New Treatment for Mast Cell Tumors (MCT)-STELFONTA

New Treatment for Mast Cell Tumors (MCT)-STELFONTA

VCA Hollywood Animal Hospital now offers STELFONTA as a cutting edge treatment for Mast Cell Tumors (MCT). STELFONTA is a prescription medicine used in dogs to treat mast cell tumors on the skin or in the tissues just under the skin. Given as an injection directly into your dog’s tumor, it destroys the tumor by breaking down cancer cells and starving their blood supply. A “pocket” or wound is left at the injection site where the tumor was. This is generally a healthy wound ready for skin and hair to grow back in a few weeks.

Pretreatment involves oral medications, including corticosteroids and antihistamines, prior to the injection of STELFONTA. These medications are very important to reduce the risks associated with inflammatory substances that can be released from the tumor as the mast cells are destroyed. Premedication is given 2 days pretreatment and continues until 7 days post treatment. It is essential that you give all medications as prescribed.

Most dogs do not need sedation or anesthesia during the procedure although occasionally, dogs may be sedated. 

Side effects reported in dogs treated with STELFONTA were generally mild and short lasting, but they can be severe, especially if not treated in a timely manner. 

The most common adverse reactions included wound formation, injection-site pain, lameness in the treated limb, vomiting, diarrhea, and hypoalbuminemia (low levels in the blood of the protein albumin). Although most side effects/adverse reactions seen in clinical studies were mild, the most serious side effects occurred in the first 4 days. Excessive pain, lameness, tiredness, refusal to eat for more than one day, repeated vomiting or diarrhea, trouble breathing, changes to the treated tumor site (including increased or excessive swelling and bruising, extensive wound formation, increased irritation) or any other symptoms should be examined immediately and treated accordingly. 

Irene Vazquez, DVM, MS, DACVIM (Oncology)

Medical Oncologist
VCA Hollywood Animal Hospital

Pet CancerCare Center

vcahollywood@vca.com

October Patient of the Month- Baby!!!!

About five months ago, Baby’s mom noticed a painful swelling in her right front leg and brought her in for an exam. Dr. Murphy discovered a mass on Baby’s right forearm just below the elbow and obtained a sample. The mass was determined to be a Mast Cell Tumor (MCT); which can be a very aggressive form of cancer. They are best treated by removing the mass with very wide margins ( 3cm in all directions). Because of the location of Baby’s MCT the only way to get that type of clean margin was to amputate Baby’s entire right front leg.

Because Baby was a 12 year old dog (but a spry 12 year old), the decision to remove her whole leg did not come easily to her parents. The possibility of a good quality of life with only three legs was discussed. Finally, because of Baby’s clear and progressively worsening pain, they moved forward with the surgery and removed her front leg. Immediately after surgery, Baby felt better and her lighter load only encouraged her playful behavior

Her recovery was long due to complications with healing. She and her family became frequent visitors to HAH as she healed. Throughout her treatment she was a joyful pet and a wonderful patient to work with.

Mast cell tumors are graded from 1 to 3, with grade 3 being the most aggressive. Grade 3 mast cells grow very quickly and usually spread microscopically to other parts of the body by the time the initial tumor is diagnosed.  Unfortunately, the pathology done on the tissue submitted after her leg was amputated showed that Baby had a grade 3 MCT.  Earlier this month her aggressive cancer spread despite surgery, and Baby passed away at home with her family. Her family never regretted their decision to remover her leg as she was able to spend three more happy months with them. She also became a cherished visitor here at the HAH.   

This month we remember Baby Gillman as our October Patient of the Month! She holds a special place in the hearts of her family both at home and at the HAH.

She was a happy girl!!!