Prognostic markers in lentigo maligna patients treated with imiquimod cream: A long-term follow-up study.

Background: More data are needed to define factors that predict long-term success after imiquimod therapy for lentigo maligna (LM).

Objective: We sought to determine the demographic, clinical, and histologic prognostic markers of relapse-free survival in patients with LM who were treated with imiquimod.

Methods: This was a single-arm, open-label, nonrandomized, prospective study.

Results: Eighty-nine patients with histologically confirmed LM and a median follow-up time of 4.8 years after imiquimod treatment were included in our study. Sixteen patients (18%) relapsed. Statistically significant indicators of an increased risk of local recurrence included: the total number of melanocytes, the number of basal and suprabasal melanocytes and the number of pagetoid spreading melanocytes.

Limitations: Our study was a single-center, nonrandomized study.

Conclusion: An assessment of different melanocyte fractions in the diagnostic baseline biopsy specimen may help to predict the response of LM to imiquimod therapy.