Vitamin D levels in breast cancer patients is linked to survival

Vast advances have been made in the diagnosis and treatment of breast cancer, but it still results in significant mortality and morbidity. In the US, breast cancer ranks second in causing cancer-related deaths. Previous epidemiological studies have linked circulating vitamin D levels to protection against breast cancer. Serum vitamin D (Serum 25OHD) levels have also been positively correlated  to better therapeutic response  and  improved disease-free survival. Now, new results from American researchers in the journal JAMA corroborate previous studies showing that Vitamin D levels are linked with lower risk of breast cancer morbidity and mortality.

The results are from a prospective cohort study of breast cancer survivors, which was initiated in 2006 with enrolment lasting until 2013. At the time of the publication of the paper, patients were still being followed up. In this study, patients with invasive breast cancer were enrolled  within 2 months of diagnosis and were  followed for health outcomes and  concurring factors at  varying time points - 12, 24, 48, 72, and 96 months. The researcher s found that Serum 25OHD concentrations were lower in women with advanced-stage tumors. Further, premenopausal women with triple-negative cancer (those whose tumors that lack estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2)  and are aggressive) had  the lowest levels. Serum 25OHD  levels were also inversely linked with disease progression and death. Importantly women with the highest levels  of 25OHD levels had increased overall survival.

 Whilst the study provides persuasive evidence on associations of vitamin D with lower risk of breast cancer morbidity and mortality, the lead author of the paper  Dr. Song Yao, Associate Professor of Oncology  at Rosewell Park Cancer Institute emphasizes the need for additional studies . ‘ The key implications of our study is that high levels of vitamin D after breast cancer diagnosis have been consistently associated with better patient survival in several studies from us and others; yet as an observational study, we cannot definitively approve the causality between vitamin D and better survival without a randomized clinical trial’ Dr. Yao cautions.

References:

1. Garland FC et al, Geographic variation in breast cancer mortality in the United States: a hypothesis involving exposure to solar radiation. Prev Med. 1990 Nov;19(6):614-22.

2. John E M et al Vitamin D and breast cancer risk: the NHANES I Epidemiologic follow-up study, 1971-1975 to 1992. National Health and Nutrition Examination Survey. Cancer Epidemiol Biomarkers Prev. 1999 May;8(5):399-406.

3. Bandera Merchan B et al.,The role of vitamin D and VDR in carcinogenesis: Through epidemiology and basic sciences. J Steroid Biochem Mol Biol. 2017 Mar;167:203-218.

4. Yao et al, Association of Serum Level of Vitamin D at Diagnosis With Breast Cancer Survival. A Case-Cohort Analysis in the Pathways Study'. JAMA Oncol. 2017 Mar 1;3(3):351-357.