title: Clinical importance of discordance of hormone receptors and Her2/neu status after neoadjuvant chemotherapy in breast cancer.
abstract: OBJECTIVE
  The aim of this study was to compare the hormone receptors' (HR) and HER2/neu status between core needle biopsy (CNB) and residual tumor after surgery of breast cancer treated with neoadjuvant chemotherapy (NAC), and also to evaluate the impact of discordance and other clinicopathological factors on survival.
  
  
  METHODS
  Oestrogen receptor (ER), progesterone receptor (PR) and HER2/neu status were evaluated by immunohistochemistry (IHC) on 90 CNBs of primary tumors and surgical specimens after NAC (study group); 53 patients without NAC served as control group, and discordance was compared between the two groups. The association between discordance of HR status after NAC and various other clinicopathological factors was tested with Spearman's test.
  
  
  RESULTS
  Pathological complete response (PCR) was achieved in 10 (11.1%) patients after NAC. ER and PR changed significantly more in the study than in the control group. ER and PR discordance was detected in 10 (12.5%) and 17 (21.2%) patients in the NAC group and in 1 (1.8%) and 2 (3.7%) patients in the control group (p=0.04 and p=0.005, respectively). ER discordance was related with HER2/neu change. Furthermore, PR discordance correlated with CNB, ER and treatment response, while HER2/ neu discordance was associated with treatment response (p=0.05). ER discordance was found to be an independent prognostic factor for progression-free survival (PFS) (p=0.02).
  
  
  CONCLUSIONS
  NAC might cause alterations in ER, PR or HER2//neu status in breast cancer, and they should be re-tested in the residual tumor after NAC to optimize adjuvant therapy.
authors.affiliation: Department of Medical Oncology, Haydarpasa Numune Education and Research Hospital.
authors.forename: Bala
authors.initials: B
authors.lastname: Basak Oven Ustaalioglu
authors.forename: Fugen
authors.initials: F
authors.lastname: Aker Vardar
authors.forename: Ahmet
authors.initials: A
authors.lastname: Bilici
authors.forename: Gunay
authors.initials: G
authors.lastname: Gurleyik
authors.forename: Burcak
authors.initials: B
authors.lastname: Erkol
authors.forename: Umut
authors.initials: U
authors.lastname: Kefeli
authors.forename: Mehmet
authors.initials: M
authors.lastname: Aliustaoglu
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy*; D016022:Case-Control Studies; D018572:Disease-Free Survival; D006801:Humans; D020360:Neoadjuvant Therapy; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone