Twenty Years of Systemic Therapy for Breast Cancer
January 01, 2006
The past 2 decades of systemic therapy for breast cancer have beena period of monumental change, in terms of both theory and technology.Adjuvant therapy developed from two strands of research-one insystemic chemotherapy and one in hormonal therapy-both of whichwere aided by the application of higher statistical methodology to clinicaltrials. The agent with the single greatest public health impact inoncology has been tamoxifen, but problems with tamoxifen therapy ledto the development of the aromatase inhibitors, and further researchled to the use of hormonal therapy in a chemopreventive capacity. Theevolution of systemic chemotherapy for breast cancer has been an interplaybetween theory-driven approaches and new agents. By the late1980s, accumulating data revealed that overexpression of HER2 (erbB2)played an important role in a substantial portion of breast cancers,which prompted the development of trastuzumab (Herceptin), an agenttargeting HER2-positive disease. Determining HER2 status proved essentialto assessing patient eligibility for trastuzumab therapy. Decodingof the human genome and application of bioinformatics furtherrevolutionized the possibilities in breast cancer treatment.