How Breast Cancer Is Diagnosed

A breast cancer diagnosis often starts with a mammogram. If something suspicious shows up, your doctor will likely start you down a multi-step process for diagnosing or ruling out breast cancer. That involves clinical evaluation, imaging tests, and biopsy procedures.

Breast cancer can be diagnosed long before symptoms occur. Breast self-checks, your doctor's clinical examinations, and yearly mammograms are diagnostic screening tools that can detect early-stage disease.

If you develop symptoms of breast cancer, you should seek medical attention. Earlier-stage breast cancer is typically more easily treated and has a better outcome than later-stage breast cancer.

breast cancer diagnosis
 Verywell / Gary Ferster

Self-Checks

Breast cancer can produce changes in the appearance or texture of your breast. Women (and men) need to pay attention to any variations, which can include:

  • Discoloration
  • A visible or palpable lump
  • Nipple discharge
  • Bleeding
  • Breast pain (rare)

You may be able to feel lumps and growths with your fingers even if they don't produce visible changes in your breasts. Although self checks are not recommend as a screen for breast cancer, regular breast exam by a health care provider may be important for women at higher risk for breast cancer.

Physical Examination

During your annual physical, your physician will typically conduct a clinical breast exam to identify lumps or variations in your breasts. They will also perform this test if you come in with symptoms that could indicate breast cancer.

Your doctor will ask you about any changes you may have noticed, such as marks on your skin or an inverted nipple. If these are congenital (meaning you've had them since birth), then they aren't necessarily concerning, even if they're unusual. Your doctor may note congenital breast abnormalities in your chart so that your medical team will be aware of them and follow up on any changes.

If you have dense or large breasts, it may be difficult for your doctor to feel small lumps during an examination.

Labs and Tests

If you have one or more lumps, your doctor will recommend further testing. In some cases, your doctor may order bloodwork, but this is more common with other types of cancer. When breast cancer is suspected, diagnosis is typically done via imaging and biopsy.

Imaging

A mammogram is an X-ray image of the breast. It's a key screening tool that can detect breast cancer up to two years before it can be felt by physical examination. Screening mammograms are recommended yearly for women over the age of 45, and sometimes for younger women or men who have a high risk of breast cancer.

Mammograms can visualize benign (non-cancerous) breast conditions and breast cancer, but they can't always verify the difference.

A few other imaging tests are also used in breast cancer diagnosis. While these techniques can help with diagnosing breast cancer, a biopsy is the only test that can confirm the disease.

Diagnostic Mammogram

While a screening mammogram looks at the whole breast, a diagnostic mammogram generally examines one section in greater detail, usually by getting more images of a small area to visualize it better. You might have a diagnostic mammogram if your doctor is concerned about something on your screening mammogram.

Ultrasound

Breast ultrasound creates images of the breast using sound waves. Sometimes used as a follow-up test after a mammogram with an abnormal finding, a breast ultrasound can help differentiate between a liquid-filled cyst and a solid mass, such as a tumor.

Breast Magnetic Resonance Imaging (MRI)

Breast MRI uses magnetic fields to create an image of the breast. It may be recommended to aid diagnosis in some instances, but it is not used in all situations. In addition, it's not as effective as a mammogram for many breast conditions.

Biopsy Procedures

During a breast biopsy, a small tissue sample is removed from an area of concern in the breast. A pathologist then examines the tissue under a microscope. Some molecular characteristics are tested as well.

Several biopsy types and methods are used to diagnose breast cancer. These procedures generally involve numbing the skin around the area, and you may need a few stitches after your procedure. You might experience mild pain for a few days after a breast biopsy, but most women do not experience any pain or adverse effects after that.

It's important to note that while the presence of breast cancer cells in a biopsy sample provides a definitive diagnosis of breast cancer, you may still have the disease even if no cells were found.

Fine-Needle Aspiration (FNA)

During fine-needle aspiration, a small amount of tissue is taken from the suspicious area using a thin needle attached to a syringe. If the sample turns out to be a cyst, the fluid can be drained. If the sample contains cancerous cells, you may need to have a larger biopsy, and you will most likely need to have your breast cancer surgically removed.

Core Needle Biopsy

A large hollow needle withdraws tissue from the suspicious area in the breast, providing a larger sample than a fine needle aspiration.

Stereotactic Core Needle Biopsy

X-ray equipment and a computer analyze pictures of the breast. The computer helps direct the needle to the exact location that requires biopsy.

MRI-Guided Biopsies

These are used for women with a suspicious area that can only be found by MRI.

Vacuum-Assisted Core Biopsy

A small incision is made and a tissue sample removed with the assistance of suctioning pressure.

Excisional Biopsy

The entire area of abnormality is removed. This is particularly common if the mass is small.

Lymph Node Biopsy

If breast cancer might have metastasized (spread beyond your breast), your surgeon may also take a sample of tissue from the lymph nodes underneath your arm. This sample will be examined to see if it contains breast cancer cells, which is evidence of metastatic breast cancer.

Staging and Grading

A pathology evaluation will detect the absence or presence of breast cancer in your biopsy sample.

The pathology report will describe the type of breast cancer and its characteristics, such as:

  • Whether it's invasive or noninvasive
  • Size
  • Growth rate
  • Hormone and genetic status
  • Other factors that will influence treatment planning

When test results are completed and reviewed, your doctor will determine the grade and stage of your cancer, if present.

Staging is the process of determining the spread of cancer at the time it is found, and this relies on imaging tests as well as a pathology report.

Cancer grade is a way of describing how aggressive the cancer is and how likely it is to grow and spread.

Breast Cancer Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Doctor Discussion Guide Woman

Differential Diagnoses

Not all lumps or suspicious mammogram images are a sign of cancer. These findings could be due to a lot of other things, including benign (harmless) breast lesions such as cysts, fibroadenomas, and fat necrosis.

A pre-cancerous lesion, such as a radial scar or carcinoma in situ, is also possible. Pre-cancerous lesions can evolve into breast cancer, but they have a very high cure rate if treated promptly.

And, while it is not common, a breast mass or lump can be the result of metastasis (spread) from another cancer in the body.

Knowing Your Risk: Genetic Testing

If you've had a breast cancer scare or are concerned about your risk of developing the disease, you may consider genetic testing.

Mutations are defects in genes that can lead to cancer. Numerous mutations are associated with breast cancer.

No blood tests can diagnose breast cancer, but genetic testing (which typically uses a blood sample or saliva) can identify a predisposition to the disease. Some women also have genetic testing for diagnosed breast cancer, although this is not standard.

This testing may be recommended for women who have already had cancer at a young age (before menopause), who have a strong family history of the disease, or who have family members who carry breast cancer genes. In some instances, men may be tested for breast cancer genes as well.

BRCA genes, including BRCA1 and BRCA2, are the most common genes associated with breast cancer. Additionally, at least 70 non-BRCA gene mutations have also been implicated. Your test will be tailored to your medical history and family history to detect the genes you are most likely to have.

Reasons to undergo genetic testing include:

  • Female breast cancer diagnosed ≤50 years
  • Triple-negative breast cancer (TNBC) diagnosed ≤60 years
  • Two or more primary breast cancers
  • Male breast cancer
  • Any HBOC-associated cancers, regardless of age at diagnosis, and of Ashkenazi (central or eastern European) Jewish ancestry
  • Breast cancer and either a relative with breast cancer diagnosed ≤50 years or ovarian cancer, or two relatives with breast, prostate, and/or pancreatic cancer, diagnosed at any age
  • BRCA pathogenic variant identified from tumor genomic analysis, regardless of tumor type

You can also order at-home genetic tests for breast cancer for yourself without a doctor's recommendation. But among some concerns about these tests, they only detect a few of the genes that are associated with breast cancer. Doctors have access to more comprehensive tests.

Genetic testing can tell you if you have a predisposition to breast cancer, but it cannot tell you whether you do or don't have the disease. You can develop breast cancer even if you don't have any breast cancer genes.

A Word From Verywell

While it may be difficult, try not to jump to conclusions about what's going on after a suspicious mammogram or if you or your doctor have found a lump. It may not be cancer at all, and if it is, you have a lot of treatment options available to you.

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Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Caplan L. Delay in breast cancer: implications for stage at diagnosis and survivalFront Public Health. 2014;2:87. doi:10.3389/fpubh.2014.00087

  2. American Cancer Society. American Cancer Society Recommendations for the Early Detection of Breast Cancer. Updated October 3, 2019.

  3. American Cancer Society. Frequently Asked Questions About the American Cancer Society’s Breast Cancer Screening Guideline. Updated January 24, 2019.

  4. American Cancer Society. Breast Ultrasound. Updated October 3, 2019.

  5. American Cancer Society. Breast MRI. Updated October 3, 2019.

  6. American Cancer Society. Breast Biopsy. Updated October 3, 2019.

  7. American Cancer Society. Staging and Grading. Updated September 20, 2019.

  8. Johns Hopkins Medicine. Common Benign Lumps.

  9. Lebeau A. Precancerous Lesions of the Breast. Breast Care (Basel). 2010;5(4):204–206. doi:10.1159/000319451

  10. American Cancer Society. Genetic Counseling and Testing for Breast Cancer Risk. Updated September 10, 2019.