Squamous cell carcinoma in situ (Bowen's disease) in renal transplant patients treated with 5% imiquimod and 5% 5-fluorouracil therapy

BACKGROUND. Depending upon the patient's age at transplant, skin type, sun exposure, and the need for immunosuppressive therapy to prevent rejection, there is escalation in the development of cutaneous malignancies in organ transplant patients a number of years after transplantation. Thus, with the expansion in these procedures over the past decades, and the ever-lengthening survival of these patients, we are seeing an increase in cutaneous malignancies in this patient population. OBJECTIVE. To determine if combined therapy with 5% 5-fluorouracil and 5% imiquimod may be useful in the treatment of squamous cell carcinoma in situ. METHODS. We present five renal transplant patients, all more than 10 years posttransplantation, three with insulin-dependent diabetes, who developed multiple areas of squamous cell carcinoma (SCC) in situ, All these patients were on chronic immunosuppressive chemotherapy to prevent rejection, but were otherwise doing well. All the patients had biopsy-proven SCC in situ on their lower extremities that even in normal patients may be a challenge to treat. RESULTS. We treated these five patients with a combination of a local immune therapy, imiquimod cream, and a topical chemotherapeutic agent, 5% 5-fluorouracil (5-FU), with clearing of the areas of SCC in situ. CONCLUSION. Although immunotherapy must be used with caution in organ transplant patients to avoid graft rejection, topical imiquimod is a local immune modulator that potentiates local innate and possible adaptive immunity without measurable effects on systemic immunity. In addition, there is evidence that cytokines induced by imiquimod may improve the therapeutic efficacy of topical 5% 5-FU in the treatment of SCC in situ.