An Overview of Stage 3 Breast Cancer

Stage 3 breast cancer is considered to be advanced breast cancer, however, it is not metastatic. This means that cancer has not spread from the breast to other organs or distant sites in the body.

In stage 3, the tumor often has reached a certain size and has spread to a number of lymph nodes above or below the clavicle (bone connecting the breastplate to the shoulder) or near the breastbone. Inflammatory breast cancer is also considered stage 3. There are several substages within stage 3 breast cancer, and it's important to understand the differences since diagnosis helps to guide treatment and prognosis.

Read on to find out more about stage 3 breast cancer, its treatment options, and living with breast cancer.

Characteristics

Stage 3 breast tumors can vary in size, but there are also types in which no tumor is found in breast tissue, as with inflammatory breast cancer. Therefore, this stage of cancer is not strictly defined only by tumor size but also by the degree of the cancer's invasiveness.

At stage 3, cancer may have spread to the chest wall or the skin of the breast, but it has not reached other organs of the body other than nearby lymph nodes.

Stage 3 is further classified by three substages: 3A, 3B, and 3C. These substages describe the number of axillary (underarm) lymph nodes affected and whether lymph nodes in the breastbone or collarbone are involved. They also factor in tumor size and more.

These substages can be further broken down by other characteristics outlined in the TNM classification of malignant tumors (also known as the TNM system).

stage 3a breast cancer
Verywell / Jessica Olah
stage 3b breast cancer
 Verywell / Jessica Olah
stage 3c breast cancer
 Verywell / Jessica Olah

TNM Staging

Since both your treatment and prognosis can be impacted by substage classifications, careful staging is needed.

Although the TNM system may seem confusing at first, the rationale is pretty straightforward. The TNM system stages cancer based on three characteristics represented by its acronym:

  • T: Tumor size
  • N: Lymph nodes
  • M: Metastases

The letters are followed by numbers that further describe the size and extent of the malignancy. Further information can be added to the diagnosis of stage 3 breast cancer by reviewing its TNM score.

Stage 3A Breast Cancer
TNM Score Definition
T0, N2, M0 No tumor has been found in breast tissue, but cancer cells have been found in the lymph nodes of your underarm or breast.
T1, N2, M0 The tumor is 2 centimeters in size or smaller and/or has extended beyond the perimeter of breast tissue. Cancer may have also spread to lymph nodes in your underarm or breast.
T2, N2, M0 The tumor is over 2 centimeters but under 5 centimeters in size. Cancer has also been found in the lymph nodes in your underarm or breast.
T3, N1, M0 The tumor is bigger than 5 centimeters but has not yet invaded breast skin or the chest wall. There will be cancer in the lymph nodes under your arm.
T3, N2, M0 The tumor is bigger than 5 centimeters but has still not affected breast skin or the chest wall. Cancer has been found in either the underarm lymph nodes or those of your breast.
Stage 3B Breast Cancer
TNM Score Definition
T4, N0, M0  The tumor may be of any size and has affected breast skin or has grown into your chest wall (without involving the pectoralis muscle connecting the front of the chest to the upper-arm and shoulder bones). This tumor may also be a rare type known as inflammatory breast cancer.
T4, N1, M0 The tumor may be of any size. It will have spread to breast skin or the chest wall, or it may be inflammatory breast cancer. Cancer will also be found in underarm lymph nodes near the affected breast.
T4, N2, M0 The tumor may be of any size. It will have spread to breast skin or the chest wall, or it may be inflammatory breast cancer. Cancer will also be found in underarm lymph nodes or nodes within the breast.
Stage 3C Breast Cancer
TNM Score Definition
T(any), N3, M0 The tumor may be of any size but will be contained within breast tissue only. Your chest wall and breast skin would be unaffected. The lymph node status can vary. Cancer may be found in the nodes of your armpit, within your breast, over your collarbone, beneath your collarbone, or in several locations at once.

Your actual outcome can vary based on the substage and other factors, including a woman's age and HER2 (human epidermal growth factor receptor 2 ) status. (HER2 is a gene that makes protein that helps breast cancer cells to grow quickly status. Your doctor will talk to you about your individual prognosis based on various factors. These can include your general health, age, and your cancer's hormone status.

Breast Cancer Doctor Discussion Guide

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

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Treatment

If you are diagnosed with stage 3 breast cancer, your treatment plan would likely include surgery, chemotherapy, and, in most cases, radiation.

The selection of drugs will depend on your cancer type. For example, if your tumor is HER2-positive, you will also be given Herceptin (trastuzumab). If it is hormone-sensitive (meaning that estrogen and/or progesterone can influence a tumor's growth), hormonal therapies will likely be prescribed for at least five years after primary treatment ends.

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Breast Cancer Treatment Options

Surgery

Smaller tumors that have not infiltrated skin or muscle may be removed with a ​lumpectomy (surgical removal of the tumor). A sentinel node biopsy will be needed to find out if cancer cells have traveled beyond your breast.

Larger tumors, including those that have invaded the chest wall, will require a mastectomy (surgical removal of the breast) along with a lymph node biopsy. Breast reconstruction may be offered, but it is sometimes delayed due to radiation therapy.

Chemotherapy

Chemotherapy is typically used in stage 3 to eliminate any stray cancer cells following surgery, reducing the likelihood of recurrence. Chemo can also be given before surgery to shrink a tumor, making it easier to remove as much of the cancer as possible.

Chemotherapy given after surgery is referred to as adjuvant chemotherapy. When given before surgery, it is called neoadjuvant chemotherapy.

If breast cancer involves the skin, it may be inflammatory breast cancer. The breast will often look swollen and red. Neoadjuvant chemotherapy is usually the first course of treatment for this less common and aggressive type of cancer. Not only can it help shrink the tumor, but it will also kill cancer cells around the margins, making it easier to remove and reducing the need for repeat surgery.

Inflammatory breast cancer almost always requires a mastectomy and axillary lymph node removal (dissection).

Immunotherapy

Immunotherapy uses medications to help a person's immune system better recognize and destroy cancer cells in the body. These drugs usually work on certain proteins in the immune system to boost the immune response.

In breast cancer, these drugs target proteins that need to be "turned on or turned off." Breast cancer cells use these proteins to avoid detection by the immune system. Immunotherapy drugs interfere with this and allow the immune system to respond to the cancer cells.

Targeted Therapy

Targeted therapies attack the proteins on cancer cells that control how the cells grow, divide, and spread. This may involve testing your tumor to see if it has targets that can be addressed with these drugs. Targeted therapy drugs help treat cancer by:

  • Helping the immune system kill cancer cells
  • Stopping cancer cells from growing
  • Preventing blood vessels from forming, thus "starving" tumors
  • Causing cancer cell death
  • Blocking hormones that fuel the cancer

Survival Rate

Survival rate can vary based on the substage and other factors, including a woman's age and HER2 status.

Survival rates are often grouped into categories depending if the cancer is localized, regional, or distant. Stage 3 breast cancer is considered regional disease, which means it has spread to regional lymph nodes.

The relative five-year survival rate for regional breast cancer, which means the percentage of those diagnosed with the disease who are alive five years after diagnosis, is 85.8%. It is important to remember that the statistics used to estimate survival are just that, statistics. Each person is different, and statistics simply give a larger overall picture.

Your doctor will talk with you about your individual prognosis based on various factors. These can include your general health, age, and your cancer's hormone status.

Furthermore, as newer and more effective therapies are being released each year, the survival rate may be very different five years from now compared to the rate today.

Keep in Mind

A five-year survival rate is the percentage of people who will live for at least five years after diagnosis. It does not mean you will only live for five years. Many women with stage 3 breast cancer will live for years and even decades more.

Follow-Up Care

Follow-up care will depend largely on your hormone and HER2 status. Once primary treatments are complete, you will have regular checkups with your oncologist for at least the next five years.

During this time, you will continue to have regular mammograms and perform regular self-exams if breast tissue is still remaining.

Women often assume that all of their breast tissue has been removed following a mastectomy. This is not necessarily the case. Speak with your oncologist (doctor specializing in diagnosing and treating cancer) to understand the extent of the surgery and your need for regular breast exams.

Your healthcare provider may also recommend periodic magnetic resonance imaging (MRI) of your other breast if it was not removed. An MRI offers 10 to 100 times greater resolution than a conventional mammogram and may be more appropriate for high-risk cases.

You may also be advised to maintain a healthy diet and regular exercise or physical therapy program to rebuild your stamina, strength, and well-being.

Coping

Living with cancer can be challenging, not just physically, but emotionally as well. Finding a support group or therapist can be helpful. Many hospitals or cancer centers have disease-specific support groups available; talk with your treatment team to see if your treatment center has one. If not, ask your provider for resources.

Even finding support online can be helpful. Connecting with people going through similar things can be validating and reduce any feelings of isolation you may be experiencing. They can also provide tips and tricks for dealing with treatment and post-treatment life.

Summary

Stage 3 breast cancer is breast cancer that is advanced but not metastatic, and it is still treatable. Depending on the tumor's characteristics, It can be treated with a variety of options including surgery, radiation, chemotherapy, targeted therapy, hormone therapy, or a combination of these. The survival rate for breast cancers with regional spread is around 86%, but remember that survival statistics may not take into account newer and more effective therapies.

Frequently Asked Questions

  • What are the types of breast cancer?

    There are many different types of breast cancer, but these represent some of the main types.

    • Invasive ductal carcinoma (IDC) is the most common type of breast cancer, representing 70%–80% of all cases. It begins in the cells lining a milk duct and spreads to other breast tissues.
    • Ductal carcinoma in situ (DCIS) is the earliest stage of ductal cancer. Cancer cells have not yet spread to other nearby areas, making it noninvasive or preinvasive.
    • Invasive lobular carcinoma (ILC) starts in lobules, or the breast glands that make milk.
    • Triple-negative breast cancer means that cancer cells lack estrogen or progesterone receptors, and create little or none of the protein HER2.
    • Inflammatory breast cancer: Lymph vessels are blocked by cancer cells, causing the breast to appear inflamed.
    • Paget's disease of the breast: Cancer cells appear on the nipple and the areola.
  • How many stages of breast cancer are there?

    There are five main stages of breast cancer that start from stage 0 (noninvasive breast cancer) and end at stage 4 (invasive cancer that has spread to other areas of the body). However, each breast cancer stage above 0 also has subcategories. For example, stage 3 breast cancer has three subcategories, which are referred to as 3A, 3B, and 3C.

  • Is Stage 3 breast cancer curable?

    In general, Stage 3 breast cancer is considered curable. However, the success of treatment depends on the extent of spread, grade of the cancer, hormone receptor status, and response to treatment.

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.
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  2. American Joint Committee on Cancer. Part XI: Breast. AJCC Cancer Staging Manual, 8th Ed. Chicago, Illinois: American College of Surgeons; 2017:589-636.

  3. American Cancer Society. Treatment of breast cancer stages I-III.

  4. American Cancer Society. Immunotherapy for breast cancer.

  5. National Cancer Institute. Targeted therapy to treat cancer.

  6. National Cancer Institute Surveillance, Epidemiology, and End Results Program. Cancer stat facts: Female breast cancer.

  7. American Cancer Society. Types of breast cancer.

  8. Breastcancer.org. Breast cancer stages.

Originally written by
Pam Stephan
Pam Stephan is a breast cancer survivor.
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