[Biology of solid cancers: breast cancer as an example. Second part: gene disregulation in breast cancer]

Several studies have been conducted to identify and determine the nature of genetic anomalies leading to breast cancer. The most frequent genetic anomalies observed in breast cancer are genetic amplification of proto-oncogenes, and mutations and deletions which inactivate suppressor genes. Abnormal protein expression has also been detected. All these modifications of the cell genome could be useful in screening, diagnosis and prognosis of breast cancer, and in the long-term, in developing new therapeutic strategies.