Biochemical response was evaluable in 34 patients: overall, 18/34 (52.9%) showed a CgA reduction >30% from baseline; specifically, 6/12 (50.0%) of those with pancreatic cancer, 7/14 (50.0%) with intestinal carcinoids or cancer of unknown primary origin, and 5/8 (62.5%) with lung or paraganglioma showed a biochemical response, whereas 14/17 patients (82.3%) with a specific syndrome obtained a symptomatic response. Here, CGA is linked to paraganglioma.