Merck Manual

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Treating Breast Cancer Based on Type and Stage

Treating Breast Cancer Based on Type and Stage

Type

Possible Treatments

Ductal carcinoma in situ (cancer confined to the milk ducts of the breast)

Mastectomy

Sometimes breast-conserving surgery (removal of the tumor, leaving as much of the breast intact as possible) with or without radiation therapy

Sometimes hormone-blocking drugs

Lobular carcinoma in situ, classic (cancer confined to the milk-producing glands of the breast)

Sometimes surgery to check for cancer

If no cancer is detected, observation plus regular examinations and mammograms

Tamoxifen or, for some postmenopausal women, raloxifene or an aromatase inhibitor (such as anastrozole, exemestane, or letrozole) to reduce the risk of invasive cancer

Rarely, bilateral mastectomy (removal of both breasts) to prevent invasive cancers

Lobular carcinoma in situ, pleomorphic (which, unlike the classic type, leads to invasive cancer)

Surgery to remove the abnormal area and some of the tissue around it

Sometimes tamoxifen or raloxifene to try to prevent cancer from developing

Stages I and II (early-stage) cancer

Chemotherapy before surgery to optimize the chances for breast-conserving surgery for some women whose tumor is stuck to the chest wall or is large in relation to the rest of the breast

Breast-conserving surgery to remove the tumor and some surrounding tissue, followed by radiation therapy

Mastectomy with or without breast reconstruction

After surgery, chemotherapy, hormone-blocking drugs, anti-HER2 drugs (such as trastuzumab), or a combination, except in some postmenopausal women with tumors smaller than 0.5 to 1.0 centimeter (about 0.2 to 0.4 inch) and no cancer in the lymph nodes

Stage III (locally advanced) cancer (including inflammatory breast cancer)

Chemotherapy or sometimes hormone-blocking drugs before surgery to reduce the tumor’s size

Breast-conserving surgery or mastectomy if the tumor is small enough to be completely removed

Usually, radiation therapy after surgery

Sometimes chemotherapy, hormone-blocking drugs, or both after surgery

For inflammatory breast cancer, mastectomy, chemotherapy, and radiation therapy

Stage IV (metastatic) cancer

If cancer causes symptoms and occurs in several sites, hormone-blocking drugs, ovarian ablation therapy,* or chemotherapy

If the cancer cells have too many HER2 receptors, trastuzumab, sometimes with pertuzumab

Radiation therapy for the following:

  • Metastases to the brain

  • Metastases that recur in the skin

  • Metastases that occur in one area of bone and that cause symptoms

For metastases to bone, bisphosphonates (such as zoledronate or pamidronate) given intravenously to reduce bone pain and bone loss

Paget disease of the nipple

If breast cancer is also present, treatment based on that type of breast cancer

Occasionally, surgical removal of only the nipple with some surrounding normal tissue (local excision)

Breast cancer that recurs in the breast or nearby structures

Mastectomy sometimes preceded by chemotherapy or hormone-blocking drugs

Sometimes radiation therapy

Chemotherapy or hormone therapy

Phyllodes tumors if cancerous

Removal of the tumor and surrounding normal tissue (wide excision)

Radiation therapy

Mastectomy if the tumor is large or if analysis of the abnormal cells suggests cancer

* Ovarian ablation therapy involves removing the ovaries or using drugs to suppress estrogen production by the ovaries. The ovaries are the main source of estrogen in women who are still menstruating.