Purpose: The diagnosis of leptomeningeal metastases is usually confirmed by the finding of malignant cells by cytological examination in the cerebrospinal fluid (CSF). More sensitive and specific cancer biomarkers may improve the detection of tumor cells in the CSF. Promoter methylation of the human telomerase (hTERT) gene characterizes most cancer cells. The aim of this study was to develop a sensitive method to detect hTERT methylation and to explore its use as a cancer biomarker in CSF. Experimental design: In 77 CSF specimens from 67 patients, hTERT promoter methylation was evaluated using real-time MS-HRM, real-time TaqMan PCR and methyl-sensitive high resolution melting (MS-HRM) in a single-tube assay. Results: Real-time MS-HRM assay was able to detect down to 1% hTERT methylated DNA in a background of unmethylated DNA. PCR products were obtained from 90% (69/77) of CSF samples. No false positive hTERT was detected in the 21 non-neoplastic control cases, given to the method a specificity of 100%. The sensitivity of the real-time MS-HRM compared to the cytological gold standard analysis was of 92% (11/12). Twenty-six CSFs from 22 patients with an hTERT methylated primary tumor showed cytological results suspicious for malignancy; in 17 (65%) of them a diagnosis of leptomeningeal metastases could be confirmed by the hTERT methylation test. Conclusion: The hTERT real-time MS-HRM approach is fast, specific, sensitive, and could therefore become a valuable tool for diagnosis of leptomeningeal metastases as an adjunct to the traditional examination of CSF.
- Received April 18, 2012.
- Revision received January 18, 2013.
- Accepted February 4, 2013.
- Copyright © 2013, American Association for Cancer Research.