A 67-year-old man has noted a 5 kg weight loss along with in…
A 67-year-old man has noted a 5 kg weight loss along with increasing fatigue over the past year. He has experienced dull abdominal pain for the past week. He has developed abdominal distention with lack of stools in the past two days. On physical examination, bowel sounds are reduced. An abdominal CT scan reveals a mass involving the descending colon. At laparotomy, a partial resection of the left colon is performed, with removal of an encircling mass. Microscopically, the mass is found to be a moderately differentiated adenocarcinoma. Which of the following laboratory test findings is most likely to be present in this man?