Heterogeneous distribution of K-ras mutations in primary colon carcinomas: implications for EGFR-directed therapy

Purpose K-ras mutations predict resistance against epidermal growth factor receptor (EGFR)-directed therapy of metastatic colorectal cancer (CRC). The purpose of this study was to analyze the distribution of K-ras mutations in primary tumors and corresponding sentinel lymph nodes (SLNs) from colon cancer patients.