Electrochemotherapy for cutaneous Kaposi Sarcoma: A European register-based cohort study from the International Network for Sharing Practices of electrochemotherapy (InspECT).

Introduction: Kaposi sarcoma (KS) is a cancer of endothelial cells involving the skin and visceral organs. Electrochemotherapy (ECT) is an alternative treatment option for patients with cutaneous malignancies of skin and non-skin origin not suitable for conventional treatments. ECT exerts anti-tumour activity through enhanced drug delivery to tumour cells and cytotoxicity, inducing immunogenic tumour cell death and through a vascular-disrupting effect.

Materials And Methods: In this multi-institutional prospective, observational study, we aimed to evaluate the outcomes of using ECT as a treatment modality for cutaneous Kaposi's Sarcoma within the InspECT (International Network for Sharing Practice on ECT) registry. Patients with superficial lesions of Kaposi Sarcoma from 19 European centres were included. They underwent at least one ECT session with bleomycin performed following the European Standard Operating Procedures, between March 2011 and June 2024.

Results: The analysis included 82 patients (mean age 71 years; median number of lesions/patient 2). Side effects were reported as mild and easily manageable. The response to treatment per patient was 80 % complete and 13 % partial. In the multivariate model, time since diagnosis to ECT and small tumour size showed a significant association with a complete response. One-year local progression-free survival (LPFS) in the whole population was 93 %, 2 years LPFS was 89 %.

Conclusions: In the present study, ECT showed antitumor activity and a favourable safety profile in patients with cutaneous Kaposi Sarcoma either not suitable for conventional treatments or that refused them. Better results were obtained in small tumours (<3 cm) using hexagonal electrodes.