How the Type of Breast Cancer and Stage Relate To Treatment

There are several different treatment modalities for breast cancer, and most are available to the majority of patients. One of the most important factors in deciding the most appropriate treatment plan is to determine the stage of the cancer. The stage is determined by the size of the tumor and whether or not, and to what extent the cancer has spread to lymph nodes or throughout the body.

The stage of your cancer is important as it, along with your overall health and menopausal status, will determine which treatment options are available to you.1

Stage 0  

Stage 0 breast cancer is also called breast cancer in situ. There are two different types of breast cancer in situ. One is ductal carcinoma in situ, which is considered to be cancer at its earliest stage requiring surgical removal, and the other is lobular carcinoma in situ, which is a marker of increased risk by 10-15% over 30 years for developing breast cancer in either breast.

Stage l

The cancer is invasive and the tumor is less than or equal to 2centimeters in diameter with or without spread to the lymph nodes at level I or II and no evidence of metastatic disease.

Stage ll

Stage ll breast cancer can be further divided into stages llA and llB. llA describes breast cancer in situ with level I or II lymph node involvement, a cancer where the tumor is no more than 2 centimeters with level I or II lymph node involvement or a tumor that is between 2 and 5 centimeters without lymph node involvement. Stage llB includes tumors that are between 2 and 5 centimeters and involve the level I or II lymph nodes, or a tumor that is greater than 5 centimeters without lymph node involvement. In stage II, there is no evidence of distant metastasis.

Stage lll

There are three categories of stage lll breast cancer. Stage lllA involves the axillary and/or internal mammary lymph nodes and a tumor that is less than 5 centimeters. Stage lllB includes a tumor of any size that invades the skin of the breast or the chest wall with or without lymph node involvement. Stage lllC cancer involves a tumor of any size that has extensive lymph node involvement. Stage III does not involve distant metastasis.

Stage lV

Stage IV cancer describes a tumor of any size with any level of lymph node involvement that has spread to distant organs. Breast cancer most often spreads to the bone, brain and lungs.

Treatment Options

The treatment options will vary based on the type of breast cancer and may range from a lumpectomy (partial mastectomy) to bilateral mastectomy. Breast cancer in situ is most often treated with breast conservation therapy, which is a partial mastectomy followed by radiation therapy. Mastectomy may be considered if the area of concern is large or if the patient has small breasts, since the risk of recurrence is higher.2 Hormone therapy for risk reduction has also been shown to be beneficial in women with lobular carcinoma in situ.3

The treatment options for stages I-IIIC are quite variable. Surgical options range from partial mastectomy to unilateral or bilateral modified radical mastectomy. The other treatment modalities that are available for these stages are radiation, chemotherapy, hormone therapy and targeted therapy.

Some stage lll breast cancer may not be operable. In these situations chemotherapy can be used to shrink the size of the tumor and prevent further spread. Often with stage lll cancer, a critical goal in treatment is to prevent metastasis.

Stage lV breast cancer is typically inoperable but surgical procedures are sometimes done to alleviate pain if the tumor has invaded nerves. Sometimes, chemotherapy is given to shrink the tumor, which can also alleviate pain.


1 Stages of Breast Cancer. (n.d.). Retrieved from

2 Silverstein, M. J., Lagios, M. D., Craig, P. H., et al. (1998). A prognostic index for ductal carcinoma in situ of the breast. Cancer , 2267-2274.

3 Fisher, B., Costantino, J. P., Wickerham, D. L., et al. (1998). Tamoxifen for Prevention of Breast Cancer: Report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study. Journal of the National Cancer Institute , 1371-1388.

4 Fisher, B., Bryant, J., Wolmark, N., et al. (1998). Effect of preoperative chemotherapy on the outcome of women with operable breast cancer. Journal of Clinical Oncology , 2672-2685.

5 Treatment Options By Stage. (n.d.). Retrieved from National Cancer Institute:

This article was originally published on July 27,2012 and last revision and update of it was 9/2/2015.