This page was reviewed under our medical and editorial policy by
Daniel Liu, MD, Plastic and Reconstructive Surgeon
This page was updated on September 20, 2022.
One of the most important parts of understanding a breast cancer diagnosis is learning about the stage of the disease. The care team stages breast cancer using information gathered during a physical exam, personal history, imaging studies and an analysis of tissue from surgery or a breast biopsy. Staging for breast cancer includes factors like the size of the breast tumor and where the cancer may have spread from its initial location. Doctors then use the stage, along with other information about the tumor, to help recommend a course of treatment.
Stage 2 breast cancer has cancer cells in a breast and/or in the lymph nodes near a breast. This disease is further defined as stage 2A and stage 2B, depending on other factors. The two substages differ in key ways.
Stage 2A breast cancers are likely to have spread into the lymph nodes in the armpit. Lymph nodes are part of the lymphatic system, which circulates a fluid called lymph throughout the body. One of the first ways cancer starts to metastasize from its original location is by spreading into the lymph nodes.
The lymph nodes most likely to be affected are in the armpit (called axillary lymph nodes). Stage 2 breast cancers typically spread to up to three lymph nodes.
Stage 2A breast cancer meets one of these criteria:
With stage 2B breast cancers, the tumor is larger or cancer cells have spread further into the lymph nodes than with stage 2A.
Stage 2B breast cancer meets one of these criteria:
Any type of breast cancer may eventually spread to other organs, including the bones. When cancer spreads, it's known as metastatic breast cancer.
Patients with stage 2 breast cancer may not experience any symptoms, and the cancer may be discovered during a routine mammogram. Possible breast cancer symptoms in stage 2 include:
Stage 2 breast cancers are typically treated with multiple types of therapies to kill as much of the cancer as possible and lower the risk of it recurring. These therapies include:
For stage 2 breast cancer, surgery may involve either breast-conserving surgery (also known as a lumpectomy) or a total mastectomy, which removes the entire breast and related structures. Many patients decide to have breast reconstruction surgery during or after a mastectomy to maintain the look of symmetry between the breasts.
The care team will test the patient's lymph nodes for cancer, likely during the same surgery. Lymph node testing may be performed with a sentinel lymph node biopsy or an axial lymph node dissection. A sentinel lymph node is the first lymph node where the cancer is likely to spread. An axillary lymph node dissection removes a greater number of lymph nodes and may be needed if a biopsy shows signs of cancer spread.
Many patients with stage 2 breast cancer need to undergo radiation therapy, especially those who have breast-conserving surgery. If testing on the removed lymph nodes finds signs of cancer, those undergoing mastectomy will also require radiation therapy.
Chemotherapy isn’t always necessary to treat stage 2 breast cancer. Depending on the features of the cancer, radiation therapy or chemotherapy or a combination of both may be used to shrink tumors and destroy microscopic cancer cells. Patients may undergo treatments before (neoadjuvant) or after (adjuvant) surgery, and sometimes both before and after.
Doctors may recommend additional treatments for some patients with stage 2 breast cancer. For example, hormone treatments may help prevent cancers defined as hormone-receptor-positive from recurring. Other specific characteristics of the cancer may respond to immunotherapy or targeted therapies. Patients should work with the care team to decide on the most appropriate treatment plan.
How long the patient is in treatment for stage 2 breast cancer depends on the specific treatment plan selected. In general, treatment may last for about six months, but some patients continue taking medications for years to prevent cancer recurrence.
The survival rate for stage 2A breast cancer may be slightly higher than for stage 2B. However, all patients with stage 2 breast cancer are considered to have a good prognosis.
The five-year relative survival rate for stage 2A breast cancer patients is 98 percent, and for 2B, it's 95.6 percent, according to data published in the American Cancer Society journal CA: A Cancer Journal for Clinicians in 2017.