Cutaneous Malignant Melanoma

Abstract

Abstract The most important prognostic factor in patients with cutaneous malignant melanoma (CMM) is the anatomic extent of disease and, specifically, presence of metastasis. In those patients without clinical metastasis at the time of diagnosis, direct measurement of tumor thickness by the method of Breslow remains the most accurate single prognostic factor. The improvement in survival rates recorded over time has been associated with a decrease in tumor thickness, and geographical differences in prognosis have been related to differences in tumor thickness. Furthermore, the prognostic effects of such features as the histologic type and level of invasion are overridden by the effect of tumor thickness. The measurement of tumor thickness by means of an ocular micrometer is also more reproducible among pathologists than the recognition of histologic subtypes and the assessment of level of invasion according to anatomical landmarks, both of which are more prone to subjective interpretation and interobserver variation. It is also apparent, however, that although tumor thickness remains the best available single prognostic index, it provides only a rough guide to the outcome for an individual patient. Increasing efforts have been made, therefore, to discover more accurate means of assessing the risk of metastasis in patients with melanoma by using multifactorial prognostic models and by searching for molecular markers of metastatic potential. Prognostic models, however, although yielding impressive results in some studies, may not always be accurate in their application to individual patients, and the search for molecular markers of metastatic potential, although providing initially promising results, has as yet failed to identify prognostic factors that are as accurate or as practically applicable as the measurement of tumor thickness.