Circulating microRNAs and therapy-associated cardiac events in HER2-positive breast cancer patients: an exploratory analysis from NeoALTTO.

PURPOSE: The relevance of cardiotoxicity in the context of HER2-positive breast cancer is likely to increase with increasing patient treatment exposure, number of treatment lines, and prolonged survival. Circulating biomarkers to early identify patients at risk of cardiotoxicity could allow personalized treatment and follow-up measures. The aim of this study is to examine the relationship between circulating microRNAs and adverse cardiac events in HER2-positive breast cancer patients. METHODS: We based our work on plasma samples from NeoALTTO trial obtained at baseline, after 2 weeks of anti-HER2 therapy, and immediately before surgery. Eleven patients experienced either a symptomatic or asymptomatic cardiac event. Circulating microRNAs were profiled in all patients presenting a cardiac event (case) and in an equal number of matched patients free of reported cardiac events (controls) using microRNA-Ready-to-Use PCR (Human panel I + II). Sensitivity analyses were performed by increasing the number of controls to 1:2 and 1:3. Normalized microRNA expression levels were compared between cases and controls using the non-parametric Kruskal-Wallis test. RESULTS: Eight circulating microRNAs resulted differentially expressed after 2 weeks of anti-HER2 therapy between patients experiencing or not a cardiac event. Specifically, the expression of miR-125b-5p, miR-409-3p, miR-15a-5p, miR-423-5p, miR-148a-3p, miR-99a-5p, and miR-320b increased in plasma of cases as compared to controls, while the expression of miR-642a-5p decreases. Functional enrichment analysis revealed that all these microRNAs were involved in cardiomyocyte adrenergic signaling pathway. CONCLUSION: This study provides proof of concept that circulating microRNAs tested soon after treatment start could serve as biomarkers of cardiotoxicity in a very early stage in breast cancer patients receiving anti-HER2 therapy.

Factors associated with surgical management following neoadjuvant therapy in patients with primary HER2-positive breast cancer: results from the NeoALTTO phase III trial.

BACKGROUND: The NeoALTTO trial showed that dual HER2 blockade nearly doubles the rate of pathologic complete response (pCR) in patients with primary HER2-positive breast cancer. However, this did not translate into a higher rate of breast-conserving surgery (BCS). PATIENTS AND METHODS: In NeoALTTO, patients with HER2-positive breast cancer were randomly assigned to either trastuzumab, lapatinib or their combination with paclitaxel before surgery with pCR as the primary end point. We investigated the association between the surgery type and clinicopathological factors and response to treatment, adjusting for the treatment arm. RESULTS: Four hundred and twenty-nine patients were subjected to breast surgery. Two hundred and forty-two (56%) and 187 (44%) patients underwent mastectomy and BCS, respectively. In a logistic regression model, negative estrogen receptor (ER), multicentricity and the presence of a palpable mass before surgery were significantly associated with a low chance of BCS. Conversely, patients with small tumors and those eligible for BCS at diagnosis were managed more with BCS, independent of the treatment arm. Radiological response was not associated with the surgical decision. CONCLUSIONS: Tumor characteristics before neoadjuvant therapy play a main role in deciding the type of surgery calling for a clear consensus on the role of BCS in patients responding to neoadjuvant therapy.