Predictive Factors for CNS Metastases in Early Breast Cancer Using Liquid Biopsy (AKRA CŽS)

Breast cancer is frequently diagnosed at an early stage. Despite appropriate curative treatment, a subset of patients develops distant metastases during follow-up. Metastases to the central nervous system (CNS) represent a serious clinical complication due to their significant impact on morbidity and mortality. At present, no validated blood-based biomarkers are available to reliably predict CNS dissemination in patients with early-stage breast cancer. The primary objective of this study is to identify genes that are differentially expressed in archived primary breast tumor tissue of patients who subsequently developed CNS metastases compared with matched controls who did not develop CNS metastases. Gene expression will be assessed using next-generation sequencing (NGS) of cDNA derived from mRNA. The secondary objective is to evaluate whether baseline serum concentrations of chemokines CX3CL1, CXCL13, and CXCL8 (IL-8), measured using enzyme-linked immunosorbent assay (ELISA), are associated with the later development of CNS metastases. The study includes two clinically comparable groups of patients with early-stage breast cancer: patients who developed CNS metastases during follow-up, and matched control patients without CNS metastases. Statistical analyses will include descriptive statistics, univariate and multivariate logistic regression models, and receiver operating characteristic (ROC) curve analysis to evaluate predictive performance of the investigated biomarkers.