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

Primož Strojan,Christina Caroline Plaschke,Avraham Eisbruch,Alfio Ferlito,Remco De Bree,William M Mendenhall,Gregor Serša,Jan B Vermorken,Robert Smee,Aleš Grošelj,Sandra Nuyts

doi:10.3390/cancers13061254

Abstract

Simple SummaryElectrochemotherapy is a topical ablative treatment based on the formation of electropores in the cell membrane exposed to an external electric field. The consequent intracellular accumulation of hydrophilic bleomycin or cisplatin molecules greatly increases their cytotoxicity. Currently, electrochemotherapy is recognized as an effective treatment for tumors of different histological types and also for some deep-seated tumors. In mucosal cancer of the head and neck, experience with electrochemotherapy is limited, primarily due to the anatomical complexity of the region and the poor accessibility of tumors, as well as the design limitations of the electrodes used to create an electric field. A systematic review of the literature and subsequent analysis of 164 patients from 16 studies treated between 1998 and 2020 confirmed that electrochemotherapy is an effective and safe treatment for mucosal cancer of the head and neck as well.Electrochemotherapy (ECT) is a local ablative treatment that is based on the reversible electroporation and intracellular accumulation of hydrophilic drug molecules, which greatly increases their cytotoxicity. In mucosal head and neck cancer (HNC), experience with ECT is limited due to the poor accessibility of tumors. In order to review the experience with ECT in mucosal HNC, we undertook a systematic review of the literature. In 22 articles, published between 1998 and 2020, 16 studies with 164 patients were described. Curative and palliative intent treatment were given to 36 (22%) and 128 patients (78%), respectively. The majority of tumors were squamous cell carcinomas (79.3%) and located in the oral cavity (62.8%). In the curative intent group, complete response after one ECT treatment was achieved in 80.5% of the patients, and in the palliative intent group, the objective (complete and partial) response rate was 73.1% (31.2% and 41.9%). No serious adverse events were reported during or soon after ECT and late effects were rare (19 events in 17 patients). The quality-of-life assessments did not show a significant deterioration at 12 months post-ECT. Provided these preliminary data are confirmed in randomized controlled trials, ECT may be an interesting treatment option in selected patients with HNC not amenable to standard local treatment.

Highlights

Head and neck cancer (HNC) is the eighth most common and lethal cancer worldwide [1]
22 publications describing 16 studies with 164 patients were found to be appropriate for systematic review [15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36]
Preliminary data suggest that ECT may be an effective local treatment option in selected patients with HNC

Summary

Introduction

Head and neck cancer (HNC) is the eighth most common and lethal cancer worldwide [1]. Electroporation pulses affect adjacent non-malignant cells in the tumor through other, indirect mechanisms, both vascular and immunological, which contribute to the effectiveness of ECT [6]. The application of electric pulses to the tumor induces “vascular lock” by causing transient vasoconstriction and a decrease in blood flow in the treated tumor as a result of entrapment with a prolonged presence of drug molecules in the tumor. ECT affects the apoptosis of endothelial cells, leading to a vascular-disrupting effect [8]. The latter is selective toward tumor vessels, predominantly small ones, and does not affect normal vessels in the surrounding healthy tissue [9]. The immune effects are triggered by the immunogenic death of tumor cells. ECT is considered an in situ vaccination, as some other ablative techniques, and can be effectively combined with immunotherapeutic approaches [10]

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