David Polsky

CONTEXT: The incidence of cutaneous melanoma has increased over the past several decades, making its early diagnosis a continuing public health priority. The ABCD (Asymmetry, Border irregularity, Color variegation, Diameter >6 mm) acronym for the appraisal of cutaneous pigmented lesions was devised in 1985 and has been widely adopted but requires reexamination in light of recent data regarding the existence of small-diameter (< or =6 mm) melanomas. EVIDENCE ACQUISITION: Cochrane Library and PubMed searches for the period 1980-2004 were conducted using search terms ABCD and melanoma and small-diameter melanoma. Bibliographies of retrieved articles were also used to identify additional relevant information. EVIDENCE SYNTHESIS: Available data do not support the utility of lowering the diameter criterion of ABCD from the current greater than 6 mm guideline. However, the data support expansion to ABCDE to emphasize the significance of evolving pigmented lesions in the natural history of melanoma. Physicians and patients with nevi should be attentive to changes (evolving) of size, shape, symptoms (itching, tenderness), surface (especially bleeding), and shades of color. CONCLUSIONS: The ABCD criteria for the gross inspection of pigmented skin lesions and early diagnosis of cutaneous melanoma should be expanded to ABCDE (to include "evolving"). No change to the existing diameter criterion is required at this time.

The highly aggressive character of melanoma makes it an excellent model for probing the mechanisms underlying metastasis, which remains one of the most difficult challenges in treating cancer. We find that miR-182, member of a miRNA cluster in a chromosomal locus (7q31-34) frequently amplified in melanoma, is commonly up-regulated in human melanoma cell lines and tissue samples; this up-regulation correlates with gene copy number in a subset of melanoma cell lines. Moreover, miR-182 ectopic expression stimulates migration of melanoma cells in vitro and their metastatic potential in vivo, whereas miR-182 down-regulation impedes invasion and triggers apoptosis. We further show that miR-182 over-expression promotes migration and survival by directly repressing microphthalmia-associated transcription factor-M and FOXO3, whereas enhanced expression of either microphthalmia-associated transcription factor-M or FOXO3 blocks miR-182's proinvasive effects. In human tissues, expression of miR-182 increases with progression from primary to metastatic melanoma and inversely correlates with FOXO3 and microphthalmia-associated transcription factor levels. Our data provide a mechanism for invasion and survival in melanoma that could prove applicable to metastasis of other cancers and suggest that miRNA silencing may be a worthwhile therapeutic strategy.