Diagnosis of Pancreatic Cancer and Prediction of Unresectability Using the Tumor-associated Antigen CA19-9

Marked elevations of the tumor-associated antigen CA19-9 are relatively specific for pancreatic carcinoma and are associated with more advanced malignancies. We retrospectively reviewed 53 patients with CA19-9 values > 90 U/ml in whom the test had been done because of clinical suspicion of pancreatic malignancy. Pancreatic cancer was found in 45 patients (85%). If a cutoff value of CA19-9 > 200 U/ml is used, 36 of 37 (97%) patients had pancreatic cancer. Thirty patients with pancreatic cancer and no radiographic criteria of unresectability underwent attempted resection; five of these patients were judged to be potentially resectable and four of them underwent attempted resection. In only one patient with a CA19-9 value > 300 U/ml was resection possible; this patient had advanced carcinoma. Our results suggest that, in patients in whom the clinician suspects pancreatic carcinoma, CA19-9 > 90 U/ml is highly suggestive of pancreatic malignancy, while CA19-9 > 200 U/ml is virtually diagnostic of pancreatic malignancy. In similar patients with CA19-9 > 300 U/ml, resection is rarely possible and tumors are advanced.