Published online Jul 21, 2014. doi: 10.3748/wjg.v20.i27.8928
Revised: January 29, 2014
Accepted: April 1, 2014
Published online: July 21, 2014
Approximately half of all patients with colorectal cancer develop local recurrence or distant metastasis during the course of their illness. Recently, the molecular detection of metastatic cancer cells in various types of clinical samples, such as lymph nodes, bone marrow, peripheral blood, and peritoneal lavage fluid, has been investigated as a potential prognostic marker. The prognostic value of molecular tumor cell detection was independent of the type of detection method used. As assays become more sensitive and quantitative, a more thorough assessment of the cancer status of patients will be based on molecular markers alone. At present, it is difficult to conclude that one specific molecular marker is superior to others. Comparative analyses are recommended to assess the prognostic impact of molecular analyses in the same patient and determine the biomarkers that provide the most accurate prognostic information.
Core tip: We focus on methods of the detection of molecular changes in metastatic colorectal cancer cells, and describe the characteristics for the methods, such as DNA methylation, mRNA, microRNA, immunomagnetic separation, protein and cancer-associated mutations. Moreover, we review the clinical significance according to the type of samples, such as blood, lymph node, bone marrow and peritoneal lavage fluid. At present, it is difficult to conclude that one specific molecular marker is superior to others. Comparative analyses are recommended to assess the prognostic impact of molecular analyses in the same patient and determine the biomarkers that provide the most accurate prognostic information.