Hello how are you? I have read your question. May God bless your mother with complete health recovery. Stage 4 breast cancer is an advanced stage of the condition which mostly requires palliative care for providing maximum pain relief and comfort to the affected person. However, treatment options are always employed with good chances of success. Local treatments such as surgery or radiation might also be used sometimes to help prevent or treat associated symptoms. Stage IV cancers which spread beyond the breast and nearby lymph nodes to other parts of the body cause serious complications and spread usually involves bones, liver, and lungs. Chemotherapy is beneficial for the patient but serious side effects occur like the problems your mother is facing.