This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Sentinel lymph node biopsy is used for \nSelect and explain. \nA. Breast carcinoma, B. Penile cacinoma, C. Retroperitoneal sarcoma, D. Hepatic carcinoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sentinel Lymph Node Mapping and Biopsy\n\nFor breast cancer, sentinel lymph node is the largest lymph node in the axilla and is the first to receive the lymph and potential metastases drained from the breast.\n\nIntraoperative lymphatic mapping and biopsy of the sentinel lymph node initially introduced for the staging of melanoma has been similarly used for the detection of axillary metastases in breast cancer, where it has also become the accepted standard of care.\n\nIn both the cases the method provides for minimally invasive surgery, and its success is now stimulating attempts to introduce it in the staging of the thyroid, gastric, colonic, lung and endometrial cancers.\nIn breast cancer surgery this technique avoids significant morbidity of axillary dissection and inexperienced hands has proven to provide acceptable rates of metastatic identification', 'role': 'assistant'}]