in 15 patients of a prospective series of postsystemic therapy LAPC in two high-volume European institutions, the General and Pancreatic Unit of the Pancreas Institute, of the University of Verona, Italy, and the Department of Surgical Oncology of the Institut Paoli-Calmettes of Marseille, France, were assessed.

RESULTS

The mean age was 66 ± 5 years, with a mean tumor size of 34.6 (±8) mm. The median number of cycles of pre-imILT chemotherapy was 6 (6-12). The procedure was performed in 13 of 15 (86.6%) cases; indeed, in two cases, the procedure was not performed; in one, the procedure was considered technically demanding; in the other, liver metastases were found intraoperatively. In all treated cases, the procedure was completed. Three late pancreatic fistulas developed over four overall adverse events (26.6%) and were attributed to imILT. Mortality was nil. A learning curve is necessary to interpret and manage the laser parameters.

CONCLUSIONS

Safety, feasibility, and device handling outcomes of using TRANBERG|Thermal Therapy System with temperature probes in feedback mode and imILT protocol on LAPC were not satisfactory. The metastatic setting may be appropriate to evaluate the hypothetic abscopal effect.#NCT02702986 and #NCT02973217.

A Novel Prediction Tool Based on Large Cohorts to Determine the Cancer-Specific Survival Probability of Patients With Locally Advanced Pancreatic Cancer After Irreversible Electroporation Treatment

Irreversible electroporation (IRE) is a novel method which was especially suitable for the treatment of locally advanced pancreatic cancer (LAPC). The purpose of this study was to evaluate probabilities of overall survival (OS) and cancer-specific survival (CSS) in patients with LAPC after IRE treatment and to construct nomograms to predict survival for these patients. Data of patients were retrospectively collected from the Surveillance, Epidemiology, and End Results (SEER) database and medical records of Sun Yat-sen University Cancer Center (SYSUCC). A total of 312 LAPC patients after IRE treatment were included into this study. The 3-year cumulative incidence of cancer-specific mortality for patients with LAPC after IRE treatment was 74.3%. Nomograms for predicting probabilities of OS, CSS, and non-cancer-specific survival (NCSS) were built and calibrated with the concordance index (C-index) and the area under receiver operating characteristic (ROC) curve (AUC). The established nomograms were well-calibrated, with C-indexes of 0.782 for OS prediction, 0.729 for CSS prediction, and 0.730 for NCSS prediction. Compared with the TNM stage system, the established nomograms displayed higher values of AUC and showed better discriminatory power for predicting OS, CSS, and NCSS. These nomograms were well-calibrated and could serve to guide management of LAPC patients after IRE treatment.