Given the task definition and input, reply with output. Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Currently, no serological prognostic marker exists for pancreatic neuroendocrine tumors (pNETs). Previous studies have suggested potential for chromogranin A (CgA); however, the prognostic capability of CgA remains controversial. Our purpose was to explore preoperative CgA levels in predicting outcomes in patients with resected pNETs.', 'Patients with preoperative CgA levels who underwent resection of a pancreatic neuroendocrine tumor between July 2002 and May 2013 were identified from a prospective database. An elevated preoperative CgA was defined as a CgA laboratory value above the normal limit of the assay. All patients had pathologically confirmed primary pancreatic tumors. Outcomes were compared between elevated and normal CgA groups.', 'A total of 38 patients were identified that met inclusion criteria. Of these, 45% were male, and the median age was 57 y (range, 17-81 y). All underwent resection with curative intent. Elevated preoperative CgA was present in 16 patients (42%). There were no differences in node positivity or margin status between the normal CgA and elevated CgA groups on univariate analysis. However, tumor size and grade were significantly different between the two groups. Both disease-free survival (DFS; P = 0.006) and overall survival (P = 0.017) were negatively impacted by an elevated preoperative CgA (median follow-up; 40 mo).
Does chromogranin A predict survival for resected pancreatic neuroendocrine tumors?