Chemotherapy or hormonal treatment after surgery for breast cancer is crucial in reducing mortality. Patients react differently to chemotherapy drugs and some women are resistant to treatment. However, since there is currently no way to distinguish between women who might respond and those who probably will not, all eligible patients are treated similarly.
Jenny Chang and colleagues from Baylor College of Medicine, Texas, USA, proposed that gene expression profiles might indicate a patient's response to docetaxel, one of the newest and most widely used chemotherapy drugs. They took biopsy samples from primary breast tumours in 24 patients before treatment, and then measured tumour response to docetaxel.
Different gene expression profiles were associated with different responses to the drug. Tumours that were sensitive to treatment had higher expression of genes involved in the cell cycle, protein transport, and protein modification, whereas resistant tumours showed enhanced expression of some transcriptional and signal transduction genes.
Dr Chang comments: "This study helps to define the molecular portrait of cancers that respond or not to docetaxel, one of the most active agents in breast cancer treatment. When validated, this type of molecular profiling could have important implications in defining the optimum treatment for individual patients, and reduce unproductive treatment, unnecessary toxicity, and overall cost. "
[See Commentary, page 340]
Contact: Dr Jenny Chang, Breast Center, Baylor College of Medicine and the Methodist Hospital, One Baylor Plaza, BCM 600, Houston, Texas, USA; T) 1-713-798-1905; F) 1-713-798-1642; E) jcchang@breastcenter.tmc.edu
Journal
The Lancet