Comparative analysis of epigenetic and protein markers in blood of non- small-cell lung cancer patients

RARβ2 and RASSF1A methylation index has been measured in extracellular DNA circulating in blood plasma and being bound with surface of blood cells of non-small-lung cancer (NSCLC) patients before treatment. Concentration of protein markers (CEA and CYFRA 21.1) has been quantified in the blood plasma of the same lung cancer patients. The RASSF1A and RARβ2 methylation index which calculated as the ratio of concentration of methylated gene copies by sum of the concentrations of methylated and unmethylated gene copies in blood provides the discrimination of NSCLC patients from healthy subjects with sensitivity and specificity of 90 % and 82 %. Immunochemical detection of CEA and CYFRA 21.1 protein markers provides the discrimination of NSCLC patients from healthy subjects with sensitivity of 43 % and 56 % and specificity of 88 % and 97 %. The association between concentration of epigenetic (RARβ2, RASSF1A, RARβ2 + RASSF1A) and protein markers (CEA, CEA + CYFRA 21.1) has been shown in blood of NSCLC patients, but not for the CYFRA 21.1 separately. The data obtained demonstrate that the analysis of RARβ2 and RASSF1A methylation index in combination with the protein markers concentration CEA and CYFRA 21.1 measuring is thought to be more effective than the detection of individual markers for lung cancer diagnostics.