Role of chromosome instability and clonal heterogeneity in breast cancer: a pilot study

Chromosomal instability (CI), defined as cell-to-cell variability in chromosome number or structure, has been recognized as a hallmark of cancer and a source of genetic variation (clonal heterogeneity-HC) that favors tumor adaptation. to stressful environments. Breast Cancer (SC) is characterized by unstable karyotypes, and recent reports have indicated that HF ​​may influence the response to different chemotherapy regimens in HER2-positive (HER2+) tumors. However, information on the role of HF in other CS subtypes is rare or absent. A better understanding of the role of HF and HC in CS could help to optimize existing therapeutic regimens. Objectives: 1) To evaluate HF and HC in a group of 40 patients with estrogen receptor-positive (ER+)/HER2-negative CS ( HER2-) and 40 patients with CS RE negative (ER-)/HER2- with prolonged follow-up, and 2) Establish associations between HF and HC with clinicopathological, sociodemographic parameters and response to treatment. Methodology: Through the application of Molecular Cytogenetics (FISH) techniques, HF and HC will be evaluated in a population of patients with CS diagnosed at the Méderien University Hospital between 2000 and 2015, and correlations between HF and HC with clinical characteristics will be determined. -pathological, sociodemographic and response to therapy. Expected results: With the completion of this study we hope to find differences of clinical impact, in the level of IC and HC according to the state of the ER, as well as we hope to find associations between the level of IC and HC with the response to the therapy and with clinicopathological and sociodemographic parameters.