Electrochemotherapy of superficial tumors - Current status:: Basic principles, operating procedures, shared indications, and emerging applications

Quality of life of women with recurrent vulvar cancer treated with electrochemotherapy

BACKGROUND

The quality of life of patients undergoing oncologic treatment has become an important issue in recent years. Owing to potential mutilation following surgery for vulvar cancer, more conservative approaches have evolved with the integration of new local ablative therapies, such as electrochemotherapy. The aim of this study was to determine the quality of life of women with vulvar cancer recurrence treated with electrochemotherapy for nonpalliative purposes.

PATIENTS AND METHODS

Eleven patients with vulvar cancer recurrence were treated with electrochemotherapy from July 2020 to December 2023. Patients completed different questionnaires: the EuroQol - 5 Dimension (EQ-5D), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Vulva Cancer 34 (EORTC QLQ-VU34) and visual analog pain scale (VAS) before and one, three and six months after electrochemotherapy. As a control group, fifteen patients with vulvar cancer recurrence treated with wide local excision completed the EORTC QLQ-C30 and VAS questionnaires before surgery and three and six months after surgery.

RESULTS

No significant differences in EQ-5D scores were found between quality of life before electrochemotherapy and at each follow-up visit. A comparison of the EORTC QLQ-C30 scores between the electrochemotherapy and surgery groups showed a significant difference in physical functioning, fatigue, insomnia, and global health status three months after the procedure and in role, cognitive, social functioning and appetite loss six months after the procedure, all of which were in favor of the electrochemotherapy group. The EORTC QLQ-VU34 questionnaire showed improvements in urinary symptoms and symptoms related to scarring and mutilation of the external genitalia in the electrochemotherapy group. The VAS score did not differ significantly between the electrochemotherapy and surgical groups.

CONCLUSIONS

The study showed that the quality of life after treatment with electrochemotherapy is better in some segments than after surgical treatment.

Comparison of Chemotherapy Combined with Percutaneous Electroporation and Chemotherapy Alone in the Management of Locally Advanced Gallbladder Carcinoma (GBC): A Study Protocol

PURPOSE

This study aims to evaluate the feasibility and efficacy of chemotherapy combined with irreversible electroporation (IRE) in patients with locally advanced gallbladder carcinoma (GBC) presenting as gallbladder masses.

MATERIALS AND METHODS

Patients with unresectable GBC masses of size greater than 2 cm and less than 6 cm without evidence of distant metastases and with no contraindication to general anaesthesia will be enrolled in the study. They will be randomized using computer generated table into two arms with 1:1 allocation ratio to include 15 patients in each group. Group I will be the chemotherapy alone arm and Group II will be the combined image-guided irreversible electroporation of the tumour and chemotherapy arm. The primary outcome assessed shall be the clinical benefit rate (complete response, CR; partial response, PR and stable disease, SD) based on the mRECIST criteria and overall survival. The secondary outcome shall be feasibility and safety of the procedure and quality of life pre and post procedure. The quality of life will be assessed by a questionnaire as given by EORTC-Quality of Life Group before starting therapy and 4 weeks after completion of therapy.

EXPECTED GAIN OF KNOWLEDGE

The combined local and systemic effects of irreversible electroporation and systemic chemotherapy respectively may improve the outcomes in inoperable cases of gallbladder carcinoma.

TRIAL REGISTRATION

Clinical Trials Registry - India ( https://ctri.nic.in/Clinicaltrials/advancesearchmain.php ). Identifier: CTRI/2021/05/033803. Primary Register of the International Clinical Trials Registry Platform (WHO ICTRP) ( http://www.who.int/ictrp/search/en/ ).

Treatment strategies with electrochemotherapy for limb in-transit melanoma: Real-world outcomes from a European, retrospective, cohort study

BACKGROUND

This study analysed treatment strategies with electrochemotherapy (ECT) in melanoma with limb in-transit metastases (ITM).

METHODS

We audited AJCC v.8 stage IIIB-IIID patients treated across 22 centres (2006-2020) within the International Network for Sharing Practices of ECT (InspECT).

RESULTS

452 patients were included, 58 % pre-treated (93 % had lower limb ITM, 44 % had ≤10 metastases [median size 1.5 cm]. Treatment strategies included first-line ECT (n = 145, 32 %), ECT with concurrent locoregional/systemic treatment (n = 163, 36 %), and salvage ECT (n = 144, 32 %). The objective response rate was 63 % (complete response [CR], 24 %), increasing to 74 % (CR, 39 %) following retreatment (median two ECT, range 1-8). CR rate in treatment-naïve and pre-treated patients was 50 % vs 32 % (p < 0.001). Bleomycin de-escalation was associated with lower CR (p = 0.004). Small tumour number and size, hexagonal electrode, retreatment, and post-ECT skin ulceration predicted response in multivariable analysis. At a median follow-up of 61 months, local and locoregional recurrence occurred in 55 % and 81 % of patients. Median local progression-free, new lesions-free, and regional recurrence-free survival were 32.9, 6.9, and 7.7 months. Grade-3 toxicity was 15 %. Concurrent treatment and CR correlated with improved regional control and survival. Concomitant checkpoint inhibition did not impact toxicity or survival outcomes. The median overall survival was 5.7 years.

CONCLUSIONS

Among patients with low-burden limb-only ITM, standard-dose bleomycin ECT results in durable local response. Treatment naivety, low tumour volume, hexagonal electrode application, retreatment, and post-ECT ulceration predict response. CR and concurrent treatment correlate with improved regional control and survival outcomes. Combination with checkpoint inhibitors is safe but lacks conclusive support.

Electrochemotherapy Treatment in a Patient with an Extended Basal Cell Carcinoma of the Face: A Case Report

BACKGROUND

Basal cell carcinomas (BCCs) are common human malignancies with a rising incidence in recent years. While BCCs have a low mortality rate, they are often associated with significant local skin damage characterized by erythema, skin ulceration, and persistent pigmentation. Surgery, radiotherapy, and systemic chemotherapy have traditionally been the principal treatments for these skin injuries. However, electrochemotherapy has recently been proposed as a novel local treatment with promising results for various skin cancers, including BCC, while avoiding the side effects of conventional therapies. ECT involves a local electrical stimulus that enhances cell membrane permeability, thereby enabling the targeted intracellular accumulation of the chemotherapeutic agent.

CASE REPORT

We report a case of a 68-year-old man with an ulcerated BCC, following his progress up to 14 months post-ECT treatment, with positive outcomes.

DISCUSSION AND CONCLUSIONS

We achieved a complete clinical response and noted an improvement in the patient's quality of life. This technique is fast, repeatable, requires minimal hospitalization, and reduces healthcare costs and adverse effects compared to major surgery. Therefore, it can be considered an alternative or complementary approach to traditional surgery for treating BCC of the head and neck.

First report of a neurofibrosarcoma in the penis of a bull

Reproductive problems in cattle are frequent and have an important impact on production. In addition, inflammatory, traumatic and other diseases may be followed by the development of tumours, which are a cause of culling of breeding males. The main types of tumours diagnosed in the bull penis are fibropapilloma and squamous cell carcinoma. The aim of this study was to characterize a case of a tumour in the glans penis of a bull from a dairy farm in Santa Fe, Argentina. The neoplastic tissue was stained with haematoxylin and eosin and then analysed by immunohistochemistry to reveal its characteristic phenotype. Results showed positivity to vimentin, neuron specific enolase, proliferating cell nuclear antigen, S100 and glial fibrillary acidic protein. This suggested that the tumour was a neoplasm of neural origin, classified as neurofibrosarcoma, a peripheral nerve sheath tumour, here reported in the penis of a bull for the first time.

Metastatic patterns and treatment options for head and neck cutaneous squamous cell carcinoma (Review)

According to current predictions, one-fifth of all Americans will develop skin cancer during their lifetime. Cutaneous squamous cell carcinoma (cSCC) most commonly occurs in the head and neck region, which is the area of the body with the highest level of sun exposure. High-risk head and neck cSCC (HNcSCC) is a broad category with numerous high-risk factors that are associated with unfavorable results. In cSCC staging systems, clinical and tumor traits that are likely to result in poor outcomes are identified. Metastasis occurs in ~2.5% of patients with cSCC, most often in the local lymph nodes, and there is some indication that lymph node metastasis has a distinct pattern based on the tumor site. Current findings on tumor molecular targets have suggested the use of systemic treatments, particularly immunotherapy (such as cemiplimab, pembrolizumab and nivolumab), over radiotherapy or chemotherapy for this type of metastasis. However, when used simultaneously with immunotherapy, radiotherapy may be beneficial in the treatment of metastatic HNcSCC by improving the efficacy of immunotherapy. The present review aims to assess the existing literature on metastatic HNcSCC pathways and treatment options, in order to define current and future directions. Notably, there is an urgent need to identify patients who may benefit from local or systemic cancer treatments. The treatment of lymph node metastasis presents a therapeutic challenge and requires comprehensive management.

Treatment of vulvar cancer recurrence with electrochemotherapy: a case-control study

BACKGROUND

Electrochemotherapy (ECT) is a combined treatment method based on electroporation and simultaneous chemotherapy. In cases where radiotherapy has previously been used, surgery is often the only treatment option for vulvar cancer recurrence with potential resection of clitoris, vagina, urethra or anal sphincter. The unique advantage of ECT is its selectivity for cancer cells while sparing the surrounding healthy tissue. The aim of the study was to compare the ECT treatment of vulvar cancer recurrence for non-palliative purposes with surgical treatment.

MATERIALS AND METHODS

Eleven patients with single vulvar cancer recurrence were treated with ECT and followed up for 12 months. As a control group, 15 patients with single vulvar cancer recurrence were treated with wide local excision. The following data were collected, analyzed and compared: Age, body mass index, comorbidities, histological type, location and size of vulvar cancer recurrence, treatment history, details of procedures and hospital stay.

RESULTS

The probability curves for local tumor control did not differ between the ECT group and the surgical group (p = 0.694). The mean hospital stay and the mean duration of procedure were statistically significantly shorter in the ECT group (p < 0.001). There were no statistically significant differences between the ECT and surgical groups in terms of mean body mass index, associated diseases, previous treatments, presence of lichen sclerosus, p16 status, gradus, anatomical site of the tumor, and type of anesthesia.

CONCLUSION

In this case-control study, treatment of vulvar cancer recurrence with ECT for non-palliative purposes was comparable to surgical treatment in terms of effectiveness. The results need to be confirmed in larger randomized trials.

The equivalence of different types of electric pulses for electrochemotherapy with cisplatin - an in vitro study

BACKGROUND

Electrochemotherapy (ECT) is a treatment involving the administration of chemotherapeutics drugs followed by the application of 8 square monopolar pulses of 100 μs duration at a repetition frequency of 1 Hz or 5000 Hz. However, there is increasing interest in using alternative types of pulses for ECT. The use of high-frequency short bipolar pulses has been shown to mitigate pain and muscle contractions. Conversely, the use of millisecond pulses is interesting when combining ECT with gene electrotransfer for the uptake of DNA-encoding proteins that stimulate the immune response with the aim of converting ECT from a local to systemic treatment. Therefore, the aim of this study was to investigate how alternative types of pulses affect the efficiency of the ECT.

MATERIALS AND METHODS

We performed in vitro experiments, exposing Chinese hamster ovary (CHO) cells to conventional ECT pulses, high-frequency bipolar pulses, and millisecond pulses in the presence of different concentrations of cisplatin. We determined cisplatin uptake by inductively coupled plasma mass spectrometry and cisplatin cytotoxicity by the clonogenic assay.

RESULTS

We observed that the three tested types of pulses potentiate the uptake and cytotoxicity of cisplatin in an equivalent manner, provided that the electric field is properly adjusted for each pulse type. Furthermore, we quantified that the number of cisplatin molecules, resulting in the eradication of most cells, was 2-7 × 107 per cell.

CONCLUSIONS

High-frequency bipolar pulses and millisecond pulses can potentially be used in ECT to reduce pain and muscle contraction and increase the effect of the immune response in combination with gene electrotransfer, respectively.

Electrochemotherapy combined with immunotherapy - a promising potential in the treatment of cancer

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.

Laser-induced vapor nanobubbles for B16-F10 melanoma cell killing and intracellular delivery of chemotherapeutics

The most lethal form of skin cancer is cutaneous melanoma, a tumor that develops in the melanocytes, which are found in the epidermis. The treatment strategy of melanoma is dependent on the stage of the disease and often requires combined local and systemic treatment. Over the years, systemic treatment of melanoma has been revolutionized and shifted toward immunotherapeutic approaches. Phototherapies like photothermal therapy (PTT) have gained considerable attention in the field, mainly because of their straightforward applicability in melanoma skin cancer, combined with the fact that these strategies are able to induce immunogenic cell death (ICD), linked with a specific antitumor immune response. However, PTT comes with the risk of uncontrolled heating of the surrounding healthy tissue due to heat dissipation. Here, we used pulsed laser irradiation of endogenous melanin-containing melanosomes to induce cell killing of B16-F10 murine melanoma cells in a non-thermal manner. Pulsed laser irradiation of the B16-F10 cells resulted in the formation of water vapor nanobubbles (VNBs) around endogenous melanin-containing melanosomes, causing mechanical cell damage. We demonstrated that laser-induced VNBs are able to kill B16-F10 cells with high spatial resolution. When looking more deeply into the cell death mechanism, we found that a large part of the B16-F10 cells succumbed rapidly after pulsed laser irradiation, reaching maximum cell death already after 4 h. Practically all necrotic cells demonstrated exposure of phosphatidylserine on the plasma membrane and caspase-3/7 activity, indicative of regulated cell death. Furthermore, calreticulin, adenosine triphosphate (ATP) and high-mobility group box 1 (HMGB1), three key damage-associated molecular patterns (DAMPs) in ICD, were found to be exposed from B16-F10 cells upon pulsed laser irradiation to an extent that exceeded or was comparable to the bona fide ICD-inducer, doxorubicin. Finally, we could demonstrate that VNB formation from melanosomes induced plasma membrane permeabilization. This allowed for enhanced intracellular delivery of bleomycin, an ICD-inducing chemotherapeutic, which further boosted cell death with the potential to improve the systemic antitumor immune response.

Electrochemotherapy in the Treatment of Bone Metastases: A Systematic Review

BACKGROUND AND AIM

Cancers are one of the most frequent causes of death and disability in humans. Skeletal involvement has a major impact on the quality of life and prognosis of cancer patients. Electrochemotherapy is a palliative and minimally invasive oncologic treatment that was first used to treat subcutaneous nodules for malignant tumors. The aim of our review is to evaluate the results of electrochemotherapy in the treatment of bone metastases.

METHODS

A systematic review of the literature indexed in the PubMed MEDLINE and Cochrane Library databases using the search key words "electrochemotherapy" AND ("metastasis" OR "metastases") was performed. The Preferred Reporting Items for Systematic Reviews and MetaAnalyses was followed. Inclusion criteria were proven involvement of the appendicular skeleton in metastatic carcinoma or melanoma, through at least one percutaneous electrochemotherapy session on the metastatic bone lesion. The exclusion criterion was no skeletal metastatic involvement.

RESULTS

Eight articles were finally included. We reached a population of 246 patients. The mean age and follow up were 60.1 years old and 11.4 months, respectively. The most represented primary tumor was breast cancer (18.9%). A total of 250 bone lesions were treated with electrochemotherapy. According to RECIST criteria, in our population we observed 55.5% stable diseases. The mean pre-electrochemotherapy VAS value was 6.9, which lowered to 2.7 after treatment. Adverse events occurred in 3.4% of patients.

CONCLUSIONS

Electrochemotherapy as a minimally invasive and tissue-sparing treatment should be considered for patients with no other alternative to obtain tumor control and improvement in quality of life.

Pulsed Electric Fields in Oncology: A Snapshot of Current Clinical Practices and Research Directions from the 4th World Congress of Electroporation

The 4th World Congress of Electroporation (Copenhagen, 9-13 October 2022) provided a unique opportunity to convene leading experts in pulsed electric fields (PEF). PEF-based therapies harness electric fields to produce therapeutically useful effects on cancers and represent a valuable option for a variety of patients. As such, irreversible electroporation (IRE), gene electrotransfer (GET), electrochemotherapy (ECT), calcium electroporation (Ca-EP), and tumour-treating fields (TTF) are on the rise. Still, their full therapeutic potential remains underappreciated, and the field faces fragmentation, as shown by parallel maturation and differences in the stages of development and regulatory approval worldwide. This narrative review provides a glimpse of PEF-based techniques, including key mechanisms, clinical indications, and advances in therapy; finally, it offers insights into current research directions. By highlighting a common ground, the authors aim to break silos, strengthen cross-functional collaboration, and pave the way to novel possibilities for intervention. Intriguingly, beyond their peculiar mechanism of action, PEF-based therapies share technical interconnections and multifaceted biological effects (e.g., vascular, immunological) worth exploiting in combinatorial strategies.

European e-Delphi process to define expert consensus on electrochemotherapy treatment indications, procedural aspects, and quality indicators in melanoma

BACKGROUND

Skin metastases are an important co-morbidity in melanoma. Despite broad adoption, electrochemotherapy implementation is hindered by a lack of treatment indications, uncertainty regarding procedural aspects, and the absence of quality indicators. An expert consensus may harmonize the approach among centres and facilitate comparison with other therapies.

METHODS

An interdisciplinary panel was recruited for a three-round e-Delphi survey. A literature-based 113-item questionnaire was proposed to 160 professionals from 53 European centres. Participants rated each item for relevance and degree of agreement on a five-point Likert scale, and received anonymous controlled feedback to allow revision. The items that reached concordant agreement in two successive iterations were included in the final consensus list. In the third round, quality indicator benchmarks were defined using a real-time Delphi method.

RESULTS

The initial working group included 122 respondents, of whom 100 (82 per cent) completed the first round, thus qualifying for inclusion in the expert panel (49 surgeons, 29 dermatologists, 15 medical oncologists, three radiotherapists, two nurse specialists, two clinician scientists). The completion rate was 97 per cent (97 of 100) and 93 per cent (90 of 97) in the second and third rounds respectively. The final consensus list included 54 statements with benchmarks (treatment indications, (37); procedural aspects, (1); quality indicators, (16)).

CONCLUSION

An expert panel achieved consensus on the use of electrochemotherapy in melanoma, with a core set of statements providing general direction to electrochemotherapy users to refine indications, align clinical practices, and promote quality assurance programmes and local audits. The residual controversial topics set future research priorities to improve patient care.

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.

Safety and Feasibility of Vulvar Cancer Treatment with Electrochemotherapy

Electrochemotherapy is a local ablative therapy used for the treatment of various superficial and deep-seated tumors. Electrochemotherapy involves the application of electric pulses locally to tumors to destabilize cell membranes and facilitate the entry of cytotoxic drugs, thereby enhancing their cytotoxicity locally. The aim of our study is to investigate the safety and feasibility of electrochemotherapy in patients with vulvar cancer recurrence used for nonpalliative purposes. Ten patients with single local vulvar cancer recurrence were treated with intravenous bleomycin, followed by a local application of electric pulses (electrochemotherapy) to the tumor. Adverse events were determined using the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The feasibility of treating vulvar cancer with electrochemotherapy was determined by an appropriate selection of electrodes based on the size and location of the tumor with safety margins included. Electrochemotherapy was feasible in all patients. No electrochemotherapy-related or other serious adverse events occurred. Our data suggest that electrochemotherapy is a feasible and safe technique for the treatment of vulvar cancer recurrence for nonpalliative purposes. Based on our results, electrochemotherapy might be a viable therapeutic tool for patients who would otherwise undergo surgery involving a mutilation of the external genitalia.

Microneedle-mediated treatment for superficial tumors by combining multiple strategies

Superficial tumors are still challenging to overcome due to the high risk and toxicity of surgery and conventional chemotherapy. Microneedles (MNs) are widely used in the treatment of superficial skin tumors (SST) due to the high penetration rate of the stratum corneum (SC), excellent biocompatibility, simple preparation process, high patient compliance, and minimal invasion. Most importantly, MNs can provide not only efficient and rarely painful delivery carriers, but also combine multi-model strategies with photothermal therapy (PTT), immunotherapy, and gene therapy for synergistic efficacy. To promote an in-depth understanding of their superiorities, this paper systematically summarized the latest application progress of MNs in the treatment of SST by delivering various types of photosensitizers, immune signal molecules, genes, and chemotherapy drugs. Just as important, the advantages, limitations, and drug release mechanisms of MNs based on different materials are introduced in the paper. In addition, the application of MN technology to clinical practice is the ultimate goal of all the work. The obstacles and possible difficulties in expanding the production of MNs and achieving clinical transformation are briefly discussed in this paper. To be anticipated, our work will provide new insights into the precise and rarely painful treatment of SST in the future.

Effects of Electrochemotherapy on Immunologically Important Modifications in Tumor Cells

Electrochemotherapy (ECT) is a clinically acknowledged method that combines the use of anticancer drugs and electrical pulses. Electrochemotherapy with bleomycin (BLM) can induce immunogenic cell death (ICD) in certain settings. However, whether this is ubiquitous over different cancer types and for other clinically relevant chemotherapeutics used with electrochemotherapy is unknown. Here, we evaluated in vitro in the B16-F10, 4T1 and CT26 murine tumor cell lines, the electrochemotherapy triggered changes in the ICD-associated damage-associated molecular patterns (DAMPs): Calreticulin (CRT), ATP, High Mobility Group Box 1 (HMGB1), and four immunologically important cellular markers: MHCI, MHC II, PD-L1 and CD40. The changes in these markers were investigated in time up to 48 h after ECT. We showed that electrochemotherapy with all three tested chemotherapeutics induced ICD-associated DAMPs, but the induced DAMP signature was cell line and chemotherapeutic concentration specific. Similarly, electrochemotherapy with CDDP, OXA or BLM modified the expression of MHC I, MHC II, PD-L1 and CD40. The potential of electrochemotherapy to change their expression was also cell line and chemotherapeutic concentration specific. Our results thus put the electrochemotherapy with clinically relevant chemotherapeutics CDDP, OXA and BLM on the map of ICD inducing therapies.

Electroporation Enhances the Anticancer Effects of Novel Cu(II) and Fe(II) Complexes in Chemotherapy-Resistant Glioblastoma Cancer Cells

Schiff base ligand (L) was obtained by condensation reaction between 4-aminopyrimidin-2(1H)-one (cytosine) with 2-hydroxybenzaldehyde. The synthesized Schiff base was used for complexation with Cu(II) and Fe(II) ions used by a molar (2 : 1 mmol ration) in methanol solvent. The structural features of ligand, Cu(II), and Fe(II) metal complexes were determined by standard spectroscopic methods (FT-IR, elemental analysis, proton and carbon NMR spectra, UV/VIS, and mass spectroscopy, magnetic susceptibility, thermal analysis, and powder X-ray diffraction). The synthesized compounds (Schiff base and its metal complexes) were screened in terms of their anti-proliferative activities in U118 and T98G human glioblastoma cell lines alone or in combination with electroporation (EP). Moreover, the human HDF (human dermal fibroblast) cell lines was used to check the bio-compatibility of the compounds. Anti-proliferative activities of all compounds were ascertained using an MTT assay. The complexes exhibited a good anti-proliferative effect on U118 and T98G glioblastoma cell lines. In addition, these compounds had a negligible cytotoxic effect on the fibroblast HDF cell lines. The use of compounds in combination with EP significantly decreased the IC₅₀ values compared to the use of compounds alone (p<0.05). These results show that newly synthesized Cu(II) and Fe(II) complexes can be developed for use in the treatment of chemotherapy-resistant U118 and T98G glioblastoma cells and that treatment with lower doses can be provided when used in combination with EP.

Enhancement of reactive oxygen species production in triple negative breast cancer cells treated with electric pulses and resveratrol

Aim

Triple negative breast cancer (TNBC) is difficult to treat since it lacks all the three most commonly targeted hormone receptors. Patients afflicted with TNBC are treated with platinum core chemotherapeutics, such as cisplatin. Despite the initial effective anticancer effects of cisplatin, TNBC attenuates its effect and develops resistance eventually, which results in tumor reoccurrence. Hence, there is a critical demand for effective, alternative, and natural ways to treat TNBC. Towards this, a promising technique for inhibiting TNBC cell proliferation involves promoting the production of reactive oxygen species (ROS), which triggers pro-apoptotic caspases 9 and 3. Resveratrol (RESV), an active bio compound found in naturally available fruits, such as grapes, is utilized in this research for that. In addition, electrochemotherapy (ECT), which involves the application of electrical pulses (EP), was utilized to enhance the uptake of RESV.

Methods

MDA-MB-231, human TNBC cells were treated with/out RESV, and eight 600-1,000 V/cm, 100 μs pulses at 1 Hz. The cells were characterized by using various assays, including viability assay, and ROS assay.

Results

A TNBC cell viability of as low as 20% was obtained at 24 h (it was 13% at 60 h), demonstrating the potential of this novel treatment. ROS production was the highest in the combination of EP at 1,000 V/cm along with RESV at 100 μmol/L.

Conclusions

Results indicate that RESV has the potential as an anti-TNBC agent and that EP + RESV can significantly enhance the cell death to reduce MDA-MB-231 cell viability by increasing ROS production and triggering apoptosis.

Laparoscopic electrochemotherapy for the treatment of hepatocellular carcinoma: Technological advancement

Electrochemotherapy is an effective treatment modality for hepatocellular carcinoma (HCC). Electrochemotherapy for HCC was initially used in the setting of open surgery. Recently, with the development of newer electrodes, percutaneous approaches have also been performed. However, laparoscopic application of electrochemotherapy for HCC has not yet been described. Two patients with unresectable HCC were enrolled in the study. The first patient was not suitable for the percutaneous approach because the tumor was located close to the gallbladder. He also had symptomatic gallstones. The second patient had HCC in close proximity to the stomach and was therefore not suitable for percutaneous access or any other ablative technique. Thus, the laparoscopic approach was chosen, using newly developed Stinger electrodes for the application of electric pulses. After intravenous administration of bleomycin, several sets of electric pulses were delivered to the whole tumor mass in both patients. Ultrasonographically, the coverage of the whole tumor was verified, as described previously. Cholecystectomy was also performed in the first patient. Follow-up abdominal computed tomography showed a complete response of the treated lesions in both patients. Minimally invasive laparoscopic electrochemotherapy is safe, feasible and effective method for the treatment of HCC. It could be used in patients in whom the percutaneous approach is unsafe (proximity to other organs) and in patients with concomitant symptomatic gallstones in whom cholecystectomy is already indicated. This technological approach thus allows broader and minimally invasive clinical applicability of electrochemotherapy.

Electroporation in Head-and-Neck Cancer: An Innovative Approach with Immunotherapy and Nanotechnology Combination

Squamous cell carcinoma is the most common malignancy that arises in the head-and-neck district. Traditional treatment could be insufficient in case of recurrent and/or metastatic cancers; for this reason, more selective and enhanced treatments are in evaluation in preclinical and clinical trials to increase in situ concentration of chemotherapy drugs promoting a selectively antineoplastic activity. Among all cancer treatment types (i.e., surgery, chemotherapy, radiotherapy), electroporation (EP) has emerged as a safe, less invasive, and effective approach for cancer treatment. Reversible EP, using an intensive electric stimulus (i.e., 1000 V/cm) applied for a short time (i.e., 100 μs), determines a localized electric field that temporarily permealizes the tumor cell membranes while maintaining high cell viability, promoting cytoplasm cell uptake of antineoplastic agents such as bleomycin and cisplatin (electrochemotherapy), calcium (Ca²⁺ electroporation), siRNA and plasmid DNA (gene electroporation). The higher intracellular concentration of antineoplastic agents enhances the antineoplastic activity and promotes controlled tumor cell death (apoptosis). As secondary effects, localized EP (i) reduces the capillary blood flow in tumor tissue ("vascular lock"), lowering drug washout, and (ii) stimulates the immune system acting against cancer cells. After years of preclinical development, electrochemotherapy (ECT), in combination with bleomycin or cisplatin, is currently one of the most effective treatments used for cutaneous metastases and primary skin and mucosal cancers that are not amenable to surgery. To reach this clinical evidence, in vitro and in vivo models were preclinically developed for evaluating the efficacy and safety of ECT on different tumor cell lines and animal models to optimize dose and administration routes of drugs, duration, and intensity of the electric field. Improvements in reversible EP efficacy are under evaluation for HNSCC treatment, where the focus is on the development of a combination treatment between EP-enhanced nanotechnology and immunotherapy strategies.

Nanosecond electric pulses are equally effective in electrochemotherapy with cisplatin as microsecond pulses

BACKGROUND

Nanosecond electric pulses showed promising results in electrochemotherapy, but the underlying mechanisms of action are still unexplored. The aim of this work was to correlate cellular cisplatin amount with cell survival of cells electroporated with nanosecond or standardly used 8 × 100 μs pulses and to investigate the effects of electric pulses on cisplatin structure.

MATERIALS AND METHODS

Chinese hamster ovary CHO and mouse melanoma B16F1 cells were exposed to 1 × 200 ns pulse at 12.6 kV/cm or 25 × 400 ns pulses at 3.9 kV/cm, 10 Hz repetition rate or 8 × 100 μs pulses at 1.1 (CHO) or 0.9 (B16F1) kV/cm, 1 Hz repetition rate at three cisplatin concentrations. Cell survival was determined by the clonogenic assay, cellular platinum was measured by inductively coupled plasma mass spectrometry. Effects on the structure of cisplatin were investigated by nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry.

RESULTS

Nanosecond pulses equivalent to 8 × 100 μs pulses were established in vitro based on membrane permeabilization and cell survival. Equivalent nanosecond pulses were equally efficient in decreasing the cell survival and accumulating cisplatin intracellularly as 8 × 100 μs pulses after electrochemotherapy. The number of intracellular cisplatin molecules strongly correlates with cell survival for B16F1 cells, but less for CHO cells, implying the possible involvement of other mechanisms in electrochemotherapy. The high-voltage electric pulses did not alter the structure of cisplatin.

CONCLUSIONS

Equivalent nanosecond pulses are equally effective in electrochemotherapy as standardly used 8 × 100 μs pulses.

Treatment of Basal Cell Carcinoma with Electrochemotherapy: Insights from the InspECT Registry (2008–2019)

This prospective registry-based study aims to describe electrochemotherapy (ECT) modalities in basal cell carcinoma (BCC) patients and evaluate its efficacy, safety, and predictive factors. The International Network for Sharing Practices of Electrochemotherapy (InspECT) multicentre database was queried for BCC cases treated with bleomycin-ECT between 2008 and 2019 (n = 330 patients from seven countries, with 623 BCCs [median number: 1/patient; range: 1–7; size: 13 mm, range: 5–350; 85% were primary, and 80% located in the head and neck]). The procedure was carried out under local anaesthesia in 68% of cases, with the adjunct of mild sedation in the remaining 32%. Of 300 evaluable patients, 242 (81%) achieved a complete response (CR) after a single ECT course. Treatment naïvety (odds ratio [OR] 0.35, 95% confidence interval [C.I.] 0.19–0.67, p = 0.001) and coverage of deep tumour margin with electric pulses (O.R. 5.55, 95% C.I. 1.37–21.69, p = 0.016) predicted CR, whereas previous radiation was inversely correlated (O.R. 0.25, p = 0.0051). Toxicity included skin ulceration (overall, 16%; G3, 1%) and hyperpigmentation (overall, 8.1%; G3, 2.5%). At a 17-month follow-up, 28 (9.3%) patients experienced local recurrence/progression. Despite no convincing evidence that ECT confers improved outcomes compared with standard surgical excision, it can still be considered an opportunity to avoid major resection in patients unsuitable for more demanding treatment. Treatment naïvety and coverage of the deep margin predict tumour clearance and may inform current patient selection and management.

Health-related quality of life trajectories in melanoma patients after electrochemotherapy: real-world insights from the InspECT register

BACKGROUND

Electrochemotherapy (ECT) effectively controls skin metastases from cutaneous melanoma.

OBJECTIVES

This study aimed to evaluate health-related quality of life (HRQoL) in melanoma patients pre-/post-ECT and its effect on treatment outcome.

METHODS

The analysis included prospective data from the International Network for Sharing Practices of ECT register. Following the Standard Operating Procedures, patients received intravenous or intratumoural bleomycin (15,000 IU/m2 ; 1000 IU mL/cm3 ) followed by 100-microsecond, 1000-V/cm electric pulses. Endpoints included response (RECIST v3.0), local progression-free survival (LPFS), toxicity (CTCAE v5.0), and patient-reported HRQoL at baseline, one, two, four and ten months (EuroQol [EQ-5D-3L], including 5-item utility score [EQ-5D] and visual analogue scale for self-reported health state [EQ-VAS]). Comparisons within/between subgroups were made for statistical and minimal important differences (MID). HRQoL scores and clinical covariates were analysed to identify predictors of response in multivariate analysis.

RESULTS

Median tumour size was 2 cm. Complete response rate, G3 toxicity and one-year LPFS in 378 patients (76% of the melanoma cohort) were 47%, 5%, and 78%. At baseline, age-paired HRQoL did not differ from the general European population. Following ECT, both EQ-5D and EQ-VAS scores remained within MID boundaries, particularly among complete responders. A subanalysis of the EQ-5D items revealed a statistically significant deterioration in pain/discomfort and mobility (restored within four months), and self-care and usual activities (throughout the follow-up) domains. Concomitant checkpoint inhibition correlated with better EQ-5D and EQ-VAS trajectories. Baseline EQ-5D was the exclusive independent predictor for complete response (RR 14.76, p=0.001).

CONCLUSIONS

HRQoL of ECT melanoma patients parallels the general population and is preserved in complete responders. Transient deterioration in pain/discomfort and mobility and persistent decline in self-care and usual activities may warrant targeted support interventions. Combination with checkpoint inhibitors is associated with better QoL outcomes. Baseline HRQoL provides predictive information which can help identify patients most likely to respond.

Cutaneous and subcutaneous Kaposi's sarcoma lesions treated with electrochemotherapy

BACKGROUND AND OBJECTIVES

Kaposi's sarcoma (KS) is a locally aggressive mesenchymal tumor that involves the lymphovascular system, with a tendency to become multifocal. Electrochemotherapy (ECT) is considered a valuable treatment option in selected patients with cutaneous and subcutaneous KS lesions.

METHODS

We report a retrospective study that included 14 classic and endemic KS patients that underwent ECT sessions for the treatment of KS cutaneous and subcutaneous lesions at our institution.

RESULTS

According to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 criteria, our patients had an overall response rate (ORR) of 100% to the ECT treatment. A complete response (CR) was obtained in 92.8% of patients after one or more ECT sessions. Only one patient had a progressive disease (PD). The treatment was well tolerated with a low complication rate, mainly transitory local pain or skin ulceration.

CONCLUSIONS

ECT represents a locoregional therapy for containment and symptomatic control of classic and endemic KS cutaneous and subcutaneous lesions. Further studies including different subtypes of KS patients should also be performed.

Impact of electrochemotherapy in metastatic cutaneous melanoma: a contemporary systematic review and meta-analysis

BACKGROUND

Electrochemotherapy (ECT) harnesses electric pulses to enhance cytotoxic drug delivery into tumors and has entered the armamentarium to treat superficially metastatic melanoma. We performed a systematic review and meta-analysis to assess treatment patterns and patient outcomes.

METHODS

PubMed, Medline, Embase, and the Cochrane Library databases were queried for publication from inception to September 2020. Primary outcome measures were overall and complete response rate (ORR and CRR); secondary outcomes included local control rate (LCR) and overall survival (OS).

RESULTS

Twenty-seven studies met the selection criteria for a total of 1161 individuals (mean age 71 years) and 5308 tumors (weighted mean size 14 mm). The majority of patients (n = 1124) underwent bleomycin-ECT. Aggregate ORR was 77.6% (95% confidence interval [CI] 71.0 - 83.2%) and CRR 48% (95% CI 42 - 54%), with no significant difference between the route of bleomycin administration (ORR, 69.2 vs. 81.9% following intravenous or intratumoral bleomycin, p = .37) and tumor size (p = .69). When reported (n = 8 studies), 1- and 2-year LCR ranged from 54 to 89% and 72 to 74%, respectively, and 1-year OS (n = 3 studies) from 67 to 89%.

CONCLUSIONS

ECT with either intratumoral or intravenous bleomycin confers a high therapeutic response in cutaneous metastatic melanoma. Moderate evidence supports its low toxicity and durability of local control.HighlightsElectrochemotherapy (ECT) is associated with a 77% overall response rate (ORR).Intravenous and intratumoral bleomycin are equally effective.There are no relevant toxicity concerns.One-year local tumor control rate ranges from 54 to 89%.Current literature has significant variation in reporting.

Adjuvant skin-sparing electrochemotherapy in a breast cancer patient with a prosthetic implant: 5-year follow-up outcomes

A 55-year-old woman with previous skin-sparing mastectomy and prosthetic reconstruction for multifocal ductal carcinoma developed homolateral axillary recurrence. Following nodal dissection, partial periprosthetic capsulectomy and the overlying breast skin excision, the pathology report revealed a positive cutaneous margin. Since further breast skin excision or radiotherapy would have compromised the prosthetic implant, and the patient was adamant about avoiding any endangering intervention, the multidisciplinary recommendation included skin-directed electrochemotherapy (ECT) in the frame of a multimodal treatment strategy. The procedure lasted 20 minutes under mild general sedation and included a bolus of intravenous bleomycin followed by local application of electric pulses using a needle electrode. The postprocedural course was uneventful, except for mild dermatologic toxicity. At 5 years, the patient is disease-free with the implant in situ. This report illustrates the proof-of-concept of adjuvant skin-sparing ECT to sterilize resection margins, preserve a breast implant and highlight procedural details to avert toxicity.

Prospektive Kohortenstudie von InspECT zur Sicherheit und Wirksamkeit der Elektrochemotherapie bei Hauttumoren und Metastasen in Abhängigkeit von Ulzeration

HINTERGRUND

Elektrochemotherapie (ECT) ist eine wirksame lokale Behandlung von Hauttumoren. Ziel dieser Studie war es, die Wirksamkeit der ECT bei ulzerierten gegenüber nichtulzerierten Tumoren zu vergleichen und den Effekt auf tumorassoziierte Symptome zu untersuchen.

METHODIK

20 Krebszentren des International Network for Sharing Practices on Electrochemotherapy (InspECT) sammelten prospektiv Daten. Die ECT wurde nach dem ESOPE-Protokoll durchgeführt. Das Therapieansprechen wurde anhand der Entwicklung der Läsionsgröße bewertet. Zusätzlich wurden Schmerzen, Symptome, Leistungsstatus (ECOG-Index) und Gesundheitszustand (EQ-5D-Fragebogen) untersucht.

ERGEBNISSE

716 Patienten mit ulzerierten (n = 302) und nichtulzerierten (n = 414) Hauttumoren und Metastasen wurden eingeschlossen (Mindest-Nachsorge 45 Tage). Nicht-ulzerierte Läsionen sprachen besser auf die ECT an als ulzerierte Läsionen (vollständiges Ansprechen: 65 % gegenüber 51 %, p = 0,0061). Nur 38 % (115/302) der Patienten mit ulzerierten Läsionen vor der ECT wiesen bei der letzten Nachuntersuchung ulzerierte Läsionen auf. Patienten mit ulzerierten Läsionen berichteten über stärkere Schmerzen und schwerere Symptome im Vergleich zu Patienten mit nichtulzerierten Läsionen, die sich nach der ECT signifikant und kontinuierlich besserten. Bei Patienten mit nichtulzerierten Läsionen hingegen nahmen die Schmerzen während der Behandlung vorübergehend zu. Es wurden keine schwerwiegenden Nebenwirkungen beobachtet.

SCHLUSSFOLGERUNGEN

Die ECT ist eine sichere und wirksame lokale Behandlung von Hauttumoren. Während die ECT die Symptome insbesondere bei Patienten mit ulzerierten Läsionen verbessert, sollte auf Basis der Daten die Implementation eines perioperativen Schmerzmanagements besonders bei nichtulzerierten Läsionen während der ECT erwogen werden.

Numerical mesoscale tissue model of electrochemotherapy in liver based on histological findings

Electrochemotherapy (ECT) and irreversible electroporation (IRE) are being investigated for treatment of hepatic tumours. The liver is a highly heterogeneous organ, permeated with a network of macro- and microvasculature, biliary tracts and connective tissue. The success of ECT and IRE depends on sufficient electric field established in whole target tissue; therefore, tissue heterogeneity may affect the treatment outcome. In this study, we investigate electroporation in the liver using a numerical mesoscale tissue model. We numerically reconstructed four ECT experiments in healthy porcine liver and computed the electric field distribution using our treatment planning framework. We compared the computed results with histopathological changes identified on microscopic images after treatment. The mean electric field threshold that best fitted the zone of coagulation necrosis was 1225 V/cm, while the mean threshold that best fitted the zone of partially damaged liver parenchyma attributed to IRE was 805 V/cm. We evaluated how the liver macro- and microstructures affect the electric field distribution. Our results show that the liver microstructure does not significantly affect the electric field distribution on the level needed for treatment planning. However, major hepatic vessels and portal spaces significantly affect the electric field distribution, and should be considered when planning treatments.

Prospective cohort study by InspECT on safety and efficacy of electrochemotherapy for cutaneous tumors and metastases depending on ulceration

BACKGROUND

Electrochemotherapy (ECT) is an effective local treatment for cutaneous tumors. The aim of this study was to compare the effectiveness of ECT in ulcerated vs. non-ulcerated tumors and investigate the effect on tumor-associated symptoms.

METHODS

Twenty cancer centers in the International Network for Sharing Practices on Electrochemotherapy (InspECT) prospectively collected data. ECT was performed following ESOPE protocol. Response was evaluated by lesion size development. Pain, symptoms, performance status (ECOG-Index) and health status (EQ-5D questionnaire) were evaluated.

RESULTS

716 patients with ulcerated (n = 302) and non-ulcerated (n = 414) cutaneous tumors and metastases were included (minimum follow-up of 45 days). Non-ulcerated lesions responded to ECT better than ulcerated lesions (complete response 65 % vs. 51 %, p = 0.0061). Only 38 % (115/302) with ulcerated lesions before ECT presented with ulcerated lesions at final follow-up. Patients with ulcerated lesions reported higher pain and more severe symptoms compared to non-ulcerated lesions, which significantly and continuously improved following ECT. In non-ulcerated lesions however, pain spiked during the treatment. No serious adverse events were reported.

CONCLUSIONS

ECT is a safe and effective local treatment for cutaneous tumors. While ECT improves symptoms especially in patients with ulcerated lesions, data suggest the implementation of a perioperative pain management in non-ulcerated lesions during ECT.

Sunitinib potentiates the cytotoxic effect of electrochemotherapy in pancreatic carcinoma cells

BACKGROUND

One of the new treatment options for unresectable locally advanced pancreatic cancer is electrochemotherapy (ECT), a local ablative therapy that potentiates the entry of chemotherapeutic drugs into the cells, by the application of an electric field to the tumor. Its feasibility and safety were demonstrated in preclinical and clinical studies; however, there is a lack of preclinical studies assessing the actions of different drugs used in ECT, their mechanisms and interactions with other target drugs that are used in clinical practice.

MATERIALS AND METHODS

The aim of the study was to determine the cytotoxicity of two chemotherapeutic drugs usually used in ECT (bleomycin and cisplatin) in the BxPC-3 human pancreatic carcinoma cell line and evaluate the interactions of ECT with the targeted drug sunitinib. First, the cytotoxicity of ECT using both chemotherapeutics was determined. In the next part, the interactions of ECT and sunitinib were evaluated through determination of combined cytotoxicity, sunitinib targets and kinetics of cell death.

RESULTS

The results demonstrate that ECT is effective in pancreatic cancer cell line, especially when bleomycin is used, with the onset of cell death in the first hours after the treatment, reaching a plateau at 20 hours after the treatment. Furthermore, we provide the rationale for combining ECT with bleomycin and the targeted drug sunitinib to potentiate cytotoxicity. The combined treatment of sunitinib and ECT was synergistic for bleomycin only at the highest used concentration of bleomycin 0.14 μM, whereas with lower doses of bleomycin, this effect was not observed. The interaction of ECT and treatment with sunitinib was confirmed by course of the cell death, also indicating on synergism.

CONCLUSIONS

ECT and sunitinib combined treatment has clinical potential, and further studies are warranted.

Cutaneous and Cerebral Metastases From Primary Peritoneal Clear Cell Carcinoma

Peritoneal tumors are very uncommon and among them, primary peritoneal clear cell carcinoma is extremely rare and often misdiagnosed as others subtypes. There are only 13 cases of primary peritoneal clear cell carcinoma previously reported in the literature and there are no reports about cutaneous metastasis in this setting and only brain metastases were described to be associated with other primary peritoneal carcinoma subtypes. More information about this topic is needed and so we are presenting a new case of primary peritoneal clear cell carcinoma with cutaneous and cerebral metastases in a 34-year-old female.

Electrochemotherapy as an Alternative Treatment Option to Pelvic Exenteration for Recurrent Vulvar Cancer of the Perineum Region

Objective: Pelvic exenteration in women with recurrent vulvar carcinoma is associated with high morbidity and mortality and substantial treatment costs. Because pelvic exenteration severely affects the quality of life and can lead to significant complications, other treatment modalities, such as electrochemotherapy, have been proposed. The aim of this study was to evaluate the feasibility and suitability of electrochemotherapy in the treatment of recurrent vulvar cancer. We aimed to analyze the treatment options, treatment outcomes, and complications in patients with recurrent vulvar cancer of the perineum. Methods: A retrospective analysis of patients who had undergone pelvic exenteration for vulvar cancer at the Institute of Oncology Ljubljana over a 16-year period was performed. As an experimental, less mutilating treatment, electrochemotherapy was performed on one patient with recurrent vulvar cancer involving the perineum. Comparative data analysis was performed between the group with pelvic exenteration and the patient with electrochemotherapy, comparing hospital stay, disease recurrence after treatment, survival after treatment in months, and quality of life after treatment. Results: We observed recurrence of disease in 2 patients with initial FIGO stage IIIC disease 3 months and 32 months after pelvic exenteration, and they died of the disease 15 and 38 months after pelvic exenteration. Two patients with FIGO stage IB were alive at 74 and 88 months after pelvic exenteration. One patient with initial FIGO stage IIIC was alive 12 months after treatment with electrochemotherapy with no visible signs of disease progression in the vulvar region, and the lesions had a complete response. The patient treated with electrochemotherapy was hospitalized for 4 days compared with the patients with pelvic exenteration, in whom the average hospital stay was 19.75 (± 1.68) days. Conclusion: Our experience has shown that electrochemotherapy might be a less radical alternative to pelvic exenteration, especially for patients with initially higher FIGO stages.

Effects of electroporation on anticancer activity of 5-FU and newly synthesized zinc(II) complex in chemotherapy-resistance human brain tumor cells

Zn(II) complex of Schiff base derived from the condensation of 4-aminopyrimidine-2(1H)-one with salicylaldehyde was prepared and characterized by various physico-chemical and spectral methods for structure determination. The cytotoxic activity of the Zn(II) complex was investigated in comparison with 5-fluorouracil (5-FU) against two different human brain tumor cell lines (T98G and U118), while primer human dermal fibroblast cells (HDF) was used as control for biocompatibility. Then, the effectiveness of electroporation (EP) on cytotoxic activities of these compounds has been examined. The cytotoxicities of the 5-FU and new Zn(II) complex, alone or in combination with electroporation, were determined by MTT assay. The Zn(II) complex showed good cytotoxicity against T98G and U118 brain tumor cell lines with IC₅₀ = 282.47 and 297.91 μM respectively, while it was safe on HDF healthy cells with IC₅₀ = 826.72 μM. The 5-FU exhibited less cytotoxicity compared to the Zn(II) complex against T98G (IC₅₀ = 382.35 μM) and U118 (IC₅₀ = 396.56 μM) tumor cell lines. The combined application of Zn (II) + EP decreased the IC₅₀ value by 5.96-fold in T98G cells and 4.76-fold in U118 cells. EP showed a similar effect in its combined application with 5-FU, resulting in a decrease of the IC₅₀ value of 4.22-fold in the T98G cells and 3.84-fold in the U118 cells. In a conclusion, the Zn(II) complex exhibited an anticancer potential against both brain tumor cell lines (T98G and U118) and EP greatly increased the cytotoxicity of Zn(II) complex and 5-FU on these chemotherapy-resistant cells.

Incorporation of electroendocytosis and nanosecond pulsed electric field in electrochemotherapy of breast cancer cells

The study aimed to evaluate the possibility to perform electrochemotherapy using nanosecond pulsed electric field (nsPEF) and low electric field (LEF) monopolar electrical impulses to alleviate the problems of conventional electroporation. Two types of pulses have been used to treat MCF-7 human breast carcinoma cell line: very low voltage (electric field strength) long trains of short unipolar electric pulses, and low frequencies of extremely intense (40kV/cm), ultra-short (10ns) electric pulses. The electropermeabilization efficiency of the formed endocytotic vesicles was measured using the cloning efficacy test. The cell viability was decreased significantly at a repetition frequency begins from 0.01 Hz by ~35% and reached complete cell loss at 1 Hz of nanosecond pulses for cells treated before with monopolar pulses at 20 V/cm in the presence of BLM with 4 µM concentration. The uptake of non-permeant drugs has been done without plasma membrane permeabilization (classical electroporation), but by endocytosis. Nanosecond electric pulses can disrupt the membrane of endocytotic vesicles and release the cytotoxic drug bleomycin.

Combination of Pembrolizumab with Electrochemotherapy in Cutaneous Metastases from Melanoma: A Comparative Retrospective Study from the InspECT and Slovenian Cancer Registry

Simple Summary

Electrochemotherapy (ECT) combines a cytotoxic agent with locally applied electric pulses to enhance its antitumor effect. Over the last 15 years, ECT has been safely applied to patients with skin metastases in combination with other oncologic treatments and, more recently, with systemic immunotherapy. In this study, we aimed to investigate the effectiveness of ECT in combination with pembrolizumab. We compared patient outcomes after the following treatments: (a) pembrolizumab, (b) pembrolizumab and ECT, and (c) ECT alone. The combined application of pembrolizumab and ECT was safe and more efficacious in preventing further growth of cutaneous metastases than pembrolizumab alone. The patients treated with pembrolizumab and ECT experienced lower disease progression rates and longer survival than those who received pembrolizumab. ECT may boost the effect of pembrolizumab by acting as an in situ vaccination against cancer cells. Further studies are required to confirm these findings.

Abstract

Electrochemotherapy (ECT) is an effective locoregional therapy for cutaneous melanoma metastases and has been safely combined with immune checkpoint inhibitors in preliminary experiences. Since ECT is known to induce immunogenic cell death, its combination with immune checkpoint inhibitors might be beneficial. In this study, we aimed to investigate the effectiveness of ECT on cutaneous melanoma metastases in combination with pembrolizumab. We undertook a retrospective matched cohort analysis of stage IIIC–IV melanoma patients, included in the International Network for sharing practices of ECT (InspECT) and the Slovenian Cancer Registry. We compared the outcome of patients who received the following treatments: (a) pembrolizumab alone, (b) pembrolizumab plus ECT, and (c) ECT. The groups were matched for age, sex, performance status, and size of skin metastases. The local objective response rate (ORR) was higher in the pembrolizumab-ECT group than in the pembrolizumab group (78% and 39%, p < 0.001). The 1 year local progression-free survival (LPFS) rates were 86% and 51% (p < 0.001), and the 1 year systemic PFS rates were 64% and 39%, respectively (p = 0.034). The 1 year overall survival (OS) rates were 88% and 64%, respectively (p = 0.006). Our results suggest that skin-directed therapy with ECT improves superficial tumor control in melanoma patients treated with pembrolizumab. Interestingly, we observed longer PFS and OS in the pembrolizumab-ECT group than in the pembrolizumab group. These findings warrant prospective confirmation.

Bleomycin Concentration in Patients' Plasma and Tumors after Electrochemotherapy. A Study from InspECT Group

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.

The impact of impaired DNA mobility on gene electrotransfer efficiency: analysis in 3D model

Background

Gene electrotransfer is an established method that enables transfer of DNA into cells with electric pulses. Several studies analyzed and optimized different parameters of gene electrotransfer, however, one of main obstacles toward efficient electrotransfection in vivo is relatively poor DNA mobility in tissues. Our aim was to analyze the effect of impaired mobility on gene electrotransfer efficiency experimentally and theoretically. We applied electric pulses with different durations on plated cells, cells grown on collagen layer and cells embedded in collagen gel (3D model) and analyzed gene electrotransfer efficiency. In order to analyze the effect of impaired mobility on gene electrotransfer efficiency, we applied electric pulses with different durations on plated cells, cells grown on collagen layer and cells embedded in collagen gel (3D model) and analyzed gene electrotransfer efficiency.

Results

We obtained the highest transfection in plated cells, while transfection efficiency of embedded cells in 3D model was lowest, similarly as in in vivo. To further analyze DNA diffusion in 3D model, we applied DNA on top or injected it into 3D model and showed, that for the former gene electrotransfer efficiency was similarly as in in vivo. The experimental results are explained with theoretical analysis of DNA diffusion and electromobility.

Conclusion

We show, empirically and theoretically that DNA has impaired electromobility and especially diffusion in collagen environment, where the latter crucially limits electrotransfection. Our model enables optimization of gene electrotransfer in in vitro conditions.

An iron oxide nanoparticle-based transdermal nanoplatform for dual-modal imaging-guided chemo-photothermal therapy of superficial tumors

Transdermal delivery is an attractive strategy for treating superficial tumors. However, the applications of existing transdermal systems have been limited by low transdermal efficiency and poor therapeutic outcomes. Here, we develop a transdermal nanoplatform (+)T-SiDs, based on superparamagnetic iron oxide core, surface-modified with cationic lipids, transdermal enhanced peptide TD, and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR), and loaded with doxorubicin. The (+)T-SiDs compositions enable MR/NIR dual-modal imaging guided synergistic chemo-photothermal therapy to superficial tumors treatment via transdermal delivery. The (+)T-SiDs exhibit good stability, efficient cellular uptake, pH/photothermal responsive drug release, and high photothermal conversion efficiency (47.45%). Importantly, the transdermal delivery of (+)T-SiDs is significantly enhanced by TD functionalization. In vivo MR/NIR imaging shows that the (+)T-SiDs exhibit high transdermal efficiency and specificity in localization to the tumor site. Moreover, in comparison with individual chemo- or photothermal therapies, the combination of chemo-photothermal therapy exhibits more efficient tumor inhibition effects. This work presents a new transdermal treatment nanoplatform for dual-modal imaging-guided chemo-photothermal therapy of superficial tumors, with efficient tumor eradication and low systemic toxicity thus offering strong potential for clinical adoption. STATEMENT OF SIGNIFICANCE: Transdermal delivery is an attractive strategy for treating superficial tumors. However, a highly efficient transdermal nanoplatform remains to be developed. Herein, we designed a multifunctional transdermal nanoplatform for dual-modal imaging-guided chemo-photothermal therapy of superficial tumors, comprised of a super-paramagnetic iron oxide (SPIO) nanoparticle, which can act as an MRI contrast agent and photothermal agent; a transdermal enhanced peptide (TD) and cationic lipids, which can accelerate skin penetration; and a NIR dye (DiR) and doxorubicin (DOX), which can achieve a synergistic enhanced chemo-photothermal therapy with NIR imaging ability. The transdermal nanoplatform achieved efficient tumor eradication and low systemic toxicity, thus offering strong potential for clinical adoption.

Electrochemotherapy with Mitomycin C Potentiates Apoptosis Death by Inhibiting Autophagy in Squamous Carcinoma Cells

We investigated the chemosensitizing effect of electroporation (EP), which, using electrical pulses, permeabilizes cancer cells to drugs. The study involved two human hypopharyngeal and tongue carcinoma cell lines. The surface and intracytoplasmic expression of P-gp were evaluated by flow cytometry, demonstrating that both lines were intrinsically resistant. After establishing the optimal dose of mitomycin C (MMC) to be used, in combination with EP, we showed, by both MTT assay and optical and electron scanning microscopy, the potentiating cytotoxic effect of EP with MMC compared to single treatments. Flow cytometry showed that the cytotoxicity of EP + MMC was due to the induction of apoptosis. In addition to verifying the release of cytochrome C in EP + MMC samples, we performed an expression analysis of caspase-3, caspase-9, Akt, pAkt, HMGB1, LC3I, LC3II, p62, Beclin1, and associated proteins with both apoptotic and autophagic phenomena. Our results were confirmed by two veterinary patients in whom the EP + MMC combination was used to control margins after the resection of corneal squamous carcinoma. In conclusion, we affirmed that the effect for which EP enhances MMC treatment is due to the inhibition of the autophagic process induced by the drug in favor of apoptosis.

Electrochemotherapy and Other Clinical Applications of Electroporation for the Targeted Therapy of Metastatic Melanoma

Electrochemotherapy (ECT) is an effective bioelectrochemical procedure that uses controlled electrical pulses to facilitate the increase of intracellular concentration of certain substances (electropermeabilization/ reversible electroporation). ECT using antitumor drugs such as bleomycin and cisplatin is a minimally invasive targeted therapy that can be used as an alternative for oncologic patients not eligible for surgery or other standard therapies. Even though ECT is mainly applied as palliative care for metastases, it may also be used for primary tumors that are unresectable due to size and location. Skin neoplasms are the main clinical indication of ECT, the procedure reporting good curative results and high efficiency across all tumor types, including melanoma. In daily practice, there are many cases in which the patient’s quality of life can be significantly improved by a safe procedure such as ECT. Its popularity must be increased because it has a safe profile and minor local adverse reactions. The method can be used by dermatologists, oncologists, and surgeons. The aim of this paper is to review recent literature concerning electrochemotherapy and other clinical applications of electroporation for the targeted therapy of metastatic melanoma.

Roles of Lipids in the Permeability Barriers of Skin and Oral Mucosa

PubMed searches reveal much literature regarding lipids in barrier function of skin and less literature on lipids in barrier function of the oral mucosa. In terrestrial mammals, birds, and reptiles, the skin’s permeability barrier is provided by ceramides, fatty acids, and cholesterol in the outermost layers of the epidermis, the stratum corneum. This layer consists of about 10–20 layers of cornified cells embedded in a lipid matrix. It effectively prevents loss of water and electrolytes from the underlying tissue, and it limits the penetration of potentially harmful substances from the environment. In the oral cavity, the regions of the gingiva and hard palate are covered by keratinized epithelia that much resemble the epidermis. The oral stratum corneum contains a lipid mixture similar to that in the epidermal stratum corneum but in lower amounts and is accordingly more permeable. The superficial regions of the nonkeratinized oral epithelia also provide a permeability barrier. These epithelial regions do contain ceramides, cholesterol, and free fatty acids, which may underlie barrier function. The oral epithelial permeability barriers primarily protect the underlying tissue by preventing the penetration of potentially toxic substances, including microbial products. Transdermal drug delivery, buccal absorption, and lipid-related disease are discussed.

Electrospray Mediated Localized and Targeted Chemotherapy in a Mouse Model of Lung Cancer

Background: An advanced stage, centrally localized invasive tumor is a major cause of sudden death in lung cancer patients. Currently, chemotherapy, radiotherapy, laser ablation, or surgical resection if possible are the available state-of-the-art treatments but none of these guarantee remedy or long-term relief and are often associated with fatal complications. Allowing localized chemotherapy, by direct and confined drug delivery only at the tumor site, could be a promising option for preoperative down staging or palliative therapy. Here we report the localized and targeted application of intra tumor delivery of chemotherapeutics using a novel device based on the principle of electrospray.

Methods: C57BL/6J mice were injected with Lewis lung carcinoma cells subcutaneously. After 15 days, the animals were anesthetized and the tumors were exposed by skin incision. Tumors were electrosprayed with 100 µg cisplatin on days 0 and 2, and tumor volumes were measured daily. Animals were sacrificed on day 7 after the first electrospray and tumors were analyzed by immunohistochemistry.

Results: In this proof-of-concept study, we report that the tumor volume was reduced by 81.2% (22.46 ± 12.14 mm³) after two electrospray mediated Cisplatin deliveries, while the control tumor growth, at the same time point, increased by 200% (514.30 ± 104.50 mm³). Moreover, tunnel and Caspase-3 positive cells were increased after Cisplatin electrospray compared to other experimental groups of animals.

Conclusion: Targeted drug delivery by electrospray is efficient in the subcutaneous mouse model of lung cancer and offers a promising opportunity for further development toward its clinical application.