Effects of calcium electroporation, electrochemotherapy, and irreversible electroporation on quality of life and progression-free survival in patients with pancreatic cancer: IREC clinical study

Background. According to the National Cancer Registry, 3486 people (1744 men and 1742 women) were diagnosed with pancreatic adenocarcinoma in Poland in 2018, resulting in 4908 deaths (2396 men and 2512 women). The only chance of successful treatment is through surgical resection, which is possible in only 20–30% of patients (stage I, II and some stage III cases).The remaining 70–80% of patients are those with stage III and IV disease, for whom resection is not possible. Mean survival in these patients is approx. 10.4 months (stage III). In the recent decade, an innovative method called electroporation, which involves destabilization of the cell membrane, has been established. This process can be reversible (RE) or irreversible (IRE), and leads to cell death. The ability to change membrane permeability has led to the development of novel methods involving electrochemotherapy (ECT) and calcium electroporation (CaEP) to treat solid tumors. Objectives. In this study, both ECT and CaEP will be used to treat pancreatic cancer patients with poor prognosis. For each patient, the best “therapeutic moment” for the procedure will be selected based on the therapeutic protocol. Materials and methods. Patients will receive reversible and irreversible electroporation (control arm-group A), CaEP (active arm-group B), or ECT with intravenous and intratumoral administration of bleomycin (active arm-group C) randomized 1:1:1. Results. The primary endpoints will be progression-free survival (PFS) and patients’ quality of life (QOL) assessed using the EORTC-PAN 26 scale. Secondary endpoints will be patient overall survival (OS), body weight, pain level, and levels of biomarkers such as Ca 19-9. Conclusions. The Irreversible Electroporation, ELectrochemotherapy and Calcium electroporation (IREC) study is necessary to examine the safety and efficiency of irreversible electroporation, electrochemotherapy and calcium electroporation in pancreatic cancer treatment.


Introduction
2][3] The fiveyear survival rate does not exceed than 7-8% and most patients are diagnosed at stage III or above, which means the tumor cannot be resected. 1As a result, this diagnosis is practically a death sentence for the patient.5][6][7] These regimens have been shown to be more effective than the previous regimens in terms of overall survival (OS) by several weeks, and on this basis they are considered superior and registered for clinical use.
Due to the anatomical location of the pancreas, the use of conventional local ablative therapy has not proven effective due to the thermal effect and the possibility of damaging large vessels and bile ducts.One method that has begun to be used in pancreatic cancer treatment is electroporation. 8,9This involves the placement of electrodes and the administration of short electrical pulses (up to 100 μs) with electric field strengths in the range of 1500-3000 V/cm.1][12][13] This method has started to be used in pancreatic, 14 liver 15 and prostate cancer treatments. 16The IRE has been shown to be effective in palliative treatment of pancreatic cancer. 17Notably, it has proved so effective that it has found its way into the British National Institute for Health and Clinical Excellence (NICE) standards for the treatment of melanoma and head and neck cancers.A protocol for its use, in combination with chemotherapy (CTH), is also described in the European Standard Operating Procedures of Electrochemotherapy (ESCOPE) for the treatment of cutaneous and subcutaneous lesions. 18n investigations of electroporation, this method has begun to be combined with chemotherapeutics.0][21][22][23][24][25] This has led to the emergence of the new field of electrochemotherapy (ECT).The drugs used in ECT include bleomycin and cisplatin, which can be administered intravenously or intratumorally. 26][29][30][31][32][33] Calcium ion electroporation (CaEP) is another recent advance in the treatment of solid tumors.5][36][37][38][39][40] It has also been demonstrated that ECT induces an immune response. 328][29][30][31][32] Moreover, ECT "breaks" chemo-resistance in solid tumors by using a vascular effect and "trapping" the chemotherapeutic agent in the region of the tumor. 25,33his concept has been shown to be efficacious and is used as a standard treatment of skin and subcutaneous cancers.In addition, there is currently a study underway to apply this method to colorectal cancers.In the course of our research, we have applied this method to patients with pancreatic cancer, which was published as the first application of its kind in the world. 41leomycin was selected as the most active chemotherapeutic agent.Originally, belomycin in ECT was used for treatment of head and neck cancer, melanoma, basal cell carcinoma (BCC) skin lesions, squamous cell carcinoma (SCC), and braest cancer.3][44][45][46] Other chemotherapeutic agents that have been tested for efficacy in vitro include daunorubicin, doxorubicin, etoposide, paclitaxel, gemcitabine, 5-fluorouracil, carboplatin, and cisplatin.While daunorubicin, etoposide, and paclitaxel were reported to be ineffective in vitro, cisplatin and bleomycin were found to be the most effective. 31,47leomycin was also found to be the most effective drug in ECT for pancreatic cancer in vitro while also increasing the immune response of the body. 38,48,49Furthermore, in an animal model, ECT with bleomycin was shown to be effective in the treatment of pancreatic cancer. 21,50he results of studies involving patients with stage III pancreatic cancer are encouraging; however, the number of procedures performed is small, 51 and the results are similar to studies on the efficacy of ECT for metastatic liver lesions. 42,52,53he ECT and CaEP are evolving therapies for which there are few studies involving only a small number of recruited patients.However, these treatments enable personalized medicine, are feasible for older patients, and offer hope of treatment to patients whose prognosis is already poor upon diagnosis.Since 2018, a project entitled "Electrochemotherapy of solid tumors of the gastrointestinal tract: research on the application of electrochemotherapy in pancreatic cancer with unresectable or oligometastatic lesions" has been conducted at the Wroclaw Medical University, Poland, after receiving approval from the Bioethics Committee (approval No. KB-330/2018).

IREC project assumptions
The project entitled "Effects of calcium electroporation, electrochemotherapy and irreversible electroporation (CaEP, ECT and IRE) on quality of life and progression-free survival in patients with pancreatic cancer" aims to answer questions about the efficacy of electroporation (group A) compared with CaEP (group B) and ECT with bleomycin (group C) in patients with unresectable pancreatic cancer.The safety of these 3 treatments will be compared, as well as their efficacy measured as progression-free survival (PFS) and OS.Another important factor being investigated is patients' quality of life (QOL) after surgery, which will be assessed using the EORTC-PAN 26 scale.
If a patient is qualified for the treatment, their data will be entered into the Case Report Form (CRF) system and the procedures will be performed at the 2 nd Department of General Surgery and Surgical Oncology of Wroclaw Medical University or at a partner center possessing the required equipment and levels of staff experience on a referral basis.Data on the treatment and hospital stay will be entered into the system.Data will include information regarding both the procedure and hospital stay.The inclusion and exclusion criteria are listed in Table 1.Patients will receive follow-up at the center where the procedure was performed for consultation and imaging examination at 1 month, 3 months and 6 months after treatment, and then every 6 months thereafter.Examinations are permitted as part of the drug program, as well as measurement of hemoglobin (Hb) [g/dL], Ca 19-9 [U/mL], protein levels [g/L], and albumin [mg/mL].Patients will be assessed as part of a clinical trial, with examinations ending upon patient death or the end of the project.
In order to jointly implement the planned project, collaboration has been established with Dr. Julie Gehl (Department of Clinical Oncology and Palliative Care, Zealand University Hospital, Roskilde, Denmark), who is a pioneer and specialist in CaEP.Doctor Gehl will contribute human and organizational resources to the project under the conditions specified in the agreement or partnership contract.

Study eligibility and IREC inclusion and exclusion criteria
The study group (Table 1) includes non-pregnant patients over the age of 18 years with unresectable pancreatic cancer (stage III), which represents the largest population at the time of diagnosis, as well as patients who have undergone resection but have had local recurrence.Histopathological confirmation of the malignancy is required, although intraoperative examination is permissible.A lesion infiltrating the superior mesenteric vein exceeding 180% of the circumference of the celiac artery, superior mesenteric artery, hepatic artery, or aorta is considered unresectable.Furthermore, patients require computed tomography (CT) scans not more than 30 days prior to joining the study.Patients with cardiac arrhythmias or pacemakers/defibrillators are disqualified due to potential device failure and synchrony of the NanoKnife device with the P wave of the electrocardiogram (ECG).Patients allergic to bleomycin or with pulmonary fibrosis are also excluded due to bleomycin administration in group C.
Patients with stage IV disease will not be eligible for the program due to the previous experience of the center and latent frailty syndrome.

Project implementation
After providing informed consent to participate in this study, patients will be randomized to 3 groups: • group A: patients undergoing IRE; • group B: patients undergoing CaEP.After electroporation, patients will be administered an appropriate dose of intratumoral calcium ions (CaCl 2 ) calculated with relation to tumor volume; or • group C: patients undergoing electrochemotherapy with intravenous and intratumoral administration of bleomycin at a dose of 15,000 IU/m 2 as a bolus over 30-60 s, approx.8-28 min before the electroporation procedure, and simultaneously intratumorally at 1000 IU/mL at a dose of 1000 UI/cm 2 in lesions less than 1 cm and 250 UI/cm 2 in lesions larger than 1 cm 3 .
All procedures will be performed under general anesthesia and following the administration of muscle relaxants to negate potential muscle spasm when the pulse is administered.A single dose of intravenous antibiotics will also be given perioperatively.The procedure will be carried out using the conventional percutaneous method.Due to complaints of postoperative pain, patients will be administered additional epidural anesthesia during the procedure, which will be maintained for 72 h.In the case of patients with gastrointestinal obstruction or hyperbilirubinemia, palliative procedures (by-pass) will be performed at the same time.
During the hospital stay, patients will be monitored daily for any deterioration in condition by analyzing morphology and Ca19-9, amylase and lipase levels.Patients will be treated with analgesics, anticoagulants and fluid therapy according to the recognized standards and individual patient's needs.Discharge will take place when their clinical condition stabilizes.Following hospital discharge, all patients will be referred to a clinical oncologist for systemic treatment in accordance with the guidelines.

Patient monitoring
Patients will be assessed as part of the clinical trial for 12 months.Each follow-up examination will consist of: • physical examination (body weight, body mass index -BMI); • health assessment according to World Health Organization (WHO); • pain assessment according to visual analogue scale (VAS); • QOL according to European Organization for Research and Treatment of Cancer (EORTC) QLQ-PAN 26 scale; • Hb level; • total protein level; • serum albumin level; • Ca19-9 marker level.
Imaging examinations utilizing abdominal CT or magnetic resonance imaging (MRI) will be performed at 1 month, 3 months, 6 months, and 1 year following treatment.Patient asessment schedule is presented in Table 2.As the majority of systemically treated patients in the drug programs already have imaging examinations scheduled, these can be used as follow-up examinations.If they are not scheduled, imaging will be prescribed by the examiner.

Analysis of the obtained results and conclusions of the IREC study
The results obtained in this non-commercial clinical trial will be compared with the results of patients who did not receive electroporation for the treatment of pancreatic cancer.Retrospective analyses will be allowed for comparison, but only for the group treated with the same chemotherapeutic regimens used as part of the current standard of care, namely, FOLFIRINOX, gemcitabine and nab-paclitaxel regimens.The PFS and QOL will be compared.One interesting result will be the OS of both groups.At present, the mean OS for stage III pancreatic cancer patients is 8-10 months from the time of diagnosis.Treatment with electroporation, CaEP or ECT has been performed in the 2 nd Department of General Surgery and Surgical Oncology at Wroclaw Medical University in 15 patients at various stages, achieving a mean survival of 26 months from diagnosis; notably, 7 of these patients are still alive.
Three of the primary outcomes are: 1) assessment of improvements in QOL using the EORTC QOL-PAN26 scale; 2) reduction of pain on the VAS; and 3) increases in body weight and protein and albumin levels as indications of patient well-being.Quality of life will be compared between patients who have undergone ablation and those who have not.
A number of secondary studies will be included as part of this project, including the determination of the Ca19-9 marker for predicting the best "therapeutic moment" and the efficacy of electroporation, CaEP and ECT.Groups A, B and C will be compared to each other in terms of safety of use and routes of administration of bleomycin and Ca 2+ ions.The comparison will include administration safety and dose.Secondary studies will also include any relevant postoperative complications measured on the Clavien-Dindo scale and the length of hospitalization.
On the basis of data concerning malignant progression (stage, tumor size and tumor location) and co-morbidities Albumin level [g/dL] X X X X Ca 19-9 market level [U/mL] X X X X CT/MRI X X X X BMI -body mass index; WHO -World Health Organization; VAS -visual analogue scale; CT -computed tomography; MRI -magnetic resonance imaging; EORTC -European Organization for Research and Treatment of Cancer.
using the Charlson Comorbidity Index, we will select a group of patients from those we believe will benefit most from the treatments.Patients will be individually analyzed in terms of the best "therapeutic moment" which, in the future, may be important in relation to new standards of management and the inclusion of this method as part of the treatment regimen for pancreatic cancer.The effectiveness of the method will be assessed using abdominal MR and/or abdominal CT.The control methods will be compared and the most effective will be selected.The characteristic changes after IRE and their predictive value for OS and PFS will also be assessed.Overall, this study will evaluate the effectiveness and safety of IRE, CaEP and ECT with bleomycin in the treatment of non-resectable pancreatic cancer.It will also address the question of which of these methods is the safest and most effective, and at which point during treatment a patient should be qualified for this procedure.The IREC project may contribute to the inclusion of a new therapeutic method in the treatment regimen for pancreatic cancer.

Table 1 .
Inclusion and exclusion criteria for the IREC project process • tumor size not larger than 6 cm on a CT scan not older than 30 days • patients undergoing chemotherapy or patients with a "de novo" diagnosis of pancreatic cancer • lesion defined as unresectable (infiltration of mesenteric vein or portal vein exceeding180 degrees or its thrombosis, infiltration of the hepatic artery, celiac artery or superior mesenteric artery) on abdominal CT not older than 30 days (stage III), or patients after resection with local recurrence of the neoplastic

Table 2 .
Patient assessment chart for the IREC project