+ Poor prognostic factors through univariate analysis: tumor location in the soles of the feet, increased disease stage, increased Breslow tumor thickness, tumor histopathology was apical and localized moles, the number of regional lymph node metastases increased, the degree of Clark invasion increased, microscopic tumor ulceration, tumor mitotic rate increased, tumor had an upright growth stage, non-tumor infiltrating lymphocytes, tumor vascular infiltration and satellite nuclei around the tumor.