Regional cerebral glucose metabolism in patients with secondary depressive episodes after fatal pancreatic cancer diagnosis

Abstract

Background Secondary depression is common in the clinical oncology setting after pancreatic cancer diagnosis, following which the patients have to face the fact that they have a cancer with an extremely poor prognosis. However, the specific pathophysiology remains unclear. The present study examined the regional cerebral glucose metabolism using F18-fluorodeoxyglucose (F18-FDG) positron emission tomography (PET) in antidepressant-naïve pancreatic cancer patients with a depressive episode after their cancer diagnosis and before their cancer treatment. Methods Regional cerebral glucose metabolism in pancreatic cancer patients without any antidepressant medication after the cancer diagnosis was measured with F18-FDG PET. A depressive episode after the cancer diagnosis was defined as including major and minor depressive episodes, and was diagnosed using the Diagnostic and Statistical Manual, Fourth Edition (DSM-IV). The prefrontal and limbic regions were the primary regions-of-interest, and an uncorrected value of p < 0.005 was used as significant. Results Six of 21 pancreatic cancer patients were diagnosed as having a depressive episode. Significantly higher glucose metabolism in depressed patients was found in the subgenual anterior cingulate cortex (sACC) (uncorrected p = 0.002). Limitations There was a small number of subjects, and there were no healthy controls. Conclusions The higher metabolism in the sACC may be associated with the pathophysiology of secondary depressive episodes in patients following pancreatic cancer diagnosis.