Abstract 4810: Utility of promoter hypermethylation for differentiating malignant and benign effusions in liquid-based cytology specimens

Abstract

Abstract Background : The cytologic differentiation between benign and malignant effusions can be difficult. Because promoter hypermethylation of tumor suppressor genes is a frequent epigenetic event in many human cancers, it could serve as a marker for the diagnosis of cancer. The aim of this study was to investigate the feasibility of promoter hypermethylation as a diagnostic tool for the differentiation between malignant and benign effusions in liquid-based cytology samples. Methods : A multiplex, nested, methylation-specific polymerase chain reaction analysis was used to examine promoter methylation of 4 genes (RAR-β, APC, Twist and HIN-1) in malignant (n=85) and benign (n=31) liquid-based cytology samples. Results : The frequencies of hypermethylation of RAR-β, APC, Twist and HIN-1 were significantly higher in malignant effusions than in benign effusions (p<0.001 for each). In receiver-operating characteristic analysis, the area under the curve (AUC) for APC was the highest. The AUC for the best two-gene combination (APC/HIN-1) was not statistically different from the best individual tumor suppressor gene (APC). Conclusions : This study suggests that promoter methylation analysis on residual liquid-based effusion samples may be a feasible approach to detect malignant effusions, and that APC is the best marker for differentiating malignant and benign effusions. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4810. doi:10.1158/1538-7445.AM2011-4810