The American Society of Clinical Oncology (ASCO) has updated its guidelines on using biomarkers to make decisions about systemic therapies after surgery to treat women diagnosed with early-stage invasive breast cancer.
The update was published online on July 10, 2017 by the Journal of Clinical Oncology. Read “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.”
ASCO is a national organization of oncologists and other cancer care providers. ASCO guidelines give doctors recommendations for treatments and testing that are supported by much credible research and experience.
Biomarkers are certain genetic characteristics in cancer cells that can help predict how the cancer will respond to certain treatments. For example, HER2 status is a biomarker. If a cancer is HER2 positive, it’s very likely that the cancer will respond to anti-HER2 medicines. Other biomarkers include estrogen-receptor status, progesterone-receptor status, and BRCA1 and BRCA2 status.
Adjuvant treatments are treatments given after breast cancer surgery to lower the risk of the cancer coming back (recurrence).
Systemic treatments are treatments that involve the entire body, not just the area where the cancer was. Chemotherapy, hormonal therapy, and targeted therapies are systemic therapies.
When a person is diagnosed with breast cancer, doctors do a biopsy and run a number of tests on the tissue removed to determine the characteristics of the cancer, including hormone-receptor and HER2 status. This information helps guide treatment decisions.
The updated ASCO guidelines address using the MammaPrint test to guide decisions about whether or not chemotherapy is needed after surgery.
The MammaPrint test is a genomic test that analyzes the activity of 70 genes in early-stage breast cancer and then calculates a recurrence score that indicates whether the cancer has a high risk or low risk of recurrence. Knowing whether the cancer has a high or low risk of recurrence can help people and their doctors decide if chemotherapy or other treatments to reduce risk after surgery are needed.
The update says:
- People diagnosed with hormone-receptor-positive, HER2-negative breast cancer with no cancer in the lymph nodes, but with clinical characteristics that indicate a high risk of recurrence may use MammaPrint test results to make decisions about chemotherapy after surgery. People diagnosed with the same type of breast cancer but with clinical characteristics that indicate a low risk of recurrence would not benefit from having the MammaPrint test.
- People diagnosed with hormone-receptor-positive, HER2-negative breast cancer with cancer in one to three lymph nodes and clinical characteristics that indicate a high risk of recurrence may use MammaPrint test results to make decisions about chemotherapy after surgery. Still, no matter the MammaPrint results, these people should be told that they are likely to benefit from chemotherapy, especially if the cancer is in more than one lymph node.
- The MammaPrint test should not be used to make decisions about systemic therapy after surgery for people diagnosed with hormone-receptor-positive, HER2-negative breast cancer with cancer in the lymph nodes, but with clinical characteristics that indicate a low risk of recurrence.
- The MammaPrint test should not be used to make decisions about systemic therapy after surgery for people diagnosed with HER2-positive breast cancer or people diagnosed with triple-negative breast cancer (estrogen-receptor-negative, progesterone-receptor-negative, and HER2-negative).
If you’ve been diagnosed with early-stage breast cancer, you and your doctor will consider a number of factors when deciding on treatments. In addition to the biomarkers listed in the ASCO guidelines, you’ll also consider:
- the results of any genetic testing you’ve had
- any treatments you’ve already had
- the type of surgery you had
- your general health
- your personal preferences
For more information, visit the Breastcancer.org Your Diagnosis pages.