Treatment of Breast Cancer Stages I-III

The stage of your breast cancer is an important factor in making decisions about your treatment. 

Most women with breast cancer in stages I, II, or III are treated with surgery, often followed by radiation therapy. Many women also get some kind of systemic drug therapy (medicine that travels to almost all areas of the body). In general, the more the breast cancer has spread, the more treatment you will likely need. But your treatment options are affected by your personal preferences and other information about your breast cancer, such as:

  • If the cancer cells have hormone receptors. That is, if the cancer is estrogen receptor (ER)-positive or progesterone receptor (PR)-positive.
  • If the cancer cells have large amounts of the HER2 protein (that is, if the cancer is HER2-positive)
  • How fast the cancer is growing (measured by grade or Ki-67)
  • Your overall health
  • If you have gone through menopause or not

Talk with your doctor about how these factors can affect your treatment options.

What type of drug treatment(s) might I get?

Most women with breast cancer in stages I, II, or III will get some kind of systemic therapy as part of their treatment. This might include:

The types of drugs that might work best depend on the tumor’s hormone receptor status, HER2 status, and other factors.

Treating stage I breast cancer

These breast cancers are still fairly small and either have not spread to the lymph nodes or have spread to only a tiny area in the sentinel lymph node (the first lymph node to which cancer is likely to spread).

Local therapy (surgery and radiation therapy)

Surgery is the main treatment for stage I breast cancer. These cancers can be treated with either breast-conserving surgery (BCS; sometimes called lumpectomy or partial mastectomy) or mastectomy. The nearby lymph nodes will also need to be checked, either with a sentinel lymph node biopsy (SLNB) or an axillary lymph node dissection (ALND).

Some women can have breast reconstruction at the same time as the surgery to remove the cancer. But if you will need radiation therapy after surgery, it is better to wait to get reconstruction until after the radiation is complete.

If BCS is done, radiation therapy is usually given after surgery to lower the chance of the cancer coming back in the breast and to also help people live longer.

In a separate group, women who are at least 65 years old may consider BCS without radiation therapy if ALL of the following are true:

  • The tumor was 3 cm (a little more than 1 inch) or less across and it has been removed completely.
  • None of the lymph nodes removed contained cancer.
  • The cancer is ER-positive or PR-positive, and hormone therapy will be given.

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

If you had a mastectomy, you are less likely to need radiation therapy, but it might be given depending on the details of your specific cancer. You should discuss if you need radiation treatment with your doctor. You might be sent to a doctor who specializes in radiation (a radiation oncologist) for evaluation.

Systemic therapy (chemo and other drugs)

If a woman has a hormone receptor-positive (ER-positive or PR-positive) breast cancer, most doctors will recommend hormone therapy (tamoxifen or an aromatase inhibitor, or one followed by the other) as an adjuvant (after surgery) treatment, no matter how small the tumor is. Women with tumors larger than 0.5 cm (about ¼ inch) across may be more likely to benefit from it. Hormone therapy is typically given for at least 5 years.

If the tumor is larger than 0.5 cm (about 1/4 inch) across, chemo after surgery (adjuvant chemotherapy) is sometimes recommended. A woman's age when she is diagnosed may help in deciding if chemo should be offered or not. Some doctors may suggest chemo for smaller tumors as well, especially if they have any unfavorable features (a cancer that is growing fast; hormone receptor-negative, HER2-positive; or having a high score on a gene panel such as Oncotype DX).

After surgery, some women with HER2-positive cancers will be treated with trastuzumab (with or without pertuzumab) for up to 1 year.

Many women with HER2-positive cancers will be treated with neoadjuvant (before surgery) chemo and trastuzumab (with or without pertuzumab) followed by surgery and more trastuzumab (with or without pertuzumab) for up to 1 year. If after neoadjuvant therapy, residual cancer is found during surgery, trastuzumab may be changed to a different drug, called ado-trastuzumab emtansine, which is given every 3 weeks for 14 doses.

For women with a BRCA mutation and hormone-positive, HER2-negative breast cancer who received neoadjuvant chemotherapy but still have residual cancer at the time of surgery, the targeted drug olaparib might be given after surgery. It is usually given for one year. When given this way, it can help some women live longer.

Treating stage II breast cancer

Stage II breast cancers are larger than stage I cancers and/or have spread to a few nearby lymph nodes.

Local therapy (surgery and radiation therapy)

Stage II cancers are treated with either breast-conserving surgery (BCS; sometimes called lumpectomy or partial mastectomy) or mastectomy. The nearby lymph nodes will also be checked, either with a sentinel lymph node biopsy (SLNB) or an axillary lymph node dissection (ALND).

Women who have BCS are treated with radiation therapy after surgery. Women who have a mastectomy are typically treated with radiation if the cancer is found in the lymph nodes. Some patients who have a SLNB that shows cancer in a few lymph nodes might not have the rest of their lymph nodes removed to check for more cancer. In these patients, radiation may be discussed as a treatment option after mastectomy.

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

If chemotherapy is also needed after surgery, the radiation will be delayed until the chemo is done.

In some women, breast reconstruction can be done during the surgery to remove the cancer. But if you will need radiation after surgery, it is better to wait to get reconstruction until after the radiation is complete.

Systemic therapy (chemo and other drugs)

Systemic therapy (drugs that travel to almost every part of the body) is recommended for some women with stage II breast cancer. Some systemic therapies are given before surgery (neoadjuvant therapy), and others are given after surgery (adjuvant therapy). For some women, systemic therapy will be started before surgery and then continued after surgery. Neoadjuvant treatments are a good option for women with large tumors, because they can shrink the tumor before surgery, possibly enough to make BCS an option.

Neoadjuvant treatment is also a preferable option for women with triple-negative breast cancer (TNBC) or HER2-positive breast cancer because the treatment given after surgery is often chosen depending on how much cancer is still in the breast and/or lymph nodes at the time of surgery. Some women with early-stage cancer who get neoadjuvant treatment might live longer if the cancer completely goes away with that treatment.

To help decide which women with stage II hormone receptor-positive, HER2-negative breast cancer will benefit from chemotherapy, a gene panel test such as Oncotype DX may be done on the tumor sample.

The drugs used will depend on the woman’s menopause status, as well as tumor test results. Treatment might include:

  • Chemotherapy: Chemo can be given before and/or after surgery.
  • HER2 targeted drugs: Some women with HER2-positive cancers will be treated with adjuvant (after surgery) chemotherapy with trastuzumab with or without pertuzumab for up to 1 year. Many women with HER2-positive cancers will be treated first with trastuzumab (with or without pertuzumab) followed by surgery and then more trastuzumab (with or without pertuzumab) for up to a year. If after neoadjuvant therapy, residual cancer is found at the time of surgery, the targeted drug, ado-trastuzumab emtansine, may be used instead of trastuzumab. It is given every 3 weeks for 14 doses. For women with hormone receptor-positive cancer found in the lymph nodes after completing 1 year of trastuzumab, the doctor might also recommend additional treatment with an oral targeted drug called neratinib for 1 year.
  • Hormone therapy: If the cancer is hormone receptor-positive, hormone therapy (tamoxifen, an aromatase inhibitor (AI), or one followed by the other) is typically used. It can be started before surgery, but because it continues for at least 5 years, it needs to be given after surgery as well.
  • Targeted drug therapy: For women with early-stage breast cancer that is hormone receptor-positive, HER2-negative, has cancer in the lymph nodes, and has a high chance of coming back, the targeted drug abemaciclib can be given after surgery along with tamoxifen or an AI. It is a pill typically given for 2 years twice a day. For women who have a BRCA mutation with a hormone receptor-positive, HER2-negative tumor who still have cancer in the tissue removed at surgery after neoadjuvant chemo, the targeted drug olaparib might be given for one year to help lower the chance of the cancer recurring.  When given this way, it can help some women live longer.
  • Immunotherapy: Women with TNBC might get the immunotherapy drug, pembrolizumab, before surgery and then again after surgery. See Treatment of Triple-negative Breast Cancer for more details.

Treating stage III breast cancer

In stage III breast cancer, the tumor is large (more than 5 cm or about 2 inches across) or growing into nearby tissues (the skin over the breast or the muscle underneath), or the cancer has spread to many nearby lymph nodes.

If you have inflammatory breast cancer: Stage III cancers also include some inflammatory breast cancers that have not spread beyond nearby lymph nodes. These cancers are treated slightly different from other stage III breast cancers. You can find more details in Treatment of Inflammatory Breast Cancer.

There are two main approaches to treating stage III breast cancer:

Starting with neoadjuvant therapy

Most often, these cancers are treated with neoadjuvant (before surgery) chemotherapy. For HER2-positive tumors, the targeted drug trastuzumab is given as well, often along with pertuzumab (Perjeta). This may shrink the tumor enough for a woman to have breast-conserving surgery (BCS). If the tumor doesn’t shrink enough, a mastectomy is done. Nearby lymph nodes will also need to be checked. A sentinel lymph node biopsy (SLNB) is often not an option for stage III cancers, so an axillary lymph node dissection (ALND) is usually done.

Often, radiation therapy is needed after surgery. If breast reconstruction is planned, it is usually delayed until after radiation therapy is done. For some, additional chemo is given after surgery as well.

After surgery, some women with HER2-positive cancers will be treated with trastuzumab (with or without pertuzumab) for up to a year. Many women with HER2-positive cancers will be treated first with trastuzumab (with or without pertuzumab) followed by surgery and then more trastuzumab (with or without pertuzumab) for up to a year. If after neoadjuvant therapy, any residual cancer is found at the time of surgery, ado-trastuzumab emtansine may be used instead of trastuzumab. It is given every 3 weeks for 14 doses. For women with hormone receptor-positive cancer that is in the lymph nodes, who have completed a year of trastuzumab, the doctor might also recommend additional treatment with an oral targeted drug called neratinib for a year.

Women with hormone receptor-positive (ER-positive or PR-positive) breast cancers will also get adjuvant hormone therapy which can typically be taken at the same time as trastuzumab.

For women with hormone receptor-positive, HER2-negative breast cancer that is in the lymph nodes, and has a high chance of coming back, abemaciclib can be given after surgery along with tamoxifen or an AI. It is a pill typically given twice a day for 2 years.

For women who have a BRCA mutation and hormone receptor-positive, HER2-negative breast cancer and still have cancer in the tissue removed at surgery after neoadjuvant chemo, the targeted drug olaparib might be given for one year to help lower the chance of the cancer recurring.  When given this way, it can help some women live longer.

Neoadjuvant treatment is a preferable option for women with stage III TNBC or HER2-positive breast cancer because the treatment given after surgery is chosen depending on how much cancer is still in the breast and/or lymph nodes at the time of surgery. Some women with stage III cancer who get neoadjuvant treatment might live longer if the cancer goes away completely with that treatment.

Women with TNBC might get the immunotherapy drug, pembrolizumab, before surgery and then again after surgery. See Treatment of Triple-negative Breast Cancer for more details.

Starting with surgery

Surgery first is an option for some women with stage III cancers. Because these tumors are fairly large and/or have grown into nearby tissues, this usually means getting a mastectomy. For women with fairly large breasts, BCS may be an option if the cancer hasn’t grown into nearby tissues. SLNB may be an option for some patients, but most will need an ALND. Surgery is usually followed by adjuvant chemotherapy, and/or hormone therapy, and/or targeted drug therapy, and/or HER2-positive treatment (trastuzumab, pertuzumab, or neratinib) depending on the traits of the cancer cells. Radiation is recommended after surgery.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Chan A, Delaloge S, Holmes FA, Moy B, Iwata H, Harvey VJ et al. Neratinib after trastuzumab-based adjuvant therapy in patients with HER2-positive breast cancer (ExteNET): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol. 2016 Mar;17(3):367-77.

Henry NL, Shah PD, Haider I, Freer PE, Jagsi R, Sabel MS. Chapter 88: Cancer of the Breast. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa: Elsevier; 2020.

Jagsi R, King TA, Lehman C, Morrow M, Harris JR, Burstein HJ. Chapter 79: Malignant Tumors of the Breast. In: DeVita VT, Lawrence TS, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.

National Cancer Institute. Physician Data Query (PDQ). Breast Cancer Treatment – Health Professional Version. 2019. Accessed at https://www.cancer.gov/types/breast/hp/breast-treatment-pdq on August 27, 2021.

National Comprehensive Cancer Network (NCCN). Practice Guidelines in Oncology: Breast Cancer. Version 7.2021. Accessed at https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf on August 27, 2021.

Sparano JA, Gray RJ, Makower KI, Pritchard KS, Albain DF, Hayes CE, et al. Adjuvant chemotherapy guided by a 21-gene expression assay in breast cancer [published online ahead of print June 3 2018]. NEJM. 2018; doi: 10.1056/NRJMoa1804710.

Taghian A. Adjuvant radiation therapy for women with newly diagnosed, non-metastatic breast cancer. In Vora SR, ed. UpToDate. Waltham, Mass.: UpToDate, 2021. https://www.uptodate.com. Last updated May 07, 2021. Accessed August 27, 2021.

References

Chan A, Delaloge S, Holmes FA, Moy B, Iwata H, Harvey VJ et al. Neratinib after trastuzumab-based adjuvant therapy in patients with HER2-positive breast cancer (ExteNET): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol. 2016 Mar;17(3):367-77.

Henry NL, Shah PD, Haider I, Freer PE, Jagsi R, Sabel MS. Chapter 88: Cancer of the Breast. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa: Elsevier; 2020.

Jagsi R, King TA, Lehman C, Morrow M, Harris JR, Burstein HJ. Chapter 79: Malignant Tumors of the Breast. In: DeVita VT, Lawrence TS, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.

National Cancer Institute. Physician Data Query (PDQ). Breast Cancer Treatment – Health Professional Version. 2019. Accessed at https://www.cancer.gov/types/breast/hp/breast-treatment-pdq on August 27, 2021.

National Comprehensive Cancer Network (NCCN). Practice Guidelines in Oncology: Breast Cancer. Version 7.2021. Accessed at https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf on August 27, 2021.

Sparano JA, Gray RJ, Makower KI, Pritchard KS, Albain DF, Hayes CE, et al. Adjuvant chemotherapy guided by a 21-gene expression assay in breast cancer [published online ahead of print June 3 2018]. NEJM. 2018; doi: 10.1056/NRJMoa1804710.

Taghian A. Adjuvant radiation therapy for women with newly diagnosed, non-metastatic breast cancer. In Vora SR, ed. UpToDate. Waltham, Mass.: UpToDate, 2021. https://www.uptodate.com. Last updated May 07, 2021. Accessed August 27, 2021.

Last Revised: April 12, 2022

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