Electrochemotherapy in Mucosal Cancer of the Head and Neck: A Systematic Review

Electrochemotherapy (ECT) in treatment of mucosal head and neck tumors. An international network for sharing practices on ECT (InspECT) study group report

The aim of this multicenter study was to evaluate the effectiveness and safety of electrochemotherapy (ECT) for the treatment of mucosal tumors in the head and neck. A total of 71 patients with 84 nodules of different histologies in the oral cavity, pharynx and larynx treated by ECT were evaluated. The data were collected from the InspECT database from 10 participating centers throughout Europe. Primary and recurrent/secondary tumors of different histologies were treated. The overall response rate was 65 %, with a 33 % complete response rate with limited side effects. The response rates of the primary and secondary tumors were not different. However, smaller tumors responded better than tumors larger than 3 cm in diameter. Furthermore, the tumors that were treated with curative intent responded significantly better than those treated with palliative intent. This study demonstrated the feasibility, safety and effectiveness of ECT in a larger cohort of patients with mucosal lesions in the head and neck region. Based on the available data, ECT can be used for the treatment of recurrent and, in some cases, primary mucosal tumors located in the oral cavity, larynx, and pharynx. A better response was obtained in patients with smaller primary tumors treated with curative intent.

Treatment benefit of electrochemotherapy for superficial squamous cell carcinoma: a systematic review and single-arm meta-analysis

OBJECTIVE

Treating aggressive superficial squamous cell carcinoma (SCC) poses challenges due to invasiveness. Palliative care is recommended for inoperable cases with extensive tumors near vital organs, risking disfigurement or functional impairment. Electrochemotherapy (ECT) is an emerging cutaneous tumor treatment, but its efficacy against superficial SCC remains uncertain. This study conducts a systematic review and single-arm meta-analysis to evaluate ECT's effectiveness against superficial SCC and provide current evidence for clinical practice.

METHODS

Embase, PubMed and Cochrane Library were searched for studies up to May 2023. The random effects model analyzed complete response (CR) and partial response (PR), with subgroup assessment based on drug dosage, treatment response evaluation, tumor size, primary/recurrent status, and tumor location.

RESULTS

Ten studies involving 162 patients and 208 tumors were included. Pooled CR and PR rates for ECT-treated superficial SCC were 66.5% (95% CI 48.4%-82.5%; I2 = 84%) and 20.3% (95% CI 10.5%-32.3%; I2 = 70%), respectively. Subgroup analysis indicated ECT's superiority in treating primary tumors (PR: 70%, CR: 30%) and tumors ≤ 3 cm (PR: 81.3%, CR: 10.1%) compared to recurrent tumors (PR: 56.7%, CR: 36.5%) and tumors > 3 cm (PR: 45.2%, CR: 34.4%).

CONCLUSION

This single-arm meta-analysis confirms ECT's efficacy against superficial SCC, especially in primary tumors and those ≤ 3 cm in diameter. The study highlights the impact of tumor location and response evaluation on ECT's benefits, warranting further investigation through additional research.

Electrochemotherapy for head and neck cancers: possibilities and limitations

Head and neck cancer continues to be among the most prevalent types of cancer globally, yet it can be managed with appropriate treatment approaches. Presently, chemotherapy and radiotherapy stand as the primary treatment modalities for various groups and regions affected by head and neck cancer. Nonetheless, these treatments are linked to adverse side effects in patients. Moreover, due to tumor resistance to multiple drugs (both intrinsic and extrinsic) and radiotherapy, along with numerous other factors, recurrences or metastases often occur. Electrochemotherapy (ECT) emerges as a clinically proven alternative that offers high efficacy, localized effect, and diminished negative factors. Electrochemotherapy involves the treatment of solid tumors by combining a non-permeable cytotoxic drug, such as bleomycin, with a locally administered pulsed electric field (PEF). It is crucial to employ this method effectively by utilizing optimal PEF protocols and drugs at concentrations that do not possess inherent cytotoxic properties. This review emphasizes an examination of diverse clinical practices of ECT concerning head and neck cancer. It specifically delves into the treatment procedure, the choice of anti-cancer drugs, pre-treatment planning, PEF protocols, and electroporation electrodes as well as the efficacy of tumor response to the treatment and encountered obstacles. We have also highlighted the significance of assessing the spatial electric field distribution in both tumor and adjacent tissues prior to treatment as it plays a pivotal role in determining treatment success. Finally, we compare the ECT methodology to conventional treatments to highlight the potential for improvement and to facilitate popularization of the technique in the area of head and neck cancers where it is not widespread yet while it is not the case with other cancer types.

Nasal Cytology Changes in Head and Neck Cancer Treatment: A Systemic Review

Nasal cytology is a non-invasive, low-cost exam that can help physicians in the diagnosis of allergic and nonallergic rhinitis, discriminating between different nasal disorders. The aim of this review is to summarize and analyze the current knowledge about nasal cytological examination in head and neck cancer, with a specific focus on the effects of different treatments. Indeed, nasal cytology is important to choose the best treatment for nasal complaints in each patient. A review of the English literature (PubMed, Scopus, Cochrane) was performed (5404 records screened). The inclusion criteria were clinical trials, cohort studies, case-control studies, case series, and case reports regarding nasal cytology in head and neck cancer treatment. Exclusion criteria were as follows: non-human studies, non-English literature, non-cytological evaluations. Two independent reviewers, working separately, extracted the data from all the eligible studies, which were subsequently cross-checked. Five studies were included in qualitative synthesis: three assessed mucosal disorders after radiation therapy and two after total laryngectomy. Radiotherapy can determine mucous or squamous cell metaplasia and neutrophil inflammation. Laryngectomees show hyperplasia of the basal zone cells and mucous cell metaplasia, and they do not develop inflammatory changes. The main limitation of this review is the low number and heterogeneity of studies present in the literature. In conclusion, nasal cytology is useful and allows for identifying mucosal disorders of the nasal cavities after surgery and/or radiotherapy for head and neck cancer. This can help physicians to better treat the nasal complaints of such patients.

Recent Advancements in Electroporation Technologies: From Bench to Clinic

Over the past decade, the increased adoption of electroporation-based technologies has led to an expansion of clinical research initiatives. Electroporation has been utilized in molecular biology for mammalian and bacterial transfection; for food sanitation; and in therapeutic settings to increase drug uptake, for gene therapy, and to eliminate cancerous tissues. We begin this article by discussing the biophysics required for understanding the concepts behind the cell permeation phenomenon that is electroporation. We then review nano- and microscale single-cell electroporation technologies before scaling up to emerging in vivo applications.

The influence of asymmetrical bipolar pulses and interphase intervals on the bipolar cancellation phenomenon in the ovarian cancer cell line

The application of negative polarity electrical pulse (↓) following positive polarity pulses (↑) may induce bipolar cancellation (BPC), a unique physiological response believed to be specific to nanosecond electroporation (nsEP). The literature lacks analysis of bipolar electroporation (BP EP) involving asymmetrical sequences composed of nanosecond and microsecond pulses. Moreover, the impact of interphase interval on BPC caused by such asymmetrical pulse needs consideration. In this study, the authors utilized the ovarian clear carcinoma cell line (OvBH-1) model to investigate the BPC with asymmetrical sequences. Cells were exposed to pulses delivered in 10-pulse bursts but as uni- or bipolar, symmetrical, or asymmetrical sequences with a duration of 600 ns or 10 µs and electric field strength equal to 7.0 or 1.8 kV/cm, respectively. It was shown that the asymmetry of pulses influences BPC. The obtained results have also been investigated in the context of calcium electrochemotherapy. The reduction of cell membrane poration, and cell survival have been observed following Ca²⁺ electrochemotherapy. The effects of interphase delays (1 and 10 µs) on the BPC phenomenon were reported. Our findings show that the BPC phenomenon can be controlled using pulse asymmetry or delay between the positive and negative polarity of the pulse.

Treatment of spontaneous canine mast cell tumors by electrochemotherapy combined with IL-12 gene electrotransfer: Comparison of intratumoral and peritumoral application of IL-12

The combined treatment of electrochemotherapy (ECT) and interleukin-12 (IL-12) gene electrotransfer (GET) has already been used in clinical studies in dogs to treat various histological types of spontaneous tumors. The results of these studies show that the treatment is safe and effective. However, in these clinical studies, the routes of administration of IL-12 GET were either intratumoral (i.t.) or peritumoral (peri.t.). Therefore, the objective of this clinical trial was to compare the two IL-12 GET routes of administration in combination with ECT and their contribution to the enhanced ECT response. Seventy-seven dogs with spontaneous mast cell tumors (MCTs) were divided into three groups: one treated with a combination of ECT + GET peri. t. (29 dogs), the second with the combination of ECT + GET i.t. (30 dogs), and the third with ECT alone (18 dogs). In addition, immunohistochemical studies of tumor samples before treatment and flow cytometry of peripheral blood mononuclear cells (PBMCs) before and after treatment were performed to determine any immunological aspects of the treatment. The results showed that local tumor control was significantly better in the ECT + GET i.t. group (p < 0.050) than in the ECT + GET peri.t. or ECT groups. In addition, disease-free interval (DFI) and progression-free survival (PFS) were significantly longer in the ECT + GET i.t. group than in the other two groups (p < 0.050). The data on local tumor response, DFI, and PFS were consistent with immunological tests, as we detected an increased percentage of antitumor immune cells in the blood after treatment in the ECT + GET i.t. group, which also indicated the induction of a systemic immune response. In addition, we did not observe any unwanted severe or long-lasting side effects. Finally, due to the more pronounced local response after ECT + GET i.t., we suggest that treatment response assessment should be performed at least two months after treatment, which meets the iRECIST criteria.

Electrochemotherapy as an Effective Alternative in the Treatment of Local Advanced Oral Squamous Cell Carcinoma: A Retrospective Analysis of Treated Cases

Advanced oral squamous cell carcinomas represent a major challenge for maxillofacial surgeons, oncologists and radiation therapists. They also account for a large share of healthcare costs. They respond little and/or poorly to conventional therapies (surgery, radiotherapy and chemotherapy). Electrochemotherapy is a new method used as a palliative treatment in patients with advanced cancer of the neck/head region who are not eligible for standard therapies. It combines the use of cytotoxic drugs with the physical principle of electroporation; it effectively controls the tumour locally and preserves organ function. To date, ECT has been little used for oral mucosal tumours, as this is difficult to access for electrodes. We report six cases of advanced oral squamous cell carcinoma treated with electrochemotherapy. This study aims to assess the debulking effect of cancer via ECT in patients with advanced oral squamous cell carcinoma. It also aims to assess the safety and tolerability of this treatment.

Comparison of general anesthesia and continuous intravenous sedation for electrochemotherapy of head and neck skin lesions

Background

Electrochemotherapy of cutaneous tumor nodules requires local or general anesthesia. For multiple and larger nodules, general anesthesia is recommended by standard operating procedures. The choice of general anesthesia is at the discretion of the treating center. Continuous intravenous sedation is also an option. Our study aimed to elucidate the tolerability, safety and possible advantages of continuous intravenous sedation in comparison to general anesthesia in patients undergoing electrochemotherapy.

Patients and methods

In the prospective study, 27 patients undergoing electrochemotherapy were either under general anesthesia or under continuous intravenous sedation. Evaluated were different endpoints, such as feasibility and safety, duration of anesthesia and compliance with the patients.

Results

Ten patients were treated under general anesthesia, and 17 patients were under continuous intravenous sedation. The comparison of the approaches indicated that continuous intravenous sedation required a lower overall dosage of propofol, a shorter duration of anesthesia, a shorter time to reach an Aldrete score &gt;8, and greater satisfaction of the patients with the procedure compared to general anesthesia.

Conclusion

The results indicate the feasibility and safety of continuous intravenous sedation for patients undergoing electrochemotherapy of cutaneous tumor nodules. This proved the preferred choice of anesthesia due to its shorter duration and better compliance with the patients compared to general anesthesia.

Palliative repeated electroporations of oral tumours in dogs: A case series

Electrochemotherapy (ECT) is a highly developed treatment for many solid tumours that provides good local control in 80% of neoplasms in dogs. ECT can be used to treat different types of tumours, particularly as an innovative approach for non-resectable masses. As reported in the literature, electroporation-based treatments are safe, simple, fast and cost-effective treatment alternatives for selected oral and maxillofacial tumours not involving the bone in dogs (e.g., small squamous cell carcinoma or malignant melanoma). In this descriptive retrospective paper, the authors describe the outcome of various types of oral tumours treated with ECT as a palliative first line treatment or as a rescue treatment in dogs with local tumour recurrence. Nineteen dogs were included and treated with at least one session of three electroporations coupled with intravenous administration of bleomycin every 21 days. Tumour size, localization, histotype, stage, recurrence, solid tumour response evaluation criteria (RECIST), local toxicity, progression free survival (PFS) and median survival time (MST) were evaluated. The small population did not allow the analysis of the ECT response by comparing different tumour types; further studies with a larger caseload are needed. However, all dogs, despite the low MST, showed a good local response to treatment with a rapid improvement in quality of life from the first ECT application; no side effects attributable to chemotherapy have been detected and toxicity due to the electroporation was minimal and well tolerated in all dogs.

Electrochemotherapy: An Alternative Strategy for Improving Therapy in Drug-Resistant SOLID Tumors

Simple Summary

Chemotherapy is becoming an increasingly difficult antitumor therapy to practice due to the multiple mechanisms of drug resistance. To overcome the problem, it is possible to use alternative techniques, such as electrochemotherapy, which involves the simultaneous administration of the electrical pulse (electroporation) and the treatment with the drug in order to improve the effectiveness of the drug against the tumor. Electroporation has improved the efficacy of some chemotherapeutic agents, such bleomycin, cisplatin, mitomycin C, and 5-fluorouracil. The results of in vitro, veterinary, and clinical oncology studies are promising on various cancers, such as metastatic melanoma. The purpose of this review is to give an update on the state of the art of electrochemotherapy against the main solid tumors in the preclinical, clinical, and veterinary field.

Abstract

Electrochemotherapy (ECT) is one of the innovative strategies to overcome the multi drug resistance (MDR) that often occurs in cancer. Resistance to anticancer drugs results from a variety of factors, such as genetic or epigenetic changes, an up-regulated outflow of drugs, and various cellular and molecular mechanisms. This technology combines the administration of chemotherapy with the application of electrical pulses, with waveforms capable of increasing drug uptake in a non-toxic and well tolerated mechanical system. ECT is used as a first-line adjuvant therapy in veterinary oncology, where it improves the efficacy of many chemotherapeutic agents by increasing their uptake into cancer cells. The chemotherapeutic agents that have been enhanced by this technique are bleomycin, cisplatin, mitomycin C, and 5-fluorouracil. After their use, a better localized control of the neoplasm has been observed. In humans, the use of ECT was initially limited to local palliative therapy for cutaneous metastases of melanoma, but phase I/II studies are currently ongoing for several histotypes of cancer, with promising results. In this review, we described the preclinical and clinical use of ECT on drug-resistant solid tumors, such as head and neck squamous cell carcinoma, breast cancer, gynecological cancer and, finally, colorectal cancer.

Synthesis, characterization, antioxidant and anticancer activities of a new Schiff base and its M(II) complexes derived from 5-fluorouracil

In this study, Schiff base ligand was obtained from the condensation reaction of benzene-1,2-diamine and 5-fluoropyrimidine-2,4(1H,3H)-dione (5-FU). Metal(II) complexes were synthesized with Fe(II), Co(II) and Ni(II) chloride salts. The synthesized ligand and metal complexes were characterized by FT-IR, UV-vis, ¹H-¹³C NMR, elemental analyses, mass spectroscopy, magnetic moments, molar conductivity and thermogravimetric analysis studies. With the help of different techniques reveal Fe(II), Co(II) and Ni(II) complexes have exhibited tetrahedral and octahedral geometry. Ligand acted as bidentate and it binds metal(II) ions through deprotonated-NH, imine-N atom and carbonyl-O atom, respectively. DPPH, ABTS, FRAP, CUPRAC and total antioxidant activity methods were used to determine the antioxidant properties of ligand and metal complexes. According to the results, the synthesized compounds showed very high antioxidant activity compared to 5-FU. The cytotoxicities of the synthesized compounds were performed on MCF-7 (human breast cancer) and L-929 (fibroblast) cell lines using the MTT assay. In addition, the effect of electroporation (EP) on the cytotoxicity of the compounds was investigated. Our results demonstrated that novel Co(II) and Ni(II) complexes show potential as new anticancer agents and ECT may be a viable treatment option for breast cancer.

Sinonasal Side Effects of Chemotherapy and/or Radiation Therapy for Head and Neck Cancer: A Literature Review

Radiotherapy and chemotherapy represent important treatment modalities for head and neck cancer. Rhinosinusitis and smell alterations are common side effects in the sinonasal region. This review will summarize and analyze our current knowledge of the sinonasal side effects of chemotherapy and/or radiation therapy for head and neck cancer (HNC), with a specific focus on mucosal and olfactory disorders. A review of the English literature was performed using several databases (PubMed, Embase, Cochrane, Scopus). Fifty-six articles were included in qualitative synthesis: 28 assessed mucosal disorders (rhinitis or rhinosinusitis), 26 evaluated olfactory alterations, and 2 articles addressed both topics. The incidence and severity of olfactory dysfunction and chronic rhinosinusitis were highest at the end of radiotherapy and at three months after treatment and decreased gradually over time. Smell acuity deterioration and chronic rhinosinusitis seemed to be related to radiation dose on olfactory area and nasal cavities, but different degrees of recovery were observed. In conclusion, it is important to establish the severity of chronic rhinosinusitis and olfactory dysfunction in order to find strategies to support patients and improve their quality of life.

Influence of extremely low-frequency magnetic field on chemotherapy and electrochemotherapy efficacy in human Caco-2 colon cancer cells

Although chemotherapy (CT) has some adverse effects on healthy tissues and cells, it is widely preferred for treating patients with cancer. Drug resistance is one of the major impediments to successful cancer treatment. Electrochemotherapy (ECT) is a technique where cancer cells are rendered permeable to medications. Thanks to this permeability, the dose of the medication required for cancer treatment decreases. Our aim in this study is to examine the effects of short-term extremely low-frequency magnetic fields (ELF-MFs) on CT and ECT treatments in Caco-2 colon cancer cells. The Caco-2 cancer cells were treated with 5-fluorouracil (5-FU, 50 µM) and ECT (strength:1125 V/cm, duration:100 µs, frequency:1 Hz), alone as well as in combinations with ELF-MF (4 mT, 10 min). MTT assay was used to determine the efficacy of the treatments. Our findings in the study showed that ECT was much more successful than 5-FU treatment alone in Caco-2 colon cancer cells. Application of 4 mT ELF-MF after CT significantly increased the viability of the Caco-2 cancer cells compared to the CT group alone (p < .05). An increase in the viability of cells treated with 4 mT after ECT was observed compared to ECT alone. Similarly, there was an increase in the viability of cells treated with MF prior to ECT treatment (p < .05). The results show that exposure to ELF-MF at 4 mT flux density significantly reduces CT and ECT treatment efficacy in Caco-2 colon cancer cells.

Quality of Life in Electrochemotherapy for Cutaneous and Mucosal Head and Neck Tumors

BACKGROUND

Primary or recurrent head and neck cancer of skin or mucosa represents a challenge for clinicians and could be debilitating for the patient. Electrochemotherapy (ECT) emerged as a local ablative procedure for cutaneous and mucosal head and neck tumors. The aim of this observational study was the evaluation of quality of life (QoL) after ECT in patients without other surgical or radiation options as curative treatment.

MATERIALS AND METHODS

The procedure was performed according the ESOPE (European Standard Operating procedure of Electrochemotherapy) protocol. Twenty-seven patients were evaluated before ECT (T0) and 1 (T1), 3 (T2), and 6 (T3) months after the procedure. QoL was assessed by means of the EORTC QLQ-C30 and EORTC QLQ-H&N35 questionnaires.

RESULTS

The objective tumor response rate was 48% (11% CR, 37% PR). Bleeding control was achieved in 7/7 patients who experienced bleeding prior to ECT. QoL improvement was observed after the procedure. In particular, global health status and social functioning were higher after ECT (p 0.026 and 0.043), while pain, pain-killers use and appetite loss decreased (p 0.045, 0.025 and 0.002).

CONCLUSION

ECT represents a safe and effective treatment for skin and mucosal head and neck tumors without other curative options. It ensures a good pain and bleeding control without worsening of QoL.