Imiquimod 5% cream as primary or adjuvant therapy for melanoma in situ, lentigo maligna type

Background Surgical resection of lentigo maligna (LM) is complicated by noncontiguous, subclinical extension and actinic melanocytic hyperplasia in sun-damaged skin of older individuals. Objective We sought to determine the long-term effectiveness of imiquimod as primary or adjuvant therapy for LM. Methods Patients were retrospectively identified from January 1, 2003, to December 31, 2013, with LM, early/evolving LM, and LM melanoma who had used topical imiquimod 5% cream for either primary therapy after diagnostic biopsy, or adjuvant therapy after narrow-margin surgical resection or complete clinical but not histologic resection of LM. Follow-up occurred through December 31, 2014. Results In all, 63 cases were identified in 61 patients, mean (SD) age 71.1 (12.4) years; 58 were analyzed for local recurrence. Imiquimod was used as primary therapy in 22 of 63 (34.9%) and adjuvant therapy in 41 of 63 (65.1%) for mean duration of 11.7 (range 2-60) weeks. Fifty cases (86.2%) demonstrated clinical clearance at mean (SD) follow-up of 42.1 (27.4) months: 72.7% primary and 94.4% adjuvant at 39.7 (23.9) and 43.1 (28.9) months, respectively. Limitations Retrospective cohort study and lack of standardized imiquimod application are limitations. Conclusion Imiquimod cream appears to be a viable option for primary or adjuvant treatment of LM in older patients who are poor surgical candidates.