Prospective study of tumor suppressor gene (TSG) methylation as a prognostic biomarker in surgically resected non-small cell lung cancer (NSCLC).

7066 Background: In the New England Journal of Medicine, Brock et al. (2008) published a nested case-control study which tested the association between early recurrence of NSCLC after surgical resection, and TSG promoter methylation in tumor and lymph nodes detected by methylation-specific PCR (MSP). They reported that promoter methylation of the TSGs p16, CDH13, RASSF1A, and APC was significantly associated with early recurrence in 51 patients with stage I NSCLC compared to matched patients without early recurrence. We attempted to confirm these findings. Methods: In a prospective study, fresh frozen tumor tissue was acquired after surgical resection in 107 patients with stage I-IIIA NSCLC between 2003-2008. The promoter methylation status of the same 4 genes examined by Brock, et al (p16, CDH13, RASSF1A, APC), as well as 6 additional TSGs (MGMT, WIF-1, METH-2, GSTP1, SOCS3, DAPK) were assessed in the tumor tissue using quantitative MSP (MethyLight assay), with any amount of methylation scored as positiv...