Adjuvant electrochemotherapy of malignant ocular melanoma in a dog

Abstract

Melanocytoma and malignant melanoma are the most typical eye tumors in dogs and cats. Due to the presence of melanin, the general appearance is often highly pigmented in a nodular formation with well-defined borders. Electrochemotherapy (ECT) is a therapy combining reversible electroporation and anti-neoplastic drugs to enhance their cytotoxic effects through increasing cellular uptake by the electroporated tumor cells. In this article, the use of adjuvant ECT for the treatment of canine ocular melanoma is reported. The pre-surgical exams (blood count, renal and liver functions, echocardiogram, and electrocardiogram) were within the normal range, as were the chest radiography and abdominal ultrasound without signs of metastases. On the day of the surgery, an excisional biopsy of the tumor was performed without safety margins by keratectomy associated with conjunctivectomy and adjuvant ECT in the surgical site and peri-tumoral region. The animal was followed for approximately 7 months and remained without evidence of tumor recurrence. A complete resolution of corneal opacification was also observed. To our knowledge, this is the first report of the use of ECT in an ocular neoplasm. From a comparative oncology perspective, this report opens the way for future therapeutic approaches in superficial ocular cancers in veterinary and human medicine.