CNA landscape of HER2-negative breast cancer during administration of taxane-containing schemes of neoadjuvant chemotherapy

Introduction. Evaluation of when and how to include taxanes in preoperative chemotherapy is becoming more important in the era when molecular and genetic approaches allow to develop biologically targeted therapeutic medications and select patients who can benefit from certain cytotoxic agents.Aim. To analyze the use of CNA genetic landscape (CNA – copy number aberration) luminal B HER2-negative (HER2 – human epidermal growth factor receptor type 2) breast cancer during taxane-containing neoadjuvant chemotherapy (NCT) for identification of the groups of potential CNA markers of objective response to treatment and CNA markers of prognosis of hematogenous metastases.Materials and methods. The study included 28 patients with luminal B HER2-negative breast cancer T1–4N0–3M0 stage IIA–IIIB aged 24–67 years (mean age 44.6 ± 0.3 years). In neoadjuvant regimen, the patients received 4–8 courses of chemotherapy per the ACT, AT schemes and taxotere as monotherapy. As study samples, paired tumor biopsies taken prior to treatment under ultrasound control and operative material after neoadjuvant therapy were used. Micromatrix analysis was performed using high density DNA CytoScanTM HD Array (Affymetrix, uSA). The results were processed using Chromosome Analysis Suite 4.0 (Affymetrix, uSA) software. Statistical data processing was performed in Statistica 8.0 (StatSoft Inc., uSA) software.Results. Objective response was observed in the absence of amplification in the 20q11.22 (р = 0.003) region and presence of amplifications in the 16p13.2 (р = 0.027) locus in the tumor prior to treatment. After NCT, hematogenous metastases developed in the tumor in the presence of a small number of amplifications in the 20q13.33 (р = 0.002) locus.Conclusion. Potential predictive CNA markers of objective response to treatment and prognostic CNA markers of hematogenous metastases during administration of taxane-containing schemes of neoadjuvant chemotherapy were identified.