**4.13 Triple-negative breast cancer**

Breast cancer is now well understood to be a diverse disease with several subforms characterised by their distinct clinico-pathological features, prognosis, and treatment responses. The absence of progesterone receptor, human epidermal growth factor receptor 2, and oestrogen receptor expression characterises triplenegative breast cancer. This kind is primarily destructive, and it is more frequent in premenopausal females. It accounts for 10–15 percent of cases in white females, with a higher frequency.
