Elevated serum CA 19-9 at screening tests: underlying conditions and role of abdominopelvic CT

Usefulness of Carbohydrate Antigen 19-9 Test in Healthy People and Necessity of Medical Follow-up in Individuals with Elevated Carbohydrate Antigen 19-9 Level

Background

Carbohydrate antigen 19-9 (CA 19-9) is a tumor marker whose level is elevated in many types of cancers and other benign conditions. CA 19-9 levels are frequently found to be elevated in individuals during general health examinations. This study aimed to investigate the clinical characteristics of such individuals and to determine the need for medical follow-up.

Methods

We investigated individuals who underwent a health inspection, including a serum CA 19-9 test, at our center. Their CA 19-9 levels, age, sex, body mass index (BMI), and personal and past histories were investigated. Additionally, subgroup analyses were performed for those who underwent follow-up study for the elevated CA 19-9 levels.

Results

Of 58,498 subjects, 581 (1.0%) had elevated CA 19-9 levels. Multivariate analyses revealed that older age, female sex, lower BMI, and diabetes were independent predisposing factors for elevated CA 19-9 level. A subgroup analysis revealed that the causative conditions were identified in 129 of 351 subjects (36.8%). Among them, the causative conditions in 31 subjects (8.8%, including four cases of cancer and 15 of benign tumors) were not detected at the initial check-up and were found during the follow-up period.

Conclusion

The use of CA 19-9 as a marker for cancer in healthy individuals is inappropriate. However, medical follow-up in individuals with elevated CA 19-9 levels may be useful because some causative diseases may be detected during follow-up.

Novel Diagnostic and Predictive Biomarkers in Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease for a multitude of reasons including very late diagnosis. This in part is due to the lack of understanding of the biological behavior of PDAC and the ineffective screening for this disease. Significant efforts have been dedicated to finding the appropriate serum and imaging biomarkers to help early detection and predict response to treatment of PDAC. Carbohydrate antigen 19-9 (CA 19-9) has been the most validated serum marker and has the highest positive predictive value as a stand-alone marker. When combined with carcinoembryonic antigen (CEA) and carbohydrate antigen 125 (CA 125), CA 19-9 can help predict the outcome of patients to surgery and chemotherapy. A slew of novel serum markers including multimarker panels as well as genetic and epigenetic materials have potential for early detection of pancreatic cancer, although these remain to be validated in larger trials. Imaging studies may not correlate with elevated serum markers. Critical features for determining PDAC include the presence of a mass, dilated pancreatic duct, and a duct cut-off sign. Features that are indicative of early metastasis includes neurovascular bundle involvement, duodenal invasion, and greater post contrast enhancement. 18-F-fluorodeoxyglucose (18-FDG) radiotracer uptake and changes following treatment may predict patient overall survival following treatment. Similarly, pretreatment apparent diffusion coefficient (ADC) values may predict prognosis with lower ADC lesions having worse outcome. Although these markers have provided significant improvement in the care of pancreatic cancer patients, further advancements can be made with perhaps better combination of markers or discovery of unique marker(s) to pancreatic cancer.