In sweden the incidence of cmm has been rising

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Unformatted text preview: (2, 3). In Sweden, the incidence of CMM has been rising rapidly during the last decades. At present, the overall incidence of cutaneous melanoma in Sweden is approximately 2100 cases per year corresponding to yearly incidence of approximately 25.5/100,000 for males and 21.3/100,000 for females and it is the eight most common cancer in Sweden (4). CMM is the most dangerous type of human skin cancer since the tumors may metastasize and often are resistant to current systemic therapy. Unfortunately, the rising incidence of cutaneous melanomas has been accompanied by an increased mortality. Melanoma tumor progression Clinical and histological studies have resulted in defining relatively distinct steps of melanoma development and progression. Step 0, normal melanocytes; step 1, common acquired and congenital nevi with structurally normal melanocytes; step 2, dysplastic nevi with structural and architectural atypia; step 3, melanoma in situ (MIS) and radial growth phase (RGP), nontumorigenic primary melanomas without metastatic competence; step 4, vertical growth phase (VGP), tumorigenic primary melanomas with competence for metastasis; and step 5, metastatic melanoma. As in any neoplastic system, individual melanomas can skip steps in their development, appearing without identifiable intermediate lesions (5). 5 Figure 1. Melanoma tumor progression. The model , developed by Drs. Clark , Elder, and Gu erry , implies that melano ma commonly develops and progresses in a sequence of steps . Ho wev er, melanoma may dev elop directly from normal (and precursor) cells. The roles of melanocyte stem cells, melanoblasts (immature melanocytes) in melanog enesis remain poorly defined . (modified from DeVita et al. (5) and www.wistar.org/herlyn/. The progression from each stage to the next is associated with specific biologic changes, which are based on experimental models and clinical and histopathologic observations. The transition from the mature melanocyte to the formation of a nevus is characterized by a disruption of cell-cell cross-talk between melanocytes and keratinocytes, which leads to an escape of the melanocyte from the regulatory control of keratinocy...
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This document was uploaded on 03/06/2014.

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