Abstract 4543: Combined analysis of cell-free DNA methylation in plasma for early detection of NSCLC

Abstract

Abstract Introduction: Detection of cell-free DNA (cfDNA) methylations in plasma samples may provide diagnostic information for non-small lung cancer (NSCLC). Here, we evaluated 5 preselected genes for methylation analysis from patient and control plasma samples. Method: Plasma samples were collected from 91 patients who were diagnosed with primary NSCLC with pathological or cytological confirmation. All the cases did not received any surgery or chemotherapy treatments when blood samples were collected. Meanwhile, 58 cases of healthy blood samples were collected as the control group. Methylation specific PCR (methylation specific-PCR, MS-PCR) was used to detect RUNX3, RASSF1A, 3-OST-2, DAPK, PTPRO genes methylation. Data was analyzed individually as well as jointly for the optimal diagnostic accuracy. Results: The DNA methylation rates for the 5 genes RUNX3, RASSF1A, 3-OST-2, DAPK, PTPRO were 47.25% (43/91), 51.65% (47/91), 27.47% (25/91), 36.26% (33/91), and 41.76% (38/91) respectively in patient plasma samples. In the normal control group, only PTPRO gene methylation was detected with the methylation rate of 5.2% (3/58), and the rest of 4 genes were not detected. Methylation of RUNX3 gene was found to have higher frequencies in adenocarcinoma than other cell types of NSCLC (P < 0.05). DAPK gene methylation was found to be associated with the stages of lung cancer, and methylation rate was higher in stage III/IV than in stage I/II (P < 0.05). Combined analysis of the 5 genes methylation rates was achieved the sensitivity 86.81% (79/91) and the specificity 79.31% (46/58). Conclusion: The combined DNA methylation analysis of RUNX3, RASSF1A, 3-OST-2, DAPK, and PTPRO genes with MS-PCR achieved a satisfied sensitivity and specificity in NSCLC diagnosis. Citation Format: Li Cao, Hao Wang, Xu Dong, Li Zhong. Combined analysis of cell-free DNA methylation in plasma for early detection of NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4543.