Breast Cancer Index® and Forecasting Risk of Recurrence

If you were recently diagnosed with early-stage hormone receptor-positive (hormone-positive or HR+) breast cancer, understanding the Breast Cancer Index® test can help you and your cancer care team determine if extending hormonal therapy for five additional years (a sum of ten years) would be beneficial. This unique, proprietary genomic test analyzes the activity of eleven genes in your tumor tissue, helping to identify your risk of breast cancer recurrence. With this life-changing knowledge in the palm of your hand, you and your healthcare team can make the right treatment decision.


What Is the Breast Cancer Index® Test®?

The Breast Cancer Index® (BCI), developed by bioTheranostics, is a diagnostic tool that predicts the chances of breast cancer coming back in individuals with early-stage HR+ breast cancer. It examines the levels of two genes in a preserved tissue taken during the initial biopsy or surgery to forecast the likelihood of distant recurrence within 5 to 10 years.

The National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology (NCCN® Guidelines) and the American Society of Clinical Oncology® (ASCO®) recognize The Breast Cancer Index® test for predicting who may reap health rewards from extending adjuvant anti-estrogen therapy after a 5-year period.


Understanding “Adjuvant Anti-Estrogen Therapy”

“Adjuvant anti-estrogen therapy,” “hormone therapy,” and other similar terms are often used interchangeably in the context of breast cancer treatment. Other terminology for this type of therapy include:

  • Endocrine therapy
  • Hormonal therapy
  • Estrogen-blocking therapy
  • Hormone-blocking therapy
  • Selective estrogen receptor modulator (SERM) therapy
  • Aromatase inhibitor therapy
  • Tamoxifen therapy (specifically for tamoxifen use)
  • Fulvestrant therapy (specifically for fulvestrant use)


What Is a Genomic Test?

Genomic testing analyzes the activity of specific genes. The genes’ activity level influences the malignancy’s behavior, including its likelihood of growing and spreading beyond the original cancer site. Genomic tests are groundbreakingly helpful in deciding whether a patient would benefit from additional treatments after a biopsy.

To clarify, genomic testing and genetic testing are not the same, though their names are similar. Medical geneticists conduct genetic testing using a sample of your saliva, blood, or other tissue. They can detect changes (also called mutations) in genes linked to a high cancer risk. Find out more about genetic testing.


How the Breast Cancer Index® Test Works

The BCI test measures the expression of two cancer-related genes, HOXB13 and IL17BR, in the tumor tissue. Higher expression of HOXB13 and lower expression of IL17BR are associated with an increased risk of recurrence. By comparing your gene expression levels to a baseline established in clinical studies, the BCI test generates a risk score to classify whether you have a low, intermediate, or high risk of distant recurrence.

Your BCI prognostic result allows your oncologist to make better-informed decisions about your treatment options, especially regarding extended anti-hormonal therapy. For example, if the BCI risk score categorizes you as high risk, you may benefit most from more endocrine therapy sessions. The test provides an objective measure of recurrence risk that complements traditional clinicopathologic factors to help optimize treatment recommendations for each patient.


Who Should Get the Breast Cancer Index® Test?

Experts recommend that testing remain focused on the following:

Patients Diagnosed with Stage I-III Breast Cancer

Individuals with early-stage breast cancer are the ideal candidates for the Breast Cancer Index® test for three reasons. First, BCI testing helps identify patients with a high risk of recurrence and may benefit from more aggressive treatments. Second, for those found to have a low recurrence risk, the test can help avoid overtreatment and its repercussions. Third, it provides personalized prognosis information to guide treatment decisions and follow-up care plans in the earliest stages, when intervention is most effective.


Patients Diagnosed with Estrogen Receptor-Positive Breast Cancer

The BCI test provides valuable information for those diagnosed with estrogen receptor-positive (ER+) breast cancer. Given that estrogen fuels the growth of ER+ breast cancers, this test helps pinpoint how likely cancer may recur or metastasize over the next ten years based on the tumor’s sensitivity to estrogen.


Patients Diagnosed with Lymph-Node Negative or Positive Disease

For those with lymph node-negative disease, meaning the cancer has not spread to the lymph nodes, BCI testing analyzes genetic markers that indicate the person’s risk of recurrence and metastasis. While many patients with node-negative disease do well, some have aggressive cancers that may recur. BCI testing can help identify these higher-risk patients who may benefit from additional treatment.   

As for patients with lymph node-positive disease, where the cancer has spread to one, two, or three lymph nodes, the BCI test examines similar genetic markers. Patients with node-positive disease are generally considered at higher risk of recurrence. However, BCI testing can further stratify this risk, distinguishing those at very high risk who may need more intensive treatment. Conversely, BCI may show that some node-positive patients have a lower risk profile, avoiding overtreatment.  


Patients Considering Extended Hormonal Therapy

For individuals with ER+ breast cancer considering hormonal therapy beyond the standard five years of tamoxifen, the BCI test can help determine whether one should proceed by providing a more accurate risk assessment. If the risk for late recurrence is low, extended therapy may not be beneficial and only exposes the patient to unnecessary side effects.


Can Men Get the BCI Test?

The Breast Cancer Index® is designed for people diagnosed with ER+ breast cancer, regardless of gender. Therefore, men with ER+ breast cancer can potentially undergo the BCI test to assess their prognosis. However, consulting with healthcare professionals is crucial to ascertain the most appropriate course of action.

The Breast Cancer Index® is a valuable tool for tailoring breast cancer treatment. It helps gain insights into a tumor’s molecular properties, allowing doctors to select therapies targeted to individual cancer characteristics and risk of recurrence. This precision approach to treatment helps ensure optimal care for breast cancer patients.

If you haven’t already, talk to your doctor about BCI testing and what to expect. We live in an age of incredible medical advancements, and one of the most important tools in the war with breast cancer is BCI testing.

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