There has been an explosion of interest in the epigenetics of cancer in the past decade. DNA methylation is one of the major epigenetic mechanisms and it is a genetic feature better reflecting disease development and, consequently, has the potential to become more conclusive biomarker for detection and diagnosis of different diseases. The presence of small amounts of tumor DNA in cell free DNA (CFDNA) circulating in the plasma or serum of cancer patients was first demonstrated 30 years ago. Since then, overall plasma DNA concentration in cancer patients and genetic or epigenetic alterations specific to tumor DNA have been investigated in patients diagnosed with different types of cancer. However, the use of methylated DNA biomarkers is still not widely used in the clinic and further efforts to establish detection methods are required.

The ubiquity of DNA methylation changes has opened the way to a host of innovative diagnostic and therapeutic strategies. The status of DNA methylation is very stable, even in the circulation. Thus it can be assessed to monitor tumor-related processes. There is promising potential of DNA methylation as a diagnostic and prognostic marker for cancer patients due to the stability of circulating DNA. Development of noninvasive biomarker assays from patient samples would allow early diagnosis, prognosis prediction, and continuing assessment of disease progression and responses to treatments.

The present special issue aims to publish high-quality research articles as well as review contributions on a variety of topics related to epigenetic biomarkers detection in noninvasive clinical samples.

Potential topics include but are not limited to the following:

• Types of epigenetic biomarkers and their significance
  • DNA methylation, circulating or noncirculating
  • MicroRNA and other noncoding RNA
  • Protein markers
• Development of different nucleic acid methods using noninvasive samples
  • Blood serum or plasma
  • Urine
  • Stool
  • Sputum
• DNA methylation detection in noninvasive samples
  • Blood serum or plasma
  • Urine
  • Stool
  • Sputum
• Other nucleic acid (RNA and noncoding RNA) detections in noninvasive samples
• Different disease methylation markers using noninvasive methods
• DNA methylation in exfoliated cell in urine samples for urothelial/prostate cancer