Background and study aims Electrochemotherapy is an anticancer treatment that uses electric pulses to facilitate uptake of chemotherapeutic drugs in
tumor cells and has proven to have a high local cytotoxic effect with minimal adverse events. Electrochemotherapy has mostly been used in treatment of cutaneous
metastases but development of a new endoscopic
electrode device has made treatment of
colorectal tumors possible. This first-in-man multicenter phase I study investigated safety and efficacy of electrochemotherapy using endoscopic electroporation in patients with
colorectal tumors. Patients and methods Seven patients with
colorectal tumors who were deemed ineligible for or had declined standard treatment were included. They were treated with
bleomycin either intratumorally or intravenously and the electric pulses were delivered through the endoscopic
electrode device. Safety and efficacy were assessed clinically and by scans immediately
after treatment and adverse events were reported. Response was evaluated up to 6 months
after treatment by scans (magnetic resonance imaging or computed tomography) and endoscopic examinations. Results Seven patients aged 62 to 88 years with multiple comorbidities were included and had one or two treatments each. Post-treatment scans showed
tumor responses in the treated areas and no damage to surrounding tissues. Only a few grade one adverse events were reported. Three patients had preoperative rectal
bleeding, of which two reported cessation of
bleeding and one reported decreased
bleeding. Conclusion This first-in-man study shows that electrochemotherapy for
colorectal tumors using the endoscopic
electrode device can induce local
tumor response and is safe also for fragile elderly patients with comorbidities.