Hi. Your cousin's prognosis would depend on several factors. The first factor is the stage of the disease. Stage refers to how big the primary tumor has grown, and how far it has spread (metastases) to other body parts. In breast cancer, staging is divided into four, with stage 1 having the smallest tumor and the least amount of spread and stage 4 signifying metastases to distant body parts. Stage 1 has the best prognosis, with an excellent chance for a cure. When the cancer reaches stage 4, it is virtually incurable, and the goal of treatment is focused more on controlling the disease and improving the patient's quality of life.
There are other tumor characteristics which affect prognosis since they imply a more aggressive tumor. The amount of estrogen and progesterone receptors (ER/PR) that the tumor has is one of these characteristics. A negative ER and PR implies a poorer prognosis since this means that the tumor is resistant to hormonal therapy. Increased levels of the epidermal growth factor receptor called HER-2 also signifies a more aggressive tumor and a poorer prognosis.