• 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.

Cancers, including breast cancer, are classified into stages, based on how far the cancer has progressed. Doctors determine the stage of a person’s breast cancer to help select the best treatment options and estimate a prognosis (outlook). Stage 2 breast cancer is a form of early-stage breast cancer, meaning the cancer has not yet metastasized (spread) to distant organs.

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

How Is Breast Cancer Stage Determined?

Breast cancer is staged using the TNM staging system, where TNM stands for “tumor, node, metastasis.” After your doctor has performed imaging such as a mammogram and other forms of testing, the system 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 to other parts of the body?

Based on how far the cancer has spread, the stages of breast cancer range from 0 to 4, with a higher number corresponding to more advanced breast cancer. Stage numbers are sometimes rendered with Roman numerals, such as stage III instead of stage 3.

Determining the best treatment options also requires additional information such as:

• Hormone receptor status — Does the cancer contain estrogen receptors (ERs) or progesterone receptors (PRs), which are types of proteins? This can be classified as hormone receptor-positive (or estrogen receptor-positive) and hormone receptor-negative.
• Tumor grade — How do the abnormal cancer cells look compared to the normal cells?
• Human epidermal growth factor receptor 2, also called HER2 status — How high are your levels of the protein HER2? If you have high levels, it is considered HER2-positive breast cancer, whereas low levels indicate a HER2-negative status.

An oncologist may also request the Oncotype Dx test, a type of genetic analysis, to help determine if 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, meaning 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 contain 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 tumor can be found in the breast, but cancer larger than 2 millimeters can be found in as many as three axillary lymph nodes or in the lymph nodes near the breast bone.
• The tumor in the breast is 2 centimeters or smaller and has spread to the axillary lymph nodes with tumors that are greater than 2 millimeters.
• 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 size, and small groups of breast cancer cells — between 0.2 millimeters and 2 millimeters in size — are found in the lymph nodes.
• The tumor is between 2 centimeters and 5 centimeters in size, and the cancer has spread to as many as 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 eliminate the tumor cells in the breast and lymph nodes. Systemic therapy — treatments that affect the whole body such as radiation and drug therapy — are used to treat residual disease and lower the chance of the cancer coming back. Systemic therapies are usually administered 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 procedure called a lumpectomy, 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.

Alternatively, a mastectomy entails removing the entire breast. This procedure may be recommended for those with larger breast tumors that cannot be easily removed. Some people may choose to have reconstructive surgery following a mastectomy to restore the appearance of their breasts.

Radiation

Radiation therapy is often given after an operation to kill off any remaining breast cancer cells that treatment may have missed.

Lymph Node Dissection

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.

Alternatively, a doctor may use a sentinel lymph node biopsy, a less invasive procedure that can be performed along with lumpectomy. This procedure has become increasingly common and can be performed before breast surgery to define the stage more accurately. Sometimes, the procedure can remove affected lymph nodes and possibly eliminate the need for surgery.

Chemotherapy

In addition to surgery and radiation, chemotherapy may be necessary to completely eliminate cancer cells. While typically used as adjuvant therapy to kill cancer cells left behind after surgery, chemotherapy sometimes can be used prior to surgery (called neoadjuvant therapy) to make the tumor easier to remove.

Hormonal Therapy

Genetic analysis can reveal the hormone receptor status of the cancer. Some breast cancers are positive for hormone receptors — specifically the estrogen receptor or progesterone receptor — that play a role in breast cancer progression.

For postmenopausal women, HER2-positive stage 2 breast cancers can be treated with tamoxifen or exemestane (Aromasin), hormonal therapy drugs that specifically target the hormone receptors. This treatment may lower the likelihood of the cancer returning after treatment.

Targeted Therapy

Targeted therapy drugs work by stopping the function of a particular protein or group of proteins. HER2 is a protein that is present at high levels in some breast cancers and affects how the cancer grows. HER2-positive stage 2 cancers may be treated with drugs that specifically target the HER2 protein.

Immunotherapy

One of the most difficult forms of breast cancer to treat is triple-negative breast cancer, which means the cancer is negative for ER, PR, and HER2. For this type of breast cancer, immunotherapy may improve outcomes. Immunotherapy drugs work by interacting with a person’s immune system so that it can recognize and fight the cancer cells.

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 survival rate of around 86 percent. This means people with this type of breast cancer are 86 percent as likely as those without cancer to live for at least five years after their diagnosis.

Early diagnosis may help improve outcomes. Also, it’s important that, along with the stage, your oncology provider assess 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, over 58,000 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 kind of cancer care have you received from your health care team? Share your experiences in the comments below, or start a conversation by posting on MyBCTeam.