ASCO Expert Panels are creating updated and initial guidelines for managing breast cancer. The Society is developing two updates on biomarkers shown to help guide decisions about various therapies for patients with metastatic and early-stage invasive breast cancer.
A third guideline represents initial recommendations on the use of endocrine therapy for women with hormone receptor–positive metastatic breast cancer. About 75% of metastatic breast cancers are estrogen receptor–positive. Although hormone therapy has long been a component of treatment for these patients, only recently have important advances been made in treatment options.
Biomarkers for Adjuvant and Metastatic Breast Cancer
Whereas the previous 2007 guideline on the use of biomarkers in breast cancer made recommendations for breast cancer both overall and involving many stages of clinical care, the current update will be split into two separate guidelines.
One guideline will focus on early-stage invasive breast cancer and the other on metastatic disease.
“It’s appropriate in my mind to separate the two because the biomarker evaluation is done in the context of the clinical situation,” said Catherine Hall Van Poznak, MD, of the University of Michigan Health System and co-chair of the metastatic breast cancer guideline along with Lyndsay Harris, MD, of Case Western Reserve University School of Medicine.
An ASCO Expert Panel performed a systematic review of blood and tissue biomarkers, including novel biomarkers, HER2, estrogen receptor (ER), and progesterone receptor (PgR), for their utility in making decisions about systemic therapy.
The metastatic breast cancer guideline, expected to be published this year, discusses testing tumor biomarkers in the initial tumor and in the metastatic lesion. The guideline will not include recommendations about the type of therapy patients should receive based on biomarker status.
“I hope that this guideline will aid in the efficient use of biomarkers that have shown clinical utility and will spur research to continue identifying biomarkers to improve patient care,” Dr. Van Poznak said.
The panel for the guideline on early-stage invasive breast cancer is studying a set of 11 tumor and blood biomarkers other than HER2, ER, and PgR. The guideline will make recommendations on biomarkers that could guide clinician decisions on adjuvant systemic therapy and choice of appropriate specific treatments or regimens.
Publication of that guideline is expected this summer.
Endocrine Therapy in HR–Positive Metastatic Breast Cancer
ASCO is in the final stages of developing the inaugural guideline on the use of endocrine therapy for women with hormone receptor–positive metastatic breast cancer.
The guideline will make recommendations on the types of appropriate therapy for premenopausal and postmenopausal women, as well as for women who are HER2-positive. Therapies include aromatase inhibitors, anti-estrogen drugs, drugs that suppress ovarian function, hormones, and pathway-targeting drugs.
“This guideline is particularly important because hormone receptor–positive breast cancer is the most common subtype of this disease in both the early and late stages,” said Hope S. Rugo, MD, of the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center, co-chair of the guideline along with Harold J. Burstein, MD, PhD, FASCO, of the Dana-Farber Cancer Institute and Harvard Medical School. “We need a guideline to discuss how hormone therapy should be used, when to employ novel agents, and the sequence of hormone therapy.”
“It’s really very timely to do a broad survey of the appropriate agents and strategies for treating the most common kind of metastatic breast cancer,” Dr. Burstein said. “There are more agents than ever available, and there are emerging data that there are survival advantages with older drugs.”
The guideline will also make recommendations concerning the type and sequence, whether before or after chemotherapy, of hormone therapy in patients with immediately life-threatening metastatic breast cancer.
The panel considered the findings of seven systematic reviews and 25 randomized trials in creating the guideline, which is also scheduled for publication this year.