Electrochemotherapy for superficially metastatic melanoma

Abstract

Cutaneous metastases are not unusual in the clinical course of malignant melanoma, occurring in 2-20% of patients, depending on primary tumor features and disease stage. Patients with superficially metastatic melanoma comprise a heterogeneous group as to prognosis, including those with local recurrences, satellite nodules, and in-transit metastases (stages IIIB and IIIC), as well as those with distant skin, subcutaneous, and soft tissue metastases (stage IV-M1a disease). Patients with superficially metastatic melanoma have peculiar supportive care needs due to increased psychosocial distress and wound care. Local treatment with electrochemotherapy (ECT) has been introduced in the management of melanoma since the 1990s. In these early clinical experiences, ECT showed sustained antitumor activity and favorable toxicity profile. In 2006, the procedure was standardized, and the European Standard Operating Procedure of Electrochemotherapy (ESOPE) entered the routine practice of dermato-oncology. More recent experiences confirm ECT as a valuable tool that ensures prolonged local control (2-year local progression-free survival estimated 74-87%), particularly in patients with locoregional disease and few, small tumor nodules. Unfortunately, the majority of patients require further ECT cycles due to disease progression outside treatment field. As a consequence, treatment intent can range from curative to merely palliative. To overcome this hurdle, researchers are actively investigating the way to implement electroporation technology as well as to rationally combine local ECT treatment with newly available immune (anti- CTLA4 [cytotoxic T-lymphocyte-associated antigen 4], anti-PD1 [programmed death-1]), or targeted (BRAF and MEK inhibitors) therapies, which have greatly improved patient survival during the past few years. In the meantime, it is advisable that clinicians recognize that the occurrence of skin metastases represents a troubling circumstance that requires immediate and focused attention. Before undergoing ECT, each patient should be managed by a multidisciplinary team, and its members should take into consideration the disparity in clinical course between patients with locoregional (in whom ECT intent can be curative) and distant metastases (in whom treatment intent is mainly palliative). Quality trial evidence is needed to clarify the impact of this innovative treatment for melanoma patients.