Randomized clinical trials in breast cancer.

Breast cancer remains the most common cancer diagnosed in women and the second leading cause of cancer-related deaths in this group. Significant advances in the treatment of breast cancer and in the ability to screen for the disease mean that it is also one of the most curable forms of cancer. Long-term updates of the trials reviewed in the previous edition of this article have demonstrated that breast-conserving therapy remains a viable option for most patients, and that local control is related to overall survival. New chemotherapeutic options and endocrine therapies are available to select subsets of patients, and the use of endocrine therapy in breast cancer prevention has been shown to be of clear benefit. The sheer number of breast cancer-related randomized, controlled trials makes it impossible to review all level Ia evidence in this article but, where possible, extensive referencing and tabular review of related trials are used to provide the reader with a clear outline of the central data dictating current standard of care.