• Breast cancer is diagnosed as stage 2 if there’s a tumor greater than 20 millimeters in size, if cancer cells are found in the lymph nodes, or both.
• Stage 2 breast cancer treatment may include some combination of surgery, lymph node dissection, chemotherapy, hormonal therapy, targeted therapy, and immunotherapy.
• The prognosis for stage 2 breast cancer is favorable, with a five-year-survival rate of 86 percent.

Breast cancer is classified into stages based on how far cancer cells have spread and other details about the condition. Doctors use a person’s breast cancer stage to help select the best treatment options and estimate a prognosis (outlook). Stage 2 breast cancer is considered early-stage breast cancer, meaning the cancer has not yet spread outside the breast.

In this article, we’ll look at what it means to have stage 2 breast cancer. We’ll also explore the available treatment options and the prognosis for people with this stage of breast cancer.

How Is Breast Cancer Stage Determined?

Breast cancer is staged using the TNM staging system, in which “TNM” stands for “tumor, node, metastasis.” Your doctor is likely to order imaging, such as a mammogram and other forms of testing. That imaging helps assess the following:

• Tumor — How large is the primary tumor?
• Node — Are there cancer cells in nearby or distant lymph nodes?
• Metastasis — Has the cancer metastasized (spread) to other parts of the body?

Stage 2 breast cancer is considered early-stage disease because cancer cells haven’t spread very far outside the breast.

Based on how far the cancer has spread, the stages of breast cancer range from 0 to 4. A higher number means more advanced breast cancer. For instance, stage 3 breast cancer is more advanced than stage 2.

Determining the best treatment options also requires information such as:

• Hormone receptor status — Do cancer cells contain a type of protein known as an estrogen receptor (ER) or a progesterone receptor (PR)? Based on these details, the cancer will be considered hormone receptor-positive or hormone receptor-negative.
• Tumor grade — How do the abnormal cancer cells look compared to normal cells?
• Human epidermal growth factor receptor 2 (HER2) status — Do cancer cells have high or low levels of the HER2 protein? High levels indicate HER2-positive breast cancer, while low levels indicate HER2-negative status.

An oncologist may also request the Oncotype DX test. This type of genetic analysis helps determine how quickly the cancer might progress and whether it will respond to treatment.

What Is Stage 2 Breast Cancer?

Stage 2 breast cancer is a form of invasive breast cancer. This means the cancer cells have begun to spread from the breast into the surrounding tissue, usually to nearby lymph nodes. At this stage, the lymph nodes under the armpit (called the axillary lymph nodes) may test positive for cancer cells.

Stage 2 breast cancer is further classified into substages — stages 2A and 2B.

Stage 2A

Breast cancer is designated as stage 2A if it meets one of the following criteria:

• No tumors are found in the breast. However, tumors larger than 2 millimeters can be found in up to three axillary lymph nodes or in the lymph nodes near the breastbone.
• The tumor in the breast is 2 centimeters or smaller. It has spread to the axillary lymph nodes.
• The tumor is between 2 centimeters and 5 centimeters in size and hasn’t spread to the axillary lymph nodes.

Stage 2B

In stage 2B breast cancer, one of the following criteria must apply:

• The tumor is between 2 centimeters and 5 centimeters. In addition, the lymph nodes contain small groups of breast cancer cells, between 0.2 millimeters and 2 millimeters in size.
• The tumor is between 2 centimeters and 5 centimeters. Plus, the cancer has spread to up to three axillary lymph nodes or to lymph nodes near the breastbone.
• The tumor is larger than 5 centimeters but hasn’t spread to the axillary lymph nodes.

Treatments for Stage 2 Breast Cancer

Generally, stage 2 breast cancer treatment includes initial surgery to remove tumors in the breast and lymph nodes. Systemic therapy is used to treat residual disease and lower the chance of the cancer coming back. Systemic therapies are treatments that affect the whole body, such as chemotherapy and drug therapy. These treatments are usually given as adjuvant therapy (after surgery) but may also be given before surgery (neoadjuvant therapy) to shrink a tumor in some people.

Surgery

To remove the affected breast tissue, a surgeon can perform a lumpectomy. This is also referred to as breast-conserving surgery or partial mastectomy. In this procedure, a surgeon removes the breast tumor and some of the surrounding normal tissue.

A mastectomy entails removing the entire breast. This procedure may be recommended when larger breast tumors can’t be easily removed. Some people may choose to have breast reconstruction surgery following a mastectomy to restore the appearance of their breasts.

Stage 2 breast cancer often involves the axillary lymph nodes in the underarms. To remove the affected tissue, the doctor may perform an axillary lymph node dissection at the same time as a mastectomy.

If there’s no evidence that the axillary lymph nodes are involved, a doctor performs a sentinel lymph node biopsy, which can be done along with a lumpectomy. This less invasive procedure has become increasingly common and can be performed before breast surgery to define the cancer stage more accurately.

For stage 2 breast cancer, radiation therapy is often given after surgery to eliminate any remaining cancer cells.

Radiation

For stage 2 breast cancer, radiation therapy is often given after an operation to eliminate any remaining breast cancer cells that surgery may have missed.

Chemotherapy

In addition to surgery and radiation, chemotherapy may be necessary to completely eliminate cancer cells. Chemotherapy is typically used to kill cancer cells left behind after surgery. However, chemotherapy sometimes can be used before surgery to make the tumor easier to remove.

Hormonal Therapy

Cancer cells are genetically tested to learn the cancer’s hormone receptor status. Some breast cancers are positive for hormone receptors — specifically, estrogen receptor or progesterone receptor — that play a role in breast cancer progression.

For postmenopausal people, hormone receptor-positive stage 2 breast cancers can be treated with tamoxifen or aromatase inhibitors, drugs that target the hormone receptors. This hormonal therapy may lower the likelihood of the cancer returning after treatment.

Targeted Therapy and Immunotherapy

Targeted therapy drugs work by stopping the function of a particular protein or group of proteins. HER2 is present at high levels in some breast cancers and affects how the cancer grows. Some stage 2 cancers are treated based on the presence of the HER2 protein or a BRCA gene mutation. Targeted therapies destroy specific cancers. In stage 2 breast cancer, targeted therapy and immunotherapy options may include:

• Abemaciclib (Verzenio)
• Ado-trastuzumab emtansine (Kadcyla)
• Neratinib (Nerlynx)
• Olaparib (Lynparza)
• Pertuzumab (Perjeta)
• Ribociclib (Kisqali)
• Trastuzumab (Herceptin)

Depending on details about your breast cancer cells, hormone therapy, targeted therapy, or immunotherapy may be recommended to help prevent cancer from returning.

Treating Triple-Negative Breast Cancer

If breast cancer cells are negative for ER, PR, and HER2, the cancer is called triple-negative breast cancer. Triple-negative breast cancer is difficult to treat effectively with standard therapies, so your treatment plan may look different if you have this type of breast cancer.

Your doctor may recommend immunotherapy drugs such as pembrolizumab (Keytruda) to help reduce the likelihood that cancer will relapse if you have triple-negative breast cancer.

Read about which types of breast cancer have the highest rates of recurrence.

Prognosis for Stage 2 Breast Cancer

Survival rates for breast cancer are determined based on whether the cancer is localized (only in the breast), regional (spread to nearby tissues), or distant (spread farther throughout the body). Metastatic breast cancer generally has a lower survival rate than localized breast cancer.

Stage 2 breast cancer exhibits regional spread and has an overall favorable prognosis, with a five-year relative survival rate of around 93 percent. This means after their diagnosis, people who have this type of breast cancer are 93 percent as likely as those without cancer to live for at least five years.

Early diagnosis can help improve outcomes. Also, it’s important that, along with staging your cancer, your oncology provider looks at the molecular features of the cancer. This ensures that you’ll receive the right therapies for your particular form of the disease.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 73,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Have you or a loved one been diagnosed with stage 2 breast cancer? What types of treatments has your cancer plan included? Share your experiences in the comments below, or start a conversation by posting on your Activities page.