Breast CA

Lobules, ducts, lymph nodes, blood vessels, connective and fat tissue are all components of the breast where several types and stages of cancer can develop and spread1. Adenocarcinoma is the term used for cancer originating in glandular tissue, while the term sarcoma is reserved for cancer originating in the fat, muscle or connective tissue. The most common histological types of adenocarcinoma are described in Table 1. The American Cancer Society mentions cancer types that are less commonly seen, such as inflammatory breast cancer, Paget disease of the nipple, phyllodes, and angiosarcoma3. Inflammatory breast cancer (IBC) is characterized by peau d’orange (erythema and edema) present on ≥ 1/3 of the skin on the breast.3 Invasive/Infiltrating ductal carcinoma (IDC) is the most common invasive breast cancer, the other being invasive/infiltrating lobular carcinoma (ILC) that is less common. Ductal carcinoma in situ (DCIS), an early stage of breast cancer that has not spread, is associated with a high cure rate and affects an estimated 1 in 5 new cases of breast cancer.


Table 1.  Histological subtypes of breast cancer. References: Henry-Tillman RS, Klimberg VS. In situ breast cancer. Curr Treat Options Oncol. 2000 Aug;1(3):199-209, Hergueta-Redondo M, et al. “New” molecular taxonomy in breast cancer. Clin Transl Oncol. 2008 Dec;10(12)777-85, Sims AH et al Origins of breast cancer subtypes and therapeutic implications. Na Clin Pract Oncol. 2007 Sep;4(9):516-25

Breast cancer treatment is now highly personalized to each patient, considering the many underlying factors to determine the best treatment approach. A solid foundation in histological and molecular subtypes provides a platform for providers to build upon with the goal of optimizing treatment.


Figure 1. Molecular subtypes of breast cancer. Reference: Malhotra GK, Zhao X, Band H, Band V. Histological, molecular and functional subtypes of breast cancers. Cancer Biology & Therapy. 2010. 10:10,955-960. Doi: 10.4161/cbt.10.10.13879


Breast Cancer Treatment available here.

Breast Cancer References and Additional Reading:

  1. National Cancer Institute. Cancer Types. Breast Cancer. Patient Version. Available at:
  2. American Cancer Society. Cancer A-Z: Understanding a Breast Cancer Diagnosis. Site Updated 8/18/16. Available at:
  3. McMaster Pathophysiology Review. Breast Cancer. Available at:
  4. Shah R, Rosso K, Nathanson SD. Pathogenesis, prevention, diagnosis and treatment of breast cancer. World J Clin Oncol 2014 August 10; 5(3):283-298. Doi: 10.5306/wjco.v5.13.283
  5. NCCN Clinical Practice Guidelines in Oncology Breast Cancer. Version 2.2017. April 2017. Available at: