A Case of Primary Duodenal Adenocarcinoma Identified by Serially Elevated Serum CEA Levels after Curative Resection for Colon Cancer

The follow-up of patients after performing potentially curative resection for colon cancer is important, yet the ideal surveillance strategy has not been defined. Periodic clinical examinations, laboratory tests, radiographic imaging, colonoscopy and carcinoembryonic antigen (CEA) testing have been utilized for surveillance, and the serial CEA measurement is the most cost-effective test for identifying the recurrence of disease. However, this test also indicates the development of secondary gastrointestinal malignancy such as gastric cancer or duodenal cancer. We report here on a case of metachronous duodenal adenocarcinoma that was revealed by the serial measurement of the serum CEA after we performed curative resection for colon cancer.