title: Chromogranin A as a predictor of radiological disease progression in neuroendocrine tumours.
abstract: BACKGROUND
  Chromogranin A (CgA) is the best established neuroendocrine biomarker. This study was aimed at investigating the prognostic value of CgA as a predictor of radiological disease progression in neuroendocrine tumour (NET) patients.
  
  
  METHODS
  Patients with metastatic NETs and evidence of radiological progression (RP) according to RECIST 1.1 were identified from a NET database. Plasma CgA levels were measured 6 and 12 months before RP and at the event of RP. CgA was measured with the Supra-regional-Assay-Service radioimmunoassay (Hammersmith Hospital).
  
  
  RESULTS
  A total of 152 patients were evaluated including 91 midgut NETs and 61 pancreatic NETs (PNETs). Of these, 56 were G1 NETs, 65 G2, 10 G3, 21 of unknown histology. For all NETs, there was a positive trend in terms of increase of CgA values 6 months prior to RP compared to 12 months before RP. Subgroup analysis at first episode of RP showed that for PNETs there was evidence of a difference in the median CgA levels. CgA 6 months before RP was 100 pmol/L [interquartile 1 (Q1) =53 and Q3 =286.25 pmol/L) and 12 months before was 52 pmol/L (Q1 =36.25 and Q3 =128 pmol/L), W=52, P=0.48. This observation was not confirmed in midgut NETs, where median CgA 6 months before RP was 389.5 pmol/L (Q1 =131.5 and Q3 =791.5 pmol/L) and 12 months before was 319 pmol/L (Q1 =158 and Q3 =753 pmol/L), W=191, P=0.39]. Low grade tumours (G1) had a median CgA value at 6 months significantly higher than at 12 months [181 (Q1 =56.25, Q3 =624) vs. 149.5 (Q1 =44, Q3 =247.25) pmol/L, W=70, P=0.48].
  
  
  CONCLUSIONS
  CgA seems to have predictive value 6 months prior to RP for PNETs and G1 tumours. Further prospective analyses are needed to enable more definitive conclusions.
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Roberta Elisa
authors.initials: RE
authors.lastname: Rossi
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Jorge
authors.initials: J
authors.lastname: Garcia-Hernandez
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Meyer
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Christina
authors.initials: C
authors.lastname: Thirlwell
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Watkins
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Nicholas Guy
authors.initials: NG
authors.lastname: Martin
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Martyn Evan
authors.initials: ME
authors.lastname: Caplin
authors.affiliation: 1 Neuroendocrine Tumour Unit, Centre of Gastroenterology, Royal Free Hospital, London, UK ; 2 Gastroenterology and Endoscopy Unit Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico and Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy ; 3 Cancer Institute, University College London, London, UK ; 4 Department of Histopathology, 5 Department of Clinical Biochemistry, Royal Free Hospital, London, UK.
authors.forename: Christos
authors.initials: C
authors.lastname: Toumpanakis
keywords: Chromogranin A (CgA); neuroendocrine tumour (NET); prognosis; radiological disease progression; tumour markers