Electrochemotherapy in the Treatment of Cutaneous Metastases from Breast Cancer: A Multicenter Cohort Analysis

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.

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.

Efficacy of Electrochemotherapy in Breast Cancer Patients of Different Receptor Status: The INSPECT Experience

Electrochemotherapy has been proven to be an efficient treatment for cutaneous metastases of various cancers. Data on breast cancer (BC) patients with cutaneous metastases were retrieved from the INSPECT database. Patients were divided by their receptor status: HER2+, HR+ (ER/PgR+), and TN (triple negative). Groups were similar for histological subtype and location of the nodules. Most patients were previously treated with surgery/systemic therapy/radiotherapy. We found no differences in the three groups in terms of response ratio (OR per patient 86% HER2+, 80% HR+, 76% TN, p = 0.8664). The only factor positively affecting the complete response rate in all groups was small tumor size (<3 cm, p = 0.0105, p = 0.0001, p = 0.0266, respectively). Local progression-free survival was positively impacted by the achievement of complete response in HER2+ (p = 0.0297) and HR+ (p = 0.0094), while overall survival was affected by time to local progression in all groups (p = 0.0065 in HER2+, p < 0.0001 in HR+, p = 0.0363 in TN). ECT treatment is equally effective among groups, despite different receptor status. Response and local tumor control seem to be better in multiple small lesions than in big armor-like lesions, suggesting that treating smaller, even multiple, lesions at the time of occurrence is more effective than treating bigger long-lasting armor-like cutaneous lesions.

Carcinoma En Cuirasse: A Rare but Striking Cutaneous Manifestation of Metastatic Breast Cancer

Carcinoma en cuirasse is a rare cutaneous metastatic presentation of breast cancer with a poor prognosis. We report a female in her 70s with a prior history of left breast ductal carcinoma in situ status post-radiation and lumpectomy who presented with skin thickening of the left breast and a few solid masses in bilateral breasts. Biopsy showed invasive ductal carcinoma of the left breast (estrogen receptor [ER]/progesterone receptor positive [PR], human epidermal growth factor receptor-2 [HER2] negative) and ductal carcinoma in situ of the right breast (ER/PR positive). She underwent a right breast lumpectomy; however, the left breast mastectomy was aborted due to the worsening of her skin findings on preoperative examination. A skin biopsy revealed poorly differentiated invasive ductal carcinoma. She was diagnosed with stage 4 breast cancer, specifically carcinoma en cuirasse. Systemic treatment was initiated, followed by a left breast mastectomy. A surgical biopsy was HER2-positive, and therefore anti-HER2 therapy was given. She remains on maintenance therapy with an excellent response at present.Any unexplained skin findings in breast cancer patients should prompt consideration of carcinoma en cuirasse. With ongoing treatment advances, many newer therapy options are available for metastatic breast cancer. Based on our case, we think that patients with this disease can have better outcomes.

Electrochemotherapy for the treatment of cutaneous squamous cell carcinoma: The INSPECT experience (2008-2020)

Introduction

Cutaneous squamous cell carcinoma (cSCC) is a frequent skin cancer with a high risk of recurrence characterized by tumor infiltration and, in advanced cases, a poor prognosis. ECT (electrochemotherapy) is an alternative treatment option for locally advanced or recurrent cSCC that is unsuitable for surgical resection. In this study, we aimed to evaluate the data in the InspECT (International Network for Sharing Practice on ECT) registry of the referral centers and to clarify the indications for the use of ECT as a treatment modality for cSCC.

Materials and methods

Patients with primary, recurrent or locally advanced cSCC from 18 European centers were included. They underwent at least one ECT session with bleomycin between February 2008 and November 2020, which was performed following the European Standard Operating Procedures.

Results

The analysis included 162 patients (mean age of 80 years; median, 1 lesion/patient). Side effects were mainly local and mild (hyperpigmentation, 11%; ulceration, 11%; suppuration, 4%). The response to treatment per patient was 62% complete and 21% partial. In the multivariate model, intravenous drug administration and small tumor size showed a significant association with a positive outcome (objective response). One-year local progression-free survival was significantly better (p<0.001) in patients with primary tumors (80% (95% C.I. 70%-90%) than in patients with locally advanced disease (49% (95% C.I. 30%-68%).

Conclusion

In the present study, ECT showed antitumor activity and a favorable safety profile in patients with complex cSCC for whom there was no widely accepted standard of care. Better results were obtained in primary and small tumors (<3 cm) using intravenous bleomycin administration.

Phase 1/2 study of topical submicron particle paclitaxel for cutaneous metastases of breast cancer

Purpose

This Phase 1/2 study evaluated safety and efficacy of a topical submicron particle paclitaxel (SPP) in an anhydrous ointment base (SOR007), primarily in breast cancer patients with cutaneous metastases (CM).

Methods

One of three concentrations of SOR007 SPP (0.15%, 1.0%, or 2.0%) was applied twice daily over an area of 50 cm² under a 3 + 3 phase 1 design for up to 28 days, with the option for expansion to an additional 28 days at the highest dose under a Phase 2a once safety was established. Efficacy was analyzed by lesion measurements and photographs to determine overall response rate (ORR), complete response (CR), and progression free survival by day 28 or 56.

Results

Twenty-three subjects were enrolled, 21 with cutaneous metastases of breast cancer (CMOBC). Four subjects received SOR007 0.15% for a median of 28 days (range = 17–29), three at a dose of 1.0% for a median of 28 days (range = 6–29), and sixteen at 2.0% for a median of  55 days (range = 6–60). All doses were well tolerated, and 19 subjects were evaluable for efficacy. At day 28 across all dose levels, 16% (95% CI 3.4 to 39.6%) of subjects achieved an ORR and another 63% (95% CI 34.9–96.8%) had stable disease (SD). The proportion of patients being progression free at 28 days across all treatments was 79% (95 CI 54–94%).

Conclusion

Application of SOR007 0.15%, 1.0%, and 2.0% to CM was safe and well tolerated with some reduction in lesion pain, and minimal systemic absorption of paclitaxel. Lesion stabilization was observed in most subjects over the study period. A randomized, placebo-controlled trial to confirm these findings is warranted.

ClinicalTrials.gov identifier

NCT03101358.

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.

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.

Diagnosis and guidance of treatment of breast cancer cutaneous metastases by multiple needle biopsy: A case report

BACKGROUND

Breast cancer patients have a high skin metastasis rate. However, reports on treatment of cutaneous metastases of breast cancer are scarce.

CASE SUMMARY

We report the treatment process for one breast cancer case with bone, lung, and skin metastases. The patient was a 43-year-old woman with advanced breast cancer and skin metastasis. She underwent pathological diagnosis by needle biopsy to guide the treatment. When the disease progressed, a new pathological diagnosis was determined by needle biopsy to guide the treatment. The patient received chemotherapy, endocrine therapy, and photodynamic dynamic therapy, followed by sonodynamic therapy.

CONCLUSION

Repeated puncture should be performed for advanced breast cancer with skin metastasis, in order to obtain the pathology and directly determine diagnosis when the disease progresses. The treatment should focus on controlling the systemic metastasis, rather than the local disease.

The Role of Electrochemotherapy in the Cutaneous and Subcutaneous Metastases From Breast Cancer: Analysis of Predictive Factors to Treatment From an Italian Cohort of Patients

The treatment of cutaneous and subcutaneous localizations from breast cancer (BC) is still a therapeutic challenge. Electrochemotherapy (ECT) is one of the available options, and it is characterized by the association between the administration of a chemotherapic agent (Bleomycin) with the temporary raise of permeability of the cellular membrane induced by the local administration of electrical impulses (electroporation). ECT represents an effective therapy for loco-regional control of this disease. This study aimed to investigate the predictive factors of response in cutaneous and subcutaneous localizations from breast cancer treated with ECT. We decided to evaluate the response to this treatment in 55 patients who underwent ECT between January 2013 and March 2020 at our Institute. We performed a monocentric retrospective cohort study. ECT was administered following the ESOPE (European Standard Operative Procedure of Electrochemotherapy) guidelines, a set of criteria updated in 2018 by a panel of European experts on ECT who defined the indications for selecting the patients who can benefit from the ECT treatment and the ones for technically performing the procedure. The responses were evaluated with the RECIST criteria (Response Evaluation Criteria in Solid Tumor). We found after 12 weeks of treatment a complete response (CR) in 64% of our patients. From the analysis divided for subgroups of covariates is emerged that lower BMI, reduced body surface, and absence of previous radiation treatment could be predictive for a better complete response. This study suggests that the efficacy of the ECT treatment is related to the concurrent systemic therapies while administering ECT. The association between ECT and immunotherapy has offered better results than the association between ECT and chemotherapy (p-value = 0.0463). So, ECT is a valuable tool in the treatment of cutaneous and subcutaneous metastases from breast cancer and its efficacy in local control of these lesions improves when it is well planned in a therapeutic scenario.

Primary breast carcinoma en cuirasse. A rare presentation of an aggressive malignancy and review of the literature

Breast carcinoma en cuirasse is a very rare form of cutaneous metastases of breast cancer. The clinical presentation is that of a diffuse indurated carcinomatous infiltration of the skin and subcutaneous tissues of the mammary region and the anterior aspect of the chest. In most cases, breast carcinoma en cuirasse develops post-mastectomy and represents a dramatic presentation of an aggressive tumor associated with a dismal prognosis. Because of the rarity of this type of malignancy, the optimal approach to treatment has not been clearly defined. The systemic treatment has been associated with limited efficacy, and the primary goal is palliative care and preservation of the quality of life through skin-directed therapies. Herein, a very rare case of primary breast carcinoma en cuirasse is presented, along with a review of the literature. Early diagnosis and prompt treatment of any potential skin metastases of breast cancer are essential to prevent the catastrophic natural progression of the disease.

Reduction of muscle contraction and pain in electroporation-based treatments: An overview

BACKGROUND

In the first studies of electrochemotherapy (ECT), small cutaneous metastases were treated and only mild or moderate pain was observed; therefore, pain was not considered a significant issue. As the procedure began to be applied to larger cutaneous metastases, pain was reported more frequently. For that reason, reduction of both muscle contractions and pain have been investigated over the years.

AIM

To present an overview of different protocols described in literature that aim to reduce muscle contractions and pain caused by the electroporation (EP) effect in both ECT and irreversible EP treatments.

METHODS

Thirty-three studies published between January 1999 and November 2020 were included. Different protocol designs and electrode geometries that reduce patient pain and the number of muscle contractions and their intensity were analysed.

RESULTS

The analysis showed that both high frequency and bipolar/biphasic pulses can be used to reduce pain and muscle contractions in patients who undergo EP treatments. Moreover, adequate electrode design can decrease EP-related morbidity. Particularly, needle length, diameter and configuration of the distance between the needles can be optimised so that the muscle volume crossed by the current is reduced as much as possible. Bipolar/biphasic pulses with an inadequate pulse length seem to have a less evident effect on the membrane permeability compared with the standard pulse protocol. For that reason, the number of pulses and the voltage amplitude, as well as the pulse duration and frequency, must be chosen so that the dose of delivered energy guarantees EP efficacy.

CONCLUSION

Pain reduction in EP-based treatments can be achieved by appropriately defining the protocol parameters and electrode design. Most results can be achieved with high frequency and/or bipolar/biphasic pulses. However, the efficacy of these alternative protocols remains a crucial point to be assessed further.

Antitumor Effects in Gas Plasma-Treated Patient-Derived Microtissues—An Adjuvant Therapy for Ulcerating Breast Cancer?

Despite global research and continuous improvement in therapy, cancer remains a challenging disease globally, substantiating the need for new treatment avenues. Medical gas plasma technology has emerged as a promising approach in oncology in the last years. Several investigations have provided evidence of an antitumor action in vitro and in vivo, including our recent work on plasma-mediated reduction of breast cancer in mice. However, studies of gas plasma exposure on patient-derived tumors with their distinct microenvironment (TME) are scarce. To this end, we here investigated patient-derived breast cancer tissue after gas plasma-treated ex vivo. The tissues were disjoint to pieces smaller than 100 µm, embedded in collagen, and incubated for several days. The viability of the breast cancer tissue clusters and their outgrowth into their gel microenvironment declined with plasma treatment. This was associated with caspase 3-dependent apoptotic cell death, paralleled by an increased expression of the anti-metastatic adhesion molecule epithelial (E)-cadherin. Multiplex chemokine/cytokine analysis revealed a marked decline in the release of the interleukins 6 and 8 (IL-6, IL-8) and monocyte-chemoattractant-protein 1 (MCP) known to promote a cancer-promoting milieu in the TME. In summary, we provide here, for the first time, evidence of a beneficial activity of gas plasma exposure on human patient-derived breast cancer tissue.

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.

The electrical pulse application enhances intra-cellular localization and potentiates cytotoxicity of curcumin in breast cancer cells

Breast cancer is the most common cancer of women, and fifth leading cause of mortality worldwide. Existing breast cancer regimens are costly and produce severe side effects. This highlights a need for the development of efficient novel therapies, which are cost effective and limit side effects. An electrical pulse (EP)-based chemo therapy, known as electrochemotherapy (ECT) using the natural compound curcumin could be an effective alternative. ECT is a non-surgical modality, which produces excellent anti-tumor efficacy at small drug concentrations due to increased uptake of drugs. In clinics, ECT is shown to be effective in treating advanced, recurrent, and metastatic breast cancers, which are refractory to multiple modalities. ECT with curcumin triggers apoptotic cell death in breast cancer cells and could be an effective alternative, due to curcumin's low cost and reduced side-effects. However, there is a lack of studies quantifying the uptake of curcumin in response to EP application. Towards this, we determined the uptake of different curcuminoids (curcumin, desmethoxycurcumin, and bisdemethoxycurcumin) upon EP application and their impact on cell cytotoxicity. Additionally, we studied the combined effect of calcium chloride (CaCl₂) and a curcuminoids (Cur) mixture, based on initial studies suggesting calcium electroporation as a potential inexpensive anti-cancer treatment. Our results indicate EP with Cur increases cellular uptake, cell shrinkage, and cytotoxicity. The EP + Cur resulted in the highest uptake of the bisdemethoxycurcumin. Further, EP also potentiated the cytotoxicity of CaCl₂ and of the Cur and CaCl₂ combination against breast cancer cells and caused apoptosis. Our preliminary data pave the way to further studies on Cur and CaCl₂ combination treating breast cancer.

Biological factors of the tumour response to electrochemotherapy: Review of the evidence and a research roadmap

The beneficial effects of electrochemotherapy (ECT) for superficial tumours and, more recently, deep-seated malignancies in terms of local control and quality of life are widely accepted. However, the variability in responses across histotypes needs to be explored. Currently, patient selection for ECT is based on clinical factors (tumour size, histotype, and exposure to previous oncological treatments), whereas there are no biomarkers to predict the response to treatment. In this field, two major areas of investigation can be identified, i.e., tumour cell characteristics and the tumour microenvironment (vasculature, extracellular matrix, and immune infiltrate). For each of these areas, we describe the current knowledge and discuss how to foster further investigation. This review aims to provide a summary of the currently used guiding clinical factors and delineates a research roadmap for future studies to identify putative biomarkers of response to ECT. These biomarkers may allow researchers to improve ECT practice by customising treatment parameters, manipulating the tumour and its microenvironment, and exploring novel therapeutic combinations.

Electrochemotherapy Modulates Mammary Tumor Growth in Rats on a Western Diet Supplemented with Curcumin

In the US, every 12 min, six women are diagnosed with breast cancer and one dies. This highlights a critical need for developing alternate therapies using natural compounds, which are cost effective and with less side effects. Curcumin, the yellow pigment of turmeric has been found to suppress initiation, progression, and metastasis of a variety of tumors. Multiple clinical trials highlight the efficacy of curcumin in treating breast cancer and other diseases. Our in vitro studies have demonstrated that the electrical pulse (EP) application can further enhance the effectiveness of curcumin against breast cancer cells in a therapy called electrochemotherapy (ECT). In a direct extension of these results, we studied the effect of ECT coupled with intratumoral curcumin administration (EP+Cur) on N-methyl-N-nitrosourea (MNU) induced mammary tumors in female Sprague Dawley rats. Beginning at the weaning and throughout the study, rats were fed either western diet (West) or western diet, supplemented with 1% curcumin (W+Cur). Our results showed that EP+Cur treatment led to a reduced growth rate in rats fed with W+Cur diet compared to West diet (57.14% vs. 16.67% in West diet). These results provide a foundation for further studies towards utilizing it in clinical practice.

Electrochemotherapy of skin metastases from breast cancer: a systematic review

Skin metastases occur in 5-30% of breast cancer (BC) patients. Standard treatments include systemic therapies (chemotherapy, endocrine therapy, and immunotherapy) and local treatments (surgery and radiotherapy). Electrochemotherapy (ECT) could be another option in this setting based on preclinical and clinical studies. Aim of this review was to analyze the available evidence on ECT in skin metastases from BC. Studies reporting on ECT in skin metastases from BC were included in this review. Studies not reporting toxicity or tumor response or not reporting results separately from other primary cancers were excluded. The search was based on Medline, Scopus, and The Cochrane Library databases. Eleven studies including 464 patients were analyzed. ECT was performed using intravenous/intratumoral bleomycin (10 studies) or intratumoral cisplatin (one study). Complete and overall pooled response rates were 46.2% (_95%CI 33.2-59.4 and 74.6% (_95%CI 60.6-86.4) in studies reporting results on a per patient basis and 61.9% (_95%CI 53.8-69.6) and 86.9% (_95%CI 80.0-92.6) in studies reporting results on a per lesion basis, respectively. Worse response rates in larger lesions were observed in three studies. The incidence of toxicity was heterogeneous but adverse events were mild and manageable in all studies. One- and 3-year local progression-free survival was 86.2% and 81.0% in two studies, respectively. ECT is tolerable and effective in terms of response in BC skin metastases especially in less advanced lesions. Further studies are justified to compare ECT with other treatments in this setting.

Cell morphology impact on the set-up of electroporation protocols for in-suspension and adhered breast cancer cells

In order to establish cancer-type-specific electroporation protocols for breast cancer, electroporation was performed in vitro in two modalities: in-suspension and adhered cells. Electroporation of cell suspensions was carried out through commercial electroporation cuvettes whereas a novel electrode for electroporation of adhered cells was designed and manufactured aimed to preserve cell structure, to provide a closer model to an in vivo scenario, and as a means to visualize the mechanical effects of electroporation on the cell membrane by using scanning electron microscopy. Electroporation protocols and electric field thresholds were predicted in silico and experimentally tuned through propidium iodide uptake and cell viability. Three breast-cancer cell lines (BT-20, MCF-7 and HCC1419) and a non-cancerous cell line (BEAS-2B) were used. Cancerous cells responded differently to electroporation depending on the electric parameters, cell histology, the cell culture modality, and the cell morphology (membrane thickness mainly), which was evaluated trough confocal and transmission electron microscopy. Particularly, it was found that electrochemotherapy may represent a promising alternative as an adjuvant treatment of metastatic breast tumours, and as a neoadjuvant therapy for Her2/neu tumours. Oppositely, triple negative breast tumours may show a high sensitivity to electroporation and therefore, they could be efficiently treated with irreversible electroporation. On the other hand, noncancerous cells demanded the highest voltage in both cell culture modalities in order to be electroporated. Hence, these cells in suspension may provide a reliable, easy-to-perform, low-cost model for the development of electroporation protocols for eradication of healthy tissue around a tumour in a safety margin.

High-throughput, Label-Free Quantitative Proteomic Studies of the Anticancer Effects of Electrical Pulses with Turmeric Silver Nanoparticles: an in vitro Model Study

Triple negative breast cancer (TNBC) represents 15–20% of the over one million new breast cancer cases occurring each year. TNBC is an aggressive cancer phenotype, with low 5-year survival rates, high 3-year recurrence rates, and increased risk of metastasis. A lack of three commonly exploited hormone receptors renders TNBC resistant to endocrine therapies and lends to its critical absence of viable therapeutic targets. This necessitates the development of alternate and effective novel therapeutic strategies for TNBC. Towards this, our current work seeks to develop the technique of Electrical pulse (EP)-mediated Turmeric silver nanoparticles (TurNP) therapy, known as Electrochemotherapy (ECT), to effectively target TNBC cells. This technique involves the efficient delivery of natural bioactive molecules with anti-cancer effects via a biophysical means. In these experiments, the bioactive molecules are turmeric, a dried rhizome of Curcuma longa that has been used for centuries, both as a dietary supplement and as a medicine in Ayurveda (science of life) in the Indian subcontinent and in traditional Chinese medicine. Our results reveal the combined effect of TurNP + EP treatment in reducing MDA-MB-231 cell viability to as low as 9% at 12 h. Showing biological selectivity, this combination treatment has a substantially lower effect on non-tumorigenic mammary epithelial MCF10A cells (67% viability). To gain mechanistic insights into the actions of TurNP-based ECT treatment, we performed high-throughput, label-free quantitative proteomics studies. Proteomics results indicate that TurNP + EP treatment significantly influenced expression of a diverse list of proteins, including receptors, transcription factors, structural proteins, kinases, and metabolic enzymes. This include the downregulation of 25 proteins in PI3K-Akt signaling pathway (such as GRB2, EGFR, EPHA2, GNB1, GNB2, 14–3–3 family, and Integrin family proteins), and 12 proteins (AKR1A1, ALDOA, ALDOC, PGK1, PGM1, PGAM1, ENO1, ENO2, GAPDH, TPI1, LDHA, and LDHB) in the glycolytic pathway with concomitant reduction in metabolite levels (glucose uptake, and intracellular- lactate, glutamine, and glutamate). Compared to TurNP alone, TurNP + EP treatment upregulated 66 endoplasmic reticulum and 193 mitochondrial proteins, enhancing several processes and pathways, including Pyruvate Metabolism, Tricarboxylic acid (TCA) cycle, and Oxidative Phosphorylation (OXPHOS), which redirected the TNBC metabolism to mitochondria. This switch in the metabolism caused excessive production of H₂O₂ reactive oxygen species (ROS) to inflict cell death in MDA-MB-231 cells, demonstrating the potency of this treatment.

Quantitative proteomic analysis of enhanced cellular effects of electrochemotherapy with Cisplatin in triple-negative breast cancer cells

Due to the lack of the three main receptors, triple negative breast cancer (TNBC) is refractive to standard chemotherapy. Hence, alternate therapies are needed. TNBCs utilize glycolysis, which heightens their growth, proliferation, invasiveness, chemotherapeutic resistance and poor therapeutic response. This calls for novel therapeutic strategies to target these metabolic vulnerabilities present in TNBC. Electroporation-mediated chemotherapy, known as electrochemotherapy (ECT) is gaining momentum as an attractive alternative. However, its molecular mechanisms need better understanding. Towards this, label-free quantitative proteomics is utilized to gain insight into the anticancer mechanisms of ECT using electrical pulses (EP) and Cisplatin (CsP) on MDA-MB-231, human TNBC cells. The results indicate that EP + CsP significantly downregulated 14 key glycolysis proteins (including ENO1, LDHA, LDHB, ACSS2, ALDOA, and PGK1), compared to CsP alone. EP + CsP caused a switch in the metabolism with upregulation of 34 oxidative phosphorylation pathway proteins and 18 tricarboxylic acid (TCA) cycle proteins compared to CsP alone, accompanied by the upregulation of proteins linked to several metabolic reactions, which produce TCA cycle intermediates. Moreover, EP + CsP promoted multiple pathways to cause 1.3-fold increase in the reactive oxygen species concentration and induced apoptosis. The proteomics results correlate well with cell viability, western blot, and qPCR data. While some effects were similar for EP, more comprehensive and long-lasting effects were observed for EP + CsP, which demonstrate the potential of EP + CsP against TNBC cells.

Cutaneous Metastasis of Internal Tumors

Cutaneous metastasis portends a poor prognosis. Therefore, a high clinical index of suspicion is necessary so that a clinician knows how to recognize the presentation of a cutaneous metastasis, while the pathologist must know the appropriate stains to order. In this review, the authors summarize the common and uncommon ways that these tumors will present. Frequently a metastatic cancer will present as a firm red nodule or as a plaque, ulcer, or papule. Less commonly they will present with a clinical clue that can alert a clinician to a likely diagnosis; these manifestations include alopecic, vesicular, blue color, sclerodermoid, acrochordon-, or pellagra-like.

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

Treatment of superficial tumors with electrochemotherapy (ECT) has shown a steep rise over the past decade and indications range from skin cancers to locally advanced or metastatic neoplasms. Based on reversible electroporation, which is a physical method to achieve transient tumor cell membrane permeabilization by means of short electric pulses, ECT increases cellular uptake of bleomycin and cisplatin and their cytotoxicity by 8,000- and 80-fold, respectively. Standard operating procedures were established in 2006 and updated in 2018. Ease of administration, patient tolerability, efficacy across histotypes, and repeatability are peculiar advantages, which make standard ECT (ie, ECT using fixed-geometry electrodes) a reliable option for controlling superficial tumor growth locally and preventing their morbidity. Consolidated indications include superficial metastatic melanoma, breast cancer, head and neck skin tumors, nonmelanoma skin cancers, and Kaposi sarcoma. In well-selected patients with oropharyngeal cancers, ECT ensures appreciable symptom control. Emerging applications include skin metastases from visceral or hematological malignancies, vulvar cancer, and some noncancerous skin lesions (keloids and capillary vascular malformations). Repeatability and integration with other oncologic therapies allow for consolidation of response and sustained tumor control. In this review, we present the basic principles of ECT, recently updated operating procedures, anesthesiological management, and provide a synthesis of the efficacy of standard ECT across histotypes.

Electrochemotherapy: A Review of Current Status, Alternative IGP Approaches, and Future Perspectives

The efficiency of electroporation (EP) has made it a widely used therapeutic procedure to transfer cell killing substances effectively to the target site. A lot of researches are being done on EP-based cancer treatment techniques. Electrochemotherapy (ECT) is the first EP-based application in the field of drug administration. ECT is a local and nonthermal treatment of cancer that combines the use of a medical device with pharmaceutical agents to obtain local tumor control in solid cancers. It involves the application of eight, 100µs, pulses at 1 or 5000 Hz frequency and specified electric field (V/cm) with a median duration of 25 minutes. The efficacy of chemotherapeutic drugs increases by applying short and intense electrical pulses. Several clinical studies proposed ECT as a safe and complementary curative or palliative treatment option (curative intent of 50% to 63% in the treatment of Basal Cell Carcinoma (BCC)) to treat a number of solid tumors and skin malignancies, which are not suitable for conventional treatments. It is used currently for treatment of cutaneous and subcutaneous lesions, without consideration of their histology. On the contrary, it is also becoming a practical method for treatment of internal, deep-seated tumors and tissues. A review of this method, needed instruments, alternative image-guided procedures (IGP) approaches, and future perspectives and recommendations are discussed in this paper.

Electrochemotherapy - Emerging applications technical advances, new indications, combined approaches, and multi-institutional collaboration

The treatment of tumors with electrochemotherapy (ECT) has surged over the past decade. Thanks to the transient cell membrane permeabilization induced by the short electric pulses used by ECT, cancer cells are exposed to otherwise poorly permeant chemotherapy agents, with consequent increased cytotoxicity. The codification of the procedure in 2006 led to a broad diffusion of the procedure, mainly in Europe, and since then, the progressive clinical experience, together with the emerging technologies, have extended the range of its application. Herein, we review the key advances in the ECT field since the European Standard Operating Procedures on ECT (ESOPE) 2006 guidelines and discuss the emerging clinical data on the new ECT indications. First, technical developments have improved ECT equipment, with custom electrode probes and dedicated tools supporting individual treatment planning in anatomically challenging tumors. Second, the feasibility and short-term efficacy of ECT has been established in deep-seated tumors, including bone metastases, liver malignancies, and pancreatic and prostate cancers (long-needle variable electrode geometry ECT), and gastrointestinal tumors (endoscopic ECT). Moreover, pioneering studies indicate lung and brain tumors as suitable future targets. A further advance relates to new combination strategies with immunotherapy, gene electro transfer (GET), calcium EP, and radiotherapy. Finally and fourth, cross-institutional collaborative groups have been established to refine procedural guidelines, promote clinical research, and explore new indications.

Bioimpedance Analysis of Epithelial Monolayers after Exposure to Nanosecond Pulsed Electric Fields

Exposures to pulsed electric fields (PEFs) are known to affect cell membranes and consequently also cell-cell interactions as well as associated characteristics. Bioimpedance analysis offers direct and non-invasive insights into structural and functional changes of cell membranes and extracellular matrices through a rigorous evaluation of electrical parameters. Accordingly, the multi-frequency impedance of confluent monolayers of rat liver epithelial WB-F344 cells was monitored in situ before and after exposure to nanosecond PEFs (nsPEFs). The results were fitted by two Cole models in series to obtain the Cole parameters for the monolayer. For an interpretation of the results, dielectric parameters, were correlated with changes of the TJ protein zonula occludens (ZO-1) and the paracellular permeability of the monolayer Cole parameters in general change as a function of pulse number and time. The findings demonstrate that impedance analysis is an effective method to monitor changes of TJs cell-cell contacts and paracellular permeability and relate them to exposure parameters.

Electrochemotherapy in Breast Cancer - Discussion of the Method and Literature Review

Breast cancer is the most common cause of skin metastases in women. The probability of their occurrence ranges from about 5% in the entire population to as much as 30% in the late stages of the disease. Although rarely life-threatening, they have a major impact on the quality of life of patients with this diagnosis, being the cause of pain, effusion, ulceration, infection, and psychological discomfort. Available methods of treatment, both local and systemic, often fail to provide adequate control of the disease. A particular challenge seems to be the treatment of those patients with cutaneous metastases who, due to the extent of their metastases, are not eligible for resection, in whom the possibility of radiation therapy has already been used, and in whom systemic therapy is ineffective or contraindicated. A new method providing the opportunity for effective treatment is electrochemotherapy (ECT). ECT combines electropulsation of tumor cells (by local application of electric pulses) and administration of antineoplastic drugs such as cisplatin or bleomycin (either intravenous or intratumoral). Several clinical studies have demonstrated that ECT provides safe, efficient, and non-invasive locoregional treatment for chest wall breast cancer recurrence.

Cutaneous Erythema at Scar Site of Modified Radical Mastectomy: An Unexpected Manifestation of Recurrent Carcinoma

A 44-year-old woman presented with marked erythema over right mastectomy scar, while on Herceptin therapy. She had neoadjuvant chemotherapy, modified radical mastectomy, and radiotherapy less than one year earlier for the treatment of invasive ductal carcinoma. On physical examination, no palpable masses were detected in the erythematous skin. A biopsy revealed permeation of the skin lymphatics by emboli of metastatic ductal carcinoma, similar to what is seen in inflammatory carcinoma. The involved skin was excised, followed by immediate reconstruction with transverse rectus abdominis muscle (TRAM) flap. On follow-up, the wound was healing well, with no signs of inflammation.

Electrochemotherapy - Supplementary Treatment for Loco-regional Metastasized Breast Carcinoma Administered to Concomitant Systemic Therapy

Background

Electrochemotherapy (ECT) is an established procedure for treating breast cancer loco-regional recurrences following surgical intervention and/or radiotherapy. Limited information is available on ECT application as a concomitant procedure to systemic therapy in recurrent breast cancer. The primary objective of this study was to determine if the application of ECT in close temporal relation to systemic chemotherapy could lead to increased local and/or systemic side effects. For this purpose we evaluated the safety of ECT as a supplemental local therapy to systemic therapy. ECT local and systemic toxicity and side effects were recorded and whether the anticipated local therapeutic effect of ECT would be influenced by the concomitant use of systemic therapies was investigated.

Patients and methods

This is an observational study. Thirty three patients with loco-regional metastasized breast carcinoma were treated and observed over a period of three years with 46 ECT applications for local tumour control in addition to established systemic therapy. A specific timeline for ECT administration was not fixed up, but was generally performed one week before the following chemotherapy administration with the aim to avoid the so called nadir, this means the peak period with risk of neutropenia.

Results

Data was collected over a period of three years on a population of 33 metastatic patients. Fifteen patients, received neo-adjuvant therapy as part of their primary treatment, but still had an advanced stage tumour. Some patients received repeated ECT applications. Objective tumour response was observed in 90% of the treated patients. Patients showed no increased local toxicity, especially no higher dermal toxicity, e.g. formation of local necrosis.

Conclusions

ECT proved to be an effective supplement to a cytotoxic systemic therapy, especially for high-risk patients who did not respond well to systemic therapy of loco-regional metastases, without creating any greater systemic or loco-regional toxicities.

The promising alliance of anti-cancer electrochemotherapy with immunotherapy

Anti-tumor electrochemotherapy, which consists in increasing anti-cancer drug uptake by means of electroporation, is now implanted in about 140 cancer treatment centers in Europe. Its use is supported by the English National Institute for Health and Care Excellence for the palliative treatment of skin metastases, and about 13,000 cancer patients were treated by this technology by the end of 2015. Efforts are now focused on turning this local anti-tumor treatment into a systemic one. Electrogenetherapy, that is the electroporation-mediated transfer of therapeutic genes, is currently under clinical evaluation and has brought excitement to enlarge the anti-cancer armamentarium. Among the promising electrogenetherapy strategies, DNA vaccination and cytokine-based immunotherapy aim at stimulating anti-tumor immunity. We review here the interests and state of development of both electrochemotherapy and electrogenetherapy. We then emphasize the potent beneficial outcome of the combination of electrochemotherapy with immunotherapy, such as immune checkpoint inhibitors or strategies based on electrogenetherapy, to simultaneously achieve excellent local debulking anti-tumor responses and systemic anti-metastatic effects.

Atypical breast adenosquamous carcinoma following acute myeloid leukemia in a middle-aged woman: A case report

Adenosquamous carcinoma of the breast is a rare cancer that develops as glands and tubules admixed with solid nests of squamous cells in a spindle cell background. Furthermore, its occurrence following AML is also rare. To the best of our knowledge, based on a review of the relevant literature, thus far there have not been any welldocumented cases. In the present case report, we report on a middle-aged woman with a 2year history of acute myeloid leukemia (AML) who was admitted to hospital due to a mass in the right breast, with concurrent cutaneous lesions on the breast. The clinical and pathological investigations resulted in the diagnosis of adenosquamous carcinoma of the breast. The patient underwent a modified radical mastectomy (MRM). Subsequently, the patient received chemotherapy, involved-field radiation therapy and target therapy. At 9 months after the final cycle of chemotherapy, and while she was on targeted therapy with trastuzumab (6 mg administered every 3 weeks), the patient presented with extensive dermatomal skin lesions. A biopsy report revealed metastatic lesions of invasive ductal carcinoma in the abdomen, so chemotherapy resumed with a course lasting for 6 cycles, with the identical treatments, but lacking trastuzumab.

Skin metastases of cervical cancer: two case reports and review of the literature

BACKGROUND

Although cervix carcinoma is one of the most common malignancies in women, hematogenous metastases are relatively not common. Cutaneous metastases, in particular, are unusual even at an advanced stage of disease. Their presence is a predictor of poor prognosis.

CASE PRESENTATION

Case 1: A 63-year-old postmenopausal Moroccan woman was diagnosed as having cervical squamous cell carcinoma. She was treated with radical concurrent chemotherapy and radiation therapy followed by low-dose brachytherapy. Six months after finishing the therapy, multiple skin nodules appeared on her abdomen and chest wall. An excision biopsy was performed and showed metastatic squamous cell carcinoma. Her disease progressed and she died before completing her fourth course of palliative chemotherapy. Case 2: A 48-year-old Moroccan woman was diagnosed as having cervical squamous cell carcinoma; she was treated with concurrent chemoradiation. Before a planned high-dose brachytherapy, she noticed many nodular lesions on her arms, thighs, and chest wall. An excision biopsy was performed and showed metastatic squamous cell carcinoma. She then underwent a series of imaging examinations, including computed tomography of her chest, abdomen, and pelvis, and a whole body bone scan that showed disseminated disease involving her lungs and bones. She died after two courses of palliative chemotherapy, 2 months after the appearance of the skin lesions.

CONCLUSION

We report two cases to illustrate a rare localization of metastasis from cervical carcinoma that is highly aggressive requiring early detection and aggressive management.

Quantification of cell membrane permeability induced by monopolar and high-frequency bipolar bursts of electrical pulses

High-frequency bipolar electric pulses have been shown to mitigate undesirable muscle contraction during irreversible electroporation (IRE) therapy. Here, we evaluate the potential applicability of such pulses for introducing exogenous molecules into cells, such as in electrochemotherapy (ECT). For this purpose we develop a method for calculating the time course of the effective permeability of an electroporated cell membrane based on real-time imaging of propidium transport into single cells that allows a quantitative comparison between different pulsing schemes. We calculate the effective permeability for several pulsed electric field treatments including trains of 100μs monopolar pulses, conventionally used in IRE and ECT, and pulse trains containing bursts or evenly-spaced 1μs bipolar pulses. We show that shorter bipolar pulses induce lower effective membrane permeability than longer monopolar pulses with equivalent treatment times. This lower efficiency can be attributed to incomplete membrane charging. Nevertheless, bipolar pulses could be used for increasing the uptake of small molecules into cells more symmetrically, but at the expense of higher applied voltages. These data indicate that high-frequency bipolar bursts of electrical pulses may be designed to electroporate cells as effectively as and more homogeneously than conventional monopolar pulses.

Electrochemotherapy guided by intraoperative fluorescence imaging for the treatment of inoperable peritoneal micro-metastases

Surgery is often the first therapeutic indication in cancer. Patient survival essentially depends on the completeness of tumor resection. This is a major challenge, particularly in patients with peritoneal carcinomatosis (PC), where tumors are widely disseminated in the large peritoneal cavity. These small tumors can be difficult to visualize and are often positioned in delicate locations, further increasing the risk of producing serious tissue/organ damage during their ablation. We propose an innovative therapeutic approach based on intraoperative fluorescence (IF) guided electrochemotherapy (ECT) for the treatment of peritoneal micro-metastases. ECT combines the effects of tissue electro-permeabilization (EP) with the administration of an antimitotic agent (bleomycin) that has poor permeability across intact membranes. IF significantly improves the detection of small tumor lesions. ECT is clinically validated for the treatment of cutaneous tumors in animals and humans, but this is the first time that it has been used along with IF imaging for the targeted treatment of peritoneal metastases in a preclinical model. We set up a murine model of PC that develops secondarily to the resection of a distant primary tumor. Tumor growth and metastasis were finely monitored by non-invasive multimodal imaging (bioluminescence and 3D fluorescence/microCT). Once metastases were detected, mice were randomized into three groups: the ECT group (bleomycin injected intravenously followed by EP) and 2 control groups (bleomycin alone and EP alone). Twenty four hours after the intravenous injection of the tumor targeting agent Angiostamp™700, mice in all groups underwent an abdominal surgery for metastases exploration assisted by fluorescence imaging with the Fluobeam®700 portative device. EP was applied to every nodule detected by IF, except in the bleomycin control group. After surgery, the metastatic invasion was tracked by bioluminescence imaging. In mice treated with bleomycin or EP alone, the metastatic load progressed very rapidly and mice showed no significant difference in lifespan compared to non-operated mice (median lifespan: 27days vs. 25days, respectively). In contrast, the mice treated with ECT displayed a decreased metastatic load and an increased survival rate (median lifespan: 34days). These results provide evidence that IF guided ECT is an effective approach for the treatment of inoperable intraperitoneal micro-metastases.

Recommendations for improving the quality of reporting clinical electrochemotherapy studies based on qualitative systematic review

BACKGROUND

Electrochemotherapy is becoming a well-established treatment for malignancies of skin and non-skin origin and its use is widening across Europe. The technique was developed and optimized from solid experimental and clinical evidence. A consensus document is now warranted to formalize reporting results, which should strengthen evidence-based practice recommendations. This consensus should be derived from high quality clinical data collection, clinical expertise and summarizing patient feedback. The first step, which is addressed in this paper, aims to critically analyze the quality of published studies and to provide the recommendations for reporting clinical trials on electrochemotherapy.

METHODS

The quality of reporting in published studies on electrochemotherapy was analyzed in order to produce procedure specific reporting recommendations. A comprehensive literature search of studies published from 2006 to 2015 was performed followed by qualitative analysis of manuscripts assessing for 47 quality criteria grouped into four major clusters: (1) trial design, (2) description of patient population, (3) description of treatment delivery and patient outcome, (4) analysis of results and their interpretation. The summary measure during literature assessment was the proportion of studies fulfilling each manuscript quality criteria.

RESULTS

A total of 56 studies were screened, from the period 2006 to 2015, of which 33 were included in the qualitative analysis, with a total of 1215 patients. Overall, the quality of reporting was highly variable. Twenty-four reports (73%) were single-center, non-comparative studies, and only 15 (45%) were prospective in nature (only 2 of them were entered into a clinical trials registry). Electrochemotherapy technique was consistently reported, with most studies (31/33) adhering closely to published standard operating procedures. The quality of reporting the patient population was variable among the analyzed studies, with only between 45% and 100% achieving dedicated quality criteria. Reporting of treatment delivery and patient outcome was also highly variable with studies only fulfilling between 3% and 100%. Finally, reporting study results critically varied, fulfilling from 27% to 100% of the quality criteria. Based on the critical issues emerging from this analysis, recommendations and minimal requirements for reporting clinical data on electrochemotherapy were prepared and summarized into a checklist.

CONCLUSIONS

There is an increasing body of published clinical data on electrochemotherapy, but more high quality clinical data are needed. Published papers often lack accurate description of study population, treatment delivery as well as patient outcome. Our recommendations, provided in the form of a summary checklist, are intended to ameliorate data reporting in future studies on electrochemotherapy and help researchers to provide a solid evidence basis for clinical practice.