250PD - Clinical significance of microRNA expression as a prognostic factor in early N+ breast cancer (BC)

Date 29 September 2012
Event ESMO Congress 2012
Session Breast cancer, early stage
Topics Breast Cancer, Early Stage
Translational Research
Presenter Eva Ciruelos
Authors E. Ciruelos1, G. De Velasco1, A. Gamez2, C. Castañeda3, J.M. Sepúlveda1, I. Ghanem1, H. Cortes-Funes4, J.A. Fresno5
  • 1Medical Oncology, University Hospital 12 de Octubre, 28041 - Madrid/ES
  • 2Medicine, Autonoma University, Madrid/ES
  • 3Medical Oncology, Instituto de Enfermedades Neoplasicas, Lima/PE
  • 4Servicio De Oncologia Medica, University Hospital 12 de Octubre, 28041 - Madrid/ES
  • 5Medical Oncology, University Hospital LaPaz, Madrid/ES

 

Abstract

Background

MicroRNAs (miRNAs) are small noncoding RNA molecules that post-transcriptionally regulate gene expression. In the present study, we describe miRNA expression in early node-positive BC and identify a 8-miRNA score that could contribute to prognosis assessment.

Methods

First, microarray analysis was performed using RNA samples extracted from primary breast cancer. The expression of miRNAs was analyzed by RT-qPCR using the TaqMan Arrays from Applied Biosystems. After a suitable normalization of the 677 miRNAs analyzed, 96 presented a good correlation between their expression in frozen and paraffin-embeded tissue. A supervised analysis was done in order to identify miR that could predict relapse.

Results

172 patients with node-positive chemotherapy-treated early BC were included in the present study. The median age at diagnosis was (53.7) years, 128 cases (74.4%) had positive estrogen receptor, and 163 patients (94,7%) received adjuvant chemotherapy. After a median follow up of 8,1 years, 71p (41.2%) relapsed. Supervised analyses identified 8 microRNAs (has miR-30e, miR-30a, miR-21, miR-210, miR-93, miR-150, miR-99b, miR-572) associated with higher risk of relapse (5 year PFS 50% vs 90%, HR 3.75, 95% CI 2.27 – 6.19) and with estimated overall survival (median not reached, HR 4.51, 95% CI 2.36 – 8.61). Interestingly, miRNAs defined 2 prognostic groups (high and low risk) regardless of type of adjuvant chemotherapy (with or without anthracyclines) and histological subtype (luminal A, B or triple negative).

Conclusions

This study suggests that miRNA expression could contribute to assess molecular prognosis of breast cancer and identifies clusters of miRNAs that could improve outcome prediction. A validation study in node-negative and triple negative disease is planned.

Disclosure

All authors have declared no conflicts of interest.