A systematic review of non‐surgical treatments for lentigo maligna

Abstract

Lentigo maligna (LM) is the most common melanocytic malignancy of the head and neck. If left untreated, LM can progress to lentigo maligna melanoma (LMM). Complete surgical excision is the gold standard for treatment, however, due to the location, size, and advanced age of patients, surgery is not always acceptable. As a result, there is ongoing interest in alternative, less invasive treatment modalities. The objective was to provide a structured review of key literature reporting the use of radiotherapy, imiquimod and laser therapy for the management of LM in patients where surgical resection is prohibited. An independent review was conducted following a comprehensive search of the National Library of Medicine using MEDLINE and PubMed, Embase, Scopus, ScienceDirect and Cochrane Library databases. Data were presented in tabular format, and crude data pooled to calculate mean recurrence rates for each therapy. 29 studies met the inclusion criteria: radiotherapy 10; topical imiquimod 10; laser therapies 9. Radiotherapy demostrated recurrence rates of up to 31% (mean 11.5%), with follow-up durations of 1-96 months. Topical imiquimod recurrence rates were up to 50% (mean 24.5%), with follow-up durations of 2-49 months. Laser therapy yielded recurrence rates of up to 100% (mean 34.4%), and follow-up durations of 8-78 months. in each of the treatment series the I 2 value measuring statistical heterogeneity exceeded the accepted threshold of 50% and as such a meta-analysis of included data were inappropriate. For non-surgical patients with LM, radiotherapy and topical imiquimod were efficacious treatments. Radiotherapy produced superior complete response rates and fewer recurrences than imiquimod although both are promising non-invasive modalities. There was no consistent body of evidence regarding laser therapy although response rates of up to 100% were reported in low quality studies. A prospective comparative trial is indicated and would provide accurate data on the long-term efficacy and overall utility of these treatments.

A two-stage treatment of lentigo maligna using ablative laser therapy followed by imiquimod: excellent cosmesis, but frequent recurrences on the nose

“…As lentigo maligna occurs mainly in the head and neck region, important secondary goals are to minimize functional and cosmetic deformities. In large facial lesions or in elderly patients, alternative nonsurgical treatments, or even a wait‐and‐see policy, may be considered …”

Ablative fractional laser‐assisted photodynamic therapy for lentigo maligna: a prospective pilot study

“…the number of histopathological LM residuals observed, was 3 out of 10 LM lesions (30%), whereas the reported recurrence rates for the standard surgical excision of LMs are in the range of 8–20% (mean 6.8% at 5 years), those for staged excision 0–7%, and those for Mohs micrographic surgery 0–2% . In a recent review of non‐surgical treatments available for LM, the recurrence rates were 0–31% (mean 11.5%) for radiotherapy, 4–50% (mean 24.5%) for imiquimod and 0–100% (mean 34.4%) for laser therapy, which are all inferior to those achieved with surgical methods . The cure rate in our present pilot study is superior to that for laser therapy, in line with imiquimod, but inferior to radiotherapy.…”

“…Due to the size and location of the LM and the age of the patient, surgery may sometimes be inappropriate or contraindicated, however . Alternative, non‐surgical treatment modalities that have been investigated with varying results in terms of recurrence rates include cryotherapy, radiotherapy, Grenz ray therapy, topical imiquimod and photodynamic therapy (PDT) . Karam et al .…”

A systematic review and meta‐analysis of locoregional treatments for in‐transit melanoma

“…Imiquimod enhances natural killer cell activity and B‐cell proliferation producing both a direct local and adaptive immune response . Recently, there has been interest in the use of topical imiquimod as a noninvasive therapy for patients with primary and metastatic melanoma . Generally, studies included patients with low to moderate volumes of predominately superficial cutaneous metastases.…”