Breast Cancer Index Test: A Complete Guide

The Breast Cancer Index (BCI) test is a genomic test that analyzes tumor genes to help guide treatment decisions for women with hormone receptor–positive, early-stage breast cancer. It is especially valuable for predicting whether extending hormonal therapy beyond 5 years can reduce the risk of recurrence.

What Is the Breast Cancer Index Test?

The Breast Cancer Index test, developed by Biotheranostics, evaluates the activity of 11 specific genes in breast cancer tissue.

Key Purposes of the Breast Cancer Index Test

• Prognostic: Measures the likelihood of cancer recurrence 5–10 years after diagnosis.
  
• Predictive: Identifies whether a patient will benefit from extending hormonal therapy to 10 years.
  

How the Breast Cancer Index Works

The test is performed on preserved tumor tissue collected during surgery or biopsy.

The Two Results You Receive

• BCI Prognostic Score
  Provides a percentage risk estimate of late recurrence.
  
• BCI Predictive Result
  A simple “Yes” or “No” answer indicating if prolonged hormonal therapy will be beneficial.
  

What Doctor Performs the Breast Cancer Test?

The oncologist is the doctor who orders and interprets the Breast Cancer Index test, while pathologists and labs handle the technical processing of the tissue.

The Breast Cancer Index (BCI) test is not a procedure that a doctor physically performs on you — instead, it’s a laboratory analysis of tissue that was already collected during your original biopsy or breast surgery.

Who Orders the Breast Cancer Index Test?

• Medical Oncologists
  These are the primary doctors who order the Breast Cancer Index test. They specialize in cancer treatment and are the ones who use the test results to guide decisions about extending hormonal (endocrine) therapy beyond 5 years.
• Breast Surgeons / Surgical Oncologists
  While they don’t usually order the test themselves, they are the ones who originally removed the tumor tissue (biopsy, lumpectomy, mastectomy). The preserved tissue is then stored and can be sent for BCI analysis later.
• Pathologists
  They prepare and maintain the preserved tumor samples. Once a test is ordered, they release the tissue block or slides to the specialized genomic testing lab (Biotheranostics).

Breast Cancer Index Test Chart

Genomic Testing vs. Genetic Testing

It’s important to distinguish between genomic and genetic tests:

• Genomic tests (like BCI) analyze tumor genes to understand cancer behavior.
  
• Genetic tests analyze inherited DNA mutations (e.g., BRCA1/2) that affect cancer risk.
  

Who Is Eligible for the Breast Cancer Index Test?

The BCI test is most commonly recommended for patients who:

• Have early-stage (Stage I–III) breast cancer
  
• Have hormone receptor–positive tumors
  
• Are lymph node–negative, or have limited lymph node involvement (1–3 nodes)
  
• Have already completed 4–5 years of hormonal therapy and are considering extending it
  

Benefits of the Breast Cancer Index Test

Personalized Treatment Decisions

• Avoids unnecessary hormonal therapy in women unlikely to benefit.
  
• Reduces exposure to side effects such as hot flashes, joint pain, and fatigue.
  

Evidence-Based Guidance

• Supported by multiple clinical trials showing accuracy in predicting late recurrence.
  
• Helps physicians tailor treatment rather than relying solely on clinical features.
  

Insurance Coverage and Cost Assistance

• Medicare and major insurance companies typically cover the test.
  
• Biotheranostics provides a Patient Services Team for coverage verification.
  
• Financial assistance programs are available to reduce out-of-pocket costs.
  

Clinical Validation of the Breast Cancer Index

Numerous peer-reviewed studies support the clinical utility of the test.

• BCI has been shown to accurately stratify recurrence risk.
  
• It is endorsed in NCCN Clinical Practice Guidelines for breast cancer.
  

Comparing the Breast Cancer Index to Other Genomic Tests

Oncotype DX, MammaPrint, and Prosigna

• These tests focus on early recurrence (0–5 years).
  
• BCI is unique in its focus on late recurrence (5–10 years).
  

Why BCI Stands Out

• Only test with predictive power for extended hormonal therapy.
  

Step-by-Step Process of Getting the Breast Cancer Index Test

1. Discuss eligibility with your oncologist.
   
2. Tissue sample from prior surgery is retrieved.
   
3. Laboratory analyzes the 11-gene panel.
   
4. Results are sent to your physician.
   
5. Treatment decisions are made collaboratively.
   

Risks and Limitations

• Not useful for triple-negative or HER2-positive breast cancers.
  
• Results must be interpreted in the context of overall health and preferences.
  
• Does not replace standard pathology or clinical judgment.
  

Lifestyle and Next Steps After Testing

Even if the test suggests low benefit from extended therapy, ongoing healthy lifestyle choices—balanced nutrition, regular exercise, and monitoring follow-ups—are critical for reducing recurrence risk.

FAQs About the Breast Cancer Index Test

What does the Breast Cancer Index test measure?

It measures the activity of 11 genes in tumor tissue to predict recurrence risk and assess the benefit of extended hormonal therapy.

How long does it take to get breast cancer test results?

Typically, results are available within 1–2 weeks after the sample reaches the lab.

Is the Breast Cancer Index test covered by insurance?

Yes. Medicare and many private insurers cover the test. Assistance programs exist for patients without coverage.

Who should not take the Breast Cancer Index test?

Women with triple-negative or HER2-positive breast cancer, or those who have not completed at least 4–5 years of hormonal therapy, are not eligible.

Can men with breast cancer take the test?

Currently, the test is validated for women with hormone receptor–positive early-stage breast cancer. Research on male breast cancer is ongoing.

How accurate is the test?

Studies show the Breast Cancer Index is a validated predictor of late recurrence and treatment benefit, making it one of the most reliable tools for long-term treatment decisions.