This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breast, Subject name: Pathology
[{'content': 'ER positive status in Ca Breast indicates \nSelect and explain. \nA. Prognosis, B. Etiology, C. Site, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The presence or absence of estrogen or progesterone receptors ; The presence of hormone receptors confers a slightly better prognosis. However, the practical reason for determining their presence is to predict the response to therapy. The highest rate of response (approximately 80%) to antiestrogen therapy (oophorectomy or tamoxifen) is seen in women whose tumor cells express both estrogen and progesterone receptors ref : Robbins Basic Pathology, 9E,page-713', 'role': 'assistant'}]