Types of Breast Cancer Overview

Breast cancer is not a single disease. There are several different types, and understanding yours helps your clinical team plan the best treatment. This video gives an overview of the main subtypes. When breast cancer cells are tested in a laboratory, doctors look for certain features. These include whether the cells have receptors for the hormones oestrogen or progesterone, and whether they have high levels of a protein called HER2. These results help guide treatment choices. Ductal carcinoma in situ, or DCIS, is an early form of breast cancer. The abnormal cells are contained inside the milk ducts, and have not spread. DCIS is not life-threatening on its own, but it is usually treated to prevent it developing into invasive cancer. Oestrogen receptor-positive breast cancer means the cancer is sensitive to the hormone oestrogen - and six to seven in 10 people diagnosed have this type. The cancer cells have receptors for oestrogen, progesterone, or both. These cancers are often treated with hormone therapy - which blocks the hormones that help the cancer grow. HER2-positive breast cancer has high levels of a protein called HER2 on the surface of the cells. Two to three, out of 10 people diagnosed have this type. This protein encourages cancer cells to grow - and these cancers can be more aggressive and more likely to spread. Targeted therapies have been developed that block HER2, and these treatments have greatly improved outcomes for people with this type. Triple-negative breast cancer is uncommon with only one to two people in 10 having this type. The cancer cells do not have oestrogen or progesterone receptors, and do not have high levels of HER2. This means hormone therapy, and HER2-targeted treatments will not work. However, chemotherapy is often very effective, and newer treatments are becoming available. Inflammatory breast cancer is a rare but fast-growing type. It causes the breast to look red and swollen because cancer cells block the lymph vessels in the skin. This type requires urgent assessment, and treatment. Secondary breast cancer, also called metastatic breast cancer, is when cancer has spread from the breast to other parts of the body such as the bones, liver, lungs, or brain. Treatment of this type focuses on controlling the cancer, and maintaining quality of life. Rarer types include Paget's disease of the nipple, which causes skin changes, and phyllodes tumours, which grow in the connective tissue of the breast. Each type has its own approach to treatment, and your team will explain what applies to you. Knowing the type and subtype of your breast cancer helps your clinical team choose the most effective treatment. If you have questions about breast cancer types, or your diagnosis, please contact us any time.