Melanomas that typically arise on sun-shielded skin are classified their anatomical location as acral melanoma (AM). These rare melanomas more commonly affect patients of Asian background, and have different aetiological mechanisms and somatic mutation signatures compared to other cutaneous melanomas. The treatment response of systemic therapy for AM is unclear. The current study systematically reviewed and meta-analysed the existing data in the literature regarding the treatment response of AM.
Five electronic databases were systematically searched from their inception to June 2019, identifying all studies that reported treatment responses of metastatic AM and ALM. Data were independently extracted by two investigators according to predefined clinical endpoints. We used a Random-effects model for data analysis based on event rates (ER) and 95% confidence interval (CI).
Ten studies, with 215 patients, met the inclusion criteria for the meta-analysis. Average complete response probabilities were ER: 9% (95% CI 4%-18%, I2 = 0.00% p < 0.001), partial response ER: 19% (95% CI 12%-29%, I2 = 0.00% p < 0.001), stable disease ER: 35% (95% CI 20%-54%, I2 = 51.94% p = 0.1) and progression of disease ER: 42% (95% CI 26%-59%, I2 = 45.36% p 0.34). Subgroup analysis of patients receiving immunotherapy compared to chronic sun damaged skin and mucosal melanoma will be presented.
Overall patients with metastatic acral melanoma had significant rates of treatment response to systemic therapy.
The authors.
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All authors have declared no conflicts of interest.