Electrochemotherapy in the treatment of metastatic malignant melanoma: A prospective cohort study by InspECT

Electrochemotherapy (ECT) is an effective local treatment for cutaneous metastasis. Treatment involves the administration of chemotherapeutic drugs followed by delivery of electrical pulses to the tumour. The aim of this study was to investigate the effectiveness of ECT in cutaneous metastases of melanoma and to identify factors which affect (beneficially or adversely) the outcome. Methods: 13 cancer centres in the International Network for Sharing Practices on Electrochemotherapy (INSPECT) consecutively and prospectively uploaded data to a common database. ECT consisted of intratumoural or intravenous injection of bleomycin, followed by application of electric pulses under local or general anaesthesia. Results: 151 patients with metastatic melanoma were identified from the database, 114 of which had follow-up data of 60 days or more. 80 of these patients (73 %) experienced an overall response (complete response + partial response = OR). 394 lesions were treated, of which 306 (77 %) revealed an OR, 229 a complete response (58 %). In multivariate analysis, factors positively associated with overall response were coverage of deep margins, absence of visceral metastases, presence of Accepted Article This article is protected by copyright. All rights reserved. lymphoedema, treatment of non-irradiated areas were factors significantly influencing treatment efficacy. Factors significant associated to a complete response to ECT treatment were: coverage of deep margins, previous irradiation of treated area, and tumour size (<3 cm). One-year overall survival in this cohort of patients was 67% (C.I. 95%: 57%-77%), whilst melanoma specific survival was 74% (C.I. 95%: 64%-84%). No serious adverse events were reported, and the treatment was in general very well tolerated. Conclusion: ECT is a highly effective local treatment for melanoma metastases in the skin, with no severe adverse effects. In the presence of certain clinical factors, ECT may be considered for local tumour control as an alternative to established local treatments, or as an adjunct to systemic treatments.