title: Stratifying the outcome after neoadjuvant treatment using pathological response classification by the Japanese Breast Cancer Society.
abstract: BACKGROUND
  Neoadjuvant chemotherapy (NAC) is one of the standard treatment for patients with operable and locally advanced breast cancer. Pathological response after NAC has been assessed according to the Japanese Breast Cancer Society (JBCS) classification in Japan. This classification that was first established in 1998 and revised in 2007 has been used in routine clinical practice in Japan. In the present study, we investigated whether the assessment of pathological response according to this classification could stratify the long-term outcome of patients with breast cancer.
  
  
  METHODS
  Patients with breast cancer who had received neoadjuvant chemotherapy between January 2003 and December 2005 in 6 hospitals participating in this study were identified. Patients whose response was judged to be Grade 2 was reassessed into Grades 2a and 2b according to the updated JBCS classification revised in 2007. Then, the association of pathological response and recurrence-free survival (RFS) was analyzed.
  
  
  RESULTS
  635 patients received NAC and 154 relapses (24 %) were observed during a median follow-up of 41.5 months (range 4.2-69.5 months). There was a statistically significant difference in RFS among each pathological response. 5-year RFS of patients with Grade 3 without residual ductal carcinoma in situ was 94 %. 5-year RFS were 88 % in Grade 3, 95 % in Grade 2b, 80 % in Grade 2a, 73 % in Grade 1b, 67 % in Grade 1a, 59 % in Grade 0, respectively.
  
  
  CONCLUSIONS
  An outcome could be stratified by assessing tumor burden following NAC according to the JBCS classification.
authors.affiliation: Division of Breast and Medical Oncology, National Cancer Center Hospital East, 6-5-1, Kashiwanoha, Kashiwa-shi, Chiba, 277-8577, Japan. hrmukai@east.ncc.go.jp.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Mukai
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Arihiro
authors.affiliation: Department of Breast and Medical Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Shimizu
authors.affiliation: Department of Surgery, National Hospital Organization Osaka National Hospital, Osaka, Japan.|Department of Breast Oncology, National Hospital Organization Osaka National Hospital, Osaka, Japan.
authors.forename: Norikazu
authors.initials: N
authors.lastname: Masuda
authors.affiliation: Department of Breast Oncology, Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Miyagi
authors.affiliation: Division of Medical Oncology, Musashino Red Cross Hospital, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Division of Breast Surgery, Saitama Cancer Center, Saitama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
mesh_terms: D000328:Adult; D000368:Aged; D018943:Anthracyclines / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007564:Japan; D008408:Mastectomy; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D043823:Taxoids / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D018943:Anthracyclines; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D043823:Taxoids; C508053:ERBB2 protein, human
keywords: Long-term outcome; Neoadjuvant chemotherapy; Pathological complete response; Residual disease