DNA methylation changes in ovarian cancer: Implications for early diagnosis, prognosis and treatment

Objective. To review epigenetic changes identified in ovarian cancer, focusing on their potential as clinical markers for detection, monitoring of disease progression and as markers of therapeutic response. Methods. A comprehensive review of English language scientific literature on the topics of methylation and ovarian cancer was conducted. Results. Genome-wide demethylation of normally methylated and silenced chromosomal regions, and hypermethylation and silencing of genes including tumor suppressors are common features of cancer cells. Epigenetic alterations, including CpG island DNA methylation, occur in ovarian cancer and the identification of specific genes that are altered by epigenetic events is an area of intense research. Aberrant DNA methylation in ovarian cancer is observed in early cancer development, can be detected in DNA circulating in the blood and hence provides the promise of a non-invasive cancer detection test. In addition, identification of ovarian cancer-specific epigenetic changes has promise in molecular classification and disease stratification. Conclusions. The detection of cancer-specific DNA methylation changes heralds an exciting new era in cancer diagnosis as well as evaluation of prognosis and therapeutic responsiveness and warrants further investigation. (c) 2007 Elsevier Inc. All rights reserved.