Injection of triamcinolone in mast cell tumors
I read with great interest the study by Case and Burgess1 on intralesional injection of mast cell tumors with triamcinolone. I have been using injectable methylprednisolone in a similar manner for the past 30 years because of the generally poor results I have seen with standard chemotherapy. The patients I have used this technique on range in age and breed. However, I have only used it on patients with mast cell tumors staged as grade I or II according to the Patnaik system, and only on patients with tumors numerous enough that surgical removal was not realistic or would have been financially prohibitive. I have not seen good results with this technique with mast cell tumors staged as grade III. Most often, I inject individual tumors with 1 to 2 mg of methylprednisolone, delivered via an insulin syringe, and only treat tumors that appear to be bothering the dog at the time. Owners are instructed to return when there is a flare-up, and I typically perform 5 or 6 injections at each visit. I see most of these dogs every 4 to 6 weeks, although they often go longer than that between treatments. I do not use oral glucocorticoids concurrently, and anecdotally, I have found the life span for treated dogs to be much longer than that for dogs given the standard treatment. Most clients are comfortable with the knowledge that this treatment will not provide a cure, but may allow the dog to coexist with the disease in relative comfort and without the often-unpleasant adverse effects associated with traditional chemotherapy.
Tom Morganti, dvm
Avon Veterinary Clinic, Avon, Conn
1. Case A, Burgess K. Safety and efficacy of intralesional triamcinolone administration for treatment of mast cell tumors in dogs: 23 cases (2005–2011). J Am Vet Med Assoc 2017;252:84–91.
The authors respond:
We appreciate Dr. Morganti's enthusiasm and experience with intralesional corticosteroid injections for dogs with cutaneous mast cell tumors; nevertheless, we wish to advise caution, as the appropriate use of this treatment is not well understood.
Although the results of our study evaluating intralesional triamcinolone administration in 23 dogs suggested that this was a safe and effective treatment, with most dogs experiencing mass regression, the overall median response duration was only 63 days. These results compare unfavorably to past studies demonstrating longer response durations for dogs treated with more conventional treatments such as vinblastine1 or toceranib phosphate.2
In summary, the findings of our study do not support intralesional triamcinolone administration as a comparable alternative to more conventional medical treatments. In our experience, given the short duration of response, intralesional triamcinolone administration seems best suited for cytoreduction prior to surgery.
Kristine E. Burgess, dvm
Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, Mass
Ashley Case, dvm
Orchard Park Veterinary Medical Center, Orchard Park, NY
1. Thamm DH, Mauldin EA, Vail DM. Prednisone and vinblastine chemotherapy for canine mast cell tumor: 41 cases (1992–1997). J Vet Intern Med 1999;13:491–497.
2. London CA, Malpas PB, Wood-Follis SL, et al. Multi-center, placebo-controlled, double-blind, randomized study of oral toceranib phosphate (SU11654), a receptor tyrosine kinase inhibitor, for the treatment of dogs with recurrent (either local or distant) mast cell tumor following surgical excision. Clin Cancer Res 2009;15:3856–3865.
