Breast cancer is the abnormal growth of the cells that line the ducts and lobes of the breast. When breast cancer has spread outside the ducts or lobes into normal breast tissue, it is said to be invasive.
The main types of invasive breast cancer are:
Some breast cancer is a mixture of both ductal and lobular carcinoma.
There are also some less common types of invasive breast cancer, such as inflammatory breast cancer and male breast cancer.
When abnormal cells in the lining of a duct or lobe of the breast haven't spread, they are said to be noninvasive, or "in situ" (say "in-SY-too"). The main types of noninvasive cancer are:
Some breast cancer cells have:
Some breast cancers need the hormones estrogen or progesterone (or both) to grow. These cancer cells have "receptors" on their surfaces. Receptors are like doorways to let hormones in. These types of cancer are called estrogen-receptor-positive (ER+) and progesterone-receptor-positive (PR+) breast cancer.
And some breast cancers also have a large amount of a protein called human epidermal growth factor receptor 2 (HER-2 or HER-2/neu). These breast cancers tend to grow faster and spread more quickly than breast cancers without as much HER-2. So, HER-2 positive (HER-2+) breast cancers are usually treated with a targeted medicine (such as trastuzumab) and chemotherapy.
If the breast cancer cells don't have estrogen receptors, progesterone receptors, or large amounts of HER-2 protein, they are said to be triple-negative. Triple-negative breast cancer is a less common type of breast cancer. It tends to grow faster and spread more quickly and is harder to treat than breast cancers that have hormone receptors. Medicines that target hormone receptors or HER-2 won't help with triple-negative cancer, but chemotherapy can help.
Current as of:
December 17, 2020
Author: Healthwise StaffMedical Review: Sarah Marshall MD - Family MedicineE. Gregory Thompson MD - Internal MedicineKathleen Romito MD - Family MedicineDouglas A. Stewart MD - Medical Oncology
Current as of: December 17, 2020
Author: Healthwise Staff
Medical Review:Sarah Marshall MD - Family Medicine & E. Gregory Thompson MD - Internal Medicine & Kathleen Romito MD - Family Medicine & Douglas A. Stewart MD - Medical Oncology
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