Serum GROβ: a potential tumor-associated biomarker for colorectal cancer

Objective: This study aimed to confirm the potential of growth-related gene product beta (GRO beta) as a biomarker for colorectal cancer. We compared serum GRO beta levels in patients with colorectal cancer, healthy individuals and individuals with non-tumor diseases. Methods: We measured serum GRO beta levels with enzyme-linked immunosorbent assay in patients with colorectal cancer (123 preoperative samples and 66 postoperative samples), 88 healthy controls and 125 individuals with other diseases. Serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were measured in all samples with an immunoluminometric assay. Statistical analyses were performed to determine associations between serum GRO beta levels and clinical parameters for colorectal cancer. A receiver operating characteristic (ROC) curve was analyzed for GRO beta, CEA and CA19-9. Results: The serum GRO beta levels were much higher in patients with colorectal cancer (median: 96.15 pg/ml) than those in healthy controls (median: 43.28 pg/ml, P < 0.01) and other disease controls (median: 57.30 pg/ml, P < 0.01). Serum GRO beta levels in colorectal cancer were correlated positively with tumor-node-metastasis staging (P < 0.01) and the depth of infiltration (P < 0.05), but not with the histological grade, tumor embolus, lymph node metastasis, gross pathologic tumor type, or patient gender. The sensitivity and specificity of the assay for serum GRO beta were 56.1% (69/123) and 95.31% (203/213), respectively. The area under the ROC curve constructed with GRO beta (0.834) was larger than that constructed with CEA (0.739) or CA19-9 (0.676) for discriminating colorectal cancer from matched controls. Conclusion: These preliminary results suggested that the serum GRO beta level could be a useful biomarker for colorectal cancer diagnoses.