A Synopsis of Serum Biomarkers in Cutaneous Melanoma Patients

Many serum biomarkers have been evaluated in melanoma but their clinical significance remains a matter of debate. In this paper, a review of the serum biomarkers for melanoma will be detailed and will be discussed from the point of view of their practical usefulness. The expression of biomarkers can be detected intracellularly or on the cell membrane of melanoma cells or noncancer cells in association with the melanoma. Some of these molecules can then be released extracellularly and be found in body fluids such as the serum. Actually, with the emergence of new targeted therapies for cancer and the increasing range of therapeutic options, the challenge for the clinician is to assess the unique risk/response ratio and the prognosis for each patient. New serum biomarkers of melanoma progression and metastatic disease are still awaited in order to provide efficient rationale for followup and treatment choices. LDH as well as S100B levels have been correlated with poor prognosis in AJCC stage III/IV melanoma patients. However, the poor sensitivity and specificity of those markers and many other molecules are serious limitations for their routine use in both early (AJCC stage I and II) and advanced stages of melanoma (AJCC stage III and IV). Microarray technology and proteomic research will surely provide new candidates in the near future allowing more accurate definition of the individual prognosis and prediction of the therapeutic outcome and select patients for early adjuvant strategies. 1. Introduction The incidence of cutaneous malignant melanoma (CMM) is still increasing in the western world despite early detection and prevention campaigns. Patients are mostly young and late diagnosis, which means thicker tumors (thicker than 1？mm, or Breslow index ≥1？mm: the Breslow index is the measurement in mm of the vertical thickness of the primary tumor) and/or involvement of regional lymph nodes, causes a greater risk of developing a disseminated disease. CMMs usually progress from an in situ proliferation to a radial growth pattern, and then to a vertical growth phase. This vertical growth phase represents a key event for the cell spread, since it allows the cells to migrate deeply in the dermis, in the lymphatics, and the bloodstream. In the 7th revision of the American Joint Committee on Cancer (AJCC) for melanoma staging and classification (2009), patients can be divided in four stages, from stage I and II (local disease) to stage III (locoregional disease) and stage IV (metastatic disease). In this classification, the only marker which has been