Functional genomics and the breast cancer problem.

The clinical treatment of primary breast cancers has been greatly complicated by the inability to accurately predict which tumors will eventually become invasive and metastatic and which will remain localized and indolent. Lacking the ability to discriminate between these two classes of breast cancer patients, oncologists often apply aggressive adjuvant therapy to women in both groups. However, the use of functional genomics analysis has now made it possible to assemble a set of gene markers, the expression of which enables one to predict, with reasonably high accuracy, whether or not the patient will relapse or remain tumor-free five years after initial diagnosis and treatment.