Plasma miRNA Levels for Predicting Therapeutic Response to Neoadjuvant Treatment in HER2-positive Breast Cancer: Results from the NeoALTTO Trial

Abstract

Purpose: To investigate the potential of circulating-miRNAs (ct-miRNA) as noninvasive biomarkers to predict the efficacy of single/dual HER2-targeted therapy in the NeoALTTO study. Experimental Design: Patients with plasma samples at baseline (T0) and/or after 2 weeks (T1) of treatment were randomized into training (n ¼ 183) and testing (n ¼ 246) sets. RT-PCR-based high-throughput miRNA profiling was employed in the training set. After normalization, ct-miRNAs associated with pathologic complete response (pCR) were identified by univariate analysis. Multivariate logistic regression models were implemented to generate treatment-specific signatures at T0 and T1, which were evaluated by RT-PCR in the testing set. Event-free survival (EFS) according to ct-miRNA signatures was estimated by Kaplan-Meier method and Cox regression model. Results: In the training set, starting from 51 ct-miRNAs associated with pCR, six signatures with statistically significant predictive capability in terms of area under the ROC curve (AUC) were identified. Four signatures were confirmed in the testing set: lapatinib at T0 and T1 [AUC 0.86; 95% confidence interval (CI), 0.73-0.98 and 0.71 (0.55-0.86)], respectively; trastuzumab at T1 (0.81; 0.70-0.92); lapatinib þ trastuzumab at T1 (0.67; 0.51-0.83). These signatures were confirmed predictive after adjusting for known variables, including estrogen receptor status. ct-miRNA signatures failed to correlate with EFS. However, the levels of ct-miR-140-5p, included in the trastuzumab signature, were associated with EFS (HR 0.43; 95% CI, 0.22-0.84). Conclusions: ct-miRNAs discriminate patients with and without pCR after neoadjuvant lapatinib-and/or trastuzumab-based therapy. ct-miRNAs at week two could be valuable to identify patients responsive to trastuzumab, to avoid unnecessary combination with other anti-HER2 agents, and finally to assist deescalating treatment strategies.

Early Modulation of Circulating MicroRNAs Levels in HER2-Positive Breast Cancer Patients Treated with Trastuzumab-Based Neoadjuvant Therapy

“…To our knowledge, this is the first attempt to report the results, although they were obtained from explorative analysis, based on biomarkers derived from liquid biopsy to track early response to treatment. As already discussed in our previous work, ct-miRNA-140-5p could be involved in the host response to therapy by reflecting the level of engagement of immune response [15], while ct-miR-148a-3p could be involved in the response of the primary tumor by reflecting the effect of treatment on tumor cells. Indeed, the GO and KEGG analysis showed no private pathways for miR-140-5p, but common pathways with other miRNAs involved in response to treatment.…”

“…By taking advantage of our previous work [15], that identified ct-miR140-5p as associated with both pCR and favorable prognosis after two weeks of treatment with trastuzumab, we performed an additional explorative analysis to address whether the changes of ct-miR-148a-3p provided overlapping or rather complementary information as compared to the levels of ct-miR 140-5p at week 2. To this end the set of 48 patients with both miRNAs was considered and for miR-148a-3p the identified UL was used as a threshold to classify patients whereas for ct-miR-140-5p patients were classified in the category "hight level" and "low level" according to the threshold previously reported [15]. By jointly considering both ct-miRs, patients with "high changes" of ct-miR-148a-3p and high values of ct-miR-140-5p (i.e., 13/48 cases, 27%) had a chance of pCR up to 54% (7/13, 95% exact CI 25%-81%); conversely, patients with "low/intermediate changes" of ct-miR-148a-3p and low values of ct-miR140-5p (i.e., 10/48 cases, 21%) had a 0% (0/10, 95% exact CI 0%-31%) chances of pCR.…”

“…Starting from the ct-miRNA high-throughput profile of the NeoALTTO cases [15], we considered the suitable scope of the present analysis, which was to identify early ct-miRNA modulation associated with pCR, patients treated within the trastuzumab arm and with available complete 752 ct-miRNA profile on plasma pairs at T0 and T1 ( Figure S4).…”

“…Our procedures for plasma preparation and RNA isolation have been previously reported [15]. Reverse transcription and ct-miRNA profile was performed using the miRCURY LNA™Universal RT microRNA PCR system according to the Exiqon manufacturer's instructions.…”

“…ct-miR-210 should be added to this unfavorable prognostic list because, while initially considered to be a predictive factor of response to trastuzumab, it was later shown to be associated with decreased event-free survival (EFS) [14]. More recently, our group reported four different treatment-and time-specific ct-miRNA signatures able to identify HER2 positive BC patients with differential response in terms of pCR to neoadjuvant trastuzumab, lapatinib and their combination followed by paclitaxel [15].…”