Rate of Recurrence of Lentigo Maligna Treated With Off-Label Neoadjuvant Topical Imiquimod, 5%, Cream Prior to Conservatively Staged Excision

Abstract

Importance: Staged excision of lentigo maligna (LM) often requires multiple stages and can result in significant cosmetic morbidity. Imiquimod cream has been used off-label as monotherapy in the treatment of LM and may be used in the neoadjuvant setting prior to staged excision as a strategy to reduce the size of the surgical margins required to confirm negative histologic margins.

Objective: To examine the rate of recurrence of LM in patients treated with neoadjuvant topical imiquimod, 5%, cream prior to conservatively staged excisions.

Design, setting, and participants: This was a retrospective medical record review of 334 patients with 345 biopsy-confirmed LM tumors from June 2004 to January 2012 who were treated with imiquimod prior to undergoing staged excisions at the University of Utah Medical Center and Huntsman Cancer Institute, large academic hospitals in Salt Lake City.

Interventions: Patients were treated with off-label imiquimod, 5%, cream 5 nights per week for 2 to 3 months. Those deemed to have an inadequate inflammatory response were also treated with tazarotene, 0.1%, gel twice weekly. Conservatively staged excisions, beginning with 2-mm margins, were then performed.

Main outcomes and measures: The rate of recurrence of LM after long-term follow-up.

Results: Patients included 235 men (70%) and 99 women (30%) with a mean (SD) age of 67 (13) years. Patients were treated with imiquimod cream for a mean of 2.5 months prior to undergoing conservatively staged excisions. There were 12 local recurrences (a rate of 3.9%) with a mean time to recurrence of 4.3 years and a mean length of follow-up of 5.5 years.

Conclusions and relevance: Neoadjuvant topical imiquimod, 5%, cream prior to conservatively staged excisions for LM allowed for negative histologic margins with a median final margin of 2 mm and a rate of recurrence similar to reported recurrence rates with standard staged excisions by either Mohs surgery or en face permanent sections.

Figure 1.. Rate of Local Recurrence After Neoadjuvant Imiquimod Prior to Staged Excision

Solid line indicates the cumulative incidence; dashed lines, 95% CIs.

Figure 2.. Comparison of Rate of Local Recurrence Between Patients Who Did and Did Not Use Tazarotene in Addition to Imiquimod Prior to Staged Excision