1. Departments of Pediatrics and Dermatology, Children's, Memorial Hospital, North-western University Medical School, Chicago, Illinois, USA
2. ^*3M Pharmaceuticals, St Paul, Minnesota, USA

Correspondence: Amy Paller, MD, Division of Dermatology #107, Children's Memorial Hospital, 2300 Children's Plaza, Chicago, Illinois 60614, USA. Email: apaller@northwestern.edu

¹Present addresses: Departments of Pediatrics and Dermatology, Children's Hospital and Regional, Medical Center, University of Washington, Seattle, WA

Received 20 March 2003; Revised 10 May 2003; Accepted 23 May 2003; Published online 31 October 2003.

Abstract

Vascular tumors occur in approximately 10% of all infants and may be associated with significant morbidity. Available therapies for vascular tumors, such as systemic corticosteroids, vincristine, and interferon-, may cause toxicity, limiting their use to complicated cases. Using a mouse hemangioendothelioma model, we investigated the efficacy and mechanism of action of imiquimod, a topically applied inducer of cytokines. Application of imiquimod cream, whether initiated at the time of cell inoculation or when tumors became visible, significantly decreased tumor growth and increased animal survival in comparison with control mice. Imiquimod-treated tumors showed decreased tumor cell proliferation, increased tumor apoptosis, and increased expression of tissue inhibitor of matrix metalloproteinase-1 with decreased activity of matrix metalloproteinase-9. The demonstration that local application of imiquimod inhibits vascular tumor enlargement in the mouse vascular tumor model suggests a novel, less toxic means of treating infantile hemangioendotheliomas and perhaps other cutaneous vascular tumors.