SAN ANTONIO — The 70-gene MammaPrint prognosis signature independently identifies a genomic low-risk subgroup of HER2-positive early breast cancer patients likely to have a good long-term clinical outcome.
Dr. Michael Knauer of the Netherlands Cancer Institute, Amsterdam, presented a validation study of 169 women with HER2-positive unilateral breast cancer drawn from six partially published studies; 46% received chemotherapy and 15% got trastuzumab.
MammaPrint classified 16% of the tumors as having a “good prognosis” signature, he said at the San Antonio Breast Cancer Symposium. Those 27 patients had a 10-year distant disease-free survival rate of 89%, compared with 64% in the 142 patients classified by MammaPrint as having a high genomic risk. In a multivariate analysis adjusted for the conventional prognostic factors along with adjuvant therapies, the MammaPrint signature and tumor size were the only independent predictors of 10-year distant disease-free survival. Agendia Inc., which markets MammaPrint, supported the study. Dr. Knauer said he has no financial conflicts of interest regarding the study.