ASCO: Updated Guidelines on Biomarkers for Early-Stage Breast Cancer

By Lindsay Modglin

• The American Society of Clinical Oncology (ASCO) has released updated guidelines on the use of biomarkers in early-stage breast cancer.
• The new guidelines now recommend the use of Breast Cancer Index (BCI) to assess the risk of breast cancer recurrence in some patients.
• This data-based approach may help doctors better personalize and guide treatment decisions for individuals.

The American Society of Clinical Oncology (ASCO) has released updated guidelines on the use of biomarkers in early-stage breast cancer.

The new guidelines, which were published in the Journal of Clinical Oncology in April, now recommend the use of Breast Cancer Index (BCI) to assess the risk of breast cancer recurrence in some patients. This data-based approach may help doctors better personalize and guide treatment decisions for individuals.

According to the April 25 press release from Hologic (the parent medical technology company that developed BCI), ASCO “now recognizes BCI as the only genomic test to help guide extended endocrine therapy decisions in early-stage, HR+ (hormone receptor-positive) breast cancer patients with node-negative or node-positive (one-three positive nodes) disease when treated with five years of primary endocrine therapy without evidence of recurrence.”

This breakthrough recommendation is based on data from recent clinical trials — including MA-17, aTTom and IDEAL — which prove the use of BCI for predicting the benefit of extended adjuvant endocrine therapy with tamoxifen or aromatase inhibitors (AI). Tamoxifen and AIs are drugs commonly used to stop estrogen from fueling the growth of hormone receptor-positive breast cancers.

What is Breast Cancer Index (BCI)?

Breast Cancer Index™ is “a test that provides individualized information to help patients and their doctors determine the appropriate length of anti-estrogen therapy for early-stage hormone receptor-positive (HR+) breast cancer,” Michelle Garsha, president of diagnostic solutions at Hologic, tells SurvivorNet.

BCI is a microarray-based test that analyzes the expression of 11 genes associated with breast cancer recurrence. According to Garsha, “The test provides two pieces of valuable information to help make a personalized decision,” including:

• A patient’s individual risk of recurrence after 5 years, based on the original tumor biology
• Whether an additional five years of anti-estrogen therapy is likely to help reduce the risk of the cancer returning

The test is used to generate a percentage that reflects the risk of recurrence within five years of diagnosis. It also helps predict the likelihood of benefit from an additional five years of hormonal therapy, giving a yes or no answer for each patient.

Those with a “no” result have a very low risk of recurrence and are unlikely to benefit from extended hormonal therapy, while those with a “yes” result have a higher risk of recurrence and may benefit from the additional treatment. Through testing of the original tumor sample, BCI provides easy-to-understand and actionable information that can help patients and their doctors make more informed decisions about treatment.

BCI to Help Reduce Unnecessary Extended Endocrine Therapy

“While continuing anti-estrogen therapy beyond five years can help some women with HR+, early-stage breast cancer reduce their risk of recurrence, not all women benefit from a full 10 years of treatment,” Garsha explains.

“Longer treatment is also associated with many potential side effects and toxicities that can negatively impact health and quality of life, such as osteoporosis, bone fractures, and joint pain,” she added. “Breast Cancer Index is the only test that can determine whether treatment beyond five years is likely to help a woman reduce her risk of the cancer returning.”

An ongoing Breast Cancer Index (BCI) Registry study is following 3,000 women with stage 1, 2, and 3 breast cancer who have completed four to seven years of primary adjuvant endocrine therapy. The study will help assess the long-term clinical utility of BCI in guiding extended endocrine therapy decisions. The data from this registry aims to provide critical information on how best to use this important technology in real-world clinical practice.

“The BCI Registry study will shed further information on a larger scale to determine the long-term clinical outcome, clinical impact, medication adherence, and quality of life in hormone receptor-positive HR+ early-stage breast cancer patients receiving BCI testing as part of routine clinical care to inform extended endocrine therapy,” says Chaitali Nangia, M.D., Director, Breast Cancer Clinical Research and Co-Director, Cellular Therapy Program at Hoag Hospital.

“It will give us more real-world experience data as to how exactly our women do,” Dr. Nangia adds. These different facets of data are critical, not just from a clinical outcome perspective, but from a quality of life perspective as well. In the meantime, BCI is already helping spare many women from unnecessary extended endocrine therapy and its potential side effects—a true personalized medicine success story.

Continued Hope For Those With Breast Cancer

As more research is done and data is collected, doctors and patients alike have access to a growing body of evidence that can help guide decision-making around treatment.

“Most HR + breast cancer patients are offered 5 years of adjuvant endocrine therapy. Until now, health care providers have been challenged to determine treatment duration decisions,” explains Dr. Nangia. “This gives a more personalized approach to determine who of these patients are at high risk of recurrence from years 5 to 10 and would thus benefit specifically from the extension of endocrine therapy beyond 5 years.”

According to Dr. Nangia, having the ability to avoid unnecessary side effects and toxicities is a major step forward in the breast cancer treatment. “This genomic testing helps identify patients that would benefit from an extension of adjuvant treatment—but even more importantly—patients who would not benefit from extending estrogen therapy beyond 5 years and thus spare them the toxicity of additional treatment.”

And while Dr. Nangia notes there is still more work to be done in terms of research and data collection for other individuals with HR+ breast cancer, including those with 4 or greater positive nodes, she is hopeful for the future of treatment.

New Recommendations Are Expected to Positively Influence Clinical Practice

The updated ASCO guidelines are expected to have a significant impact on the clinical management of early-stage breast cancer. BCI is the only genomic test that currently predicts the risk of recurrence in patients with HR+ breast cancer who are treated with primary endocrine therapy.

“The clinical decision to either extend or end adjuvant endocrine (or anti-estrogen) therapy after 5 years is a challenging decision for doctors and their patients,” Garsha says. “Having an extensive body of clinical evidence supporting the ability of BCI to predict which patients are likely to benefit from longer treatment, and its recognition by major oncology clinical guidelines like those from ASCO further underscores the test’s value in clinical decision-making regarding extension of adjuvant endocrine therapy.”

According to the updated ASCO guideline, BCI is now recommended to help guide therapy in patients who:

• Are postmenopausal or age > 50 years with early-stage estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative (ER1 and HER2-) breast cancer that is node-negative or with 1-3 positive nodes
• Are postmenopausal patients with node-negative ER1 and HER2- breast cancer
• With 0-3 positive nodes who received five years of endocrine therapy without evidence of recurrence to guide decisions about extended endocrine therapy

In the meantime, the new guidelines provide much-needed clarity on the appropriate use of BCI. With these recommendations, we now have a data-based approach to help optimize treatment and reduce unnecessary side effects in many women facing a breast cancer diagnosis.

“We’re hopeful that with this data and additional guideline recognition, that more doctors continue to use BCI for their breast cancer patients to individualize treatment decisions and ensure patients receive the right length of treatment for them,” Garsha concludes.

Dr. Nangia adds, “Some important takeaways are that some of our HR + patients (not all) are at higher late-term ( >5 years) risk of breast cancer recurrence. We now have a data driven genomic tool that can help us identify these patients and offer extension of estrogen therapy in an individualized treatment approach.”

BCI is currently available through Biotheranostics’ CLIA-certified and CAP-accredited laboratory. It’s covered by Medicare and many private insurers. For more information on BCI, visit www.breastcancerindex.com.