Core needle biopsy breast cancer testing

Hearing the words “you need a biopsy” or “we found something suspicious” during a clinical breast exam, mammogram, or MRI can stop everything in its tracks. Feeling worried or uncertain in that moment is completely natural. One of the first steps toward clarity is the core needle biopsy—a minimally invasive procedure that provides crucial information about what is happening inside the breast.

Although it may seem like a routine diagnostic procedure, a core needle biopsy holds powerful information that can provide the earliest, most meaningful insights into the biology of a tumor—information that can guide your treatment from the very beginning. Behind every biopsy is a person, and behind every genomic test—MammaPrint® and BluePrint®—is a more personalized path to care.

What the Biopsy Procedure Entails

A core needle biopsy uses a thin, hollow needle to remove small samples of breast tissue. It is not surgery; think of it as a brief tissue sampling procedure to help rule in or rule out breast cancer. Most people feel little to no pain because the breast is numbed with a local anesthetic. The procedure is quick, requires no sedation, and yes—it’s typically an easy in-and-out visit.

Using imaging such as ultrasound, MRI, or stereotactic mammography for guidance, the radiologist guides a needle to the exact spot that needs to be sampled. A spring-loaded device then collects small tissue cores. You may feel pressure or a light pushing and pulling sensation, but it’s generally not painful.

Once the samples are taken, they’re sent to a pathologist for analysis.

The tissue samples collected during a core needle biopsy give the pathologist what they need to evaluate the cells under a microscope—using special stains, measurements, and counts—to assemble a detailed pathology report. From this, they create a detailed pathology report that informs your physician’s early treatment decisions.

A core needle biopsy allows the pathologist to assess:

  • Hormone receptors (ER and PR)
  • HER2 status
  • Tumor type and grade
  • Whether genomic testing is appropriate

This information helps your care team understand how the tumor behaves and what treatments may be most effective.

Why Core Needle Biopsy Matters:

  • It is accurate and minimally invasive.
  • It provides early biological insights—before surgery.
  • It opens the door to additional testing—such as genomic testing with MammaPrint® and BluePrint®—that can provide deeper insight into the tumor biology.

Why Genomic Testing on Core Needle Biopsy Tissue Matters

After the pathologist examines the biopsy for abnormal cells, the same tissue can be sent to Agendia for genomic testing. Here, MammaPrint® and BluePrint® provide a more detailed molecular analysis of the tumor, offering deeper insights into its biology.

At Agendia, our mission is to help physicians choose the right therapy for each patient as early as possible. Genomic testing on core needle biopsy samples supports that mission by offering reliable tumor biology before surgical decisions are made.

Clinical studies show that tests like MammaPrint® and BluePrint® can help determine:

  • Who is likely to benefit from chemotherapy1—or safely avoid it2,3,4
  • Who may respond to therapy before surgery (neoadjuvant therapy)5,6,7,8,9
  • Who may benefit from anthracycline9,10 or immunotherapy11
  • Who may safely adjust hormone therapy duration12,13
  • Whether the tumor has Triple Negative-like characteristics14
  • The tumor’s molecular subtype (Luminal A/B, HER2-type, Basal-like)

Benefits of early genomic testing include:

  • Guiding pre-surgery or therapy decisions before surgery
  • Avoiding delays in treatment planning
  • Supporting personalized, multidisciplinary decision-making

By integrating clinical, pathological, and genomic data early, patients and care teams gain clarity and confidence in choosing the best path forward.

Looking Ahead: A Future Guided by Tumor Biology

As breast cancer care evolves, early biological insight is becoming increasingly important—and the core needle biopsy is a powerful first step. It provides more than answers; it offers direction.

At Agendia, genomic insights from the core needle biopsy help provide every patient with clear, personalized information early in their care journey. Early understanding doesn’t just guide treatment—it brings clarity, confidence, and the courage to move forward with calm and hope.

References:

  1. Brufsky AM et al. JNCI Cancer Spectr. 2025 Sept;1(5):pkaf079.doi: 10.1093/jncics/pkaf079
  2. Cardoso F et al. N Engl J Med. 2016 Aug 25;375(8):717-29.
  3. Piccart M et al. Lancet Oncol. 2021;22(4):476-488.
  4. Lopes-Cardozo J et al. J Clin Oncol. 2022;40(12):1335-1345.
  5. Whitworth P et al. Ann Surg Oncol. 2017 Mar;24(3):669-675
  6. Whitworth P et al. JCO Precis Oncol. 2022 Apr;6(1):e2100463
  7. Whitworth P et al. Ann Surg Oncol. 2022 Apr 4;29(7):4141-4152
  8. Whitworth P et al. JCO Precis Oncol. 2022 Sep:6:e2200197.
  9. Audeh MW et al. 2024. MBCC. Poster #29.
  10. O’Shaughnessy J et al. 2021. ASCO. Abstract #563
  11. Pusztai L et al. 2021. Cancer Cell. Jul 12;39(7):989-998.e5.
  12. Rastogi P et al. J Clin Oncol. 2024;00:1-9.
  13. van ‘t Veer L et al. JAMA Netw Open. 2024. Nov 4;7(11):e2447530.
  14. Groenendijk, F, et al. NPJ Breast Cancer. 2019;5:15.