Biochemical prognostic indicators for pancreatic neuroendocrine tumors and small bowel neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) comprise 3-5% of pancreatic malignancies and have a better prognosis than pancreatic exocrine tumors (1). Approximately 1,000 are diagnosed per year in the United States (1). Significant prognostic factors include tumor grade, tumor size, nodal status, presence of metastatic disease, Ki-67 protein index, and neurovascular invasion. Predicting prognosis can be difficult as some tumors follow an indolent course, while others are more aggressive. Common tumor markers that facilitate the diagnosis and follow-up of these patients include chromogranin A (CgA), pancreatic polypeptide, and the specific hormone over-secreted in functional PNETs