Cutaneous melanoma frequently develops cutaneous and subcutaneous metastases, which may cause significant morbidity and negatively affect quality of life. Electrochemotherapy (ECT) is an established local treatment modality for cutaneous and subcutaneous tumor lesions that combines the administration of cytotoxic drugs with the application of electric pulses to increase drug uptake into tumor cells.

In addition to its direct cytotoxic effects, electrochemotherapy may induce changes in the tumor microenvironment, including immune cell infiltration, vascular alterations, and other biological responses that could influence tumor control.

The aim of this study is to evaluate changes in the tumor microenvironment of cutaneous and subcutaneous melanoma metastases following electrochemotherapy with either intravenous bleomycin or intratumoral cisplatin. Tumor tissue samples collected before and after treatment will be analyzed to characterize microenvironmental changes and to compare treated and untreated lesions.

The results of this study may improve understanding of biological effects of electrochemotherapy in melanoma metastases and support further development of treatment strategies.

This is a prospective interventional clinical study designed to investigate electrochemotherapy-induced changes in the tumor microenvironment of cutaneous and subcutaneous melanoma metastases.

Electrochemotherapy is a local treatment approach that combines electroporation with cytotoxic agents in order to increase intracellular drug delivery and enhance tumor cell death. The treatment is routinely used for superficial tumor lesions, including melanoma metastases, and can be performed using intravenous bleomycin or intratumoral cisplatin.

The primary objective of this study is to characterize changes in the tumor microenvironment in melanoma metastases following electrochemotherapy. Tumor tissue samples will be collected from untreated lesions and from lesions treated with electrochemotherapy. Histopathological and immunohistochemical analyses will be performed to evaluate changes in the tumor microenvironment, including cellular and stromal components, immune-related features, and other relevant biological markers.

The study will include patients with cutaneous melanoma presenting with cutaneous and/or subcutaneous metastases who are eligible for electrochemotherapy as part of their clinical management. Electrochemotherapy will be performed according to established clinical procedures using intravenous bleomycin or intratumoral cisplatin. Biopsy or surgical samples will be collected before and after treatment to enable comparative analyses of treated and untreated tumor tissue.

Collected clinical and pathological data will be used to assess associations between treatment-related microenvironmental changes and patient and lesion characteristics. The study aims to provide additional insight into biological effects of electrochemotherapy beyond local tumor control and may contribute to improved understanding of mechanisms involved in treatment response.

Inclusion Criteria:

• Adults aged 18 years or older
• Histologically confirmed cutaneous melanoma
• Presence of cutaneous and/or subcutaneous metastases eligible for electrochemotherapy
• Candidate for electrochemotherapy with intravenous bleomycin or intratumoral cisplatin according to standard clinical practice
• Ability to provide written informed consent

Exclusion Criteria:

• Contraindication to electrochemotherapy or study drugs (bleomycin or cisplatin)
• Pregnancy or breastfeeding
• Severe comorbidities preventing electrochemotherapy
• Inability to comply with study procedures