MicroRNA in diagnosis and therapy monitoring of early-stage triple-negative breast cancer

Mustafa Kahraman,Thomas Laufer,Michael G Schrauder,Christina Backes,Anne Röske,Hannah Schrörs,Matthias Rübner,Fabian Kern,Eckart Meese,Andreas Keller,Jochen Kohlhaas,Tobias Fehlmann,Cassandra Zabler,Matthias W Beckmann,Nicole Ludwig,Reiner Strick,Anna Saiz,Peter A Fasching

doi:10.1038/s41598-018-29917-2

Abstract

Breast cancer is a heterogeneous disease with distinct molecular subtypes including the aggressive subtype triple-negative breast cancer (TNBC). We compared blood-borne miRNA signatures of early-stage basal-like (cytokeratin-CK5-positive) TNBC patients to age-matched controls. The miRNAs of TNBC patients were assessed prior to and following platinum-based neoadjuvant chemotherapy (NCT). After an exploratory genome-wide study on 21 cases and 21 controls using microarrays, the identified signatures were verified independently in two laboratories on the same and a new cohort by RT-qPCR. We differentiated the blood of TNBC patients before NCT from controls with 84% sensitivity. The most significant miRNA for this diagnostic classification was miR-126-5p (two tailed t-test p-value of 1.4 × 10−5). Validation confirmed the microarray results for all tested miRNAs. Comparing cancer patients prior to and post NCT highlighted 321 significant miRNAs (among them miR-34a, p-value of 1.2 × 10−23). Our results also suggest that changes in miRNA expression during NCT may have predictive potential to predict pathological complete response (pCR). In conclusion we report that miRNA expression measured from blood facilitates early and minimally-invasive diagnosis of basal-like TNBC. We also demonstrate that NCT has a significant influence on miRNA expression. Finally, we show that blood-borne miRNA profiles monitored over time have potential to predict pCR.

Highlights

Breast cancer is a heterogeneous disease with distinct molecular subtypes including the aggressive subtype triple-negative breast cancer (TNBC)
To study the impact of platinum-based neoadjuvant chemotherapy (NCT) on microRNA expression, 63 blood samples were investigated from 21 patients with early-stage basal-like TNBC, taken before and after NCT, and from 21 healthy age-matched women
Subsequent, reverse transcription quantitative polymerase chain reaction (RT-qPCR) validation steps were performed in the same cohort and in a new study group of patients with basal-like TNBC and controls

Summary

Introduction

Breast cancer is a heterogeneous disease with distinct molecular subtypes including the aggressive subtype triple-negative breast cancer (TNBC). We compared blood-borne miRNA signatures of earlystage basal-like (cytokeratin-CK5-positive) TNBC patients to age-matched controls. The miRNAs of TNBC patients were assessed prior to and following platinum-based neoadjuvant chemotherapy (NCT). Validation confirmed the microarray results for all tested miRNAs. Comparing cancer patients prior to and post NCT highlighted 321 significant miRNAs (among them miR-34a, p-value of 1.2 × 10−23). In conclusion we report that miRNA expression measured from blood facilitates early and minimally-invasive diagnosis of basal-like TNBC. Mean age at TNBC diagnosis Mean age of healthy controls Proportion of patients with pCR Proportion of patients with positive lymph nodes after NCT Histological tumour type in all patients Molecular tumour subtype in all patients Mean proliferation index (Ki-67) Mean positivity for CK5 Neoadjuvant chemotherapy regimen in all patients. Predicting the response to NCT is a critical issue that needs to be addressed, in patients with TNBC

Methods

Results

Conclusion