El Paso Zoo veterinary staff and keepers, alongside Dr. Joseph Impellizeri of Veterinary Oncology Services in New York, have successfully completed a fourth cancer treatment procedure on 52-year-old Asian elephant Juno.
“Our goal with electrochemotherapy and electrogene therapy is to decrease the size of the mass, make the disease static, and keep Juno comfortable without systemic side effects,” said El Paso Zoo Veterinarian Dr. Victoria Milne.
Juno is recovering and is being closely monitored by zookeepers. She was diagnosed with a malignant mass in her right mammary gland in October 2016.
On Wednesday, October 16, Juno was placed under general anesthesia for approximately an hour and a half to perform electrochemotherapy treatment, along with a new localized IL-12 gene therapy to enhance her immune system’s ability to recognize and fight the tumor.
During the procedure, the tumor was infused with a chemotherapy drug and the IL-12 gene, then treated with a small electric pulse that drives the agents into the cancer cells. The move allows localized treatment of the mass with fewer systemic side effects.
The first treatment was performed in March of 2017, the second in September of 2017, and the third in January 2018. According to veterinary experts, the mass has responded to the previous treatments, and the overall mass size decreased, but over time, it has grown again.
Without surgery, it is unlikely the mass will completely disappear; however, due to the non-aggressive nature of the mass and the high risk of surgery in a geriatric elephant such as Juno, this treatment modality was chosen rather than surgery.
Juno is one of two Asian elephants at the El Paso Zoo.
Asian elephants are part of the Association of Zoos and Aquariums (AZA)’s collaborative conservation programming. They are also an AZA SAFE species; SAFE (Saving Animals from Extinction) focuses the collective expertise within AZA-accredited zoos and aquariums and leverages their massive audiences to save species.