Vitamin D Improves Bone Treatment Response in Breast Cancer Patients
Zoledronic acid is a drug used as part of treatment of cancer patients to reduce or delay bone complications from bone metastases. Researchers found that response to this treatment may be influenced by a patient’s vitamin D status.
Researchers from the University of Sheffield in the United Kingdom have found that breast cancer patients who have insufficient vitamin D levels could have a worse prognosis after standard treatment with zoledronic acid than in patients with normal levels of vitamin D. On the other hand, postmenopausal women who have sufficient levels of the vitamin are less likely to experience breast cancer recurrence in their bones when they received chemotherapy with zoledronic acid, according to Robert Coleman, MD.
For the study, Coleman and his colleagues used stored blood samples from 872 of the 3,360 participants of the AZURE trial before they began therapy. This subgroup included both premenopausal and postmenopausal women with breast cancer. The AZURE trial previously compared standard systemic local therapy given either alone or combined with zoledronic acid in patients with stage II to III of the disease.
Vitamin D level was considered “insufficient” if it measured 30 nanograms per milligrams of blood or less, and was considered “sufficient” if it was above that level. Coleman reported that only 10% of women in the subgroup had sufficient vitamin D levels.
The investigators also measured markers of bone turnover at baseline and after 53 months of follow-up. They found that low vitamin D levels predicted cancer recurrence to bone, which suggests a poorer prognosis for the disease. Experts believe that these results suggest that maintaining normal vitamin D levels is important in the treatment of cancer patients because it can help improve the outcome of treatment.
Johnson, K. Vitamin D: ‘Surprise’ Prognostic Marker in Breast Cancer. Medscape.
Smith, M. Vitamin D Tied to Breast Cancer Outcome. MedPage Today.