This is a randomized controlled trial investigating efficacy of electrochemotherapy for early colorectal cancer

This is a phase 2 randomized controlled trial. The study is blinded. The aim of this study is to establish the safety and efficacy of treating patients with early colorectal cancer with electrochemotherapy, compared with electroporation alone, as a down staging and immune-response enhancing treatment prior to intended curative surgery. The study involves recruitment of patients with histologically verified rectal and sigmoid colon cancer with no indication for neoadjuvant chemoradiotherapy (experimental or standard care based) prior to intended curative surgery. In total the study will involve 24 patients, of these, 12 patients are treated with electrochemotherapy (bleomycin) and 12 patients with electroporation alone (placebo)

In relation to the intervention, clinical examination, blood samples, biopsies and questionnaires will be collected to evaluate safety, tumor respons and immunologic response to the treatment.

Patients will be followed for one month after the elective surgery.

Inclusion Criteria:

• Patients must be mentally capable of understanding the information given.
• Patients must give written informed consent.
• Endoscopically suspected or histologically verified malignant tumor of the rectum or sigmoid colon.
• Tumor described as passable at index endoscopy.
• Men or women aged at least 18 years.
• Case reviewed by MDT (surgery, radiology, oncology). Case considered curable with standard surgical resection.
• ASA class I-II (Classification of the American Society of Anesthesiology)

Exclusion Criteria:

• Indication for neoadjuvant chemoradiation or chemotherapy prior to surgery
• Uncorrectable coagulation disorder.
• Patients with ICD or pacemaker units.
• Ongoing immunosuppressive treatment.
• Patients with concomitant use of phenytoin.
• Myocardial insufficiency, defined as NYHA class >2
• Concurrent treatment with an investigational medicinal product.
• Patients with any other clinical condition or prior therapy that, in the opinion of the investigator, would make the patient unsuitable for the study or unable to comply with the study recruitments.
• Advanced tumor stages, clinical UICC stage IV.
• Acute surgical resection.
• Pregnancy
• Medical history of severe pulmonary disease.
• Previous cumulative dose of bleomycin exceeding 250mg/m2.
• BMI > 35
• Renal impairment, defined as eGFR <40 ml/min

Patients and investigators are blinded. The allocation list is located at the pharmacy.