Breast cancer can be determined by immunohistochemistry tests to determine if it is triple negative breast cancer. Triple negative breast cancer is a specific molecular subtype of breast cancer. If you want to determine whether you have triple negative breast cancer, you can do so by obtaining tumor tissue for immunohistochemical testing. If the ER (estrogen receptor), PR (progesterone receptor), and HER2 (human epidermal growth factor) are all negative, triple-negative breast cancer is identified. Triple-negative breast cancer is a high-risk type of breast cancer with a poor prognosis. It is not sensitive to endocrine therapy and molecularly targeted drug therapy is often ineffective, making it relatively difficult to treat. Once diagnosed, it should be treated as soon as possible with doctor’s intervention to avoid delay.