OBJECTIVETo investigate the predictive value of molecular subtypes and the evaluational value of dynamic contrast-enhanced MRI of neoadjuvant chemotherapy for breast cancer.

METHODSFrom January 2010 to December 2011, the 79 patients diagnosed as primary invasive breast cancer, having received 6 cycles of neoadjuvant chemotherapy and finished the mastectomy or the breast conserving surgery entered this study. A total of 79 patients participated in this prospective study. There were 6 (7.6%) luminal A cases, 42 (53.2%) luminal B cases, 14 HER-2 (17.7%) positive cases and 17 (21.5%) triple negative cases. The associations between molecular subtypes and clinical response as well as the pathological response were analyzed. The predictive value of molecular subtypes for the neoadjuvant chemotherapy was studied.

RESULTSClinical effective rate was 85.3% (66/79). There was no statistical correlation between molecular subtypes and clinical effective rate. Pathologic effective rate was 79.7% (63/79). There was no statistical correlation between molecular subtypes and pathologic effective rate. Twenty-seven case achieved pathologic complete remission (pCR) in all the patients. No case achieved pCR in the patients classified as Luminal A. Twelve cases (28.6%, 12/42) achieved pCR in the luminal B patients.Five cases (5/14) achieved pCR in the HER-2 overexpression patients. Ten cases (10/17) achieved pCR in the triple-negative patients. There was a statistical correlation between the molecular subtypes and the pCR rate (P = 0.039), and between clinical evaluation by dynamic contrast-enhanced MRI and evaluation of pathological response (r = 0.432, P = 0.000).

CONCLUSIONSMolecular subtypes and dynamic contrast-enhanced MRI have a good value of predicting and evaluating the response of neoadjuvant chemotherapy on breast cancer.