2020 年 32 巻 2 号 p. 115-123
Serum levels of tumor markers, such as carcinoembryonic antigen （CEA） and carbohydrate antigen 19-9 （CA19-9）, are often measured to detect potential malignancy. When these levels are high, the presence or absence of malignancy is confirmed via a more detailed examination using gastrointestinal （GI） endoscopy and computed tomography. The rate of confirmation of malignancy upon such a follow-up is unknown. This study aimed to investigate the malignancy detection rate via GI endoscopy for patients with high levels of serum CEA and CA19-9. All patients who underwent such GI endoscopy between January 2018 and February 2019 at Showa University Hospital were included in this study. The patients were divided into a follow-up group and a screening group, depending on the purpose of measuring their serum CEA/CA19-9 levels. There were 156 patients who underwent GI endoscopy because of high CEA/CA19-9 levels within the study period. Advanced malignant lesions were detected in 10 patients （6.4％）, including seven cases of colorectal cancer and three cases of upper GI malignancies. In the screening group, six cases （5.7％） of GI malignancies were detected, none of which were found in asymptomatic patients without anemia. In the follow-up group, four cases （7.8％） of GI malignancies were detected; three patients were asymptomatic, and one patient had anemia. Our findings suggest that high serum CEA/CA19-9 levels in asymptomatic patients without anemia and without a history of malignancy do not indicate the presence of malignancy. However, high serum CEA/CA19-9 levels may indicate the potential presence of GI malignancies for patients with a history of malignant tumors, even if they are asymptomatic and do not have anemia.
