Abstract 4707: Electrochemotherapy for the treatment of head and neck squamous cell carcinoma

Abstract Squamous cell carcinoma (SCC) is the second most prevalent type of skin cancer after basal cell carcinoma, with the highest incidence occurring in sun-exposed regions of the body, particularly the head and neck. Approximately 300,000 new cases are diagnosed each year, imposing significant financial burdens on healthcare systems due to treatment costs and on the economy due to productivity losses. Surgery remains the primary treatment option; however, patients, particularly those with advanced-stage disease, may decline surgery due to concerns about functional and cosmetic outcomes. Other effective treatments include cryosurgery, radiotherapy, topical therapies, photodynamic therapy, and Mohs micrographic surgery. Recently, electrochemotherapy (ECT) has emerged as a novel treatment option. ECT involves administering bleomycin followed by electric pulses targeted at the tumor and surrounding margins, inducing transient cell membrane permeabilization. This enhances drug uptake and amplifies cytotoxic effects by over 1,000-fold. Since 2006, ECT has been a standard therapy in Europe and was introduced in Argentina in 2020, offering a new approach for patients who are unsuitable for or decline other treatments. In this study, we present outcomes from six patients with head and neck SCC treated with ECT on an outpatient basis. Most patients required only a single 60-minute treatment session. Observed side effects included grade 1-2 edema, pain, and flu-like symptoms per CTCAE 4.0. Tumor response was assessed using RECIST criteria, with results showing 71.4% complete response (5 of 7 lesions), 14.3% partial response (1 lesion), and 14.3% progressive disease, yielding an objective response rate of 85.7%.In conclusion, electrochemotherapy proved to be a safe and effective treatment for select head and neck SCC patients who are not candidates for surgery, providing a promising alternative in the therapeutic landscape. Citation Format: Felipe H. Maglietti, Sebastian D. Michinski, Lorna A. Evans, Raquel Lertora. Electrochemotherapy for the treatment of head and neck squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4707.