<unk>  <unk>  is any breast<unk>  that lacks or show low levels of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) overexpression and amplification (i.e. the tumor is<unk>  on all three tests giving the name<unk><unk> .<unk><unk>  is sometimes used as a surrogate term for basal-like.<unk> s comprise a very heterogeneous group of<unk> s. Some types of<unk>  are known to be more aggressive, with poor prognosis, while other types have very similar or better prognosis than hormone receptor positive breast<unk> s. Among breast<unk>  patients, 15–20% of women have been diagnosed as<unk><unk>  and<unk>  affects more young women or women with a mutation in the BRCA1 gene than other breast<unk> s.<unk>  is the most challenging breast<unk>  type to treat. Hormone therapy that is used for other breast<unk> s does not work for<unk> . In its early stages, the<unk>  is typically treated through surgery, radiation and chemotherapy. In later stages where surgery is not possible or the<unk>  has spread from the initial localised area, treatment is limited to chemotherapy and in some cases further targeted therapy.<unk> s have a relapse pattern that is very different from hormone-positive breast<unk> s: the risk of relapse is much higher for the first 3–5 years, but drops sharply and substantially below that of hormone-positive breast<unk> s afterwards. This relapse pattern has been recognized for all types of<unk><unk><unk> s for which sufficient data exist, although the absolute relapse and survival rates differ across subtypes.
Triple-negative breast cancer
Hereditary lobular breast cancer
Hormone receptor positive breast tumor
Paget's disease of the breast
Mucinous carcinoma of the breast
Medullary breast carcinoma
Inflammatory breast cancer
Hormone-sensitive cancer