Over the past decade, our tests have been evaluated through extensive clinical trials and research collaborations resulting in hundreds of publications that demonstrate the prognostic ability and clinical utility of MammaPrint and BluePrint.
MammaPrint is supported by the highest level of clinical evidence (level 1A) from MINDACT,1 a landmark independent trial published in the New England Journal of Medicine in 2016.
MINDACT stands for Microarray In Node-negative (or 1-3 positive lymph node) Disease may Avoid ChemoTherapy. It was a phase III, prospective, randomized, clinical study for a breast cancer recurrence test.
The trial investigated the clinical utility of MammaPrint, when compared to (or used along with) standard pathological criteria for the selection of patients unlikely to benefit from adjuvant chemotherapy.
Participants were categorized as low or high risk for cancer recurrence in two ways: first, through analysis of tumor tissue using MammaPrint; and second, using Adjuvant! Online, a tool which calculates risk of breast cancer recurrence based on common clinicopathological factors.
Patients characterized as low risk with both clinical and genomic assessments were spared chemotherapy, while patients characterized as high risk with both were advised to undergo chemotherapy. Those with discordant results were randomized to use either clinical or genomic (MammaPrint) risk evaluation to decide on chemotherapy treatment.
of MINDACT clinically high risk patients were reclassified as genomically low risk by MammaPrint and therefore could be spared adjuvant chemotherapy
for clinically high risk patients who were reclassified by MammaPrint as genomically low risk, 95% were free of distant metastasis* at 5 years without chemotherapy
for patients who were high clinical risk but MammaPrint low risk with 1-3 involved lymph nodes, 96% were free of distant metastasis* at 5 years without chemotherapy
In 2015, PROMIS2 (Prospective Study of MammaPrint in Breast Cancer Patients with an Intermediate Recurrence Score) evaluated 840 patients with early-stage breast cancer who had received an “intermediate” recurrence result from the Oncotype DX genomic test. The aim was to assess the change in physician treatment decisions after receiving a MammaPrint result.
In a study3 published in 2017, MammaPrint was used to analyze 652 patient samples with 20-year follow-up data from the prospective,† randomized‡ Stockholm Tamoxifen Trial.
It demonstrated that a new MammaPrint threshold could identify a subgroup of patients with exceedingly low risk of cancer recurrence 20 years after diagnosis (Late Recurrence (20yr) Low Risk).
These patients, most of whom received only two years of treatment with tamoxifen, had an observed 20-year breast cancer specific survival of 97%. Patients with a Late Recurrence (20yr) Low Risk result who did not receive any treatment post-surgery (neither chemotherapy nor hormone therapy) had a 94% breast cancer specific survival rate.
This information can be helpful to physicians in deciding whether to recommend extended, standard, or limited hormone therapy for certain patients. It gives both physicians and their patients more options for better management of the disease.
Note: Access to the STO trial results requires a paid subscription to JAMA or OpenAthens or Shibboleth. For more information about the trial, please contact us via email at [email protected].
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*The time to appearance of distant metastasis. A distant metastasis refers to cancer that has spread from the original tumor to distant organs.
†Prospective refers to when patients are recruited to a clinical study and followed forward in time.
‡Randomization is a procedure to allocate clinical study participants into different groups. By using chance to allocate participants, the groups are likely to be similar and allow the effects of the treatments to be compared more fairly.
1 Cardoso F, van’t Veer LJ, Bogaerts J, et al. 70-Gene Signature as an Aid to Treatment Decisions in Early-Stage Breast Cancer. N Engl J Med. 2016; 375(8):717-29
2 Tsai M, Lo S, Audeh W, et al. Association of 70-Gene Signature Assay Findings With Physicians’ Treatment Guidance for Patients With Early Breast Cancer Classified as Intermediate Risk by the 21-Gene Assay. JAMA Oncol. 2018; 4(1):e173470
3 Esserman LJ, Yau C, Thompson CK, et al. Use of Molecular Tools to Identify Patients With Indolent Breast Cancers With Ultralow Risk Over 2 Decades. JAMA Oncol. 2017; 3(11):1503-1510