GISEL (Italian Senologic Group for Electrochemotherapy): Prospective Multicenter Registry of Breast Cancer Patients With Skin Metastases Treated by Electrochemotherapy

In patients with metastatic breast cancer, the skin is affected in 5-30% of cases. Although a relatively uncommon event in absolute terms, the occurrence of skin metastases generally represents an unfavourable prognostic factor (due to simultaneous or imminent disease progression in other sites), as well as a condition of difficult therapeutic management. Even in the most favourable cases, in which the disease is still confined to the locoregional level, cutaneous metastases often entail a worsening of the patients' quality of life, linked to their psychological impact and to the related symptoms (pain, ulceration, bleeding, infection). It is therefore of paramount importance that patients receive timely and effective treatment. Surgical excision represents the simplest and quickest approach to ensure local control of the disease; when the surgical option is not radically feasible, locoregional treatments may be considered. Electrochemotherapy (ECT) has been proposed as a new treatment option for the palliation of skin metastases from breast cancer. Briefly, it consists of the combination of chemotherapy with the local application (at the tumour) of electrical impulses. Through the application of short, intense electrical impulses, a physical phenomenon (reversible electroporation) is produced, which consists of the temporary opening of pores through the cell membrane that increase its permeability. This mechanism allows the diffusion into the cytoplasm of drugs that are in themselves not very permeable. The final effect is an increase in the cytotoxic effect of the drug. The enhancement of cytotoxic action ranges from 80 (in the case of cisplatin) up to 8000 times (in the case of bleomycin). In current clinical practice, ECT is used, as a complementary or alternative treatment, in the management of patients with skin tumours and superficial metastases that cannot be surgically removed or are not amenable to treatment by radiotherapy or systemic oncological therapies. Due to its relative ease of application and favourable toxicity profile, ECT is currently an effective tool for the palliation of symptomatic (bleeding, ulcerated, painful) superficial metastases, thus contributing to the preservation of the patient's quality of life.Recent retrospective studies based on patients with skin metastases from breast cancer treated with ECT found local response rates to treatment of 90%, with 58% of patients reporting complete regression. If these preliminary observations were confirmed in a prospective, larger case series study, the criteria for selecting breast cancer patients eligible for treatment with ECT could be improved.