Potential diagnostic value of methylation profile in pleural fluid and serum from cancer patients with pleural effusion

Abstract

BACKGROUND.The objective of this study was to investigate the diagnostic value of methylation profiles for discrimination between malignant and benign pleural effusions. A secondary objective was to examine the concordance of methylation in samples of serum and pleural fluid.METHODS.The authors used methylation‐specific polymerase chain reaction (MSP) analysis to examine the promoter methylation status of 4 genes in patients with pleural effusion: death‐associated protein kinase (DAPK), Ras association domain family 1A (RASSF1A), retinoic acid receptor β (RARβ), and p16/INK4a. Pleural effusions were collected from 87 patients who had their diagnoses confirmed on cytologic and/or histologic examinations and clinical evolution. Pleural effusions were classified as malignant (n = 53 patients) or benign (n = 34 patients).RESULTS.Methylation was detected in serum from 45.3% of patients with malignant pleural effusions and from 0% of patients with benign pleural effusions, and it was detected in pleural fluid samples from 58.5% of patients with malignant pleural effusions and from 0% of patients with benign pleural effusions (P = .001). The sensitivity of MSP was greater than that of cytologic examination alone (39.1%; P = .001). When MSP was used together with cytologic examination, sensitivity increased to 69.8% (P = .001).CONCLUSIONS.Cell‐free methylated DNA in pleural fluid can be detected in patients with neoplastic malignancy in a single extraction by thoracocentesis. Adequate management of the extracted pleural fluid can provide a rapid and reliable diagnosis in patients with pleural effusions who have suspected malignancy. MSP, used together with cytologic examination, may obviate the need for other invasive diagnostic tests. Cancer 2006. © 2006 American Cancer Society.

Detection and comparison of epidermal growth factor receptor mutations in cells and fluid of malignant pleural effusion in non-small cell lung cancer

“…The presence of tumor cells makes it a good source of tumor genomic DNA, whereas the little amount of soluble DNA in cell-free pleural fluid has been proved to be sufficient for most molecular analysis. Several studies have reported their determination of methylated DNA spectrum and somatic mutations of the genes of K-ras, Rho, P53 and FHIT in cell-free pleural fluid in patients with various neoplastic malignancies [8][9][10]. All above collectively demonstrate the importance of pleural effusion in genetic and epigenetic studies.…”

Pre-analytical issues in effusion cytology

“…Effusion specimens studied for DNA methylation have been frozen at -80°C prior to analysis in the majority of studies [84][85][86][87], although freezing at -20°C has also been used [88]. Studies of effusion specimens applying proteomics used fresh samples, as well as samples frozen at -20°C or -80°C [89][90][91][92][93].…”

Prognostic value of aberrant hypermethylation in pleural effusion of lung adenocarcinoma

“…21,25 Certain genes such as DAPK, RASSF1A, p15, p16/INK4a, RARβ, MGMT and APC, are known to be methylated in many cancers, and have been studied in patients with MPE. [13][14][15][16] In these studies, methylation analyses (combined or not with cytology) improved diagnosis of MPE [13][14][15][16] avoiding the need of other invasive diagnostic tests. However, the application of methylation as a prognostic tool is still poorly explored in patients with MPE.…”

“…[9][10][11][12] The transcriptional inactivation caused by promoter hypermethylation affects genes involved in important cellular pathways, and has been suggested as a diagnostic tool for PE. [13][14][15][16] However, there is practically no evidence of its relation with prognosis in patients with MPE. 17 Therefore we aim to analyze the hypermethylation status of the promoter region of tumor suppressor genes p16/INK4a, MGMT (O6-methylguanine-DNA-methyltransferase), BRCA1 (breastcancer susceptibility gene 1) and RARβ (retinoic acid receptor β) in pleural fluid, and its association with survival and other common clinical parameters in patients with MPE.…”