Oncology 2.5 Mg is used to treat specific forms of breast cancer in women, such as hormone-receptor-positive breast cancer. Oncology is furthermore utilised to aid stop the cancer from coming back. A natural hormone called oestrogen has the ability to accelerate the growth of some breast tumours. Oncology 2.5 Mg helps to reduce or stop the progression of certain breast cancers by reducing the amount of oestrogen the body produces. It functions by reducing the body's production of oestrogen. This is safe to consume.