CASE STUDY 32.2 A 65-year-old man presents to the emergency department after he had abnormally tarry-colored stool on multiple occasions. He has had gastrointestinal discomfort and has felt...

Extracted text: CASE STUDY 32.2 A 65-year-old man presents to the emergency department after he had abnormally tarry-colored stool on multiple occasions. He has had gastrointestinal discomfort and has felt increasingly tired during the past 2 months. Physical examination reveals a guaiac-positive stool. A subsequently colonoscopy identified a circumferential mass in the sigmoid colon. A biopsy was performed, which identified the mass as an adenocarcinoma. CEA level was obtained as part of the presurgery workup. questions 1. Is the CEA test useful as a screening test for colon carcinoma? 2. What other conditions can result in elevated CEA levels? 3. How is CEA used to monitor patients after surgery for colon cancer?