RESUMEN
BACKGROUND: Observational studies have suggested that 25-hydroxyvitamin D [25(OH)D] is associated with better outcomes in patients with malignant melanoma (MM). OBJECTIVES: To study the relationship between serum 25(OH)D levels and clinical parameters in a large German cohort of patients with MM. METHODS: We prospectively investigated the 25(OH)D serum levels of 764 patients with MM using the direct competitive chemiluminescence LIAISON immunoassay. Patients with MM who were taking 25(OH)D supplements were not included. RESULTS: Median serum 25(OH)D baseline levels were 12·3 ng mL (lower quartile: 7·3 ng mL , upper quartile: 20·2 ng mL ). Of the 764 patients, 564 (73·8%) had 25(OH)D deficiency [25(OH)D < 20 ng mL ], 145 (18·8%) had 25(OH)D insufficiency [25(OH)D ≥ 20, < 30 ng mL ] and only 55 (7·2%) had serum 25(OH)D levels within the normal range (≥ 30 ng mL ). Using a multiple regression model, lower 25(OH)D levels were significantly associated with higher Breslow tumour thickness (class: < 1 mm; 1-4 mm; > 4 mm, regression coefficient -1·45, P = 0·028) and higher American Joint Committee on Cancer 2002 melanoma stage (regression coefficient: -0·79, P = 0·036). CONCLUSIONS: In patients with MM, decreased 25(OH)D serum levels are associated with increased tumour thickness and advanced tumour stage. Hence, evidence is accumulating that patients with MM might benefit from 25(OH)D supplements.