Serum Vitamin D Levels Impacts Pathologic Complete Response in Patients Undergoing Neoadjuvant Systemic Therapy for Operable Breast Cancer
Clinical Breast Cancer, online 11 December 2017, https://doi.org/10.1016/j.clbc.2017.12.001
VitaminDWiki suspects Chemotherapy effacacy is reduced by low vitamin D in more than Breast Cancer
There has been increasing interest in the potential benefit of vitamin D (vitD) in improving breast cancer outcome. Pre-clinical studies suggest vitD enhances chemotherapy-induced cell death. We investigated the impact of serum vitD levels during neoadjuvant chemotherapy (NAC) on the rates of achieving pathologic complete response (pCR) following breast cancer NAC.
Patients from one of two Iowa registries who had serum vitD level measured before or during NAC were included. French patients enrolled in a previous study of the impact of NAC on vitD and bone metabolism were also eligible for this study. Vitamin D deficiency was defined as < 20 ng/mL. pCR was defined as no residual invasive disease in breast and lymph nodes. A Firth penalized logistic regression multivariable model was used.
The study included 144 women. There was no difference between the French and Iowa cohorts with regard to age at diagnosis (p=0.20), clinical stage (p=0.22), receptor status (p=0.32) and pCR rate (p=0.34). French women had lower body mass index (mean 24.8 vs 28.8, p<0.01) and lower vitD levels (mean 21.5 vs 27.5, p<0.01) compared to Iowa patients. In multivariable analysis, after adjusting for the effects of cohort, clinical stage and receptor status, vitD deficiency increased the odds of not attaining pCR by 2.68 times (95%CI: 1.12-6.41, p=0.03).
Low serum vitD levels was associated with not attaining a pCR. Prospective trials could elucidate if maintaining vitD levels during NAC, a highly modifiable variable, may be utilized to improve cancer outcomes.