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Hadzialjevic B, Omerzel M, Trotovsek B, Cemazar M, Jesenko T, Sersa G, Djokic M. Electrochemotherapy combined with immunotherapy - a promising potential in the treatment of cancer. Front Immunol 2024; 14:1336866. [PMID: 38292489 PMCID: PMC10825954 DOI: 10.3389/fimmu.2023.1336866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 12/29/2023] [Indexed: 02/01/2024] Open
Abstract
Electrochemotherapy is a novel, locoregional therapy that is used to treat cutaneous and deep-seated tumors. The electric pulses used in electrochemotherapy increase the permeability of the cell membranes of the target lesion and thus enhance the delivery of low-permeant cytotoxic drugs to the cells, leading to their death. It has also been postulated that electrochemotherapy acts as an in situ vaccination by inducing immunogenic cell death. This in turn leads to an enhanced systemic antitumor response, which could be further exploited by immunotherapy. However, only a few clinical studies have investigated the role of combined treatment in patients with melanoma, breast cancer, hepatocellular carcinoma, and cutaneous squamous cell carcinoma. In this review, we therefore aim to review the published preclinical evidence on combined treatment and to review clinical studies that have investigated the combined role of electrochemotherapy and immunotherapy.
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Affiliation(s)
- Benjamin Hadzialjevic
- Department of Abdominal Surgery, University Medical Center Ljubljana, Ljubljana, Slovenia
- Department of Surgery, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Masa Omerzel
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Blaz Trotovsek
- Department of Abdominal Surgery, University Medical Center Ljubljana, Ljubljana, Slovenia
- Department of Surgery, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Maja Cemazar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
- Faculty of Health Sciences, University of Primorska, Izola, Slovenia
| | - Tanja Jesenko
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Gregor Sersa
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
- Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - Mihajlo Djokic
- Department of Abdominal Surgery, University Medical Center Ljubljana, Ljubljana, Slovenia
- Department of Surgery, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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2
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Das R, Langou S, Le TT, Prasad P, Lin F, Nguyen TD. Electrical Stimulation for Immune Modulation in Cancer Treatments. Front Bioeng Biotechnol 2022; 9:795300. [PMID: 35087799 PMCID: PMC8788921 DOI: 10.3389/fbioe.2021.795300] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/17/2021] [Indexed: 12/17/2022] Open
Abstract
Immunotherapy is becoming a very common treatment for cancer, using approaches like checkpoint inhibition, T cell transfer therapy, monoclonal antibodies and cancer vaccination. However, these approaches involve high doses of immune therapeutics with problematic side effects. A promising approach to reducing the dose of immunotherapeutic agents given to a cancer patient is to combine it with electrical stimulation, which can act in two ways; it can either modulate the immune system to produce the immune cytokines and agents in the patient's body or it can increase the cellular uptake of these immune agents via electroporation. Electrical stimulation in form of direct current has been shown to reduce tumor sizes in immune-competent mice while having no effect on tumor sizes in immune-deficient mice. Several studies have used nano-pulsed electrical stimulations to activate the immune system and drive it against tumor cells. This approach has been utilized for different types of cancers, like fibrosarcoma, hepatocellular carcinoma, human papillomavirus etc. Another common approach is to combine electrochemotherapy with immune modulation, either by inducing immunogenic cell death or injecting immunostimulants that increase the effectiveness of the treatments. Several therapies utilize electroporation to deliver immunostimulants (like genes encoded with cytokine producing sequences, cancer specific antigens or fragments of anti-tumor toxins) more effectively. Lastly, electrical stimulation of the vagus nerve can trigger production and activation of anti-tumor immune cells and immune reactions. Hence, the use of electrical stimulation to modulate the immune system in different ways can be a promising approach to treat cancer.
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Affiliation(s)
- Ritopa Das
- Department of Biomedical Engineering, University of Connecticut, Mansfield, CT, United States
| | - Sofia Langou
- Department of Physiology and Neurobiology, University of Connecticut, Mansfield, CT, United States
| | - Thinh T. Le
- Department of Mechanical Engineering, University of Connecticut, Mansfield, CT, United States
| | - Pooja Prasad
- Department of Cell and Molecular Biology, University of Connecticut, Mansfield, CT, United States
| | - Feng Lin
- Department of Mechanical Engineering, University of Connecticut, Mansfield, CT, United States
| | - Thanh D. Nguyen
- Department of Biomedical Engineering, University of Connecticut, Mansfield, CT, United States
- Department of Mechanical Engineering, University of Connecticut, Mansfield, CT, United States
- Institute of Materials Science, University of Connecticut, Mansfield, CT, United States
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Russano F, Del Fiore P, Di Prata C, Pasqual A, Marconato R, Campana LG, Spina R, Gianesini CM, Collodetto A, Tropea S, Dall’Olmo L, Carraro S, Parisi A, Galuppo S, Scarzello G, De Terlizzi F, Rastrelli M, Mocellin S. The Role of Electrochemotherapy in the Cutaneous and Subcutaneous Metastases From Breast Cancer: Analysis of Predictive Factors to Treatment From an Italian Cohort of Patients. Front Oncol 2021; 11:772144. [PMID: 34993137 PMCID: PMC8724516 DOI: 10.3389/fonc.2021.772144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/29/2021] [Indexed: 11/29/2022] Open
Abstract
The treatment of cutaneous and subcutaneous localizations from breast cancer (BC) is still a therapeutic challenge. Electrochemotherapy (ECT) is one of the available options, and it is characterized by the association between the administration of a chemotherapic agent (Bleomycin) with the temporary raise of permeability of the cellular membrane induced by the local administration of electrical impulses (electroporation). ECT represents an effective therapy for loco-regional control of this disease. This study aimed to investigate the predictive factors of response in cutaneous and subcutaneous localizations from breast cancer treated with ECT. We decided to evaluate the response to this treatment in 55 patients who underwent ECT between January 2013 and March 2020 at our Institute. We performed a monocentric retrospective cohort study. ECT was administered following the ESOPE (European Standard Operative Procedure of Electrochemotherapy) guidelines, a set of criteria updated in 2018 by a panel of European experts on ECT who defined the indications for selecting the patients who can benefit from the ECT treatment and the ones for technically performing the procedure. The responses were evaluated with the RECIST criteria (Response Evaluation Criteria in Solid Tumor). We found after 12 weeks of treatment a complete response (CR) in 64% of our patients. From the analysis divided for subgroups of covariates is emerged that lower BMI, reduced body surface, and absence of previous radiation treatment could be predictive for a better complete response. This study suggests that the efficacy of the ECT treatment is related to the concurrent systemic therapies while administering ECT. The association between ECT and immunotherapy has offered better results than the association between ECT and chemotherapy (p-value = 0.0463). So, ECT is a valuable tool in the treatment of cutaneous and subcutaneous metastases from breast cancer and its efficacy in local control of these lesions improves when it is well planned in a therapeutic scenario.
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Affiliation(s)
- Francesco Russano
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | - Paolo Del Fiore
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
- *Correspondence: Paolo Del Fiore,
| | - Claudia Di Prata
- Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
| | - Andrea Pasqual
- Department of Medicine, University of Padua, Padua, Italy
| | - Roberto Marconato
- Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
| | - Luca Giovanni Campana
- Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
| | - Romina Spina
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | - Carlo Maria Gianesini
- Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
| | - Alessandra Collodetto
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | - Saveria Tropea
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | - Luigi Dall’Olmo
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
- Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
| | - Sabrina Carraro
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | - Alessandro Parisi
- Radiotherapy Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | - Sara Galuppo
- Radiotherapy Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | - Giovanni Scarzello
- Radiotherapy Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
| | | | - Marco Rastrelli
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
- Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
| | - Simone Mocellin
- Soft-Tissue, Peritoneum and Melanoma Surgical Oncology Unit, Veneto Institute of Oncology, IOV-IRCCS, Padua, Italy
- Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
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Bleomycin Concentration in Patients' Plasma and Tumors after Electrochemotherapy. A Study from InspECT Group. Pharmaceutics 2021; 13:pharmaceutics13091324. [PMID: 34575400 PMCID: PMC8469090 DOI: 10.3390/pharmaceutics13091324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/14/2021] [Accepted: 08/19/2021] [Indexed: 11/16/2022] Open
Abstract
The plasma concentration profile of bleomycin in the distribution phase of patients younger than 65 years is needed to determine the suitable time interval for efficient application of electric pulses during electrochemotherapy. Additionally, bleomycin concentrations in the treated tumors for effective tumor response are not known. In this study, the pharmacokinetic profile of bleomycin in the distribution phase in 12 patients younger than 65 years was determined. In 17 patients, the intratumoral bleomycin concentration was determined before the application of electric pulses. In younger patients, the pharmacokinetics of intravenously injected bleomycin demonstrated a faster plasma clearance rate than that in patients older than 65 years. This outcome might indicate that the lowering of the standard bleomycin dose of 15,000 IU/m2 with intravenous bleomycin injection for electrochemotherapy is not recommended in younger patients. Based on the plasma concentration data gathered, a time interval for electrochemotherapy of 5-15 min after bleomycin injection was determined. The median bleomycin concentration in tumors 8 min after bleomycin injection, at the time of electroporation, was 170 ng/g. Based on collected data, the reduction of the bleomycin dose is not recommended in younger patients; however, a shortened time interval for application of electric pulses in electrochemotherapy to 5-15 min after intravenous bleomycin injection should be considered.
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Campana LG, Edhemovic I, Soden D, Perrone AM, Scarpa M, Campanacci L, Cemazar M, Valpione S, Miklavčič D, Mocellin S, Sieni E, Sersa G. Electrochemotherapy - Emerging applications technical advances, new indications, combined approaches, and multi-institutional collaboration. Eur J Surg Oncol 2018; 45:92-102. [PMID: 30528893 DOI: 10.1016/j.ejso.2018.11.023] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 11/30/2018] [Indexed: 12/18/2022] Open
Abstract
The treatment of tumors with electrochemotherapy (ECT) has surged over the past decade. Thanks to the transient cell membrane permeabilization induced by the short electric pulses used by ECT, cancer cells are exposed to otherwise poorly permeant chemotherapy agents, with consequent increased cytotoxicity. The codification of the procedure in 2006 led to a broad diffusion of the procedure, mainly in Europe, and since then, the progressive clinical experience, together with the emerging technologies, have extended the range of its application. Herein, we review the key advances in the ECT field since the European Standard Operating Procedures on ECT (ESOPE) 2006 guidelines and discuss the emerging clinical data on the new ECT indications. First, technical developments have improved ECT equipment, with custom electrode probes and dedicated tools supporting individual treatment planning in anatomically challenging tumors. Second, the feasibility and short-term efficacy of ECT has been established in deep-seated tumors, including bone metastases, liver malignancies, and pancreatic and prostate cancers (long-needle variable electrode geometry ECT), and gastrointestinal tumors (endoscopic ECT). Moreover, pioneering studies indicate lung and brain tumors as suitable future targets. A further advance relates to new combination strategies with immunotherapy, gene electro transfer (GET), calcium EP, and radiotherapy. Finally and fourth, cross-institutional collaborative groups have been established to refine procedural guidelines, promote clinical research, and explore new indications.
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Affiliation(s)
- Luca G Campana
- Department of Surgery Oncology and Gastroenterology (DISCOG), University of Padua, Italy; Surgical Oncology, Veneto Institute of Oncology IOV-IRCCS, Padua, Italy.
| | - Ibrahim Edhemovic
- Department of Surgical Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | | | - Anna M Perrone
- Oncologic Gynecology Unit, Sant'Orsola-Malpighi Hospital, Bologna, Italy
| | - Marco Scarpa
- Surgical Oncology, Veneto Institute of Oncology IOV-IRCCS, Padua, Italy
| | - Laura Campanacci
- 3rd Orthopaedic and Traumatologic Clinic Prevalently Oncologic, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Maja Cemazar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Sara Valpione
- Christie NHS Foundation Trust, CRUK Manchester Institute, The University of Manchester, Manchester, M20 4GJ, UK
| | - Damijan Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia
| | - Simone Mocellin
- Department of Surgery Oncology and Gastroenterology (DISCOG), University of Padua, Italy; Surgical Oncology, Veneto Institute of Oncology IOV-IRCCS, Padua, Italy
| | - Elisabetta Sieni
- Department of Industrial Engineering, University of Padua, Italy
| | - Gregor Sersa
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
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Groselj A, Kranjc S, Bosnjak M, Krzan M, Kosjek T, Prevc A, Cemazar M, Sersa G. Vascularization of the tumours affects the pharmacokinetics of bleomycin and the effectiveness of electrochemotherapy. Basic Clin Pharmacol Toxicol 2018; 123:247-256. [DOI: 10.1111/bcpt.13012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 03/12/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Ales Groselj
- Department of Otorhinolaryngology and Cervicofacial Surgery; University Medical Centre Ljubljana; Ljubljana Slovenia
- Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
| | - Simona Kranjc
- Department of Experimental Oncology; Institute of Oncology Ljubljana; Ljubljana Slovenia
| | - Masa Bosnjak
- Department of Experimental Oncology; Institute of Oncology Ljubljana; Ljubljana Slovenia
| | - Mojca Krzan
- Faculty of Medicine; Department of Pharmacology and Experimental Toxicology; University of Ljubljana; Ljubljana Slovenia
| | - Tina Kosjek
- Department of Environmental Sciences; Jozef Stefan Institute; Ljubljana Slovenia
| | - Ajda Prevc
- Department of Experimental Oncology; Institute of Oncology Ljubljana; Ljubljana Slovenia
| | - Maja Cemazar
- Department of Experimental Oncology; Institute of Oncology Ljubljana; Ljubljana Slovenia
- Faculty of Health Sciences; University of Primorska; Izola Slovenia
| | - Gregor Sersa
- Department of Experimental Oncology; Institute of Oncology Ljubljana; Ljubljana Slovenia
- Faculty of Health Sciences; University of Ljubljana; Ljubljana Slovenia
- Faculty of Health Sciences; University of Primorska; Izola Slovenia
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Tremble LF, O'Brien MA, Forde PF, Soden DM. ICOS activation in combination with electrochemotherapy generates effective anti-cancer immunological responses in murine models of primary, secondary and metastatic disease. Cancer Lett 2018; 420:109-115. [PMID: 29408339 DOI: 10.1016/j.canlet.2018.01.081] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 12/21/2022]
Abstract
Electrochemotherapy is an evolving therapy which has recently been shown to induce an immunogenic form of cell death. It is hypothesized that the immunogenic cell death induced by electrochemotherapy may compliment the responses seen with anti-cancer immunotherapies. We therefore examined the effect of electrochemotherapy in combination with ICOS activation, which promotes the activity of previously activated T cells. In comparison to either monotherapy which resulted in no curative outcomes in any model, in a CT26 primary tumour 50% of mice were cured, with 100% of cured mice surviving tumour rechallenge. In a dual flank CT26 model mimicking secondary disease 20% of mice were cured, and 30% of mice were cured using an aggressively metastatic Lewis Lung Carcinoma model. We have shown the novel combination of electrochemotherapy with ICOS activation can inhibit local and distal tumour growth, including total tumour clearance with long lasting immunological memory.
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Affiliation(s)
- Liam F Tremble
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Western Road, Cork, Ireland
| | - Morgan A O'Brien
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Western Road, Cork, Ireland
| | - Patrick F Forde
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Western Road, Cork, Ireland.
| | - Declan M Soden
- Cork Cancer Research Centre, Western Gateway Building, University College Cork, Western Road, Cork, Ireland
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Norum OJ, Fremstedal ASV, Weyergang A, Golab J, Berg K. Photochemical delivery of bleomycin induces T-cell activation of importance for curative effect and systemic anti-tumor immunity. J Control Release 2017; 268:120-127. [PMID: 29042319 DOI: 10.1016/j.jconrel.2017.10.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/09/2017] [Accepted: 10/13/2017] [Indexed: 12/27/2022]
Abstract
Photochemical internalization (PCI) is a technology to enhance intracellular drug delivery by light-induced translocation of endocytosed therapeutics into the cytosol. The aim of this study was to explore the efficacy of PCI-based delivery of bleomycin and the impact on systemic anti-tumor immunity. Mouse colon carcinoma cells (CT26.CL25), stably expressing the bacterial β-galactosidase, were inoculated into the legs of athymic or immuno-competent BALB/c mice strains. The mice were injected with the photosensitizer AlPcS2a and bleomycin (BLM) prior to tumor light exposure from a 670nm diode laser. Photochemical activation of BLM was found to induce synergistic inhibition of tumor growth as compared to the sum of the individual treatments. However, a curative effect was not observed in the athymic mice exposed to 30J/cm2 of light while >90% of the thymic mice were cured after exposure to only 15J/cm2 light. Cured thymic mice, re-challenged with CT26.CL25 tumor cells on the contralateral leg, rejected 57-100% of the tumor cells inoculated immediately and up to 2months after the photochemical treatment. T-cells from the spleen of PCI-treated mice were found to inhibit the growth of CT26.CL25 cells in naïve thymic mice with a 60% rejection rate. The results show that treatment of CT26.CL25 tumors in thymic mice by PCI of BLM induces a systemic anti-tumor immunity.
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Affiliation(s)
- Ole-Jacob Norum
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital - Radium Hospital, Montebello, 0379 Oslo, Norway; Division of Orthopaedic Surgery, Oslo University Hospital, Montebello, 0379 Oslo, Norway
| | - Ane Sofie Viset Fremstedal
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital - Radium Hospital, Montebello, 0379 Oslo, Norway
| | - Anette Weyergang
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital - Radium Hospital, Montebello, 0379 Oslo, Norway
| | - Jakub Golab
- Department of Immunology, Medical University of Warsaw, 1A Banacha Str, F building, 02-097 Warsaw, Poland
| | - Kristian Berg
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital - Radium Hospital, Montebello, 0379 Oslo, Norway.
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Abstract
Anti-tumor electrochemotherapy, which consists in increasing anti-cancer drug uptake by means of electroporation, is now implanted in about 140 cancer treatment centers in Europe. Its use is supported by the English National Institute for Health and Care Excellence for the palliative treatment of skin metastases, and about 13,000 cancer patients were treated by this technology by the end of 2015. Efforts are now focused on turning this local anti-tumor treatment into a systemic one. Electrogenetherapy, that is the electroporation-mediated transfer of therapeutic genes, is currently under clinical evaluation and has brought excitement to enlarge the anti-cancer armamentarium. Among the promising electrogenetherapy strategies, DNA vaccination and cytokine-based immunotherapy aim at stimulating anti-tumor immunity. We review here the interests and state of development of both electrochemotherapy and electrogenetherapy. We then emphasize the potent beneficial outcome of the combination of electrochemotherapy with immunotherapy, such as immune checkpoint inhibitors or strategies based on electrogenetherapy, to simultaneously achieve excellent local debulking anti-tumor responses and systemic anti-metastatic effects.
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Hribernik A, Cemazar M, Sersa G, Bosnjak M, Snoj M. Effectiveness of electrochemotherapy after IFN-α adjuvant therapy of melanoma patients. Radiol Oncol 2016; 50:21-7. [PMID: 27069446 PMCID: PMC4825333 DOI: 10.1515/raon-2015-0048] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 11/30/2015] [Indexed: 12/21/2022] Open
Abstract
Background The combination of electrochemotherapy with immuno-modulatory treatments has already been explored and proven effective. However, the role of interferon alpha (IFN-α) adjuvant therapy of melanoma patients and implication on electrochemotherapy effectiveness has not been explored yet. Therefore, the aim of the study was to retrospectively evaluate the effectiveness and safety of electrochemotherapy after the previous adjuvant treatment with IFN-α in melanoma patients. Patients and methods The study was a retrospective single-center observational analysis of the patients with advanced melanoma, treated with electrochemotherapy after previous IFN-α adjuvant therapy. Five patients, treated between January 2008 and December 2014, were included into the study, regardless of the time point of IFN-α adjuvant therapy. Results Electrochemotherapy of recurrent melanoma after the IFN-α adjuvant therapy proved to be a safe and effective treatment. Patients with one or two metastases responded completely. Among patients with multiple metastases, there was a variable response rate. In one patient all 23 metastases responded completely, in second patient more than 85% of all together 80 metastases responded completely and in third patient all 5 metastases had partial response. Taking into account all metastases from all patients together there was an 85% complete response rate. Conclusions The study showed that electrochemotherapy of recurrent melanoma after the IFN-α adjuvant therapy is a safe and effective treatment modality, which results in a high complete response rate, not only in single metastasis, but also in multiple metastases. The high complete response rate might be due to an IFN-α immune-editing effect, however, further studies with a larger number of patients are needed to support this presumption.
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Affiliation(s)
- Andrejc Hribernik
- Department of Surgical Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Maja Cemazar
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Gregor Sersa
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Maša Bosnjak
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
| | - Marko Snoj
- Department of Surgical Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia
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11
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Sersa G, Teissie J, Cemazar M, Signori E, Kamensek U, Marshall G, Miklavcic D. Electrochemotherapy of tumors as in situ vaccination boosted by immunogene electrotransfer. Cancer Immunol Immunother 2015; 64:1315-27. [PMID: 26067277 PMCID: PMC4554735 DOI: 10.1007/s00262-015-1724-2] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 05/26/2015] [Indexed: 12/21/2022]
Abstract
Electroporation is a platform technology for drug and gene delivery. When applied to cell in vitro or tissues in vivo, it leads to an increase in membrane permeability for molecules which otherwise cannot enter the cell (e.g., siRNA, plasmid DNA, and some chemotherapeutic drugs). The therapeutic effectiveness of delivered chemotherapeutics or nucleic acids depends greatly on their successful and efficient delivery to the target tissue. Therefore, the understanding of different principles of drug and gene delivery is necessary and needs to be taken into account according to the specificity of their delivery to tumors and/or normal tissues. Based on the current knowledge, electrochemotherapy (a combination of drug and electric pulses) is used for tumor treatment and has shown great potential. Its local effectiveness is up to 80 % of local tumor control, however, without noticeable effect on metastases. In an attempt to increase systemic antitumor effectiveness of electrochemotherapy, electrotransfer of genes with immunomodulatory effect (immunogene electrotransfer) could be used as adjuvant treatment. Since electrochemotherapy can induce immunogenic cell death, adjuvant immunogene electrotransfer to peritumoral tissue could lead to locoregional effect as well as the abscopal effect on distant untreated metastases. Therefore, we propose a combination of electrochemotherapy with peritumoral IL-12 electrotransfer, as a proof of principle, using electrochemotherapy boosted with immunogene electrotransfer as in situ vaccination for successful tumor treatment.
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Affiliation(s)
- Gregor Sersa
- Department of Experimental Oncology, Institute of Oncology Ljubljana, Zaloska 2, 1000, Ljubljana, Slovenia,
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12
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Consolidation electrochemotherapy with bleomycin in metastatic melanoma during treatment with dabrafenib. Radiol Oncol 2015; 49:71-4. [PMID: 25810704 PMCID: PMC4362609 DOI: 10.2478/raon-2014-0035] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 07/31/2014] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Small molecules that inhibit V600 mutated BRAF protein, such as vemurafenib and dabrafenib, are effective in treatment of metastatic melanoma. CASE REPORT We here describe the clinical course of a V600E BRAF mutated metastatic melanoma patient with systemic disease, who developed tumor progression on superficial soft-tissue metastases during treatment with dabrafenib. Bleomycin electrochemotherapy during dabrafenib treatment was administered to control the soft-tissue progressing metastases and ensured sustained local control without significant toxicity. CONCLUSIONS The new combined approach maintained the patient quality of life and allowed for the prosecution of the target therapy, which proved to be still effective on systemic disease, up to 17 months.
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Cadossi R, Ronchetti M, Cadossi M. Locally enhanced chemotherapy by electroporation: clinical experiences and perspective of use of electrochemotherapy. Future Oncol 2014; 10:877-90. [PMID: 24799067 DOI: 10.2217/fon.13.235] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Electroporation is used to enhance drug diffusion and gene delivery into the cytosol. The combination of electroporation and cytotoxic drugs, electrochemotherapy (ECT), is used to treat metastatic tumor nodules located at the skin and subcutaneous tissue. The objective response rate following a single session of treatment exceeds 80%, with minimal toxicity for the patients. The efficacy of ECT in the bone and visceral metastasis is currently investigated, and Phase II studies have been completed. ECT has been used to treat skin primary tumors, except melanoma, and is under investigation for locally advanced pancreatic cancer. Early evidence suggests that treatment of tumor nodules with ECT recruits components of the immune system and eliciting a systemic immune response against cancer is a challenging clinical perspective. Considering the proven safety in several different clinical applications electroporation should be viewed as a clinical platform technology with wide perspectives for use in ECT, gene therapy and DNA vaccination.
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Affiliation(s)
- Ruggero Cadossi
- Clinical Research, IGEA SpA, Via Parmenide 10/A, Carpi, Italy
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14
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Calvet CY, Famin D, André FM, Mir LM. Electrochemotherapy with bleomycin induces hallmarks of immunogenic cell death in murine colon cancer cells. Oncoimmunology 2014; 3:e28131. [PMID: 25083316 PMCID: PMC4111940 DOI: 10.4161/onci.28131] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/04/2014] [Accepted: 02/06/2014] [Indexed: 01/08/2023] Open
Abstract
Electrochemotherapy (ECT) is a local cancer treatment that has been used over the course of more than 2 decades for the removal of cutaneous and subcutaneous tumors. Several lines of evidence support the premise that the immune system is an important factor underlying anticancer treatment efficacy, potentially including patient responses to ECT. The concept of immunogenic cell death (ICD) arose a few years ago, stating that some cancer treatments generate danger-associated molecular patterns (DAMPs) that trigger an adaptive immune response against tumors. Hence, dying cancer cells behave as a therapeutic vaccine, eliciting a cytotoxic immune response against surviving malignant cells. In our study, we sought to evaluate the ability of ECT to generate cancer cell death encompassing the immunostimulatory characteristics of ICD. To this end, we assayed CT26 murine colon cancer cells in vitro in response to either electric pulses (EPs) application only or in combination with the anticancer drug bleomycin (that is ECT) by quantification of calreticulin (CRT) membrane externalization, as well as the liberation of adenosine triphosphate (ATP) and high mobility group box 1 (HMGB1) protein. We show here that cell permeabilizing yet non-lethal electric pulses induce CRT exposure on the cell surface of EP-only treated cancer cells, as well as ATP release. However, the association of electric pulses along with the chemotherapeutic agent bleomycin was mandatory for HMGB1 release coincident with regimen-induced cell death. These data obtained in vitro were then substantiated by vaccination protocols performed in immunocompetent mice, showing that the injection of dying ECT-treated cells elicits an antitumor immune response that prevents the growth of a subsequent administration of viable cancer cells. We also confirmed previous results showing ECT treatment is much more efficient in immunocompetent animals than in immunodeficient ones, causing complete regressions in the former but not in the latter. This supports a central role for immunity in this beneficial outcome. In conclusion, we show that ECT not only possesses an intrinsic cytotoxic property toward cancer cells but also generates a systemic anticancer immune response via the activation of ICD. Hence, ECT may represent an interesting approach to treat solid tumors while preventing recurrence and metastasis, possibly in combination with immunostimulating agents.
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Affiliation(s)
- Christophe Y Calvet
- Univ Paris-Sud; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; CNRS, Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; Gustave Roussy; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France
| | - Delphine Famin
- Univ Paris-Sud; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; CNRS, Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; Gustave Roussy; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France
| | - Franck M André
- Univ Paris-Sud; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; CNRS, Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; Gustave Roussy; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France
| | - Lluis M Mir
- Univ Paris-Sud; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; CNRS, Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France ; Gustave Roussy; Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, UMR 8203; Villejuif, France
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Potentiation of electrochemotherapy by intramuscular IL-12 gene electrotransfer in murine sarcoma and carcinoma with different immunogenicity. Radiol Oncol 2012; 46:302-11. [PMID: 23412658 PMCID: PMC3572893 DOI: 10.2478/v10019-012-0044-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 08/15/2012] [Indexed: 01/08/2023] Open
Abstract
Background. Electrochemotherapy provides good local tumor control but requires adjuvant treatment for increased local response and action on distant metastasis. In relation to this, intramuscular interleukin-12 (IL-12) gene electro-transfer, which provides systemic shedding of IL-12, was combined with local electrochemotherapy with cisplatin. Furthermore, the dependence on tumor immunogenicity and immunocompetence of the host on combined treatment response was evaluated. Materials and methods. Sensitivity of SA-1 sarcoma and TS/A carcinoma cells to electrochemotherapy with cisplatin was tested in vitro. In vivo, intratumoral electrochemotherapy with cisplatin (day 1) was combined with a single (day 0) or multiple (days 0, 2, 4) intramuscular murine IL-12 (mIL-12) gene electrotransfer. The antitumor effectiveness of combined treatment was evaluated on immunogenic murine SA-1 sarcoma in A/J mice and moderately immunogenic murine TS/A carcinoma, in immunocompetent BALB/c and immunodeficient SCID mice. Results. Electrochemotherapy in vitro resulted in a similar IC50 values for both sarcoma and carcinoma cell lines. However, in vivo electrochemotherapy was more effective in the treatment of sarcoma, the more immunogenic of the tumors, resulting in a higher log cell kill, longer specific tumor growth delay, and also 17% tumor cures compared to carcinoma where no tumor cures were observed. Adjuvant intramuscular mIL-12 gene electrotransfer increased the log cell kill in both tumor models, potentiating the specific tumor growth delay by a factor of 1.8-2 and increasing tumor cure rate by approximately 20%. In sarcoma tumors, the potentiation of the response by intramuscular mIL-12 gene electrotransfer was dose-dependent and also resulted in a faster onset of tumor cures. Comparison of the carcinoma response to the combined treatment modality in immunocompetent and immunodeficient mice demonstrated that the immune system is needed both for increased cell kill and for attaining tumor cures. Conclusions. Based on the comparison of the antitumor effectiveness of electrochemotherapy to intratumoral cisplatin administration, we can conclude that the fraction of cells killed and the tumor cure rate are higher in immunogenic sarcoma tumor compared to moderately immunogenic carcinoma tumor. The tumor cell kill and cure rate depend on the immune response elicited by the destroyed tumor cells, which might depend on the tumor immunogenicity. The effect of adjuvant intramuscular mIL-12 gene electrotransfer is dependent on the amount of IL-12 in the system and the immune competence of the host, as demonstrated by the dose-dependent increase in the cure rate of SA-1 tumors after multiple intramuscular mIL-12 gene electrotransfer and in the differential cure rate of TS/A tumors growing in immunocompetent and immunodeficient mice.
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16
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Gothelf A, Mir LM, Gehl J. Electrochemotherapy: results of cancer treatment using enhanced delivery of bleomycin by electroporation. Cancer Treat Rev 2003; 29:371-87. [PMID: 12972356 DOI: 10.1016/s0305-7372(03)00073-2] [Citation(s) in RCA: 333] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Over the last decade a new cancer treatment modality, electrochemotherapy, has emerged. By using short, intense electric pulses that surpass the capacitance of the cell membrane, permeabilization can occur (electroporation). Thus, molecules that are otherwise non-permeant can gain direct access to the cytosol of cells in the treated area.A highly toxic molecule that does not usually pass the membrane barrier is the hydrophilic drug bleomycin. Once inside the cell, bleomycin acts as an enzyme creating single- and double-strand DMA-breaks. The cytotoxicity of bleomycin can be augmented several 100-fold by electroporation. Drug delivery by electroporation has been in experimental use for cancer treatment since 1991. This article reviews 11 studies of electrochemotherapy of malignant cutaneous or subcutaneous lesions, e.g., metastases from melanoma, breast or head- and neck cancer. These studies encompass 96 patients with altogether 411 malignant tumours. Electroporation was performed using plate or needle electrodes under local or general anaesthesia. Bleomycin was administered intratumourally or intravenously prior to delivery of electric pulses. The rates of complete response (CR) after once-only treatments were between 9 and 100% depending on the technique used. The treatment was well tolerated and could be performed on an out-patient basis.
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Affiliation(s)
- Anita Gothelf
- Department of Oncology, Rigshospitalet, University of, Copenhagen, Denmark
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Cabrales LB, Ciria HC, Bruzón RP, Quevedo MS, Aldana RH, De Oca LM, Salas MF, Peña OG. Electrochemical treatment of mouse Ehrlich tumor with direct electric current. Bioelectromagnetics 2001; 22:316-22. [PMID: 11424154 DOI: 10.1002/bem.56] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Electrochemical treatment of cancer utilizes direct electric current (DEC) to produce direct alterations and chemical changes in tumors. However, the DEC treatment is not established and mechanisms are not well understood. In vivo studies were conducted to evaluate the effectiveness of DEC on animal tumor models. Ehrlich tumors were implanted subcutaneously in sixty male BALB/c mice. When the tumor volumes reached 850 mm(3), four platinum electrodes were inserted into the tumors. DEC of 4 mA was applied for 21 min to the treated group; the total charge was 5 C. The healthy and sick control groups were subjected to the same conditions but without DEC. Hematological and chemical parameters as well as histopathological and peritumoral findings were studied. After the electrochemical therapy it was observed that both tumor volume decrease and necrosis percentage increase were significant in the treated group. Moreover, 24 h after treatment an acute inflammatory response, as well as sodium ion decrease, and potassium ion and spleen weight increase were observed in this group. It was concluded that both electrochemical reactions (fundamentally those in which reactive oxygen species are involved), and immune system stimulation induced by cytotoxic action of the DEC could constitute the most important antitumor mechanisms.
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Affiliation(s)
- L B Cabrales
- División de Magnetoterapia, Centro Nacional de Electromagnetismo Aplicado, Universidad de Oriente, Santiago de Cuba, Cuba.
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Omura S, Tsuyuki Y, Ohta S, Li X, Bukawa H, Fujita K. Rapid tumor necrosis induced by electrochemotherapy with intratumoral injection of bleomycin in a hamster tongue cancer model. Int J Oral Maxillofac Surg 2000. [DOI: 10.1016/s0901-5027(00)80008-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Omura S, Tsuyuki Y, Ohta S, Bukawa H, Fujita K. In vivo antitumor effects of electrochemotherapy in a tongue cancer model. J Oral Maxillofac Surg 1999; 57:965-72. [PMID: 10437724 DOI: 10.1016/s0278-2391(99)90019-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE This study investigated the in vivo antitumor effects of electrochemotherapy (ECT) using electroporation and bleomycin in a hamster tongue cancer model to assess its clinical applicability. MATERIALS AND METHODS Twenty animals with chemically induced tongue cancer were divided into four experimental groups designated B-E-, B-E+, B+E-, and B+E+. The B+E+ and B+E- groups received an intraperitoneal injection of 100 microg bleomycin. Fifteen minutes after the injection, the B+E+ animals received electric pulses. The B-E+ group received only electric pulses. The B-E- group received neither bleomycin nor electric pulses. Each group received the same treatment twice. The antitumor effects were assessed based on tumor volume reduction and histologic findings. RESULTS The B+E+ group showed remarkable tumor volume reduction, decreasing an average to 8.8% of its original volume 14 days after the treatment. Complete loss of the protruding tumor was observed in two of the five animals. Histologically, the tumors of the B+E+ group consisted of severely degenerated tumor cells and desquamative keratinizing cells. No living cancer cells were detected in three animals. The B+E-, B-E+, and B-E- groups showed progressive tumor growth, exceeding 200% of initial tumor volume during the experimental period. CONCLUSION The current study showed remarkable antitumor effects of ECT with bleomycin in the hamster tongue cancer model. ECT with bleomycin may be clinically applicable to the treatment of oral cancer.
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Affiliation(s)
- S Omura
- Department of Oral and Maxillofacial Surgery, Yokohama City University School of Medicine, Japan.
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Chazal M, Benchimol D, Baqué P, Pierrefite V, Milano G, Bourgeon A. Treatment of hepatic metastases of colorectal cancer by electrochemotherapy: an experimental study in the rat. Surgery 1998. [PMID: 9736907 DOI: 10.1016/s0039-6060(98)70100-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Electrochemotherapy, which consist of local or systemic administration of a cytotoxic agent followed by application of electric pulses to a tumor, has proved effective for various types of tumors in animals and for cutaneous and head and neck cancers in human beings. This is the first study to investigate the efficacy of electrochemotherapy for treatment of hepatic metastases of colorectal cancer in the rat. METHODS After induction of a solitary hepatic metastasis in 36 male BDIX rats, the animals were randomized to one of four groups: B-E-(no treatment), B+E-(intratumoral bleomycin), B-E+ (application of electric pulses to the tumor), and B+E+ (electrochemotherapy: intratumoral bleomycin followed by application of electric pulses). RESULTS Groups B-E and B-E+ had no tumor response. Group B+E had one partial response. Group B+E+ had seven partial responses and two complete responses. The difference in terms of response between group B+E+ and the other three groups was statistically significant (P < .05). Comparison of the mean posttherapy tumor volumes (B-E-, 50.6 mm3; B+E-, 58.7 mm3; B-E+, 46 mm3; and B+E+, 5.65 mm3) revealed a significantly smaller residual tumor in group B+E+ than in the other three groups (P < .05). CONCLUSIONS Electrochemotherapy is an effective means to reduce the volume of hepatic metastases of colorectal cancer in the rat. Additional research is required to determine the optimum treatment duration, dose effects, volume of tumor that can be treated by electrochemotherapy, and impact on survival. Such experimental studies are indispensable prerequisites for clinical trials.
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Affiliation(s)
- M Chazal
- Service de Chirurgie Abdominale et Thoracique, Hpital de 1 Archet 11, Nice France
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Cemazar M, Miklavcic D, Sersa G. Intrinsic sensitivity of tumor cells to bleomycin as an indicator of tumor response to electrochemotherapy. Jpn J Cancer Res 1998; 89:328-33. [PMID: 9600128 PMCID: PMC5921803 DOI: 10.1111/j.1349-7006.1998.tb00566.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Electrochemotherapy (ECT) involves the use of locally applied electric pulses to increase delivery of chemotherapeutic drugs into cells in tissues. ECT with bleomycin (BLM) is a very effective local treatment, but different tumors have different response rates to ECT. The aim of our study was to compare the responsiveness of SA-1 and EAT tumors to BLM and ECT in vitro and in vivo, in order to find possible reasons for the observed difference in response rate. The difference in sensitivity to ECT in vitro between the SA-1 and EAT cells was 10-fold and was the same as the difference in sensitivity to chronic BLM exposure, as measured by tetrazolium-based colorimetric (MTT) assay. This difference in sensitivity between SA-1 and EAT to ECT was also reflected in tumor cure rate. A six-times lower dose of BLM was needed to obtain local tumor control in SA-1 than in EAT tumors. Therefore, we suggest that the difference in sensitivity to BLM and ECT predominantly reflects the difference in intrinsic sensitivity of the cells to BLM.
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Affiliation(s)
- M Cemazar
- Department of Tumor Biology, Institute of Oncology, Ljubljana, Slovenia
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