Overview of the science
DNA within cells may be modified by the addition of a methyl group (-CH3) to certain sites within the genome. In particular, the DNA base cytosine can be methylated at the C-5 position of the cytosine ring (5-methylcytosine, 5-mC). This type of DNA modification is not a mutation that alters the coding potential of the genome. Instead, this type of DNA modification acts as a heritable but reversible marker of gene expression, called an epigenetic marker.
During malignant transformation (the process by which normal cells transform into cancer cells), there are significant changes in gene expression. These changes in gene expression are highly correlated to changes to the methylation pattern of genomic DNA. Therefore, normal cells and cancer cells can be differentiated by detecting which sites within the genome are methylated.
The genomic DNA of cancer cells is shed into circulation due to cancer cell death (apoptosis or necrosis) or release from viable cells. Once the genomic DNA of a cancer cell is shed into the blood stream, it is called cell-free DNA (cfDNA). This cfDNA retains the DNA methylation pattern of the cancer cell from which is was shed.
The IvyGene test is a blood test that uses advanced DNA sequencing methods to detect the DNA methylation pattern of cfDNA in blood samples in order to both confirm the presence of cancer and give quantifiable data about cancer presence.