Electrochemotherapy in Experimental Bone Metastases

INTRODUCTION: The skeleton is a common site of metastases for a number of different cancers. They include lung, breast, prostate, kidney, thyroid cancers and multiple myeloma. It has been reported that in 70% of patients with metastatic breast cancer, bone metastases will develop [1]. Cancer cells in bone disrupt normal bone remodelling, resulting in the case of breast tumour cells in osteolytic lesions causing pain and fracture. Electrochemotherapy (ECT) refers to the combination of electroporation and administration of hydrophilic anticancer drugs for the local treatment of cutaneous and subcutaneous tumoural lesions of any histotypes [2]. Electroporation induces transient permeabilization of cell membrane by applying short and intense electric pulses; electroporation allows low permeant or non permeant anticancer drugs diffusion into the cytosol increasing their cytotoxicity by order of magnitude[3]. Previous studies showed that electroporation of osteoblasts lining the trabeculae as well as of osteocytes can be achieved with no alteration of the mineral component or mechanical competence (microhardness) of the bone tissue[4]. No experience has been ever reported on ECT application in bone metastases. Purpose of our study was to assess the efficacy of ECT in the treatment of in vivo rat mammary adenocarcinoma MRMT-1 bone metastases.