Stage 3 Breast Cancer

April 10, 2025

This page was reviewed under our medical and editorial policy by Susan Yost, Ph.D., staff scientist, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte

Doctors categorize breast cancer by stage, using several factors, including the size of the tumor, how many (if any) lymph nodes the cancer has invaded, if it has spread from where it first formed and the extent of the metastasis (spread). In general, lower numbered stages mean the cancer has not spread as much.

Stage 3 breast cancer is sometimes called locally advanced cancer, and it is one of five stages of the disease:

• Stage 0 breast cancer (carcinoma in situ)
• Stage 1 breast cancer
• Stage 2 breast cancer
• Stage 3 breast cancer
• Stage 4 (metastatic) breast cancer

People whose diagnostic tests show that Stage 3 breast cancer is present receive a pathology report that outlines the details of their diagnosis. The doctor will also explain what Stage 3 breast cancer means for patients, including how it affects their treatment options.

What Is Stage 3 Breast Cancer?

Locally advanced or Stage 3 breast cancer is diagnosed when:

A tumor measures more than 2 inches across (more than 5 centimeters) or

• The tumor grows out of the site where it first formed to invade nearby breast skin or muscle or
• The cancer cells invade nearby lymph nodes in the breast

One other marker of Stage 3 breast cancer is that, while it does grow beyond its original site to nearby tissues and structures, it does not grow and spread to distant parts of the body.

Stage 3a Breast Cancer

A patient will be diagnosed with Stage 3a breast cancer if:

• A breast tumor is larger than about 2 inches (5 centimeters) and the cancer has spread to three axillary (armpit) lymph nodes or sternum-area (breastbone) lymph nodes or
• The cancer has spread to four to nine axillary or breastbone-area lymph nodes, but it has not spread anywhere else

Stage 3b Breast Cancer

A patient is diagnosed with Stage 3b breast cancer if:

• The cancer has spread to the chest wall (breast fat, tissue or breastbone) and potentially to area lymph nodes, but not throughout the body or
• The cancer has spread to the breast skin (causing an ulcer or swelling) and potentially to area lymph nodes, but not throughout the body

Stage 3b breast cancer that spreads to the skin of the breast and causes swelling may be inflammatory breast cancer (IBC), which means cancer cells are blocking the skin’s lymph vessels.

Stage 3c Breast Cancer

A patient may be diagnosed with Stage 3c breast cancer if:

• A cancer tumor of any size has spread to at least 10 axillary (armpit) lymph nodes or
• The cancer has spread to the chest wall or the breast skin, but not to distant parts of the body

Stage 3 Breast Cancer Symptoms

Breast cancer symptoms that may be present during the locally advanced cancer stage include:

• A lump or mass in the breast
• Swelling of the breast
• Swollen lymph nodes (under the arms and by the collarbone)
• Dimpling of the skin
• Breast pain
• Thickened, red, itching or flaking breast or nipple skin
• Partial breast swelling
• Nipple discharge (other than breast milk) or pain

One type of aggressive breast cancer known as inflammatory breast cancer is already considered Stage 3 (or sometimes Stage 4) upon diagnosis. This is because the disease typically spreads quickly out of its site of origin into surrounding tissues and lymph nodes in just a matter of weeks or months.

Symptoms of IBC may include:

• Skin that is thick or pitted (indented) like an orange peel
• Redness in one breast, where more than a third of the breast is red
• Breast asymmetry, where one breast is larger, warmer and/or heavier than the other
• Swollen lymph nodes under the arm
• Itchy, tender and painful breasts
• An inverted or retracted (pulled inward) nipple

Diagnosing Stage 3 Breast Cancer

Breast cancer is typically diagnosed using a pathological test called a breast biopsy. A tissue sample is removed for examination under a microscope by a doctor (pathologist) trained to diagnose disease by studying cells and tissues.

Different imaging tests may also be used to help determine if breast cancer is Stage 3, including:

• Mammogram
• Chest X-ray
• Computed tomography (CT) scan
• Breast ultrasound
• Magnetic resonance imaging (breast MRI) scan
• Bone scan
• Positron emission tomography (PET) scan

These tests may also be used to help pinpoint the cancer’s grade, which is a comparison of the cancer cells to normal cells. A lower grade means that the cancer is more likely to grow and spread slowly, while a higher grade indicates that it may grow and spread more quickly.

Stage 3 Breast Cancer Treatment

Treating Stage 3 cancer typically combines more than one type of procedure or therapy.

Before surgery: Many times, doctors first prescribe neoadjuvant chemotherapy for breast cancer, which is given before surgery to shrink cancer cells. In addition, certain types of breast cancers have estrogen or progesterone hormone receptors on the cancer cells that help them grow, and these patients may receive hormone therapy alongside chemotherapy to help block the cell growth. Some breast cancer cells also have a high amount of HER2 protein, which helps cancer grow, and patients may be given drugs that help block this protein.

Breast cancer surgery: Either breast-conserving surgery (such as a partial mastectomy) or breast removal surgery (mastectomy) may be recommended. Surgery may also include removing axillary and sentinel lymph nodes if the cancer has spread to them. Sometimes doctors begin Stage 3 breast cancer treatment with surgery rather than with chemotherapy, hormone therapy and/or targeted drug therapy.

After surgery: Radiation therapy for breast cancer is often given after surgery to help destroy any potential cancer that may remain. Chemotherapy may also be given postsurgery, alongside breast cancer hormone therapy or HER2 targeted drug therapy (or both). Cancer cells sometimes have other cell changes or mutations that lead to cancer cell growth, such as a flawed BRCA gene, and targeted drug therapy may be prescribed for these patients as well. Patients with normal levels of HER2 and whose cancer cells do not contain hormone receptors are diagnosed with triple-negative breast cancer, and they may be treated with breast cancer immunotherapy to help their body’s immune system fight the cancer.

For those diagnosed with Stage 3 inflammatory breast cancer, treatment is typically a little different. Patients will usually undergo a modified radical mastectomy surgery rather than breast-conserving surgery because the cancer affects a large portion of the skin. This includes the removal of the entire breast and axillary (armpit) lymph nodes.

Stage 3 Breast Cancer Survival Rate

Stage 3 breast cancer survival rates are estimates based on how many patients in the recent past were still alive five years or more after their diagnosis.

In a 2018 study of more than 50,000 patients conducted by researchers in JAMA Oncology, the following five-year survival rate ranges were observed for Stage 3 breast cancer.

Stage 3a: 86% to 98%.

Stage 3b: 82% to 97%.

Stage 3c: 66% to 86%.

The National Cancer Institute’s tracking system calculates survival rates based on three general stages: localized, regional and distant cancer spread.

For localized cancer that has not spread beyond the breast, the five-year relative survival rate between 2014 to 2020 was 99.6%.

For regional cancer that has spread outside the breast to area lymph nodes and structures, the five-year relative survival rate was 86.7%.

For advanced cancer that has spread to distant sites, the five-year relative survival rate was 31.9%.

It is important to note that many factors are not included in the five-year relative survival rate that may impact a patient’s chances of recovery, including their overall health, age, the type of breast cancer and how the disease responds to treatment.

Care at City of Hope

Patients who are treated for Stage 3 breast cancer at City of Hope are offered fast, convenient appointment scheduling and a comprehensive team of compassionate breast cancer experts. Doctors, surgeons, technologists and support care staff are dedicated to providing each person with multiple treatment options that take into account the complexity of the disease and their unique treatment goals.