Islet amyloid polypeptide is not a satisfactory marker for detecting pancreatic cancer

Background and Aims: Islet amyloid polypeptide (IAPP) levels are elevated in pancreatic cancer and may be a useful marker of pancreatic cancer-associated diabetes. The aim of this study was to compare the sensitivity and specificity for pancreatic cancer of IAPP with that of CA19-9, examine clinical characteristics of diabetes in pancreatic cancer, and define the relationship of lAPp to diabetes of pancreatic cancer. Methods: Fasting serum glucose, IAPP, and CA 19-9 were measured in 130 subjects with pancreatic cancer, 250 subjects with other pancreatic and peripancreatic diseases, and 116 controls. In pancreatic cancer patients, we noted tumor stage and the presence and duration of diabetes. Results: IAPP was markedly elevated in pancreatic cancer, especially in patients with diabetes. However, the sensitivity of IAPP for pancreatic cancer was less than that of CA 19-9 (40% vs. 75%; P < 0.001). Diabetes was present in 46% of pancreatic cancers and 55% of resectable tumors. In pancreatic cancer with diabetes, the sensitivity of IAPP was only 50%. In resectable cancer it was 27%. Conclusions: IAPP is elevated in pancreatic cancer but is not sensitive enough to replace or complement existing tests. Diabetes occurs early and frequently in pancreatic cancer. Development of a sensitive and specific marker for pancreatic-associated diabetes might lead to diagnosis of resectable pancreatic cancer.