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': 'A patient with history of increased lethargy and significant loss of weight found to have elevated carcinoembryonic antigens (CEA) in laboratory examination. He may have all of the following conditions, EXCEPT: \nSelect and explain. \nA. Lung cancer, B. Breast cancer, C. Colon cancer, D. Osteogenic sarcoma', 'role': 'user'}, {'content': "Answer: D \nExplanation: Carcinoembryonic antigen (CEA) is a glycoprotein found in the embryonic endodermal epithelium. Elevated CEA levels have been detected in patients with primary colorectal cancer as well as in patients with breast, lung, ovarian, prostate, liver, and pancreatic cancer. Levels of CEA also may be elevated in benign conditions such as diveiculitis, peptic ulcer disease, bronchitis, liver abscess, and alcoholic cirrhosis, especially in smokers and in elderly persons. Ref: Meric-Bernstam F. (2010). Chapter 10. Oncology. In T.R. Billiar, D.L. Dunn (Eds), Schwaz's Principles of Surgery, 9e.", 'role': 'assistant'}]