Detection of Genetic Markers Involved in Metastatic Colorectal Carcinoma to Lymph Nodes

Abstract

Background Locoregional lymph node metastasis represents the first step of metastasis in colorectal carcinomas (CRC). Identifying genetic mutations that may promote metastasis will help optimize the treatment of patients at risk of lymph node metastasis. Method Out of 43 identified consented cases of CRCs with and without corresponding metastasis to lymph nodes; 5 cases of CRC with lymph node metastasis were retrieved and matched with another 5 cases of CRC with negative lymph node metastasis. Whole exome sequencing was performed on the primary CRC and their corresponding lymph node metastasis; their genetic profile was compared to the whole-genome sequence of glioblastoma multiforme. Results 115 variant mutations affecting 110 genes were identified. Focusing on variants with significant biological consequences, 31 of these variant mutations affecting 31 genes with putative role in CRC metastasis were selected. These variants are annotated as missense, splice site or “in frame deletion”. Conclusion The identified mutations may be further evaluated clinically as cancer markers for patients at risk for lymph node metastasis.