Identification of genomic alterations associated with the axillary breast cancer metastatic process using exome sequencing

• Grant number: 13/02268-0
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: September 15, 2013
• End date: December 14, 2013
• Field of knowledge: Biological Sciences - Genetics - Human and Medical Genetics
• Principal Investigator: Luiz Paulo Kowalski
• Grantee: Luiz Paulo Kowalski
• Visiting researcher: Luciane R. Cavalli
• Visiting researcher institution: Georgetown University , United States
• Host Institution: A C Camargo Cancer Center. Fundação Antonio Prudente (FAP). São Paulo , SP, Brazil
• City of the host institution: São Paulo
• Associated research grant: 08/57887-9 - National Institute of Oncogenomics, AP.TEM

Abstract

The development of breast cancer metastasis is the main responsible for the observed high mortality rate in patients with breast cancer. The presence of tumor cells in the axillary lymph nodes, the first metastatic site in the breast, is the most effective prognostic factor of tumor recurrence. Genomic and gene expression studies have showed evidences that the molecular alterations that confer the metastatic capability to the tumor cells occur in an early phase of the tumorigenic process. Based on this information we propose to identify in this study the genomic alterations that are associated with the axillary metastatic process using exome sequencing. This analysis will be conducted in two distinct groups of patients, selected based on the presence of axillary metastasis. The genomic profile obtained from the primary tumors from these patients will be compared, as well as from their corresponding peripheral blood, in order to differentiate somatic from germ line exome mutations. In addition, the genomic alterations will be correlated with patient's clinical-pathological parameters including age, reproductive history, tumor size and grade and positivity for the endocrine (ER and PR) and epidermal growth factor (ERBB2) receptors.This study will allow the identification of genomic alterations in specific exomic regions inserted in known oncogenes and tumor suppressor genes and/or will allow the identification of novel genes associated with the metastatic process. Once these alterations are validated in an independent set of primary tumors (validation set) they could be potentially used as predictive molecular markers for the risk of developing axillary metastasis. This prediction, conducted in an early stage of the disease, could influence the clinical axillary management, contributing for the reduction of invasive procedures for axillary lymph node dissection and their associated morbidity, in breast cancer patients with low risk of developing axillary metastasis. Conversely, the early identification of patients with a high risk of developing metastasis, would allow the adoption of more aggressive therapies and high clinical surveillance, reducing the chance of axillary and/or hematogenic metastasis occurrence, conferring therefore a higher survival rate. (AU)