MammaPrint

MammaPrint is the commercial product, marketed by Agendia, based on the well-known Amsterdam 70-gene breast cancer gene signature as published by van 't Veer et al in Nature 2002. In February, 2007 the FDA cleared the MammaPrint test for marketing in the U.S. for node negative women under 61 years of age with tumors of less than 5cm. MammaPrint is a microarray analysis and the result classifies analyzed tumors as low or righ risk for recurrence of the disease.

Clinical validation
There have been four papers validating and testing the use of the 70-gene profile in clinical conditions. This table was edited from a submission by Agendia, the corporation that performs the MammaPrint assay, to the US FDA.

So far, there are no clinical trials assessing the utility of adjuvant therapy in high risk versus low-risk individuals. This means that the MammaPrint is prognostic not predictive. From another perspective, since so few of the patients got adjuvant chemotherapy in the study, researchers cannot conclude that the high-risk patients would be more likely than the low-risk patients to benefit from chemotherapy.

Sampling technique
Unlike the Oncotype-DX assay, MammaPrint works on fresh tissue specimen collected in a special container. A tumor sample must be taken with a company-provided punch from an unfixed tumor specimen within an hour of surgery. The sample is then placed in a company-provided container, which is then shipped to Agendia. The whole process alters the surgical technique, since in many cases, tissue is immediately placed in formalin for processing in the pathology laboratory.

Cost
The cost of the assay is $3,200, as reported in an Agendia press release.