Desmoid tumors are proliferations of fibroblasts, myofibroblasts, and dense collagen. They are histologically similar to superficial fibromatoses such as palmar (Dupuytren’s disease) and plantar fibromatoses, as well as keloids. Unlike the superficial fibromatoses, desmoid tumors are located in the deep tissue and stratified based on an abdominal or extra-abdominal location. Historically, wide surgical resection was the treatment of choice. This often resulted in a disfiguring appearance and recurrence was common. Additionally, radiation and systemic therapies are performed with an approximate 26% rate of objective response based on RECIST. These therapies are however not without side effects.
Corticosteroids, such as triamcinolone acetonide, have long been used in the treatment of hypertrophic scars and keloids in order to decrease the size of the lesion. Proposed mechanisms of action include a decrease in the production of collagen, dissolution of insoluble collagen, a decrease in the local inflammatory process, and an increased rate of apoptosis of fibroblast and inflammatory cells. Recent reports have also evaluated the use of corticosteroid in palmar fibromatosis with promising results. We therefore aim to perform a pilot study to evaluate the response rate and tolerability of intralesional injections of triamcinolone acetonide into desmoid tumors, using RECIST to evaluate for response.
In addition to evaluating for response of the triamcinolone acetonide we will perform genetic testing for CTNNB1 mutations. New research has shown specific mutations, such as the 45F have been correlated with worse recurrence-free survival following treatment. We will observe the frequency of CTNNB1 mutations in our patient population.
LAY VERSION OF ABSTRACT- “A Pilot Study of Intralesional Injection of Triamcinolone Acetonide for desmoid tumors.”