Gene expression signatures as predictors of chemotherapeutic response in breast cancer
The purpose of this study is to evaluate a novel 22-gene signature as a predictor of response to chemotherapy in breast cancer. The extent of residual viable tumor following chemotherapy is the most important predictor of long-term outcome in breast cancer. It is essential to identify patients who will not respond to chemotherapy to avoid ineffective therapies as well as unnecessary side effects. The rate of complete pathologic response to chemotherapy is relatively low, ranging from 3% to 27% of patients. Much work has been performed to predict chemotherapy responsiveness, but, as of yet, no test is effective and widely used in the clinic. Results show that the 22-gene signature accurately predicts response to multiple primary chemotherapies (p<0.05). Importantly, the 22-gene signature outperformed other signatures with highly significant p-values in all datasets tested.