Serial expression analysis of breast tumors during neoadjuvant chemotherapy reveals changes in cell cycle and immune pathways associated with recurrence and response.
Breast Cancer Res, 2015/5/29;17:73.
Magbanua MJ[1, 2], Wolf DM[3], Yau C[4, 5, 6], Davis SE[7, 8], Crothers J[9, 10], Au A[11, 12], Haqq CM[13], Livasy C[14], Rugo HS[15, 16], I-SPY 1 TRIAL Investigators, Esserman L[17, 18], Park JW[19, 20], van 't Veer LJ[21, 22]
Affiliations
PMID: 26021444DOI: 10.1186/s13058-015-0582-3
Impact factor: 8.408
Abstract
introduction: The molecular biology involving neoadjuvant chemotherapy (NAC) response is poorly understood. To elucidate the impact of NAC on the breast cancer transcriptome and its association with clinical outcome, we analyzed gene expression data derived from serial tumor samples of patients with breast cancer who received NAC in the I-SPY 1 TRIAL.
methods: Expression data were collected before treatment (T1), 24-96 hours after initiation of chemotherapy (T2) and at surgery (TS). Expression levels between T1 and T2 (T1 vs. T2; n = 36) and between T1 and TS (T1 vs. TS; n = 39) were compared. Subtype was assigned using the PAM50 gene signature. Differences in early gene expression changes (T2 - T1) between responders and nonresponders, as defined by residual cancer burden, were evaluated. Cox proportional hazards modeling was used to identify genes in residual tumors associated with recurrence-free survival (RFS). Pathway analysis was performed with Ingenuity software.
results: When we compared expression profiles at T1 vs. T2 and at T1 vs. TS, we detected significantly altered expression of 150 and 59 transcripts, respectively. We observed notable downregulation of proliferation and immune-related genes at T2. Lower concordance in subtype assignment was observed between T1 and TS (62 %) than between T1 and T2 (75 %). Analysis of early gene expression changes (T2 - T1) revealed that decreased expression of cell cycle inhibitors was associated with poor response. Increased interferon signaling (TS - T1) and high expression of cell proliferation genes in residual tumors (TS) were associated with reduced RFS.
conclusions: Serial gene expression analysis revealed candidate immune and proliferation pathways associated with response and recurrence. Larger studies incorporating the approach described here are warranted to identify predictive and prognostic biomarkers in the NAC setting for specific targeted therapies.
clinical trial registration: ClinicalTrials.gov identifier: NCT00033397 . Registered 9 Apr 2002.
MeSH terms
Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Breast Neoplasms; Cell Cycle; Cluster Analysis; Female; Gene Expression Profiling; Humans; Ki-67 Antigen; Middle Aged; Neoadjuvant Therapy; Neoplasm Grading; Neoplasm Recurrence, Local; Neoplasm Staging; Prognosis; Signal Transduction; Time Factors; Transcriptome; Treatment Outcome; Tumor Burden
More resources
Full text:
Europe PubMed Central; PubMed Central
EndNote: Download