Detection of progression of colorectal cancer: genetic and epigenetic profiling of primary tumors, micrometastasis and distant metastases.
Abstract
Sporadic colorectal cancer has after introduction of secondary screening programs, a high frequency of primary captures. The primary tumor is, however,after surgery often followed by progression to the lymph nodes and distant metastasis formation.
This indicates that this generalization often occur within the first 5 years due to the free spread of cancer cells and formation of micrometastases. The specific feature of this tumor type is characterized by changes at the DNA sequence (point mutations, microsatellite instability, allelic loss, etc.).
Recently, in addition to these genetic changes were described changes at the level of DNA methylation (epigenetic). It is assumed that genetic and epigenetic characteristics of the primary tumor are transported to distant metastases.
Monitoring of residual disease based on the detection of the profile of primary tumor and circulating tumor cells should be a potentially valuable tool for post-operational monitoring.