Vitamin D Deficiency and Tumor Response Failure in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy at a Medical Center in Mexico

Background: Vitamin D deficiency has been associated with not achieving a complete pathological response in patients with breast cancer after neoadjuvant chemotherapy. The objective of this study was to determine whether vitamin D deficiency is associated with tumor response failure in patients with breast cancer operated and who received neoadjuvant chemotherapy. Materials and Methods: This was a prospective, cross-sectional, analytical and observational study. Vitamin D was measured in patients with breast cancer who had received neoadjuvant chemotherapy and its association with tumor response was determined. For the inferential analysis, the Student’s t-test, chi-square test, and Fisher’s exact test were used. A p value <0.05 was considered statistically significant. Results: Thirty-six patients were included. There was tumor response failure to treatment in 69.3% and vitamin D deficiency occurred in 58.3%. No association was found between vitamin D deficiency and tumor response failure (p = 0.729), histological type (p = 0.691), molecular profile (p = 0.969), clinical stage (p = 0.468) or menopause status (p = 0.701). Conclusion: Vitamin D deficiency is not associated with tumor response failure in breast cancer patients who received neoadjuvant chemotherapy.