New Developments in Oncology – Electrochemotherapy

The Oncology service at Northwest Veterinary Specialists is overseen by Mary Marrington and Jessica Grant, both of whom are RCVS and European Oncology Specialists. Over the last year, we have continued to expand the service and now have 2 oncology residents, Lavra Zajc and Estel.la  Ciriano Cerda together with 3 dedicated oncology nurses. We strive to see referrals quickly and to offer patients the most appropriate treatment options alongside compassionate care.

One exciting new treatment option which we can provide at NWVS is ‘electrochemotherapy’ (fig 1). This is a new, cutting-edge, local treatment for solid tumours as an alternative to surgery or radiation therapy. It uses an electrical field which is directly delivered to a tumour. It destroys cancer cells through enhancing the delivery of chemotherapy agents to the tumour, altering the blood supply to the tumour, and through modifying the immune system. It is mainly used to treat superficial tumours where surgical excision is incomplete or where surgery is not feasible. One of the advantages of electrochemotherapy is that it can be effective as a single treatment only. However, in the case of partial tumour response or subsequent tumour progression it can be repeated several times with equal or improved effectiveness.

The treatment is performed under a short sedation or general anaesthesic.  An intravenous injection with a chemotherapy drug called bleomycin is initially administered. An electrical current is then applied directly to the tumour either with plates for superficial tumours, or needles for more deeply located tumours (fig 2). The treatment is generally tolerated very well with side-effects typically limited to local tissue inflammation and necrosis (fig 3).

A variety of malignancies have been proven to be sensitive to electrochemotherapy treatment in both canines and felines. Squamous cell carcinoma (fig 4), fibrosarcoma, mammary adenocarcinoma, anal sac carcinoma, mast cell tumours, melanoma and perianal tumours have all shown promising responses to electrochemotherapy treatment. It can be a highly effective treatment with up to 80% of patients with cutaneous and subcutaneous tumours having an objective response which in many cases can be long lasting. Electrochemotherapy is a relatively quick, inexpensive and well tolerated treatment for a variety of tumour types. It can be a suitable alternative, particularly where radical surgery or radiation therapy are not considered to be appropriate, so improving patient survival and quality of life. We are always happy to discuss any cases where this treatment might be appropriate.