A genome-wide assessment of variations of primary colorectal cancer maintained in metastases.

Colorectal cancer (CRC) is a highly heterogeneous disease that is the third leading cause of cancer-related deaths worldwide. This study presents a genome-wide assessment of variations in primary colorectal cancer maintained in metastases, even in distant metastases. The purpose of this study was to determine whether intratumor heterogeneity is related to disease progression and metastasis in CRC. The results showed that 882 single nucleotide polymorphism (SNP) associated genes and 473 copy number variant (CNV) associated genes specific to metastasis were found. In addition, 57 SNPs mapped to miRNAs showed significant differences between primary tumors and metastases. Functional annotation of metastasis-specific genes suggested that adhesion and immune regulation may be essential in the development of tumors. Moreover, the locus rs12881063 in the fourteenth chromosome was found to have a high rate of the G/C type in metastases. The rate of the G/C type in nearby lymph node metastases was 66.7%, while the rate of the G/C type in distance lymph node metastases was 83.3%. These results indicate that rs12881063 may be the basis for clinical diagnosis of CRC metastasis.