Annals of Oncology Advance Access published online on August 28, 2009
Annals of Oncology, doi:10.1093/annonc/mdp348
A simple system for grading the response of breast cancer to neoadjuvant chemotherapy
1 Department of Medical Oncology
2 Department of Data Center
3 Department of Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
4 Department of Surgery, The Netherlands Cancer Institute, Amsterdam, The Netherlands
* Correspondence to: Dr S. Rodenhuis, Department of Medical Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands. Tel: +31-20-512 2870; Fax: +31-20-512 2858; E-mail: s.rodenhuis{at}nki.nl
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.
Patients and 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.
breast cancer, chemotherapy, neoadjuvant, response evaluation
Received for publication May 22, 2009. Accepted for publication June 3, 2009.