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 (chance of survival). In general, the earlier the stage, the better the prognosis will be.

Breast cancer staging

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

Clinical staging includes results from a health care provider’s physical exam, tests and/or imaging, such as mammography. Sometimes, these findings may add to the pathologist’s findings and may help with staging.

TNM system of staging

The main 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)

A “p” before the T or N shows these are pathology findings from the tumor or lymph nodes removed during surgery.

In the past, tumor stage was classified using only the 3 TNM 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 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 and breast cancer staging

Neoadjuvant therapy is treatment, such as chemotherapy, HER2-targeted therapy, hormone therapy or immunotherapy, given before surgery. If you will get neoadjuvant therapy, your breast cancer will be staged differently from someone who has surgery as their first treatment.

Neoadjuvant therapy can shrink tumors in the breast and 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.

Learn about information on a pathology report for people who get neoadjuvant therapy.

Stages of breast cancer

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

The highest stage (stage IV) is any breast 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 disease.

Most often, the higher the stage of the cancer, the poorer the prognosis (chance of survival) will be.

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

The following is a 3D interactive model showing the stages of breast cancer from 0 to IV. Click the arrows to move through the model to learn more about breast cancer.

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	Any	Any	Any	Any	0
T1* N0 M0 T0 N1mi M0 T1* N1mi M0	G1	Positive	Positive	Positive	IA
				Negative	IA
			Negative	Positive	IA
				Negative	IA
		Negative	Positive	Positive	IA
				Negative	IA
			Negative	Positive	IA
				Negative	IA
	G2	Positive	Positive	Positive	IA
				Negative	IA
			Negative	Positive	IA
				Negative	IA
		Negative	Positive	Positive	IA
				Negative	IA
			Negative	Positive	IA
				Negative	IB
	G3	Positive	Positive	Positive	IA
				Negative	IA
			Negative	Positive	IA
				Negative	IA
		Negative	Positive	Positive	IA
				Negative	IA
			Negative	Positive	IA
				Negative	IB
T0 N1*M0 T1N1**M0 T2 N0 M0	G1	Positive	Positive	Positive	IA
				Negative	IB
			Negative	Positive	IB
				Negative	IIA
		Negative	Positive	Positive	IA
				Negative	IB
			Negative	Positive	IB
				Negative	IIA
	G2	Positive	Positive	Positive	IA
				Negative	IB
			Negative	Positive	IB
				Negative	IIA
		Negative	Positive	Positive	IA
				Negative	IIA
			Negative	Positive	IIA
				Negative	IIA
	G3	Positive	Positive	Positive	IA
				Negative	IIA
			Negative	Positive	IIA
				Negative	IIA
		Negative	Positive	Positive	IB
				Negative	IIA
			Negative	Positive	IIA
				Negative	IIA
T2 N1***M0 T3 N0 M0	G1	Positive	Positive	Positive	IA
				Negative	IIB
			Negative	Positive	IIB
				Negative	IIB
		Negative	Positive	Positive	IA
				Negative	IIB
			Negative	Positive	IIB
				Negative	IIB
	G2	Positive	Positive	Positive	IB
				Negative	IIB
			Negative	Positive	IIB
				Negative	IIB
		Negative	Positive	Positive	IB
				Negative	IIB
			Negative	Positive	IIB
				Negative	IIB
	G3	Positive	Positive	Positive	IB
				Negative	IIB
			Negative	Positive	IIB
				Negative	IIB
		Negative	Positive	Positive	IIA
				Negative	IIB
			Negative	Positive	IIB
				Negative	IIIA
T0 N2 M0 T1* N2 M0 T2 N2 M0 T3 N1*** M0 T3 N2 M0	G1	Positive	Positive	Positive	IB
				Negative	IIIA
			Negative	Positive	IIIA
				Negative	IIIA
		Negative	Positive	Positive	IB
				Negative	IIIA
			Negative	Positive	IIIA
				Negative	IIIA
	G2	Positive	Positive	Positive	IB
				Negative	IIIA
			Negative	Positive	IIIA
				Negative	IIIA
		Negative	Positive	Positive	IB
				Negative	IIIA
			Negative	Positive	IIIA
				Negative	IIIB
	G3	Positive	Positive	Positive	IIA
				Negative	IIIA
			Negative	Positive	IIIA
				Negative	IIIA
		Negative	Positive	Positive	IIB
				Negative	IIIA
			Negative	Positive	IIIA
				Negative	IIIC
T4 N0 M0 T4 N1*** M0 T4 N2 M0 Any T N3 M0	G1	Positive	Positive	Positive	IIIA
				Negative	IIIB
			Negative	Positive	IIIB
				Negative	IIIB
		Negative	Positive	Positive	IIIA
				Negative	IIIB
			Negative	Positive	IIIB
				Negative	IIIB
	G2	Positive	Positive	Positive	IIIA
				Negative	IIIB
			Negative	Positive	IIIB
				Negative	IIIB
		Negative	Positive	Positive	IIIA
				Negative	IIIB
			Negative	Positive	IIIB
				Negative	IIIC
	G3	Positive	Positive	Positive	IIIB
				Negative	IIIB
			Negative	Positive	IIIB
				Negative	IIIB
		Negative	Positive	Positive	IIIB
				Negative	IIIC
			Negative	Positive	IIIC
				Negative	IIIC
Any T Any N M1	Any	Any	Any	Any	IV
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.