How Triple-Negative Breast Cancer Is Diagnosed

Results from a breast biopsy play a crucial role

Triple-negative breast cancer is diagnosed through hormone receptor and HER2/neu testing of a biopsy sample.

Diagnosing triple-negative breast cancer doesn’t take additional time compared to other forms of breast cancer. What can cause a delay in diagnosis is a lapse in awareness, whether it be neglecting self-checks, physical examinations, or frequent mammograms, depending on your age.

diagnosing triple-negative breast cancer

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One of the most effective ways to detect triple-negative breast cancer early is to get in the habit of doing regular breast self-exams at home. While research has been conflicting over the years as to whether or not self-exams have proven effective enough to be part of a breast cancer screening schedule (and because of this, the American Cancer Society does not recommend regular breast self-exams) it’s important to be familiar with how your breasts look and feel so that you can report any changes to your healthcare provider.

Breasts can be naturally lumpy due to tissue buildup, benign conditions, or hormone fluctuations (particularly during the week of your menstrual cycle) and giving yourself a self-exam at least once a month will help you distinguish between what feels normal for your breasts and what does not. When done combined with other screening tools (like a mammogram), a self-exam may spark you to mention any concerns to your healthcare provider, which could lead to an earlier triple-negative breast cancer diagnosis.

When performing a self-exam, it’s important to keep in mind:

  • The time of month you’re doing the exam. If you still have a menstrual cycle, do your exam several days after it ends, when your hormones have balanced out.
  • Some lumps may be normal. Different areas of the breast and armpit may have lumps or small bumps that are benign. If you’re concerned it’s always worth a mention to your healthcare provider but keep in mind that not all lumps may be directly linked to triple-negative breast cancer.
  • Don’t forget to check your nipples. Make note if there are any indents, bumps, or discharge.

Physical Examination

While the American Cancer Society puts clinical exams and self-exams in the same category, no longer recommending them for breast cancer screening protocols, this doesn’t mean these tests shouldn’t be done. In fact, most healthcare providers will still give you a clinical breast exam, especially if you are in your 20s or 30s. Your family healthcare provider or gynecologist may perform a clinical exam during your next visit, and this is essentially the same steps that you’ll take if you do a self-exam at home. If they don’t do one and you’d like them to, it’s important to let them know that during your visit as well as ask them about any concerns you may have about your breast health.


Whether you’ve made an appointment with your healthcare provider because you’re concerned about a lump you may have found during a self-exam, or your healthcare provider has recommended additional testing after a clinical exam, there are a number of labs and tests used to diagnose all breast cancers, including triple-negative breast cancer.

The usual order of labs and tests to diagnosis triple-negative breast cancer are:

  • Diagnostic mammograms: Different from screening mammograms, which are routinely given to women in their 40s, a diagnostic mammogram will give a more detailed X-ray of what’s going on in the breast, showing multiple views as well as the ability to zoom in on an the area of the breast in question to see if any abnormalities are present and what exactly they are.
  • Ultrasound: If you are under 30 years old, pregnant, or breastfeeding, your healthcare provider may recommend an ultrasound to examine any breast lumps, which will show if any masses are present in the breasts and whether they appear solid or liquid-filled. Ultrasounds are also given after a screening mammogram that shows masses in the breast.
  • Magnetic resonance imaging (MRI): A healthcare provider may recommend an MRI to get an idea of the extent of the condition. This test will show a detailed view of the breast tissue, helping your healthcare provider get an idea of what (if any) tissue areas are diseased.

Labs and Tests

Depending on the results from a patient’s imaging, a healthcare provider may recommend a biopsy of the breast area as a next step. A biopsy is the only test that can definitively determine if the abnormal area in the breast is cancerous and if it is triple-negative breast cancer.

To do a biopsy, tissues or fluid are removed from the breast area and examined under a microscope. Removal is done by three common procedures depending on the patient’s breast mass size, density, and location: fine-needle aspiration, core needle biopsy, and surgical biopsy. In some cases, a healthcare provider may choose to do a fine-needle or core biopsy and then later a surgical biopsy in the event cancer cells are found to determine the type and stage of breast cancer.

If a patient’s biopsy comes back positive, the next step is to test for hormone receptors. The test is done on tissue from a biopsy using a procedure called immunohistochemical staining and this will show if a patient’s breast cancer is progesterone receptor-positive, estrogen receptor-positive, or neither. The second test will be a HER2/neu test that will look at the breast tissue, or possibly a blood draw to determine if the sample is HER2 positive, meaning the cancer may have a large amount of protein genes that will make the cancer grow and spread more rapidly.

If both the hormone receptor test and the HER2/neu test all come back negative, this is what becomes diagnosed as triple-negative breast cancer, which will affect the treatment plan a patient and healthcare provider will discuss.

Differential Diagnoses

There are many benign breast conditions that do not turn into triple-negative breast cancer. These include:

While these conditions may not increase your risk of developing triple-negative (or any) breast cancer, they don’t decrease your overall risk of developing breast cancer (one in eight women in the U.S.), so it’s important to stay on top of your breast screening schedule even after discovering a benign breast cancer condition.

A Word From Verywell

Feeling a lump in your breast can be distressing, but it’s important to keep in mind that 80% of women who have a breast biopsy do not have breast cancer. And while it’s impossible to determine if you have triple-negative breast cancer without getting the appropriate tests, making sure you get the required imaging you need first to help determine what tests are appropriate for diagnosis can make all the difference when it comes to diagnosis and treatment. Have peace of mind knowing that breast lumps can be a normal part of tissue makeup but stay vigilant enough to notice any differences in your breast as well as getting the appropriate screenings and checks to keep your breasts healthy.

Frequently Asked Questions

  • Who's most at risk for triple-negative breast cancer?

    Triple-negative breast cancer is diagnosed most often in people who:

    • Are relatively young (under 50)
    • Are Black or Hispanic
    • Have inherited the BRCA1 mutation, who make up around 70% of people diagnosed with TNBC
  • What are the signs and symptoms of triple-negative breast cancer?

    Although it's more aggressive than most other types of breast cancer, the symptoms of TNBC are the same, with the most common being a new lump, mass, or growth in the breast. Other symptoms of breast cancer include:

    • Swelling of the breast, even if there's no distinct lump
    • Skin changes, such as dimpling (an orange peel-like textures), or redness, dryness, flaking, or thickening that can affect nipples as well
    • Pain in the breast or nipple
    • Nipple changes, including inversion (turning inward) and/or a discharge that isn't breast milk
    • Swollen lymph nodes (which sometimes can occur before a lump can be felt)
  • Where does triple-negative breast cancer tend to spread?

    Studies show the most common sites of metastatic TNBC are the brain and lungs, followed by the bones and liver. Because it's so aggressive, triple-negative breast cancer is more likely to metastasize than other types of breast cancer, although the risk is relatively low five years after diagnosis and treatment.

  • What is the prognosis for triple-negative breast cancer?

    According to the National Cancer Institute, the relative survival rate for someone with TNBC is:

    • 91% if the cancer has not spread beyond the original site in the breast (localized)
    • 65% if the cancer has spread to nearby tissues or lymph nodes (regional)
    • 12% if the cancer has spread to the distant parts of the body (distant)
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Cancer Society. American Cancer Society Recommendations for the Early Detection of Breast Cancer.

  2. American Cancer Society. American Cancer Society Recommendations for the Early Detection of Breast Cancer.

  3. Risk of Developing Breast Cancer.

  4. National Breast Cancer Foundation, Inc. Biopsy.

  5. Triple-negative breast cancer.

  6. American Cancer Society. Breast cancer signs and symptoms.

  7. Pogoda K, Niwińska A, Murawska M, et al. Analysis of pattern, time and risk factors influencing recurrence in triple-negative breast cancer patientsMed Oncol. 30(1):388. doi:10.1007/s12032-012-0388-4

  8. American Cancer Society. Triple-negative breast cancer.

Additional Reading

By Colleen Travers
Colleen Travers writes about health, fitness, travel, parenting, and women’s lifestyle for various publications and brands.