Systematic review of carbohydrate antigen (CA 19-9) as a biochemical marker in the diagnosis of pancreatic cancer.

BACKGROUND: Although many biochemical markers have been examined in pancreatic cancer none are definitive for pre-operative diagnosis. This systematic review examines studies using biochemical markers for the diagnosis of pancreatic cancer in order to appraise their role in contemporary management algorithms. METHODS: A search of the MEDLINE database was undertaken using the key words pancreatic neoplasm and serum tumour marker. Only studies providing original data on sensitivity and specificity are included and data are presented on diagnostic accuracy, effect of cholestasis and the relation of tumour stage to blood levels of markers. RESULTS: CA 19-9 is the most extensively evaluated with pooled data from 2283 patients. The median sensitivity of CA 19-9 for diagnosis is 79 (70-90%) and median specificity 82 (68-91%). CA 19-9 elevation in non-malignant jaundice results in a fall in specificity. Combination with other markers improves accuracy. CONCLUSION: As the most extensively evaluated marker, CA 19-9 should be used in contemporary algorithms for the diagnosis of pancreatic cancer. Elevated values should be repeated after relief of jaundice.