title: A prognostic model based on combining estrogen receptor expression and Ki-67 value after neoadjuvant chemotherapy predicts clinical outcome in locally advanced breast cancer: extension and analysis of a previously reported cohort of patients.
abstract: BACKGROUND
  Ki-67 expression has gained attention as a breast cancer prognostic factor, however its significance in the remaining malignant cells after neoadjuvant chemotherapy (NAC) has been rarely examined. This investigation, extension and analysis of a previously reported cohort of patients, evaluates the significance of Ki-67 and estrogen receptor (ER) expression after NAC in LABC (locally advanced breast cancer).
  
  
  METHODS
  clinical stage, tumor size, clinical and pathological lymph node involvement, Ki-67, ER, progesterone receptor (PgR), HER2 expression, grading and clinical response were evaluated before and after NAC in 110 patients with LABC. Ki-67 expression was assessed both in pre and post-therapy histological samples, using >15% positive cells as cut-off value to distinguish high from low Ki-67 expressing tumors.
  
  
  RESULTS
  six patients (5.45%) attained pCR after NAC. A significant relationship between elevated post-CT Ki-67 and ER expression was showed at Cox multivariate analysis of disease free survival (DFS). On univariate analysis high post-chemotherapy Ki-67 and ER status were associated with worse survival; at multivariate model included these results were confirmed. Based on these two parameters, a prognostic model identified two different groups: low risk (low postchemotherapy Ki-67 and ER positive, or either high post-chemotherapy Ki-67 or ER negative), and high risk (high post-chemotherapy Ki-67 and ER negative). The low risk group showed a good prognosis (median OS still not reached), while the high risk group had a worse OS (median 41 months).
  
  
  CONCLUSIONS
  Ki-67 value after NAC and ER status could predict a worse prognosis among LABC patients treated with NAC.
authors.affiliation: S.C. Oncologia Medica A, IRCCS AOU San Martino - IST, Genoa, Italy. Electronic address: loredana.miglietta@hsanmartino.it.
authors.forename: L
authors.initials: L
authors.lastname: Miglietta
authors.forename: F
authors.initials: F
authors.lastname: Morabito
authors.forename: N
authors.initials: N
authors.lastname: Provinciali
authors.forename: L
authors.initials: L
authors.lastname: Canobbio
authors.forename: P
authors.initials: P
authors.lastname: Meszaros
authors.forename: C
authors.initials: C
authors.lastname: Naso
authors.forename: R
authors.initials: R
authors.lastname: Murialdo
authors.forename: M
authors.initials: M
authors.lastname: Boitano
authors.forename: S
authors.initials: S
authors.lastname: Salvi
authors.forename: M
authors.initials: M
authors.lastname: Ferrarini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate
chemical_list: D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
keywords: Estrogen receptor; Immunohistochemical score; Ki-67; Locally advanced breast cancer; Neoadjuvant chemotherapy; Prognosis