title: A simple system for grading the response of breast cancer to neoadjuvant chemotherapy.
abstract: BACKGROUND
  The response of primary breast cancer to chemotherapy is usually expressed either as a pathological complete remission (pCR) or as 'no pCR'. A more quantitative measure is called for.
  
  
  METHODS
  The 'neoadjuvant response index' (NRI) was calculated by adding a breast response score (a number from a five-point scale) to an axillary response score (a number from a three-point scale) and dividing this by the score that would have been obtained in case of a pCR in both breast and axilla. Consequently, the NRI is a number between 0 (representing no response) and 1 (a pCR of both breast and axilla).
  
  
  RESULTS
  The NRI was calculated in 267 patients who had received neoadjuvant chemotherapy. The average NRI was 0.48 (median 0.40). Forty-one patients (15%) had an NRI of 0; 55 patients (21%) had an NRI of 1 (pCR). 'Highly endocrine responsive' tumors responded substantially less than 'incompletely endocrine responsive' ones. In triple negatives, an NRI of >0.70 was associated with a better recurrence-free survival than a lower NRI.
  
  
  CONCLUSIONS
  The NRI proposed here may be useful to better reflect the efficacy of neoadjuvant systemic regimens than the binary pCR-'no pCR' system.
authors.affiliation: Department of Medical Oncology. Electronic address: s.rodenhuis@nki.nl.
authors.forename: S
authors.initials: S
authors.lastname: Rodenhuis
authors.affiliation: Department of Data Center.
authors.forename: I A M
authors.initials: IAM
authors.lastname: Mandjes
authors.affiliation: Department of Pathology.
authors.forename: J
authors.initials: J
authors.lastname: Wesseling
authors.affiliation: Department of Pathology.
authors.forename: M J
authors.initials: MJ
authors.lastname: van de Vijver
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: M-J T D F Vrancken
authors.initials: MTDFV
authors.lastname: Peeters
authors.affiliation: Department of Medical Oncology.
authors.forename: G S
authors.initials: GS
authors.lastname: Sonke
authors.affiliation: Department of Medical Oncology.
authors.forename: S C
authors.initials: SC
authors.lastname: Linn
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012074:Remission Induction; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases