ABSTRACT
Neuroendocrine gastroenteropancreatic tumor diagnosis is a very difficult and expensive procedure. This study compared Chromogranin A (CgA) to Neuron-specific enolase (NSE) in 55 patients affected by neuroendocrine tumors. Advanced local or metastatic neoplasia was found in 43 patients. Radical operation was performed in 12 patients. Seventeen cases of lung microcystoma, 23 cases of other intestinal tumors and 19 patients affected by irritable bowel syndrome were used as controls. CgA sampling demonstrated sensitivity of 73% and specificity of 66%, a positive predictive value of 77% and a negative predictive value of 61% while NSE sampling showed sensitivity of 100%, specificity of 36%, a positive predictive value of 15% and a negative predictive value of 100%. CgA values demonstrated a statistically significant difference between patients with neuroendocrine tumors and tumor-free resected patients (p = 0.0015), microcystoma patients (p = 0.0087), other types of neoplasia (p = 0.01) and irritable bowel syndrome patients (p = 0.0004). No significant difference was found among the same groups when NSE values were analyzed. The high diagnostic accuracy of CgA sampling renders it very useful in early neoplastic detection, even in cases of nonfunctioning neoplasms or absence of liver metastases. In addition, CgA sampling may be an effective screening test in patients with irritable bowel syndrome or with liver or lung metastases when there is no evidence of the primitive tumor.
