title: CA 15-3 is predictive of response and disease recurrence following treatment in locally advanced breast cancer.
abstract: BACKGROUND
  Primary chemotherapy (PC) is used for down-staging locally advanced breast cancer (LABC). CA 15-3 measures the protein product of the MUC1 gene and is the most widely used serum marker in breast cancer.
  
  
  METHODS
  We retrospectively investigated the role of CA 15-3 in conjunction with other clinico-pathological variables as a predictor of response and time to disease recurrence following treatment in LABC. Pre and post primary chemotherapy serum concentrations of CA 15-3 together with other variables were reviewed and related to four outcomes following primary chemotherapy (clinical response, pathological response, time to recurrence and time to progression). Persistently elevated CA 15-3 after PC was considered as consecutively high levels above the cut off point during and after PC.
  
  
  RESULTS
  73 patients were included in this study. Patients received PC (AC or AC-T regimen) for locally advanced breast cancer. 54 patients underwent surgery. The median follow up was 790 days. Patients with high concentrations of CA 15-3 before PC treatment had a poor clinical (p = 0.013) and pathological (p = 0.044) response. Together with Her-2/neu expression (p = 0.009) and tumour lympho-vascular space invasion (LVI) (p = 0.001), a persistently elevated CA 15-3 post PC (p = 0.007) was an independent predictive factor of recurrence following treatment in LABC.
  
  
  CONCLUSIONS
  Elevated CA 15-3 level is predictive of a poor response to chemotherapy. In addition, persistently elevated CA 15-3 levels post chemotherapy in conjunction with lympho-vascular invasion and HER2 status predict a reduced disease free survival following treatment in locally advanced breast cancer.
authors.affiliation: Department of Surgery, St, Vincent's University Hospital, Dublin, Ireland. dhafir66@hotmail.com
authors.forename: Dhafir
authors.initials: D
authors.lastname: Al-azawi
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Kelly
authors.forename: Eddie
authors.initials: E
authors.lastname: Myers
authors.forename: Enda W
authors.initials: EW
authors.lastname: McDermott
authors.forename: Arnold D K
authors.initials: AD
authors.lastname: Hill
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Duffy
authors.forename: Niall O
authors.initials: NO
authors.lastname: Higgins
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D003131:Combined Modality Therapy; D018450:Disease Progression; D005260:Female; D006801:Humans; D018396:Mucin-1 / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018396:Mucin-1