Summary

Molecular profiling is used in three stages of breast cancer development: cacinoma in situ, primary, and metastatic. The treatment of in situ carcinoma of the breast is controversial. In the molecular progression from normal tissue to invasion, in situ carcinoma is a late-occurring step associated with an increased risk of the subsequent development of invasive carcinoma [Bombonati A, Sgroi DC. J Pathol 2011]. This article discusses data on molecular profiling of in situ carcinoma of the breast, an overview of molecular profiling of breast cancer, and the current use of genomic and molecular tests in routine practice and clinical research in metastatic breast cancer.