Stages of Breast Cancer

Learn about the stages of breast cancer with CHRISTUS Health

Understanding the stage of breast cancer is an important part of diagnosis and treatment planning. The stage describes how far cancer has developed or spread within the breast or to other parts of the body.

When you choose CHRISTUS Health, you get care from our specialists who use advanced imaging, pathology, and genetic testing to ensure every diagnosis is accurate, making sure your treatment plan is as personalized as possible.


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How is Breast Cancer Staged?

To determine the stage of breast cancer, doctors use the TNM system, which stands for Tumor size (T), Node involvement (N), and Metastasis (M). Staging is vital because it's how your health care team develops a personalized treatment plan just for you.

The TNM system helps to answer the following questions:

  • How big is the tumor (T)?
  • Has it spread to the lymph nodes (N)?
  • Has it spread to distant parts of the body (M)? 

Which Tests Determine the Stage of Breast Cancer?

These tests analyze the actual cancer cells and nearby tissue to tell us the crucial details about the tumor's identity.

  • Biopsy: The tissue collected during your core, or surgical biopsy is thoroughly analyzed not just to confirm cancer, but to determine the tumor’s grade (how aggressive the cells look).
  • Sentinel Lymph Node Biopsy: This surgical procedure checks the first few lymph nodes the cancer would most likely travel to. If these "sentinel" nodes are clear, you may be able to avoid a more extensive surgery. This is essential for determining the 'N' (Nodes) part of your stage.
  • Hormone Receptor & HER2 Status: Lab work on your biopsy tissue determines if your cancer cells feed off Estrogen (ER), Progesterone (PR), or overproduce the HER2 protein. This information is critical, as it dictates what types of targeted medications you can receive.
  • Genomic/Multigene Tests: In some cases, your doctor may order a test that looks at the genes within the tumor. This helps predict your risk of recurrence and guides the discussion about whether chemotherapy is beneficial for you.

Which Scans are Used to Determine the Stage of Breast Cancer?

These are the scans used to see inside your body, measure the tumor, and confirm there has been no spread outside the breast area.

  • Diagnostic Mammogram, Ultrasound, and MRI: These detailed images determine the exact size and location of the tumor (the 'T'). The breast MRI is often used to map out the full extent of the disease in your breast(s) with high precision.
  • CT, PET-CT, and Bone Scans: If your tumor is large or if there is reason to suspect the cancer has traveled, your doctor may order these whole-body scans. These are used to look for spread to your bones, lungs, or liver—the 'M' (Metastasis) component of your staging.

Together, the results from these tests will provide you, and your health care team, with the definitive breast cancer stage, allowing you to move confidently into the treatment phase.

What are the Stages of Breast Cancer?

The stages of breast cancer range from stage 0 to stage 4. Early-stage breast cancers are often curable, while advanced stages may require more comprehensive care and management.




Breast Cancer Stages Explained

Stage 0: Ductal Carcinoma In Situ (DCIS)

This is a non-invasive stage, meaning cancer cells are confined to the milk ducts and have not spread into surrounding breast tissue. DCIS is considered highly treatable, and with prompt care, the outlook is excellent. Treatments often include surgery (lumpectomy or mastectomy) and possibly radiation therapy.

Stage 1: Early Stage Breast Cancer

In Stage 1, the tumor is small—typically less than 2 centimeters—and may or may not have spread to nearby lymph nodes. Most women at this stage are treated successfully with a combination of surgery, radiation, and sometimes hormone or targeted therapy. Early detection through regular mammography significantly improves outcomes at this stage.

Stage 2: Localized Spread

Cancer at Stage 2 is considered invasive, meaning it has spread beyond the ducts or lobules into nearby breast tissue or lymph nodes. Treatment may include a combination of surgery, chemotherapy, and radiation. Many patients at this stage achieve full remission with timely, coordinated care.

Stage 3: Regional Spread

Stage 3 cancer has spread more extensively to lymph nodes near the breast or chest wall but not to distant organs. It is often called “locally advanced” breast cancer. Treatment usually involves a combination of therapies, such as chemotherapy to shrink the tumor, followed by surgery and radiation—to reduce recurrence risk.

Stage 4: Metastatic Breast Cancer

In Stage 4, cancer has spread (metastasized) to other areas of the body, such as the lungs, liver, bones, or brain. While not considered curable, metastatic breast cancer is treatable. Many people live fulfilling, active lives for years with ongoing treatment that manages symptoms and slows disease progression. CHRISTUS Health provides access to the latest systemic therapies, clinical trials, and compassionate support resources.

Why Does Early Detection of Breast Cancer Matter?

Early detection through mammograms and regular breast exams remains the most effective way to identify breast cancer before it spreads.

Finding breast cancer in Stage 0 or Stage 1 often means simpler treatments, fewer side effects, and better long-term survival rates.

Check Your Risk For Breast Cancer

Complete the CHRISTUS Health Breast Cancer Assessment to receive a report with your breast cancer risk factors and tips on reducing those risks.

Check My Risk

Genetic Testing for Breast Cancer

Genetic testing for breast cancer can help you understand your risk so you can decide to have earlier mammography screenings, or in some cases, treatments or procedures that prevent breast cancer.

Understand Genetic Testing

Take the Next Step

If you’ve recently been diagnosed or are seeking a second opinion, our CHRISTUS breast care specialists are here to help you understand your options.

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