Irreversible Electroporation in pancreatic ductal adenocarcinoma: Is there a role in conjunction with conventional treatment? Eur J Surg Oncol. 2018;44:1486-1493. [PMID: 30146253 DOI: 10.1016/j.ejso.2018.07.047]

Advancements in the application of ablative therapy and its combination with immunotherapy in anti-cancer therapy

Cancer is a significant health issue impacting humans. Currently, systemic therapies such as chemotherapy have significantly increased the life expectancy of cancer patients. However, some patients are unable to endure systemic treatment due to its significant adverse effects, leading to an increased focus on local therapies including radiation and ablation therapy. Ablation therapy is a precise, low-toxicity, and minimally invasive localized therapy that is increasingly acknowledged by clinicians and cancer patients. Many cancer patients have benefited from it, with some achieving full recovery. Currently, numerous studies have shown that ablation therapy is effective due to its ability to kill cancer cells efficiently and activate the body's anti-cancer immunity. It can also convert "cold cancers" into "hot cancers" and enhance the effectiveness of immunotherapy when used in combination. In this article, we categorize ablation therapy into thermal ablation, cryoablation, photodynamic therapy (PDT), irreversible electroporation (IRE), etc. Thermal ablation is further divided into Radiofrequency ablation (RFA), microwave ablation (WMA), high-frequency focused ultrasound (HIFU), photothermal therapy (PTT), magnetic heat therapy (MHT), etc. We systematically review the most recent advancements in these ablation therapies that are either currently used in clinic or are anticipated to be used in clinic. Then, we also review the latest development of various ablative therapies combined with immunotherapy, and its future development. CLINICAL RELEVANCE STATEMENT: Ablation therapy, an invasive localized treatment, offers an alternative to systemic therapies for cancer patients who cannot tolerate their adverse effects. Its ability to kill cancer cells efficiently and activate anti-cancer immunity. This article reviews recent advancements in ablation therapies, including thermal, cryoablation, PDT, and IRE, and their potential clinical applications, both standalone and in combination with immunotherapy.

Irreversible electroporation as an intraoperative adjunctive treatment for locally advanced pancreatic cancer after neoadjuvant therapy: An initial clinical experience

Backgrounds/Aims

Irreversible electroporation (IRE) may have a potential application as either a "back-up therapy" or for margin accentuation during trial dissection of locally advanced pancreatic cancer (LAPC). The aim of this report was to describe our experience with IRE in terms of its potential applications mentioned above.

Methods

A clinical policy to use IRE in LAPC patients undergoing exploratory surgery after neoadjuvant therapy (NAT) was initiated in 2017. If resection was feasible, IRE was used for margin accentuation. If not, then IRE was undertaken as a "back-up therapy" of non-resectable tumor. Data on baseline characteristics, perioperative 90-day morbidity, recurrence-free survival (RFS) and overall survival (OS) were collected.

Results

IRE was successfully performed in 18 (95%) patients. IRE was abandoned in one case for technical reasons. Nine patients who were found to have an unresectable disease underwent IRE as a "back-up therapy" while the remaining patients received IRE for margin accentuation. Complications were recorded in 33% patients. There was no procedure-related mortality. In the group receiving IRE for margin accentuation, the median RFS was 10.0 months (range, 4.5-15.0 months). The median OS of our cohort was 22 months (range, 14.75-27.50 months).

Conclusions

This report shows that in patients with LAPC undergoing exploratory surgery following NAT, IRE seems technically feasible for margin accentuation or as a "back-up therapy". More data are needed to determine procedure-related morbidity, mortality, and any effects of IRE on cancer-related survival.

A pancreatic adenocarcinoma mimicking hepatoid carcinoma of uncertain histogenesis: A case report and literature review

In rare cases, metastatic adenocarcinomas of different origin may exhibit the features of hepatoid carcinoma (HC), a rare malignant epithelial tumor, most commonly occurring in the ovaries and stomach, as well as in the pancreas and biliary ducts. A case of a 72-year-old female patient who developed a highly aggressive, poorly differentiated pancreatic ductal adenocarcinoma with peritoneal carcinomatosis, demonstrating hepatoid differentiation upon conventional hematoxylin and eosin staining is reported in the present study. The patient presented with severe abdominal pain, and the radiological investigations performed revealed ovarian and hepatic tumor masses and peritoneal lesions, which were surgically removed. The gross examination of the peritoneum and omentum revealed multiple solid, firm, grey-white nodules, diffusely infiltrating the adipose tissue. The microscopic examination revealed a malignant epithelial proliferation, composed of polygonal cells with abundant eosinophilic cytoplasm and irregular, pleomorphic nuclei. Certain cells presented with intracytoplasmic mucus inclusions, raising suspicion of a HC with an uncertain histogenesis. Immunohistochemical staining was performed, and the tumor cells were found to be positive for cytokeratin (CK)7, CK18 and mucin 5AC, whereas negative staining for CK20, caudal-type homeobox transcription factor 2, α-fetoprotein, paired box gene 8, GATA-binding protein 3 and Wilms tumor 1 were documented. Thus, the diagnosis of metastatic pancreatic adenocarcinoma was established. The main aim of the present study was to provide further knowledge concerning poorly differentiated metastatic adenocarcinoma resembling HC, emphasizing the histopathological and immunohistochemical features of these malignant lesions and raising awareness of the diagnostic difficulties that may arise, as well as the importance of the use immunohistochemistry in differentiating carcinomas of uncertain histogenesis.

Needle tract seeding following percutaneous irreversible electroporation for hepatocellular carcinoma

Irreversible electroporation (IRE) is a non-thermal ablative technique for unresectable liver malignancies deemed unsuitable for traditional thermal ablation due to proximity to biliary and/or vascular structures. Needle tract tumour seeding is a well-recognised complication following thermal ablation, while little is known about its risk with IRE use. We present a case of tumour seeding after IRE for unresectable hepatocellular carcinoma in a man in his 70s. The procedure was complicated by bleeding from a pseudoaneurysm, which required coil embolisation and blood transfusion. He initially progressed well, however, imaging at 12 months indicated a new tumour in the right intercostal space along the tract of one of the IRE needles; consistent with seeding. Although the patient subsequently underwent systemic therapy with sorafenib, his disease progressed, and unfortunately he passed away 20 months following IRE. This report adds to mounting evidence of needle tract tumour seeding as a complication following IRE.

Clinical challenges associated with utility of neoadjuvant treatment in patients with pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an increasingly common cancer with a persistently poor prognosis, and only approximately 20% of patients are clearly anatomically resectable at diagnosis. Historically, a paucity of effective therapy made it inappropriate to forego the traditional gold standard of upfront surgery in favour of neoadjuvant treatment; however, modern combination chemotherapy regimens have made neoadjuvant therapy increasingly viable. As its use has expanded, the rationale for neoadjuvant therapy has evolved from one of 'downstaging' to one of early treatment of micro-metastases and selection of patients with favourable tumour biology for resection. Defining resectability in PDAC is problematic; multiple differing definitions exist. Multidisciplinary input, both in initial assessment of resectability and in supervision of multimodality therapy, is therefore advised. European and North American guidelines recommend the use of neoadjuvant chemotherapy in borderline resectable (BR)-PDAC. Similar regimens may be applied in locally advanced (LA)-PDAC with the aim of improving potential access to curative-intent resection, but appropriate patient selection is key due to significant rates of recurrence after excision of LA disease. Upfront surgery and adjuvant chemotherapy remain standard-of-care in clearly resectable PDAC, but multiple trials evaluating the use of neoadjuvant therapy in this and other localised settings are ongoing.

Safety and efficacy of irreversible electroporation treatment in hepatobiliary and pancreatic tumours: a single-centre experience

AIM

To report initial experience with irreversible electroporation (IRE) in a single tertiary oncology centre and to describe its role in the management of liver and pancreatic tumours.

MATERIALS AND METHODS

The present study was a retrospective review of the technical success rate, complications, and treatment efficacy of patients who had undergone IRE treatment for hepatobiliary and pancreatic tumours between February 2014 to January 2020. The patients were divided into two cohorts: first 30 patients (cohort A) and subsequent 70 patients (cohort B) after a change in protocol.

RESULTS

One hundred IRE procedures (n=69 liver lesions; n=28 pancreatic lesions, n=3 nodal disease) were reviewed. The overall technical success rate was 99%. Early and immediate complications were 4% and 3%, respectively. In cohort A, the complete tumour ablation rate was 65% (13/20) for hepatic tumours, 20% (1/5) for locally advanced pancreatic adenocarcinoma, 50% (2/4) for pancreatic neuroendocrine tumours, and 0% (0/1) for nodal metastasis. For cohort B, the rate improved to 87.76% (43/49) for hepatic tumours, 28.57% (4/14) for locally advanced pancreatic adenocarcinoma, 80% (4/5) for pancreatic neuroendocrine, and 50% (1/2) for nodal metastasis. After the initial cohort A, cohort B showed a significant increase in the initial complete ablation rate in hepatic tumours (p=0.028).

CONCLUSION

IRE is a complex technique with a steep learning curve. It is safe, effective, and is valuable in the treatment of liver tumours that are unsuitable or considered high risk for conventional thermal ablation. Its role in the management of pancreatic tumours is less clear and requires larger studies.

Gemcitabine plus concurrent irreversible electroporation vs gemcitabine alone for locally advanced pancreatic cancer

BACKGROUND

Locally advanced pancreatic cancer (LAPC) is a common malignant digestive system tumor that ranks as the fourth leading cause of cancer-related death in the world. The prognosis of LAPC is poor even after standard treatment. Irreversible electroporation (IRE) is a novel ablative strategy for LAPC. Several studies have confirmed the safety of IRE. To date, no prospective studies have been performed to investigate the therapeutic efficacy of conventional gemcitabine (GEM) plus concurrent IRE.

AIM

To compare the therapeutic efficacy between conventional GEM plus concurrent IRE and GEM alone for LAPC.

METHODS

From February 2016 to September 2017, a total of 68 LAPC patients were treated with GEM plus concurrent IRE n = 33) or GEM alone n = 35). Overall survival (OS), progression free survival (PFS), and procedure-related complications were compared between the two groups. Multivariate analyses were performed to identify any prognostic factors.

RESULTS

There were no treatment-related deaths. The technical success rate of IRE ablation was 100%. The GEM + IRE group had a significantly longer OS from the time of diagnosis of LAPC (19.8 mo vs 9.3 mo, P < 0.0001) than the GEM alone group. The GEM + IRE group had a significantly longer PFS (8.3 mo vs 4.7 mo, P < 0.0001) than the GEM alone group. Tumor volume less than 37 cm3 and GEM plus concurrent IRE were identified as significant favorable factors for both the OS and PFS.

CONCLUSION

Gemcitabine plus concurrent IRE is an effective treatment for patients with LAPC.

Safety and Feasibility of Electrochemotherapy of the Pancreas in a Porcine Model

OBJECTIVES

The use of thermal ablative therapies in the pancreatic tumors is limited because of the risk of the vessel injury and potential pancreatitis or fistula formation. Electrochemotherapy (ECT) is an ablative therapy with an established role in the treatment of cutaneous and liver tumors. This study was designed to evaluate the safety and feasibility of ECT of the pancreas in a porcine survival model.

METHODS

In the first group, 4 animals underwent computed tomography (CT)-guided percutaneous ECT with bleomycin of the pancreatic tail. In the second group (4 animals), the intraoperative ECT with bleomycin of pancreatic tail and head was performed. Animals were followed for 7 days and then killed. Clinical parameters, CT imaging, laboratory, and histologic analysis were performed.

RESULTS

All pigs survived the ECT procedure and none of them developed clinical signs of acute pancreatitis or related complications. There were no signs of acute pancreatitis or damage to the large vessels present in the follow-up CT scans. No significant change in laboratory parameters was obtained after procedure.

CONCLUSIONS

This study shows that ECT with bleomycin is feasible and safe in the pancreatic parenchyma. Clinical studies are needed to evaluate the efficacy of ECT in pancreatic cancer.

Comparison of Survival Between Irreversible Electroporation Followed by Chemotherapy and Chemotherapy Alone for Locally Advanced Pancreatic Cancer

Locally advanced pancreatic cancer (LAPC) has a dismal prognosis even after standard chemotherapy, and local progression contributes to nearly one-third of the deaths of these patients. As a local destructive method, irreversible electroporation (IRE) can feasibly treat LAPC. The aim of this study was to evaluate IRE combined with chemotherapy as a new treatment and compare its efficacy with that of chemotherapy alone in patients with LAPC. The data of LAPC patients who received chemotherapy with or without IRE were extracted from Surveillance, Epidemiology, and End Results (SEER) database and medical records of Sun Yat-sen University Cancer Center (SYSUCC). The efficacy of these two treatments was compared using propensity score matching (PSM) analysis. LAPC patients treated with the combination therapy had better overall survival (OS). Significantly higher cancer-specific survival (CSS) and progression-free survival (PFS) rates were also observed in patients after IRE combined with chemotherapy, compared with chemotherapy alone. IRE combined with chemotherapy was established as a favorable factor for OS, CSS, and PFS in LAPC patients. This combination method may be a more suitable treatment for patients with LAPC.

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

BACKGROUND

Ablative techniques provide in patients with locally advanced pancreatic cancer (LAPC) symptomatic relief, survival benefit and potential downsizing. Irreversible Electroporation (IRE) represents potentially an ideal solution as no thermal tissue damage occurs. The purpose of this review is to present an overview on safety, feasibility, oncological results, survival and quality of life improvement obtained by IRE.

METHODS

A systematic search was performed in PubMed, regarding the use of IRE on PC in humans for studies published in English up to March 2019.

RESULTS

15 original studies embodying 691 patients with unresectable LAPC who underwent IRE were included. As emerged, IRE works better on tumour sizes between 3-4 cm. Oncological results are promising: median OS from diagnosis or treatment up to 27 months. Two groups investigated borderline resectable tumours treated with IRE before resection with margin attenuation, whereas IRE has proved to be effective in pain control.

CONCLUSIONS

Electroporation is bringing new hopes in LAPC management. The first aim of IRE is to offer a palliative treatment. Further efforts are needed for patient selection, as well as the use of IRE for 'margin accentuation' during surgical resection. Even if promising, IRE needs to be validated in large, randomized, prospective series.

Ablative, Endovascular, and Biliary Interventions for Patients with Pancreatic Cancer

Interventional radiologists have multiple points of involvement in the treatment and management of patients with pancreatic adenocarcinoma. There is increasing interest in cytoreductive treatment of the primary tumor as well as metastatic disease via arterial and ablative techniques. The focus of this article is on the current evidence for pancreatic irreversible electroporation. For patients undergoing curative surgery or terminal palliation, interventional radiology can manage complications and symptoms. In this article, therapeutic and palliative options in this group of patients including postoperative embolization, biliary drainage, and stent placement are reviewed.

Irreversible electroporation versus radiotherapy after induction chemotherapy on survival in patients with locally advanced pancreatic cancer: a propensity score analysis

BACKGROUND

Locally advanced pancreatic cancer (LAPC) represents more than one third of pancreatic cancers and owns poor survival after the standard chemotherapy. Irreversible electroporation (IRE) is a novel method and has been recently used in LAPC. The aim of this study was to compare the efficacy of IRE and radiotherapy after induction chemotherapy for patients with LAPC.

METHODS

From August 2015 to August 2017, a total of 76 patients with biopsy proven LAPC and who had received IRE or radiotherapy after chemotherapy were included. Thirty-two pairs of patients were selected through propensity score matching (PSM) analysis and the efficacy of two treatments was compared.

RESULTS

Before PSM analysis, after induction chemotherapy, patients with LAPC benefited more in terms of overall survival (OS) and progression free survival (PFS) from IRE, compared with radiotherapy (2-year OS rates, 53.5% vs 26.9%, p = 0.039; 2-year PFS rates, 28.4% vs 13.3%, p = 0.045). After PSM analysis, the survival benefits of OS and PFS of patients after induction chemotherapy followed by IRE were more obvious than those of patients treated with radiotherapy (2-year OS rates, 53.5% vs 20.7%, p = 0.011; 2-year PFS rates, 28.4% vs 5.6%, p = 0.004). Multivariate Cox regression analysis indicated that IRE after induction chemotherapy was identified as a significant favourable factor for both OS and PFS in both the whole and matched cohort.

CONCLUSIONS

Induction chemotherapy followed by IRE is superior to induction chemotherapy followed by radiotherapy for treating LAPC. A randomized clinical trial comparing the efficacy of IRE and radiotherapy after the induction chemotherapy is therefore considerable.