The possibility of diagnosing small pancreatic cancer (less than 4.0 cm) by measuring various serum tumor markers. A retrospective study.

Comparative studies measuring various tumor markers such as SPan-1, CA 19-9, carcinoembryonic antigen (CEA), DUPAN-2, and elastase I were done in 74 patients with small pancreatic cancer including 23 cases of T1 pancreatic cancer (tumor size less than 2.0 cm) and 51 cases of T2 pancreatic cancer (tumor size between 2.1 to 4.0 cm), retrospectively. Although the mean value of these tumor markers in T1 and T2 pancreatic cancer were higher than those of the control cutoff levels, their sensitivities were different. In T1 pancreatic cancer, 13 of 23 cases (56.5%) of SPan-1 and 14 of 23 cases of (60.7%) of CA 19-9 had levels above normal. Although the numbers of patients were small, sensitivities of CEA, DUPAN-2, and elastase I were 30.8%, 22.2%, and 28.6%, respectively. In T2 pancreatic cancer, 41 of 51 cases (80.4%) of SPan-1 and 40 of 51 cases (78.4%) of CA 19-9 showed higher levels than normal, but only 46.9% of CEA, 40.0% of DUPAN-2, and 52.6% of elastase I were positive. The overall sensitivities in small pancreatic cancer (less than 4.0 cm) were 73% for SPan-1 and CA 19-9 but were less for CEA, DUPAN-2, and elastase I. These results indicate that even small pancreatic cancers release detectable pancreatic cancer-associated antigens in serum in more than 70% of cases, especially SPan-1 and CA 19-9. The measurement of these two tumor markers makes it possible to detect small pancreatic cancers after using imaging diagnostic procedures.