Mammaprint Validation

MammaPrint has Extensive International Clinical Validation


MammaPrint has been independently validated in studies on over 2,375 breast cancer patients, with results published in leading peer reviewed medical and scientific journals.


The first validation for MammaPrint, published in the New England Journal of Medicine, was undertaken in a series of 295 consecutive women with breast cancer. The proportion of patients who remained free from distant metastases at ten years was 87% in the low risk group and 44% in the high risk group.  The profile was a statistically independent predictor and added to the power of standard clinico-pathologic parameters; HR = 4.6 (95% CI 2.3 - 9.2).(4)


Another independent validation study of 302 adjuvantly untreated patients with at least ten years of follow-up, published in the Journal of the National Cancer Institute, was performed by the TRANSBIG Consortium. The proportion of patients who remained free from distant metastases at 10 years was 90% in the low risk group and 71% in the high risk group. MammaPrint was found to provide prognostic information beyond what could be determined from patient age, tumor grade, tumor size, and ER status in a population of LN0 patients, none of whom received any adjuvant chemotherapy.(3)


Additional studies have been published in Lancet Oncology,(8) Breast Cancer Treatment and Research(9) and Clinical Cancer Research(10) in which the MammaPrint results were further validated. One study revealed that MammaPrint validates in older American breast cancer patients studied at Massachusetts General Hospital.(10) While another study demonstrated that MammaPrint has strong prognostic value in patients with 1-3 positive lymph nodes.(11)


With more than 14,000 patient results reported to date, the technical robustness and reliability of MammaPrint is well established. MammaPrint is a considerable step forward in the advancement of personalized cancer treatment –aiding treating physicians make more informed, individualized treatment decisions.



3)   Buyse M, Loi S, Van’t Veer L, et. al., J Natl Cancer Inst 2006; 98(17):1183-1192

4)   van de Vijver MJ, He YD, van’t Veer LJ, et. al.,New Engl J Med 2002; 347(25):1999-2009

8)   Bueno-de-Mesquita J, van Harten WH, Petel VP, et. al., Lancet Oncology 2007; 8(12): 1079-87

9)   Bueno-de-Mesquita JM, Linn SC, Keijzer R, et. al., Breast Cancer Research 2008; Sept 26

10) Wittner BS, Sgroi, DC, Ryan PD, et. al., Clinical Cancer Research 2008; 14(10): 2988-2993

11) Mook S, Schmidt MK,Viale G, et. al., Breast Cancer Res Treat, 2008; July 27


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