Reduced serum 25-hydroxyvitamin D levels in stage IV melanoma patients

Reduced serum 25-hydroxyvitamin D3 (25(OH)D) levels are associated with an increased incidence and an unfavorable outcome of various types of cancer. However, the influence of serum 25(OH)D on the incidence and outcome of patients with malignant melanoma is unknown.

The association between serum 25(OH)D levels and clinical and histopathological data among 205 patients with malignant melanoma was examined. Additionally, 141 healthy controls were investigated. All the blood samples were taken between October and April to minimize seasonal variations; basal serum 25(OH)D levels were analyzed using the LIAISON 25-OH Vitamin D-Assay (DiaSorin, Dietzenbach, Germany). The study started in 1997. The patients were observed until death or March 2007, whichever came first.

Serum 25(OH)D levels were significantly reduced in stage IV melanoma patients as compared to stage I melanoma patients (p=0.006). A trend toward a greater tumor thickness of the primary cutaneous melanomas was seen in the patients with low (<10 ng/ml) serum 25(OH)D levels (median: 2.55 mm) as compared to those with 25(OH)D serum levels >20 ng/ml (median: 1.5 mm), although this difference was not statistically significant (p=0.078). The patients with low 25(OH)D serum levels (<10 ng/ml) had earlier distant metastatic disease (median: 24.37 months) as compared to those with 25(OH)D serum levels >20 ng/ml (median: 29.47 months), although this difference was also not statistically significant (p=0.641).

Among the patients with malignant melanoma, significantly reduced serum 25(OH)D levels were found in the stage IV patients as compared to stage I patients, and those with low 25(OH)D serum levels (<10 ng/ml) may develop earlier distant metastatic disease compared to those with higher 25(OH)D serum levels (>20 ng/ml). Further study of the vitamin D pathway and its influence on pathogenesis and progression of malignant melanoma is warranted.