The Who, What, Where, When and Sometimes, Why.

Breast Cancer Stages and Staging

Breast cancer stage

Breast cancer stage describes the extent of the cancer within your body. 

The stage of your breast cancer helps plan your treatment.

Breast cancer stage is the most important factor for prognosis. In general, the earlier the stage, the better the prognosis will be.

Breast cancer staging

Pathologic staging is based on a pathologist’s study of the tumor tissue and any lymph nodes removed during surgery. It’s the standard way to stage breast cancer.

Sometimes, results from a health care provider’s physical exam and/or tests such as mammography may help with staging.

TNM system of staging

The most widely used method of pathologic staging for breast cancer is the TNM system.

TNM stands for:

  • T = Tumor size
  • N = Lymph Node status (the number and location of lymph nodes with cancer)
  • M = Metastases (whether or not the cancer has spread to other parts of the body)

In the past, tumor stage was classified using only these 3 measures. Starting in 2018, the TNM system added these measures:

Learn more about tumor size (T) and staging.

Learn more about lymph node status (N) and staging.

Learn more about metastases (M) and staging.

Why were new measures added to the staging system?

The new measures give specific information on the biology of the tumor that affects prognosis. Adding these measures improved staging.

For example, with breast cancer, a large tumor may have a better prognosis than a small tumor, based on biological measures. In the same way, a small tumor may have a worse prognosis than a large tumor based on these measures.

What if I was diagnosed with breast cancer before 2018?

If you were diagnosed before 2018, your breast cancer was staged a bit differently than it would be today.

Find information on breast cancer staging before 2018.

Neoadjuvant therapy

If you will get neoadjuvant therapy (treatment, such as chemotherapy, before surgery), your breast cancer will be staged differently from someone who has surgery as a first treatment.

Neoadjuvant therapy can shrink tumors in the breast and/or lymph nodes, changing the original tumor size and lymph node status. So, your breast cancer is staged using information from physical exams, imaging and biopsies done before neoadjuvant therapy, rather than information from the tumor removed during surgery.

The stages shown in the table below are only used to classify breast cancers in people who have surgery as their first treatment.

If you will get neoadjuvant therapy, talk with your health care provider about how your breast cancer will be staged.

Stages of breast cancer

The stages of breast cancer range from 0 to IV (0 to 4).

The highest stage (stage IV) is any cancer with metastases (M1), no matter the size of the tumor, the lymph node status or other factors. This is known as metastatic breast cancer and is the most advanced stage of breast cancer. 

Most often, the higher the stage of the cancer, the poorer the prognosis will be.

The table below lists the TNM classifications for each stage of breast cancer for people who have surgery as their first treatment.

When TNM is…And Grade is…And HER2 Status is…And ER Status is…And PR Status is…Then the Pathological Prognostic Stage Group is…

Tis N0 M0

AnyAnyAnyAny0

T1* N0 M0

T0 N1mi M0

T1* N1mi M0

G1PositivePositivePositiveIA
NegativeIA
NegativePositiveIA
NegativeIA
NegativePositivePositiveIA
NegativeIA
NegativePositiveIA
NegativeIA
G2PositivePositivePositiveIA
NegativeIA
NegativePositiveIA
NegativeIA
NegativePositivePositiveIA
NegativeIA
NegativePositiveIA
NegativeIB
G3PositivePositivePositiveIA
NegativeIA
NegativePositiveIA
NegativeIA
NegativePositivePositiveIA
NegativeIA
NegativePositiveIA
NegativeIB

T0 N1**M0

T1*N1**M0

T2 N0 M0

G1PositivePositivePositiveIA
NegativeIB
NegativePositiveIB
NegativeIIA
NegativePositivePositiveIA
NegativeIB
NegativePositiveIB
NegativeIIA
G2PositivePositivePositiveIA
NegativeIB
NegativePositiveIB
NegativeIIA
NegativePositivePositiveIA
NegativeIIA
NegativePositiveIIA
NegativeIIA
G3PositivePositivePositiveIA
NegativeIIA
NegativePositiveIIA
NegativeIIA
NegativePositivePositiveIB
NegativeIIA
NegativePositiveIIA
NegativeIIA

T2 N1***M0

T3 N0 M0

G1PositivePositivePositiveIA
NegativeIIB
NegativePositiveIIB
NegativeIIB
NegativePositivePositiveIA
NegativeIIB
NegativePositiveIIB
NegativeIIB
G2PositivePositivePositiveIB
NegativeIIB
NegativePositiveIIB
NegativeIIB
NegativePositivePositiveIB
NegativeIIB
NegativePositiveIIB
NegativeIIB
G3PositivePositivePositiveIB
NegativeIIB
NegativePositiveIIB
NegativeIIB
NegativePositivePositiveIIA
NegativeIIB
NegativePositiveIIB
NegativeIIIA

T0 N2 M0

T1* N2 M0

T2 N2 M0

T3 N1*** M0

T3 N2 M0

G1PositivePositivePositiveIB
NegativeIIIA
NegativePositiveIIIA
NegativeIIIA
NegativePositivePositiveIB
NegativeIIIA
NegativePositiveIIIA
NegativeIIIA
G2PositivePositivePositiveIB
NegativeIIIA
NegativePositiveIIIA
NegativeIIIA
NegativePositivePositiveIB
NegativeIIIA
NegativePositiveIIIA
NegativeIIIB
G3PositivePositivePositiveIIA
NegativeIIIA
NegativePositiveIIIA
NegativeIIIA
NegativePositivePositiveIIB
NegativeIIIA
NegativePositiveIIIA
NegativeIIIC

T4 N0 M0

T4 N1*** M0

T4 N2 M0

Any T N3 M0

G1PositivePositivePositiveIIIA
NegativeIIIB
NegativePositiveIIIB
NegativeIIIB
NegativePositivePositiveIIIA
NegativeIIIB
NegativePositiveIIIB
NegativeIIIB
G2PositivePositivePositiveIIIA
NegativeIIIB
NegativePositiveIIIB
NegativeIIIB
NegativePositivePositiveIIIA
NegativeIIIB
NegativePositiveIIIB
NegativeIIIC
G3PositivePositivePositiveIIIB
NegativeIIIB
NegativePositiveIIIB
NegativeIIIB
NegativePositivePositiveIIIB
NegativeIIIC
NegativePositiveIIIC
NegativeIIIC
Any T Any N M1AnyAnyAnyAnyIV

*T1 includes T1mi.

**N1 does not include N1mi. T1 N1mi M0 and T0 N1mi M0 cancers are included for prognostic staging with T1 N0 M0 cancers of the same prognostic factor status.

***N1 includes N1mi. T2, T3 and T4 cancers with N1mi are included for prognostic staging with T2 N1, T3 N1 and T4 N1, respectively.

Used with permission of the American College of Surgeons, Chicago, Illinois. The original source for this information is the AJCC Cancer Staging Manual, Eighth Edition (2017) published by Springer International Publishing.

 

Oncotype DX® and breast cancer stage

Oncotype DX is part of breast cancer staging for some estrogen receptor-positive, lymph node-negative tumors.

Learn more about Oncotype DX.

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