Vitamin D deficiency leads to inferior survival rates, as well as poor prognostic characteristics, among patients with breast cancer, according to a study published in JAMA Oncology.1
Analyses have reported mixed results between 25-hydroxyvitamin D (25OHD) levels, which indicate vitamin D status in vivo, and breast cancer risk. For the present prospective study, researchers evaluated whether serum 25OHD levels were indicative of prognostic characteristics and clinical outcomes in breast cancer.
Deficient levels of 25OHD were associated with inferior survival outcomes. Patients with clinical disease stage II or worse had, on average, deficient vitamin D levels. Premenopausal women with higher 25OHD levels also had higher rates of breast cancer-specific survival, recurrence-free survival, and invasive disease-free survival.
Poorly differentiated tumors were linked to lower vitamin D levels.
The authors did not, however, establish a causal relationship between 25OHD levels and disease prognosis, as it is possible that treatment has an effect on vitamin D status. Disease severity may also be a factor of vitamin D status, rather than a consequence thereof.
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The authors concluded, nonetheless, that vitamin D deficiency is indicative of inferior survival among patients with breast cancer. Sufficient vitamin D levels are defined as at least 30 ng/mL; deficient levels are below 20 ng/mL.
High body mass index (BMI), smoking, and being of African American or Hispanic descent are all factors linked with lower vitamin D levels.
- Yao S, Kwan ML, Ergas IJ, 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. 2016 Nov 10. doi: 10.1001/jamaoncol.2016.4188 [Epub ahead of print]