Understanding The Stages Of Breast Cancer: 0, 1, 2, 3 & 4

A breast cancer diagnosis raises many concerns, including what stage your cancer is. Millions of women face similar questions: According to the American Cancer Society, breast cancer is the most frequent cancer among women. One-third of new female malignancies are caused by it.

Your doctor will use diagnostic tests to stage your breast cancer after a diagnosis. Knowing your cancer stage helps you choose the best therapy and predict your survival chances.

Physicians utilize the AJCC TNM method to stage breast cancer. T stands for tumor size, N for lymph node involvement, and M for body spread. Each factor is described by numbers or letters following T, N, and M. Advanced cancer has higher numbers.

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Stages Of Breast Cancer

American Society of Clinical Oncology (ASCO) classifies breast cancer stages as 0, 1, 2, 3, and 4. Expert advice and five-year relative survival rates at each stage are below.

Stage 0 Breast Cancer

Stage zero (0) breast cancer is also known as noninvasive or in situ cancer and occurs solely in the breast’s milk ducts (Tis, N0, M0).

In stage 0 of breast cancer, almost all patients survive (99%).

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Stage 1 Breast Cancer

Lymph node metastasis (Stage IB): tumor size is more than 0.2 mm but less than 2 mm. A breast tumor is either absent or less than 20 millimeters in size (T0 or T1, N1mi, M0).

The five-year survival rate for women with stage I breast cancer ranges from 86% (Stage IB) to 99.6%. (Stage IA).

Stage 2 Breast Cancer

Stage IIA:

• Despite no breast tumor, the malignancy has progressed to 1–3 axillary (underarm) lymph nodes. Cancer has not spread (T0, N1, M0).
• A breast tumor of 20 mm or less and malignancy in 1 to 3 axillary lymph nodes (T1, N1, M0).
• The tumor is bigger than 20 mm but less than 50 mm and has not migrated to the axillary lymph nodes (T2, N0, M0).

Stage IIB:

• The tumor is 20–50 mm. 1–3 axillary lymph nodes contain it (T2, N1, M0).
• No axillary lymph nodes are detected in the 50-mm tumor (T3, N0, M0).

The five-year survival rate for stage 2 breast cancer varies from 86% to 99.9%, depending on whether or not the disease has progressed to the lymph nodes.

Stage 3 Breast Cancer

Stage IIIA: A tumor of any size has progressed to four to nine axillary lymph nodes or internal mammary lymph nodes but not elsewhere (T0, T1, T2, or T3; N2; M0). This stage may also contain a tumor greater than 50 mm that has migrated to one to three axillary lymph nodes (T3, N1, M0).

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Stage IIIB: The tumor infiltrated the chest wall or produced breast ulceration or edema. Nine axillary or internal mammary lymph nodes may have malignancy. It hasn’t spread (T4; N0, N1 or N2; M0). Inflammatory breast cancer may have been detected.

Stage IIIC: Any size tumor infiltrating 10 or more axillary, internal mammary, or collarbone lymph nodes. No other bodily parts are affected (any T, N3, M0).

The 5-year survival rate for women with stage 3 breast cancer is 86%.

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Stage 4 Breast Cancer

This stage encompasses any size tumor. Cancer has progressed to the bones, brain, liver, lungs, distant lymph nodes, or chest wall (any T, any N, M1). De novo metastatic breast cancer occurs in six percent of cases. Metastatic breast cancer is usually diagnosed after early-stage breast cancer therapy.

The five-year survival rate for stage 4 breast cancer is 30%.

Understanding breast cancer’s five phases and which one you have can help you make the best treatment options and reduce stress.