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Jul 19, 2012 05:52 AM Timothy wrote:
Vitamin D Status at Breast Cancer Diagnosis: Correlation With Tumor Characteristics, Disease Outcome and Genetic Determinants of Vitamin D Insufficiency
Carcinogenesis. 2012 May 23;[Epub Ahead of Print], S Hatse, D Lambrechts, A Verstuyf, A Smeets, B Brouwers, T Vandorpe, O Brouckaert, G Peuteman, A Laenen, L Verlinden, C Kriebitzsch, AS Dieudonne, R Paridaens, P Neven, MR Christiaens, R Bouillon, H Wildiers
Abstract
A large cohort study correlated vitamin D levels with tumor size and overall survival, showing improved breast-cancer specific outcomes associated with increased vitamin D levels in postmenopausal women.
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A large cohort study correlated vitamin D levels with tumor size and overall survival, showing improved breast-cancer specific outcomes associated with increased vitamin D levels in postmenopausal women.
SUMMARY
OncologySTAT Editorial Team
Hatse and colleagues set out to examine the association between serum 25-hydroxyvitamin D3 (25OHD) levels, dietary vitamin D intake, and the risk of cancer. They noted that vitamin D supplementation has not yet been a standard element of cancer prevention. The controversy surrounding the effect of vitamin D supplementation on certain malignancies and whether its use should be encouraged is particularly relevant in women with breast cancer. It is known that more than 60% of cases occur in postmenopausal women, a population characterized by a high prevalence of vitamin D deficiency and osteoporosis.
In this study, 1,800 patients were randomly classified into three categories according to 25OHD levels: low, intermediate, and high. Patients in the low group had 25OHD levels <20 ng/mL. The intermediate group had 25OHD levels between 20 and 30 ng/mL. The high group had levels of 25OHD >30 ng/mL. In all, 35.9% of patients were in the high group, 31.7% were in the intermediate group, and 32.4% were in the low group.
The investigators utilized linear regression models to examine the association between 25OHD levels and tumor characteristics. These characteristics included tumor size, tumor grade, nodal stage, estrogen receptor levels, and HER2 status. Lymph node involvement was also analyzed. Primary outcomes were twofold: disease-specific survival (DSS) and disease-free interval (DFI). The latter was defined as the time elapsing between breast cancer diagnosis and local recurrence and/or lymph node metastasis and/or distant metastasis. Regarding overall survival, significant effects were observed for age, tumor size, lymph node involvement, tumor grade, and estrogen-receptor status.
In terms of DSS, the investigators found a significant inverse correlation between serum 25OHD levels and the risk of breast cancer-related mortality. High 25OHD levels were associated with improved DSS in postmenopausal women (hazard ratio [HR], 0.15 for 25OHD > 30 ng/mL vs ≤30 ng/mL; 95% CI, 0.03-0.63; P = .0097), compared with premenopausal women (HR, 0.93; 95% CI, 0.43-2.02; P = .8527). In addition, favorable vitamin D status appeared to be linked to improved outcomes in postmenopausal women.
It was suggested by the investigators that this vitamin D benefit in postmenopausal women may be due to the favorable effect of vitamin D on bone density and metabolism and the low estrogen environment in bone. In premenopausal women, higher levels of estrogen may negate the bone-protecting benefits of vitamin D supplementation.
In closing, this study demonstrated that reduced 25OHD levels were associated with increased tumor size in women with breast cancer and improved outcome in postmenopausal women. Vitamin D could be involved in local growth-inhibitory effects on breast tumors. However, further studies are warranted to clarify the role of vitamin D supplementation as a cancer preventive or inhibitory therapy.
Concerned husband