VITAMIN D LEVEL AND ITS RELATIONSHIP WITH CANCER STAGE IN PATIENTS WITH DIFFERENTIATED THYROID CARCINOMA

Background. Differentiated thyroid carcinoma (DTC) has witnessed an increase in incidence and although it is considered to have a slow grow potential and a 90% 10-year survival rate, local or distant metastases can be observed in 20%. It is essential to recognize other factors associated with malignancy and poor prognosis. Vitamin D and its deficiency has proven useful as a prognostic biomarker for many types of cancer, including thyroid cancer. Aim. Evaluate the relationship between vitamin D status in DTC and benign thyroid disorders patients and correlation between vitamin D and histopathological findings in DTC group. Methods. Study included 170 patients with confirmed DTC and 200 with benign thyroid pathology. Evaluation included 25-hydroxy vitamin D [25(OH)D], ultrasound and histopathologic features. Results. In DTC patients, mean value of vitamin D was significantly lower (17.86 ng/mL +/- 9.31 DS versus 20.26 ng/mL +/- 9.31 DS, p=0.029). Statistical analysis confirmed a negative correlation between vitamin D levels and tumor size (T) according to TNM classification (r=-0.176, p=0.02). Conclusions. Vitamin D level was significantly lower in the DTC group and 25(OH)D levels may be correlated with histopathology features like tumor size and aggressiveness according to TNM classification.