Exploring chromosomal instability and clonal heterogeneity in breast cancer.

Chromosomal instability (CIN), characterized by fluctuations in chromosome number or structure within cells, stands out as a hallmark of cancer, enabling tumors to thrive in hostile conditions. CIN serves as a driver of genetic diversity, giving rise to clonal heterogeneity (CH). Emerging evidence points to a potential correlation between CIN, CH, and the prognosis of breast cancer (BC) patients, especially in tumors exhibiting overexpression of the human epidermal growth factor receptor 2 (HER2+).