Immediate results of electrochemotherapy for
 malignant tumors of the skin and soft tissues,
 cutaneous and subcutaneous metastases
 of melanoma

Abstract

Relevance: Surgical removal of locally advanced forms of skin cancer and multiple cutaneous and subcutaneous metastases of melanoma does not always provide satisfactory aesthetic, functional, and long-term results. The treatment outcomes
 depend on the size, shape, location, and some other characteristics of the tumor. The relapse rate after surgical removal of
 locally advanced skin cancer is 12.5-34%, and the long-term survival of patients with cutaneous and subcutaneous metastases
 of melanoma does not exceed 30%. Cutaneous and subcutaneous metastases of melanoma and some superficial tumors are
 usually initially inoperable. Their complications such as bleeding, infection, pain, and pitting cause serious clinical problems
 and often require local therapy even at the 4th stage of the disease.
 Electrochemotherapy (ECT) is one of the modern treatment methods for skin cancer, soft tissue sarcoma, and metastatic
 melanoma. ECT is a treatment of choice in the presence of contraindications to surgical and radiation therapy. ECT combines
 the physical properties of current-induced electroporation with the chemical properties of chemotherapeutic drugs. In this
 method, an electric current affecting the tissue causes a temporary increase in cell membrane permeability, thereby providing
 free access to the cell of large molecules, including cytostatic drugs, which are not initially transferred to the cytosol. This significantly increases the potential toxicity of cytostatic drugs.
 The purpose of this study was to demonstrate the immediate results of ECT in patients with malignant tumors of the skin,
 soft tissue, cutaneous, and subcutaneous melanoma metastases.
 Results: Since 2017, 27 patients were treated by ECT at the Centre for bone and soft tissue tumors and melanomas of Kazakh Institute of Oncology and Radiology (Almaty, Kazakhstan). After two months, 67% of patients had a complete response
 (CR), 26% – a partial response (PR), and 7% had progression of the tumor. Side effects included local edema (n=13, 40%)
 which independently disappeared within several days to 2 weeks, local pains (12%) which disappeared within six months in 3%
 and within a month after treatment in 11%, and hyperthermia in the early postoperative period in 6% of patients which was
 stopped within 10-15 min after the procedure.