Fuksiewicz M, et al. - Authors sought to assess the clinical utility of the chromogranin A determination in patients with NENs of the digestive system, as well as to evaluate the correlation between a concentration of NENs and PFS and OS. In this study, serum concentrations of CgA were established prior to treatment in 131 patients with NENs, including those with tumors located in the pancreas, the small intestine, caecum, appendix and in the colon. They discovered that in patients with NENs in the pancreas, CgA levels were related to disease progression. On the other hand, in patients with NENs in small intestine and caecum its concentration was a prognostic indicator for PFS and OS.