Ingenol Mebutate as Treatment of Squamous Cell Carcinoma In Situ: A Case Series

February 2021 | Volume 20 | Issue 2 | Original Article | 169 | Copyright © February 2021


Published online January 10, 2021

Yasmin Khalfe BAa, Ted Rosen MDb

aBaylor College of Medicine, Houston,TX
bDepartment of Dermatology, Baylor College of Medicine, Houston,TX

Abstract
Ingenol mebutate (IM) is a novel drug currently only FDA-approved for the treatment of actinic keratosis. However, it has been extensively used off-label to treat multiple other skin disorders. In recent years, literature has emerged providing evidence for IM’s use as treatment for dermatologic disorders beyond actinic keratosis, including squamous cell carcinoma in situ. Here, we report a case series in which topical 0.05% ingenol mebutate was used to treat squamous cell carcinoma in situ, with five of six patients demonstrating successful results.

J Drugs Dermatol. 20(2):169-171. doi:10.36849/JDD.2021.5602

INTRODUCTION

Squamous cell carcinoma in situ (SCCIS), also known as Bowen’s Disease, is an intra-epidermal malignancy with a 3–5% risk of progressing to invasive squamous cell carcinoma.1 Treatment options include excisional surgery, curettage and electrodesiccation, cryotherapy, photodynamic therapy, radiotherapy, topical 5-fluorouracil and topical imiquimod. Evidence for the efficacy of the agent, ingenol mebutate, has additionally emerged as a potential treatment in recent years. Ingenol mebutate (IM) is a novel drug currently only FDA-approved for the treatment of actinic keratosis. However, IM has also been extensively used off-label to treat multiple other skin disorders. In a recent review, we synthesized the current literature and found evidence for the successful use of IM as treatment for dermatologic disorders, including SCCIS.2 With this in mind, we treated a group of patients with SCCIS using topical 0.05% ingenol mebutate. We report herein six squamous cell carcinoma in situ patients, each treated with ingenol mebutate, with five displaying excellent results.

CASE REPORTS

Six patients with an age range from 51 to 84 years old were treated. Of the patients, four were female and two were male. The six patients were diagnosed with squamous cell carcinoma in situ by small punch biopsy (2mm). For various reasons, all patients had refused standard of care surgical intervention. All patients were treated with 0.05% IM once daily (overnight) for three consecutive days. Following treatment, all patients reported an initial, brisk inflammatory response that was largely limited to the area of affected skin. Of the six patients treated, five ultimately showed complete clinical resolution of their lesions. One patient showed minimal response to IM treatment. At follow up, the five successfully treated patients showed no lesional recurrence, with a mean follow up time of approximately 2 years (range 17–50 months). Details of each patient treated are summarized in Table 1.