Acral melanoma (AM), as a peculiar subgroup of melanoma, is rare in Caucasians but has higher incidence in Asians.,Large series of study on AM with clinicopathological features and prognostic factors is still limited, especially in Asian population.,We retrospectively collected clinical, pathological and follow-up data of 142 AM cases.,All patients were Chinese, with the age ranging from 24 to 87 years (mean 62.0; median 62.0).,The Breslow thickness of primary lesions ranged from 0.6 to 16.3 mm (mean 4.9; median 3.7).,85.9% of the patients had acral lentiginous histologic subtype.,Plantar was the most frequently involved site, followed by heels.,Statistically, duration of the lesion before diagnosis (≤2.5 years), Breslow thickness >4.0 mm (T4), high mitotic index (>15 mm−2), presence of vascular invasion, regional lymph node metastasis at diagnosis and pathologic stage (II/III/IV) were found to be independent prognostic factors in both univariate and multivariate analyses.,The prognosis of AM in Chinese is extremely poor.,Our 5- and 10-year disease-specific survival (DSS) rates were 53.3% and 27.4%, respectively.,Therefore, AM in Asians represents a more biologically aggressive melanoma subtype and is thought to carry a worse prognosis when compared with other races or cutaneous melanomas in other anatomic sites.
The incidence of malignant melanoma is increasing faster than that for any other cancer.,Histological examination of skin excision biopsies remains the standard method for melanoma diagnosis and prognosis.,Significant morphological overlap between benign and malignant lesions complicates diagnosis, and tumour thickness is not always an accurate predictor of prognosis.,To identify improved molecular markers to support histological examination, we used microarray analysis of formalin-fixed and paraffin-embedded samples from different stages of melanomagenesis to identify differentially expressed microRNAs (miRNAs).,Differential expression was validated by qRT-PCR, and functional studies were carried out after transfection of miRNA precursors or inhibitors into melanoma cells to modulate miRNA expression.,In all, 20 miRNAs showed highly significant differential expression between benign naevi and either primary or metastatic melanomas, the majority being downregulated in melanoma, whereas only 2 miRNAs, namely miR-203 and miR-205, were differentially expressed between primary and metastatic melanomas.,In functional in vitro assays, overexpression of miR-200c and miR-205 inhibited anchorage-independent colony formation and overexpression of miR-211 inhibited both anchorage-independent colony formation and invasion.,We have identified a series of differentially expressed miRNAs that could be useful as diagnostic or prognostic markers for melanoma and have shown that three miRNAs (namely miR-200c, miR-205 and miR-211) act as tumour suppressors.