Pathologic complete response in breast cancer patients receiving anthracycline- and taxane-based neoadjuvant chemotherapy: evaluating the effect of race/ethnicity.
BACKGROUND
The current study was conducted to evaluate the influence of race/ethnicity and tumor subtype in pathologic complete response (pCR) following treatment with neoadjuvant chemotherapy.


METHODS
A total of 2074 patients diagnosed with breast cancer between 1994 and 2008 who were treated with neoadjuvant anthracycline- and taxane-based chemotherapy were included. pCR was defined as no residual invasive cancer in the breast and axilla. The Kaplan-Meier product-limit was used to calculate survival outcomes. Cox proportional hazards models were fitted to determine the relationship of patient and tumor variables with outcome.


RESULTS
The median patient age was 50 years; 14.6% of patients were black, were 15.2% Hispanic, 64.3% were white, and 5.9% were of other race. There were no differences in pCR rates among race/ethnicity (12.3% in black, 14.2% in Hispanics, 12.3% in whites, and 11.5% in others, P = .788). Lack of pCR, breast cancer subtype, grade 3 tumors, and lymphovascular invasion were associated with worse recurrence-free survival (RFS) and overall survival (OS) (P </= .0001). Differences in RFS by race/ethnicity were noted in the patients with hormone receptor-positive disease (P = .007). On multivariate analysis, Hispanics had improved RFS (hazard ratio [HR], 0.69; 95% confidence interval [95% CI], 0.49-0.97) and OS (HR, 0.63; 95% CI, 0.41-0.97); blacks had a trend toward worse outcomes (RFS: HR, 1.28 [95% CI, 0.97-1.68] and OS: HR, 1.32 [95% CI, 0.97-1.81]) when compared with whites.


CONCLUSIONS
In this cohort of patients, race/ethnicity was not found to be significantly associated with pCR rates. On a multivariate analysis, improved outcomes were observed in Hispanics and a trend toward worse outcomes in black patients, when compared with white patients. Further research was needed to explore the potential differences in biology and outcomes.
Chavez-Macgregor
Mariana
M
Division of Cancer Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030-4009, USA.
Litton
Jennifer
J
Chen
Huiqin
H
Giordano
Sharon H
SH
Hudis
Clifford A
CA
Wolff
Antonio C
AC
Valero
Vicente
V
Hortobagyi
Gabriel N
GN
Bondy
Melissa L
ML
Gonzalez-Angulo
Ana Maria
AM
D018943:Anthracyclines / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000208:ethnology* / Q000401:mortality / Q000473:pathology; D001952:Bridged-Ring Compounds / Q000008:administration & dosage*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D043823:Taxoids / Q000008:administration & dosage*; D016896:Treatment Outcome
D018943:Anthracyclines; D001952:Bridged-Ring Compounds; D043823:Taxoids; C080625:taxane