Treatment of Breast Cancer Stages I-III

Surgery is the main treatment for stage I breast cancer.

These cancers can be treated with either:

• Breast-conserving surgery (also called lumpectomy or partial mastectomy)
• Mastectomy

Nearby lymph nodes may also need to be checked, either with a sentinel lymph node biopsy (SLNB) or an axillary lymph node dissection (ALND).

Radiation therapy is usually given after breast-conserving surgery.

Most people who have breast-conserving surgery will get radiation therapy afterward. Radiation can lower the chance of the cancer coming back in the breast and can also help people live longer.

Breast-conserving surgery without radiation therapy: People who are at least 65 years old may consider breast-conserving surgery without radiation therapy if all of the following are true:

• The tumor was 3 cm (about 1 inch) or less and was fully removed.
• None of the lymph nodes removed had cancer.
• The cancer is ER-positive or PR-positive.
• Hormone therapy will be given.

Radiation therapy given to people with these characteristics still lowers the chance of the cancer coming back, but it has not been shown to help them live longer.

Radiation after mastectomy: If you had a mastectomy, you may or may not need radiation. This depends on the details of your cancer. Your doctor might refer you to a radiation oncologist to help decide.

Breast reconstruction: Some people can have breast reconstruction at the same time as the surgery to remove the cancer. But if you need radiation therapy, it may be better to wait on reconstruction until after you finish radiation.

Hormone therapy

Most doctors recommend hormone therapy after surgery if a breast cancer is ER-positive or PR-positive, no matter how small the tumor is. Hormone therapy is usually taken for at least 5 years.

Chemotherapy

Chemotherapy after surgery is sometimes recommended for tumors larger than 0.5 cm (about ¼ inch).

It may also be considered for smaller tumors that are fast-growing, hormone receptor-negative, HER2-positive, or have a high score on a gene panel test such as Oncotype DX.

If your cancer is HER2-positive: Treatment after surgery typically includes trastuzumab (Herceptin), with or without pertuzumab (Perjeta), for up to 1 year.

• Many people with larger tumors get chemotherapy plus trastuzumab and pertuzumab before surgery. Treatment with trastuzumab will continue for up to 1 year after surgery, with or without pertuzumab.
• If cancer is still found in the tissue removed during surgery in people who received neoadjuvant therapy, trastuzumab may be switched to ado-trastuzumab emtansine (T-DM1, Kadcyla). It is given every 3 weeks for 14 doses.

If you have a BRCA mutation and hormone receptor-positive, HER2-negative breast cancer: The targeted drug olaparib might be given after surgery if you received neoadjuvant chemotherapy (before surgery) but still have residual cancer at the time of surgery. This drug is usually given for one year. When given this way, it can help some people live longer.

Treatment for stage II breast cancer usually includes surgery.

These cancers are treated with either:

• Breast-conserving surgery (also called lumpectomy or partial mastectomy)
• Mastectomy

Nearby lymph nodes will also be checked, either with a sentinel lymph node biopsy (SLNB) or an axillary lymph node dissection (ALND).

Radiation after breast-conserving surgery: People who have breast-conserving surgery are treated with radiation therapy after surgery.

Radiation after mastectomy: People who have a mastectomy are usually treated with radiation if the cancer is found in the lymph nodes. If you have an SLNB that shows cancer in a few lymph nodes, you might not have the rest of your lymph nodes removed to check for more cancer. In this case, radiation may be discussed as a treatment option after mastectomy.

If you had a systemic treatment before surgery: If you were initially diagnosed with stage II breast cancer and given a systemic treatment such as chemotherapy or hormone therapy before surgery, radiation therapy might be recommended if cancer is found in your lymph nodes during the mastectomy. A radiation oncologist may talk with you to see if radiation would be helpful.

Timing of radiation therapy: If you need chemotherapy after surgery, your radiation will be delayed until you finish chemo. Some people can have breast reconstruction at the same time as the surgery to remove the cancer. But if you need radiation therapy, it may be better to wait on reconstruction until after you finish radiation.

Systemic therapy may be given:

• Before surgery (neoadjuvant)
• After surgery (adjuvant)
• Both before and after surgery

Systemic therapy before surgery is often a good option for people with larger tumors because this type of treatment can shrink the tumor. Sometimes the tumor shrinks enough to make breast-conserving surgery possible instead of mastectomy.

Treatment before surgery is also preferred for people with triple-negative breast cancer (TNBC) or HER2-positive breast cancer. Your cancer care team will assess how much cancer remains after this initial treatment. That will help determine what additional treatment you may need after surgery.

Treatment options

Your treatment options may include:

Chemotherapy before and/or after surgery

If your stage II breast cancer is hormone receptor-positive and HER2-negative, certain gene panel tests may help determine if chemotherapy is likely to be useful.

Hormone therapy

Hormone therapy is usually recommended if the cancer is hormone receptor-positive. This will be either tamoxifen, an aromatase inhibitor (AI), or one followed by the other. It is typically given for at least 5 years. It can be started before surgery but must also continue after surgery.

HER2-targeted drugs

People with HER2-positive cancer usually receive trastuzumab (Herceptin) with chemo, with or without pertuzumab (Perjeta). This is given before and/or after surgery for up to 1 year.

If cancer is still found in the tissue removed during surgery, ado-trastuzumab emtansine (T-DM1, Kadcyla) or trastuzumab deruxtecan (Enhertu) may be used instead of trastuzumab. They are given every 3 weeks.

If your cancer is hormone receptor-positive, HER2-positive, and at high risk of recurrence, your doctor may also recommend neratinib (Nerlynx) for 1 additional year after you finish 1 year of trastuzumab-based therapy.

Targeted therapy

For people with hormone receptor-positive, HER2-negative cancer at high risk of recurrence, two CDK4/6 inhibitors are approved as adjuvant treatment after surgery.

• Abemaciclib (Verzenio) given with tamoxifen or an AI for 2 years, for people with lymph node involvement
• Ribociclib (Kisqali) is given with an AI for 3 years in people with stage II or III disease at high risk of recurrence. This includes some people without lymph node involvement

Olaparib (Lynparza) may be given after surgery for people who have:

• A BRCA mutation and HER2-negative cancer, and
• Cancer remaining after chemotherapy given before surgery

This targeted drug may be given for 1 year to lower the risk of recurrence and improve survival.

Immunotherapy

People with TNBC may receive pembrolizumab (Keytruda) with chemo before and after surgery. See Treatment of Triple-negative Breast Cancer for more details.

Stage III cancers are most often treated with chemotherapy before surgery.

For HER2-positive tumors, common options include:

• Chemotherapy combined with trastuzumab (Herceptin) and pertuzumab (Perjeta)
• Trastuzumab deruxtecan (T-DXd, Enhertu) given first, followed by chemotherapy with trastuzumab (Herceptin) and pertuzumab (Perjeta)

Treatment given before surgery can shrink the tumor. This may make it possible to remove only the tumor instead of the whole breast.

Nearby lymph nodes will need to be checked.

This is usually done with an axillary lymph node dissection (ALND). A sentinel lymph node biopsy (SLNB) is often not an option for stage III cancers, but it may be possible in some cases when chemotherapy given before surgery has been effective.

Additional treatment is usually given after surgery.

• Radiation therapy is typically needed after surgery.
• If you plan to get breast reconstruction, it will probably be delayed until after you finish radiation.
• In some cases, additional chemotherapy is given after surgery as well.
• Capecitabine (Xeloda) may be an option for people with triple-negative breast cancer (TNBC) if chemo was given before surgery and cancer is still present after chemo.

If your cancer is HER2-positive:

• After surgery, you will continue trastuzumab, with or without pertuzumab, for up to 1 year.
• If cancer is still found in the tissue removed during surgery, ado-trastuzumab emtansine (T-DM1, Kadcyla) or trastuzumab deruxtecan (Enhertu) may replace trastuzumab for 14 doses given every 3 weeks.
• If your cancer is also hormone receptor-positive and at high risk of recurrence, your doctor may also recommend neratinib (Nerlynx) for 1 additional year after you finish 1 year of trastuzumab-based therapy.

If your cancer is hormone receptor-positive, you will also get hormone therapy after surgery. This can usually be started at the same time as your anti-HER2 therapy, including ado-trastuzumab emtansine (T-DM1, Kadcyla) or trastuzumab deruxtecan (Enhertu).

If you have hormone receptor-positive, HER2-negative cancer in the lymph nodes at high risk of recurrence, a CDK4/6 inhibitor may be recommended after surgery:

• Abemaciclib (Verzenio) taken as a pill twice a day for 2 years, given with tamoxifen or an aromatase inhibitor (AI).
• Ribociclib (Kisqali) given with an AI for 3 years.

If you have a BRCA mutation and hormone receptor-positive, HER2-negative cancer, or triple-negative breast cancer: You may get Olaparib (Lynparza) after surgery if there is any cancer remaining after chemotherapy that was given before surgery. This targeted drug may be given for 1 year to reduce the risk of recurrence and improve survival.

If you have TNBC: People with TNBC may receive pembrolizumab (Keytruda) before and after surgery. See Treatment of Triple-negative Breast Cancer for more details.

Surgery first is an option for some people with stage III cancer.

• Mastectomy: People with stage III breast cancer usually need a mastectomy because these tumors tend to be large or growing into nearby tissues. 
• Breast-conserving surgery: For people with larger breasts, breast-conserving surgery may be possible if the cancer has not grown into nearby tissues.

Sentinel lymph node biopsy (SLNB) may be an option for checking nearby lymph nodes in some people. But most people will need an axillary lymph node dissection (ALND).

Radiation 

Radiation is recommended after surgery.

Systemic treatments after surgery

Surgery is usually followed by one or more of these treatments:

• Chemotherapy
• Hormone therapy
• Targeted therapy

HER2-directed treatment such as trastuzumab, pertuzumab, ado-trastuzumab emtansine (T-DM1), or neratinib may be given for high-risk hormone receptor-positive, HER2-positive disease, depending on the type of cancer.