The breasts are paired, hemispherical-shaped, glandular organs of variable size on the chest of a woman (between the 2nd and 6th ribs and anterior to pectoral muscles). They are mostly made up of adipose (fatty) tissue and connective (fibrous) tissue that surrounds and support about 12 to 20 lobes. The nipple is surrounded by the dark skin called the areola.
Epithelial breast carcinoma or adenocarcinoma (affecting epithelial cells of the glandular tissue within breast) is the most commonly encountered (more than 95% of all cases) type of breast cancer. Breast adenocarcinoma includes ductal carcinoma in situ, invasive ductal carcinoma, and invasive lobular carcinoma.
Breast Cancer Hormone Receptors:
Normal breast cells and some breast cancer cells have specialized proteins on/in their surface called hormone receptors. Hormones – estrogen and progesterone can bind to these receptors (estrogen receptor [ER] and progesterone receptor [PR], respectively) and promote the growth of these cells.
Some breast cancer cells have another growth-promoting protein on/in their surface known as the human epidermal growth factor receptor 2 (HER2/neu or HER2). Certain breast cancer cells do not have any of the above receptors, that is, negative for ER, PR, and HER2. These are called triple-negative breast cancer.
Let's understand breast cancer with a series of videos.