Association of Vitamin D Level with Clinicopathological Features in Breast Cancer

A population-based relationship between low vitamin D status and increased cancer risk is now generally accepted. However there were only few studies reported on prognostic impact. To determine the effect of low vitamin D on progression of breast cancer, we conducted a cross-sectional analysis of vitamin D levels and clinico-pathological characteristics in 200 cases of breast cancer diagnosed during 2011-2012 at the National Cancer Institute of Thailand. Vitamin D levels were measured by high-performance liquid chromatography (HPLC). Clinical and pathological data were accessed to examine prognostic effects of vitamin D. We found that the mean vitamin D level was $23.0{\pm}6.61ng/ml$. High vitamin D levels (${\geq}32ng/ml$) were detected in 7% of patients, low levels (<32 ng/ml) in 93% Mean vitamin D levels for stages 1-4 were $26.1{\pm}6.35$, $22.3{\pm}6.34$, $22.2{\pm}6.46$ and $21.3{\pm}5.42ng/ml$ respectively (P=0.016) and 24.1 and 21.3 ng/ml for lymph node negative and positive cases (P=0.006). Low vitamin D level (<32 ng/ml) was significantly found in majority of cases with advanced stage of the disease (P=0.036), positive node involvement (P=0.030) and large tumors (P=0.038). Our findings suggest that low and decreased level of vitamin D might correlate with progression and metastasis of breast cancer.