Tracking and Treating Malignant Melanoma Metastases

Cutaneous malignant melanoma (CMM) is a neoplasm which has always evoked scientific interest out of proportion to its frequency. Over the past decades, CMM has shown the most rapidly increasing neoplasm in yearly incidence. Such increased incidence outweighed the moderate improvements in therapy, causing a global increase in mortality. The disease progresses from the primary CMM (stages I and II) to a locoregional disease (stage III) and a disseminated metastatic disease (stage IV). Surgery represents the mainstay often curative for thin primary CMM that have not yet given rise to distant metastases. Beyond that stage, the therapeutic options remain unsatisfactory. Indeed, according to the American Joint Committee on Cancer (AJCC), the percentage of patients with metastatic melanoma surviving 1-year ranges from 33 to 62%. The present special issue contains ten papers focused on new developments in the field of CMM progression toward the metastatic disease. Two papers deal with imaging procedures used for detecting metastases and with unusual clinical evolution of metastases. Two papers focus on serum biomarkers, and one covers the interpretation of CMM cell migration along specific skin structures. A series of four papers regard peculiar aspects of molecular biology associated with the CMM metastatic process. Finally, one paper addresses some recent developments in biologic treatments. In the paper entitled " Review of diagnostic imaging modalities for the surveillance of melanoma patients, " Y. Xing et al. present a meta-analysis evaluating the current state of imaging modalities for detecting CMM metastases. They compare the sensitivity, specificity, and positive predictive values of ultrasonography, computed tomography (CT), positron emission tomography (PET), and CT-PET combined. Ultrasonography was found to be the most sensitive and specific for detecting lymph node metastases, and PET-CT was the most sensitive and specific for detecting distant metastases. In the paper entitled " Smouldering malignant melanoma and metastatic dormancy, " G. E. Piérard et al. explore two peculiar evolutions of the versatile CMM metastatic disease, namely, the smouldering CMM and the CMM dormancy. A long disease-free interval (CMM dormancy) occasionally occurs before the surge of overt metastases. The so-called CMM smouldering phenomenon refers to the condition where regional metastases wax and wane for long periods of time on restricted skin regions. Local micrometastases often predict sentinel lymph node involvement but they do not always reflect progression of the primary CMM to full-blown visceral metastatic competence. A combination of factors impacts the versatile CMM metastasic progression. The putative …