Predictive Importance of Vitamin D on Response toNeoadjuvant Chemotherapy in Turkish Patients with LocallyAdvanced Hormone Receptor Positive Breast Cancer

Abstract

Objectives: To investigate the relationship between the level of vitamin D with pathological response rates to neoad juvant chemotherapy in breast cancer patients. Methods: The pathological responses of patients treated with neoadjuvant chemotherapy for locally advanced breastcancer regarding Miller-Payne grading system were noted as ≤90% and >90% response. Vitamin D deficiency was de fined as 90 to neoadjuvant chemotherapy, respectively. In univariate analysis,tumor size, menopause status, and histologic grade were found to be statistically significant for pathological response.In multivariate analysis, progesteron receptor positivity, premenopause, and higher tumor diameter were associatedwith decreasing pathologic response. The level of vitamin D was not statistically significant on pathological responseto neoadjuvant chemotherapy. Conclusion: The level of vitamin D level was not associated with pathologic response rates to neoadjuvant chemother apy in Turkish population. This may be explained with vitamin D receptor polymorphism in different ethnicities whichshould be evaluated in future studies in terms of pathologic response to neoadjuvant chemotherapy.