Circulating tumor cells in metastatic colorectal cancer from basic understandig to clinical practice

Colorectal cancer (CRC) represents the third most diagnosed cancer type worldwide, accounting for more than 600.000 deaths in 2012, which approximately represents 8,5% of all cancer-related deaths. It arises from the inner intestinal layer, usually from preexisting polyps that, after a series of molecular and genetic alterations, finally generate colorectal tumors. It is very important to consider that in CRC patients, the appearance of cancer metastasis, tumor masses that originate from primary tumors at distant sites, strongly determine patient prognosis. Only 8-10% of patients diagnosed with CRC at advanced stages survive after five years of follow up, which reinforces the importance of metastasis research to improve patient management and survival rates in CRC.