Doxorubicin response prediction in neoadjuvant breast cancer therapy.

Abstract

e12119 Background: Neoadjuvant treatment for breast cancer (BC) is an important remedy if the tumors are responding adequately. Still, there is no biomarker guidance resulting in many patients receiving chemotherapy with no efficient antitumor effect. We study a multigene mRNA-based technology for drug response prediction (DRP). DRP has been thoroughly validated in other settings, latest in prediction of epirubicin efficacy in advanced BC [1]. Here are the results of the DRP method in the prediction of response to neoadjuvant doxorubicin in early BC. Methods: The DRP correlates sensitivity of the applicable drug in cell lines with background mRNA. This is combined with gene expression patterns from >2.000 tumors of different origin to ensure clinically usefulness. The higher DRP score, the higher likelihood of response. Blinded predictions of doxorubicin DRP scores were compared to response data which originated from a phase II trial [2], where the study population received neoadjuvant doxorubicin and cyclophosphamide (N=279). The patients had histologically confirmed primary invasive breast adenocarcinoma (T2-3, N0-3, M0, tumor size ≥ 2.0 cm, ER+/- and HER2+/-). Statistical analysis was done using logistic regression. Results: Table shows the distribution of response and DRP scores, showing higher DRPs are correlated to better clinical outcome. This is demonstrated by logistic regression ( p=0.002), odds ratio for response 2.2 (95% CI:1.3-3.4). Multivariate analysis showed that the DRP was independent of other covariates. Conclusions: The DRP can predict which patients will be high likelihood responders to neoadjuvant doxorubicin. Modern multigene technologies may help assist clinicians in choosing between upfront surgery or neoadjuvant chemotherapy. Complete response (CR), Partial response (PR), Stable disease (SD), Progression of Disease (PD). 1. Buhl ASK, et al. (2018): Predicting efficacy of epirubicin by a multigene assay in advanced breast cancer within a Danish Breast Cancer Cooperative Group (DBCG) cohort: a retrospective-prospective blinded study. Breast cancer research and treatment. doi: 10.1007/s10549-018-4918-4. 2. Horak CE et al. (2013): Biomarker analysis of neoadjuvant doxorubicin/cyclophosphamide followed by ixabepilone or Paclitaxel in early-stage breast cancer. Clinical cancer research. doi: 10.1158/1078-0432.ccr-12-1359.[Table: see text]