Clinical observations of pancreatic diabetes caused by pancreatic carcinoma, and survival period

Background. Pancreatic carcinoma is often associated with diabetes mellitus. The interrelationship between them is very interesting and important for clinical examination and treatment. Methods. We examined diabetes mellitus in our patients with pancreatic carcinoma, especially those with invasive ductal pancreatic carcinoma, who were admitted to the National Kyushu Cancer Center between 1972 and 1998, in relation to secondary (pancreatic) diabetes, obstructive pancreatitis, angiopathies, treatment, and prognosis. Results. Diabetes mellitus was found at a high frequency (53.1%) in patients with invasive ductal pancreatic carcinoma and was mostly thought to be secondary diabetes (45.9%), caused, in part, by obstructive pancreatitis following pancreatic tumor recognized on the first admission. Control of blood glucose with insulin was sometimes difficult, but was indispensable for the treatment of pancreatic carcinoma. Diabetic angiopathies are usually not seen in patients with pancreatic diabetes caused by pancreatic carcinoma, because the survival period of patients with pancreatic carcinoma has been limited. Furthermore, in spite of the absence of angiopathies, the survival period was significantly lower in pancreatic carcinoma patients with diabetes than in those without diabetes. Conclusion. Diabetes in patients with invasive ductal pancreatic carcinoma is usually secondary diabetes, occurring in part as a consequence of obstructive pancreatitis shown at the beginning of the clinical course. The duration of diabetes is too short for marked diabetic angiopathies to develop, and the survival period in patients with invasive ductal pancreatic carcinoma with diabetes is also short compared with that of those patients without diabetes.