title: Locoregional Recurrence by Tumor Biology in Breast Cancer Patients after Preoperative Chemotherapy and Breast Conservation Treatment.
abstract: OBJECTIVE
  The purpose of this study is to determine whether breast cancer subtype can affect locoregional recurrence (LRR) and ipsilateral breast tumor recurrence (IBTR) after neoadjuvant chemotherapy (NAC) and breast-conserving therapy (BCT).
  
  
  METHODS
  We evaluated 335 consecutive patients with clinical stage II-III breast cancer who received NAC plus BCT from 2002 to 2009. Patients were classified according to six molecular subtypes: luminal A (hormone receptor [HR]+/HER2-/Ki-67 < 15%, n=113), luminal B1 (HR+/HER2-/Ki-67 ≥ 15%, n=33), luminal B2 (HR+/HER2+, n=83), HER2 with trastuzumab (HER2[T+]) (HR-/HER2+/use of trastuzumab, n=14), HER2 without trastuzumab (HER2[T-]) (HR-/HER2+, n=31), and triple negative (TN) (HR-/HER2-, n=61).
  
  
  RESULTS
  After a median follow-up period of 7.2 years, 26 IBTRs and 37 LRRs occurred. The 5-year LRR-free survival rates were luminal A, 96.4%; B1, 93.9%; B2, 90.3%; HER2(T+), 92.9%; HER2(T-), 78.3%; and TN, 79.6%. The 5-year IBTR-free survival rates were luminal A, 97.2%; B1, 93.9%; B2, 92.8%; HER2(T+), 92.9%; HER2(T-), 89.1%; and TN, 84.6%. In multivariate analysis, HER2(T-) (IBTR: hazard ratio, 4.2; p=0.04 and LRR: hazard ratio, 7.6; p < 0.01) and TN subtypes (IBTR: hazard ratio, 6.9; p=0.01 and LRR: hazard ratio, 8.1; p < 0.01) were associated with higher IBTR and LRR rates. A pathologic complete response (pCR) was found to show correlation with better LRR and a tendency toward improved IBTR controls in TN patients (IBTR, p=0.07; LRR, p=0.03).
  
  
  CONCLUSIONS
  The TN and HER2(T-) subtypes predict higher rates of IBTR and LRR after NAC and BCT. A pCR is predictive of improved IBTR or LRR in TN subtype.
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.|Department of Radiation Oncology, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Eunjin
authors.initials: E
authors.lastname: Jwa
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.|Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Ja Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.|Department of Radiation Oncology, Soonchunhyang University Hospital, Soonchunhyang University College of Medicine, Seoul, Korea.
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Park
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: So-Youn
authors.initials: SY
authors.lastname: Jung
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: In Hae
authors.initials: IH
authors.lastname: Park
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Keun Seok
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Jungsil
authors.initials: J
authors.lastname: Ro
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Yeon-Joo
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000145:classification / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D018572:Disease-Free Survival; D004358:Drug Therapy / Q000379:methods; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000503:physiopathology; D009367:Neoplasm Staging; D011300:Preoperative Care; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*; D000068878:Trastuzumab / Q000008:administration & dosage
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human
keywords: Breast neoplasms; Ipsilateral breast tumor recurrence; Local neoplasm recurrence; Molecular subtype; Neoadjuvant chemotherapy