Mechanisms of Breast Cancer Resistance to Chemotherapy.

With the advent and evolution of the era of molecular research into cancer, the hallmark of cancer has been conclusively established as the failure of cancer cells to repair and maintain the integrity of their genome. It is generally true that in this respect breast cancer is a clonal disease arising from one aberrant cell having dysregulated growth-control signals. However, within the expanding population of daughter cells there is ever greater heterogeneity in terms of accumulated mutations in the inherited background parent genome. Naturally, each subsequent round of cell division accelerates the destabilization of the genome which, in turn, expresses itself in greater derangements of cellular biology, ultimately leading to the emergence of the most feared phenotype: that of the metastatic cancer cell. [ABSTRACT FROM AUTHOR]