title: Vitamin D (25-0H D3) status and pathological response to neoadjuvant chemotherapy in stage II/III breast cancer: Data from the NEOZOTAC trial (BOOG 10-01).
abstract: BACKGROUND
  Serum levels of 25-OH vitamin D3 (vitamin D) have been shown to be prognostic for disease-free survival in patients with breast cancer. We investigated the predictive value of these levels for pathological response after neoadjuvant chemotherapy in patients with breast cancer taking part in the NEOZOTAC phase-III trial. Additionally, the effect of chemotherapy on vitamin D levels was studied.
  
  
  METHODS
  Serum vitamin D was measured at baseline and before the last cycle of chemotherapy. The relationship between these measurements and clinical outcome, as defined by pathological complete response in breast and lymph nodes (pCR) was examined.
  
  
  RESULTS
  Baseline and end of treatment vitamin D data were available in 169 and 91 patients, respectively. Median baseline vitamin D values were 58.0 nmol/L. In patients treated with chemotherapy only, serum vitamin D levels decreased during neoadjuvant chemotherapy (median decrease of 16 nmol/L, P = 0.003). The prevalence of vitamin D levels < 50 nmol/L increased from 38.3% at baseline to 55.9% after chemotherapy. In the total population, baseline and end of therapy vitamin D levels were not related to pathological response. No associations were found between pCR and vitamin D level changes.
  
  
  CONCLUSIONS
  The significant decrease in vitamin D post-neoadjuvant chemotherapy suggests that vitamin D levels should be monitored and in case of decrease of vitamin D levels, correction may be beneficial for skeletal health and possibly breast cancer outcome.
authors.affiliation: Leiden University Medical Center, Department of Medical Oncology, The Netherlands; Leiden University Medical Center, Department of Surgery, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Charehbili
authors.affiliation: Leiden University Medical Center, Department of Endocrinology & Metabolic Diseases, The Netherlands.
authors.forename: N A T
authors.initials: NA
authors.lastname: Hamdy
authors.affiliation: Leiden University Medical Center, Department of Pathology, The Netherlands.
authors.forename: V T H B M
authors.initials: VT
authors.lastname: Smit
authors.affiliation: Deventer Ziekenhuis, Department of Clinical Oncology, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Kessels
authors.affiliation: Zaans Medisch Centrum, Department of Clinical Oncology, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: van Bochove
authors.affiliation: Radboud Universiteit Nijmegen/AMC Amsterdam, Department of Medical Oncology, The Netherlands.
authors.forename: H W
authors.initials: HW
authors.lastname: van Laarhoven
authors.affiliation: Leiden University Medical Center, Department of Medical Statistics, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Putter
authors.affiliation: Leiden University Medical Center, Department of Surgery, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Meershoek-Klein Kranenbarg
authors.affiliation: Dutch Breast Cancer Research Group (BOOG), The Netherlands.
authors.forename: A E
authors.initials: AE
authors.lastname: van Leeuwen-Stok
authors.affiliation: Leiden University Medical Center, Department of Medical Oncology, The Netherlands.
authors.forename: J J M
authors.initials: JJ
authors.lastname: van der Hoeven
authors.affiliation: Leiden University Medical Center, Department of Surgery, The Netherlands.
authors.forename: C J H
authors.initials: CJ
authors.lastname: van de Velde
authors.affiliation: Leiden University Medical Center, Department of Medical Oncology, The Netherlands.
authors.forename: J W R
authors.initials: JW
authors.lastname: Nortier
authors.affiliation: Leiden University Medical Center, Department of Medical Oncology, The Netherlands. Electronic address: j.r.kroep@lumc.nl.
authors.forename: J R
authors.initials: JR
authors.lastname: Kroep
mesh_terms: D000328:Adult; D000368:Aged; D054316:Biomarkers, Pharmacological / Q000097:blood; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000473:pathology*; D002112:Calcifediol / Q000097:blood*; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000009:adverse effects*; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D016896:Treatment Outcome
chemical_list: D054316:Biomarkers, Pharmacological; D002112:Calcifediol
keywords: 25-Hydroxy-vitamin D; Breast cancer; Neoadjuvant chemotherapy; Zoledronic acid