title: Comparison of different definitions of pathologic complete response in operable breast cancer: a pooled analysis of three prospective neoadjuvant studies of JBCRG.
abstract: BACKGROUND
  Neoadjuvant chemotherapy (NAC) has been accepted as one of the standard treatments for operable breast cancer. However, the term pathologic complete response (pCR) has not been consistently defined.
  
  
  METHODS
  This study was a pooled analysis of three prospective studies of NAC conducted by JBCRG and was performed to compare the prognostic significance of different definitions of pCR. pCRs were defined as follows: QpCR, few or no remaining invasive cancer cells in the breast; CpCR, ypT0/is; CpCRbn, ypT0/isypN0; SpCR, ypT0; SpCRbn, ypT0ypN0; Grade 2b, only a few remaining cancer cells in the breast.
  
  
  RESULTS
  A total of 353 patients were included. A Cox proportional hazards model revealed that hazard ratios (HRs) of each pCR were lower than 1; however, pCR was significant for disease-free survival (DFS) and overall survival (OS) only when QpCR, CpCR, and CpCRbn were used (DFS; QpCR, 0.27; CpCR, 0.39; CpCRbn, 0.42, SpCR, 0.57, SpCRbn, 0.68: OS; QpCR, 0.12; CpCR, 0.17; CpCRbn, 0.16; SpCR, 0.30, SpCRbn, 0.45). Grade 2b was also a significant prognostic variable for DFS and OS (HR: DFS, 0.19; OS, 0.15). Neither bone nor brain was the first site of recurrence in patients who achieved pCR, irrespective of the definition of pCR. Triple-negative and Her2-positive tumors tended to recur in soft tissue more frequently than the other subtypes, and luminal tumors had the lowest rate of recurrence in the brain.
  
  
  CONCLUSIONS
  Prognostic significance of pCR varied according to the definition of pCR, and the pattern of recurrence might be different according to pathologic response and subtype.
authors.affiliation: Department of Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo, 113-8677, Japan. kurochan@dd.iij4u.or.jp.
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Kuroi
authors.affiliation: Department of Surgery (Breast Surgery), Graduate School of Medicine Kyoto University, Kyoto, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Toi
authors.affiliation: Department of Clinical Oncology, The Clinical Institute of NHO Kyusyu Cancer Center, Fukuoka, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ohno
authors.affiliation: Division of Breast Surgical Oncology, Department of Surgery, Showa University School of Medicine, Tokyo, Japan.|Department of Breast Surgical Oncology, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, Aichi, Japan.
authors.forename: Hiroji
authors.initials: H
authors.lastname: Iwata
authors.affiliation: Department of Surgery, Breast Oncology, NHO Osaka National Hospital, Osaka, Japan.
authors.forename: Norikazu
authors.initials: N
authors.lastname: Masuda
authors.affiliation: Department of Breast Oncology, Niigata Cancer Center Hospital, Niigata, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Sato
authors.affiliation: Department of Basic Pathology, National Defense Medical College, Saitama, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tsuda
authors.affiliation: Department of Pathology, Saitama Cancer Center, Saitama, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kurosumi
authors.affiliation: Department of Pathology, The Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Futoshi
authors.initials: F
authors.lastname: Akiyama
mesh_terms: D001859:Bone Neoplasms / Q000556:secondary; D001932:Brain Neoplasms / Q000556:secondary; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012074:Remission Induction; D009626:Terminology as Topic; D016896:Treatment Outcome; D064726:Triple Negative Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Breast cancer; Neoadjuvant chemotherapy; Pathologic response; Subtype