The concentration of CYFRA 21-1, NSE and CEA in cerebro-spinal fluid can be useful indicators for diagnosis of meningeal carcinomatosis of lung cancer.

PURPOSES: We aimed to investigate the concentration of CYFRA 21-1, NSE and CEA in cerebro-spinal fluid (CSF) and to explore their clinical value in the meningeal carcinomatosis (MC) of lung cancer. So that, sensitive and specificity of CSF examination can be improved in the initial diagnosis of MC.

METHOD: A total of 35 lung cancer patients and 35 patients with benign brain tumor in the same period enrolled in this study. The concentrations of tumor markers CEA, CYFRA 21-1 and NSE in CSF and peripheral blood were examined.

RESULT: The concentrations of three tumor markers of CYFRA 21-1, NSE and CEA in blood serum and CSF were obviously higher than that of benign disease group. In MC patients, the concentrations of three tumor markers of CYFRA 21-1, NSE and CEA in blood serum were significant lower than that in CSF. The maximum of Youden's index was identified as the cutoff value of indicator of MC in three tumor markers in CSF which were CEA > 4.7 μg/L, NSE > 14.6 μg/L and CYFRA21-1 > 5.5 μg/L respectively. Based on the cutoff values, the CEA had the highest sensitivity while the CYFRA21-1 had the highest specificitiy. Three tumor markers in the CSF had higher positive rate than those in blood serum. We combined the levels of CEA, NSE and CYFRA21-1 in CSF to diagnosis of MC. Positive of CEA or CYFRA21-1 had the greatest sensitivity of 100% while the specificity of 91.4%; the positive of both CEA and CYFRA21-1 had the highest specificity of 100% while the sensitivity of 74.3%. Both positive predictive value and negative predictive value were 100% when combination positive were confirmed when the all three markers were positive.

CONCLUSION: The combination of CEA and CYFRA21-1 can be recommended in early screening of meningeal carcinoma. Especially, for the patient who was difficult to be diagnosed by CSF histology and MRI, it will be a useful auxiliary marker in diagnosis of MC. The combination of CEA, NSE and CYFRA21-1 can be an effective clinically confirmation and exclusively diagnose indictor of MC.