Circulating Chromogranin A as a Surveillance Biomarker in Patients with Carcinoids—The CASPAR Study

• Published in: Clinical cancer research Vol. 30; no. 24; pp. 5559 - 5567
• Main Authors: Meng, Qing H., Halfdanarson, Thorvardur R., Bornhorst, Joshua A., Jann, Henning, Shaheen, Shagufta, Shi, Run Zhang, Schwabe, Andrej, Stade, Katrin, Halperin, Daniel M.
• Format: Journal Article
• Language: English
• Published: United States American Association for Cancer Research 16.12.2024
• Subjects: Adult; Aged; Aged, 80 and over; Biomarkers; Biomarkers, Tumor - blood; Carcinoid Tumor - blood; Carcinoid Tumor - diagnosis; Carcinoid Tumor - diagnostic imaging; Carcinoid Tumor - pathology; Chromogranin A - blood; Clinical Trial Results; Clinical Trials: Targeted Therapy; Clinical-stage Research; Disease Progression; Endocrine-related Cancers; Female; Gastrointestinal Cancers; Humans; Intestinal Neoplasms - blood; Intestinal Neoplasms - diagnosis; Intestinal Neoplasms - pathology; Male; Middle Aged; Neuroendocrine Tumors - blood; Neuroendocrine Tumors - diagnosis; Neuroendocrine Tumors - pathology; Pancreatic Neoplasms - blood; Pancreatic Neoplasms - diagnosis; Pancreatic Neoplasms - pathology; Prospective Studies; Stomach Neoplasms - blood; Stomach Neoplasms - diagnosis; Stomach Neoplasms - diagnostic imaging; Stomach Neoplasms - pathology
• ISSN: 1078-0432; 1557-3265; 1557-3265
• DOI: 10.1158/1078-0432.CCR-24-1875

Gastroenteropancreatic neuroendocrine tumors (GEP-NET) are relatively indolent but can be more aggressive. The current recommendations for using serum chromogranin A (CgA) for patients with GEP-NET are equivocal. This study was designed to validate an automated CgA immunofluorescence assay for monitoring disease progression in patients with GEP-NET. A prospective, multicenter, blinded observational study was designed to validate an automated CgA immunofluorescence assay for monitoring disease progression in patients with GEP-NET. Tumor progression was evaluated with RECIST 1.1 by CT/MRI. An increase ≥50% above the prior CgA concentration to a value >100 ng/mL in the following CgA concentration was considered positive. A total of 153 patients with GEP-NET were enrolled. Using the prespecified cut-off of CgA change for tumor progression, specificity was 93.4% (95% confidence interval, 90.4%-95.5%; P < 0.001), sensitivity 34.4% (25.6%-44.3%), positive predictive value 57.9% (45.0-69.8), negative predictive value 84.3% (80.5-87.6), and AUC 0.73 (0.67-0.79). Changes in serial measurements of serum CgA had a favorable specificity and negative predictive value, making this test a useful adjunct to routine radiographic monitoring.