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: Surgery
Estrogen receptor activity is clinically useful in predicting 
Select and explain. 
A. The presence of ovarian cancer, B. The presence of metastatic disease, C. Response to chemotherapy, D. Response to hormonal manipulation
D: Response to hormonal manipulation
Answer: D: Response to hormonal manipulation 
Explanation: The likelihood of response of a breast cancer to hormonal therapy is dependent on the presence of hormone receptors in the cytoplasm of the breast cancer cells. Receptors for corticosteroids, progesterone, prolactin, and estrogen have been identified. Eighty percent of patients with tumors that exhibit receptors to both estrogen and progesterone respond favorably to hormonal manipulation. Estrogen receptor activity has no predictive value in diagnosing ovarian cancer or metastatic disease, forecasting the development of osteoporosis, or determining the likelihood of a beneficial response to chemotherapy.