32534mma1 MammaPrint Identifies Low Risk HER2+ Breast Cancer
We have covered Agendia‘s MammaPrint® DNA microarray test in a February 2007 post. The latest news is that this gene expression profiling test has shown its utility in identifying a subgroup of patients with a good clinical outcome in HER2+ early breast cancer. The identified subtype of patients has an approximate 90% ten year survival rate.
32534mma2 MammaPrint Identifies Low Risk HER2+ Breast Cancer
From the press release issued by Agendia:

Dr. Michael Knauer from the Netherlands Cancer Institute today announced data uncovering a substantial group of traditionally miscategorized low risk HER2+ patients. Agendia’s highly accurate breast cancer tumor recurrence test, MammaPrint(R), was used to differentiate between patients at high and low risk for recurrence.
HER2+ patients are commonly identified as high risk, yet MammaPrint was able to identify a low risk subgroup of HER2+ patients, who subsequently experienced a 10 year disease-free survival of close to 90 percent even in the absence of (neo)adjuvant trastuzumab (Herceptin(R)) and chemotherapy. Additionally, in a subgroup of highly endocrine responsive HER2/NEU positive patients, MammaPrint(R) low risk patients had no relapse.

32534mma3 MammaPrint Identifies Low Risk HER2+ Breast Cancer

The results were presented by Dr. Michael Knauer during the 2008 San Antonio Breast Cancer Symposium (SABCS). In the study population of 169 HER2+ patients MammaPrint(R) classified 16 percent of patients as having a good prognosis signature with a 10-year distant disease-free survival (DDFS) of 89 percent, compared to 84 percent of patients classified as having a poor prognosis signature with a DDFS of 64 percent.
MammaPrint(R)’s robustness is underscored by the 70 gene panel unique to the test and a resulting gene profile that covers all molecular pathways associated with breast cancer. HER2/NEU-overexpression is observed in 15-20 percent of invasive breast cancers and is widely considered to be a negative prognostic factor. As a result, current treatment guidelines classify all HER2-positive breast cancer patients at high risk of relapse, and recommend trastuzumab and chemotherapy.
MammaPrint(R) accurately identified a subgroup of patients with a good clinical outcome in HER2+ early breast cancer. These patients will be further studied in the ongoing MINDACT-trial (Microarray for Node-negative and 1-3 positive node Disease may Avoid ChemoTherapy) to determine the prospects of withholding chemotherapy and/or trastuzumab in HER2+, MammaPrint(R) low risk patients.

Product page: MammaPrint…
Press release: Agendia’s Breast Cancer Test MammaPrint(R) Identifies New Subset of Low Risk HER2+ Patients…