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This study is about:
The use of MammaPrint to guide treatment decisions on the use of adjuvant chemotherapy for patients with early-stage invasive breast cancer.
The "Microarray in Node-Negative and 1 to 3 Positive Lymph Node Disease May Avoid Chemotherapy" (MINDACT) is a study that looked at almost 7,000 European women with early-stage invasive breast cancer. Researchers compared participants’ risk of recurrence using two separate means:
- Clinical risk of recurrence using a program called Adjuvant! Online
- Genomic risk of recurrence to determine risk for recurrence using MammaPrint—a tumor genomic test that looked at 70 genes within the tumor tissue.
Participants with discordant clinical and genomic risk (either high clinical risk and low genomic risk or low clinical risk and high genomic risk) were randomly assigned to have chemotherapy or not. Results from the MINDACT study published August 2016 in the New England Journal of Medicine showed that 94.7% of patients with high clinical risk but low genomic risk as assessed by MammaPrint who did not receive chemotherapy were alive without distant metastasis at 5 years. This is 1.5% fewer than the number of similar patients who received chemotherapy, demonstrating that chemotherapy does not provide benefit for the vast majority of these patients.
Why is this study important?
Reducing overtreatment in patients with early-stage breast cancer is important. Based on the results of the MINDACT trial, the American Society of Clinical Oncology (ASCO) recently updated their Clinical Practice Guidelines. While ASCO guidelines are regularly updated, guidelines are also revised when new, potentially practice-changing data is published. In August, 2017 ASCO updated it guidelines on the use of MammaPrint to help early-stage invasive breast cancer patients and health care providers to decide which women can forgo adjuvant chemotherapy based on the MINDACT trial results.
The MINDACT study showed that the MammaPrint test could predict which patients will have a favorable prognosis without adjuvant chemotherapy.
What does this mean for me?
ASCO now recommends that MammaPrint may be used to help clinicians identify which early-stage invasive breast cancer patients may have limited benefit from adjuvant chemotherapy.
The MammaPrint test is appropriate for patients with hormone receptor-positive (ER–positive and PR-positive) HER2-negative breast cancer with 0-3 positive lymph nodes for whom Adjuvant! Online predicts a high clinical risk. However, no test is perfect. Some patients in the MINDACT study developed recurrent disease, even though MammaPrint testing suggested otherwise; other patients with poor MammaPrint scores remain disease free, even without chemotherapy.
If you have recently been diagnosed with early-stage invasive breast cancer, your physician may recommend the MammaPrint test. Based on the results, you may choose to forego adjuvant chemotherapy.
This article is relevant for:
Women diagnosed with ER-positive, Her2-negative early-stage breast cancer with 0-3 positive nodes
This article is also relevant for:
Breast cancer survivors
Women under 45
Women over 45
Be part of XRAY:
- What is a genomic test versus a genetic test?
- What exactly is MammaPrint?
- Are you aware of the updated ASCO guidelines on using MammaPrint to guide adjuvant treatment?
- Is MammaPrint a test I should consider based on my diagnosis and stage of breast cancer?
- What costs are associated with MammaPrint testing? Will my insurance cover it?
- What are the risks of overtreating my cancer? What are the risks of undertreating it?
- Does my MammaPrint score agree with my clinical risk score?
The following study is looking at tumor prognostic tests used for decision-making in early-stage breast cancer:
- NCT03053193: MammaPrint, BluePrint, and Full-genome Data Linked With Clinical Data to Evaluate New Gene EXpression Profiles (FLEX). The FLEX Registry is a large-scale, population based, prospective registry. All patients with stage I to III breast cancer who receive MammaPrint® and BluePrint testing on a primary breast tumor are eligible for entry into the FLEX Registry.
Who covered this study?
ASCO panel backs gene assay for breast cancer This article rates 4.5 out of 5 stars
Agendia’s MammaPrint® recommended by ASCO breast cancer guideline in focused update based on landmark MINDACT Trial data This article rates 3.0 out of 5 stars
CBS SF Bay Area
MammaPrint identifies breast cancer patients who can skip chemotherapy This article rates 1.5 out of 5 stars
IN-DEPTH REVIEW OF RESEARCH
From 2001 to 2007 researchers organized a large randomized trial in Europe to see whether a commercial genomic tumor test called MammaPrint could reduce overtreatment with chemotherapy in patients with early-stage invasive breast cancer. More than 6,600 women participated at 112 institutions in 9 nations. Each participant’s clinical risk of cancer recurrence was determined using a web-based tool called Adjuvant! Online. Patient’s tumors were also tested using MammaPrint, which produced a genomic score. Participants with discordant clinical and genomic risk (either high clinical risk and low genomic risk or low clinical risk and high genomic risk) were randomly assigned to receive adjuvant chemotherapy or not. The results, which were published in the New England Journal of Medicine in August 2016, suggest that approximately 46% of women with breast cancer who are at high clinical risk for recurrence might not benefit from adjuvant chemotherapy. As a result, ASCO updated guidelines on the use of MammaPrint to guide decisions on the use of adjuvant chemotherapy in an ASCO Special Article published in the Journal of Clinical Oncology in August, 2017.
Researchers of this study wanted to know:
Can MammaPrint, a commercially available genomic test, help to reduce overtreatment in patients with early-stage breast cancer?
Population(s) looked at in the study:
MINDACT was a randomized trial that looked at 6,693 women with operable invasive breast cancer, 0 to 3 positive lymph nodes, and no distant metastases. Eligible patients were women between the ages of 18 and 70. Initially, only patients with node-negative disease were enrolled; however, the study was later amended in 2009 to include women with 1 to 3 positive nodes. Researchers determined participants’ clinical risk (using a modified version of Adjuvant! Online), genomic risk (using MammaPrint) and tumor samples.
The patients were divided into 4 main groups according to their clinical and genomic risk, and received either adjuvant chemotherapy or no therapy:
- Low clinical risk and low genomic risk: 2,745 patients (41.0%)
- No adjuvant therapy
- Low clinical risk and high genomic risk: 592 patients (8.8%)
- Randomized to chemotherapy or no chemotherapy
- High clinical risk and low genomic risk: 1,550 patients (23.2%)
- Randomized to chemotherapy or no chemotherapy
- High clinical risk and high genomic risk: 1,806 patients (27.0%)
- Adjuvant chemotherapy
Among women with early-stage breast cancer who were at high clinical risk and low genomic risk for recurrence and did not receive chemotherapy, the 5-year survival rate was 94.7%; the survival rate for those who did receive chemotherapy was 96.2%. This difference of 1.5 percentage points suggests that approximately 46% of women with early-stage invasive breast cancer who are at high clinical risk and low genomic risk do not receive benefit from adjuvant chemotherapy.
ASCO used the results of the MINDACT trial to revise its clinical guidelines regarding the use of MammaPrint for decision making regarding use of adjuvant chemotherapy for patients with early-stage invasive breast cancer. MammaPrint may inform patients with ER-positive or PR-positive, HER2-negative breast cancer and 0-3 positive lymph nodes and their clinicians whether or not to forego adjuvant chemotherapy. Although MammaPrint can be used to identify patients with high clinical risk who may receive limited benefit from chemotherapy, women with low clinical risk of recurrence did not benefit from chemotherapy, regardless of their MammaPrint risk group. Thus, ASCO does not recommend the use of MammaPrint for patients with low clinical risk.
Krop I, Ismaila N, Andre F, et al. “Use of Biomarkers to Guide Decisions on Adjuvant Systemic Therapy for Women With Early-Stage Invasive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Focused Update.” Journal of Clinical Oncology 35, no. 24 (August 2017) 2838-2847.
Harris L, Ismaila N, McShane L, et. al. "Use of Biomarkers to Guide Decisions on Adjuvant Systemic Therapy for Women With Early-Stage Invasive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline." Journal of Clinical Oncology 34, no. 10 (April 2016) 1134-1150.
Cardosa F, Van t’ veer LJ, Boegerts J, et al. “70-Gene Signature as an Aid to Treatment Decisions in Early-Stage Breast Cancer.” New England Journal of Medicine 2016; 375:717-729 August 25, 2016