The types of breast cancer

Breast cancer is not one disease, but a group of types and subtypes, each with features that guide treatment. In this video, I'll explain the main categories and what each subtype means for your care and treatment options. Understanding your specific cancer type helps you make informed decisions, and prepares you for conversations with your clinical team. Some types are more common than others and each is treated in a tailored way. An important first distinction is whether your cancer is "in situ" or "invasive"; this guides everything that follows. "In situ" means the abnormal cells are contained within the milk ducts where they started; with no spread. Invasive means the cells have started to spread into the surrounding breast tissue; beyond the duct or lobule. There are two main forms of in situ breast cancer, which we call DCIS and LCIS. DCIS is more common and usually appears on a mammogram as tiny calcium deposits called microcalcifications. LCIS is considered a warning sign of higher future breast cancer risk, rather than cancer itself. For invasive cancers, we identify the specific subtype before agreeing the best approach for you. This depends on hormone receptors and a protein called HER2 on the cancer cell surface. Hormone receptor positive cancer is the most common type, affecting around seven in every ten patients diagnosed. The cancer cells carry receptors that respond to the hormones oestrogen, progesterone, or sometimes both of these. These cancers usually respond well to hormone therapy, with drugs such as tamoxifen or aromatase inhibitors that block this effect. HER2 positive cancer makes up around two to three in every ten cases, and produces high levels of the HER2 protein on the cell surface. Targeted treatments such as trastuzumab, block HER2 and have greatly improved outcomes for people diagnosed with this type. Triple negative breast cancer is less common, affecting around one or two in every ten patients. The cells lack oestrogen, progesterone, and HER2 receptors - so hormone therapy and HER2 treatments don't work. However, chemotherapy is usually very effective, and immunotherapy is now an option for some patients. Other invasive types include inflammatory breast cancer; which is rare but fast-growing, and needs urgent specialist treatment. It can cause the breast to look red and warm, with skin dimpling or wrinkling, and is sometimes mistaken for an infection. Secondary breast cancer, sometimes called metastatic disease, is when cancer has spread to other parts of the body. Common sites include the bones, lungs, liver, and brain, with different symptoms in each location. Treatment focuses on controlling the cancer and protecting quality of life over the long term. Recurrent breast cancer means the disease has returned at some point after the initial treatment. It can come back locally in the breast or chest, or in another part of the body. Although far less common than in women; men can also develop breast cancer at any age. In the UK, fewer than four hundred men are diagnosed each year, with peak incidence in their sixties. Treatment principles follow the same approach as for women, with care tailored to each individual. Knowing the type and subtype of your breast cancer really matters, because it shapes every treatment decision and discussion. Modern breast cancer care is carefully built around the specific biology of your individual cancer; giving the best possible chance of a successful outcome. For further information, Cancer Research UK has clear, reliable resources on the different types of breast cancer. If you would like to understand your own subtype in more detail, my team can arrange a consultation to talk it through.