High concordance rate of KRAS/BRAF mutations and MSI-H between primary colorectal cancer and corresponding metastases

Abstract

Genetic testing is needed for the treatment of colorectal cancer (CRC), especially molecular-targeted therapy. The effects of anti-EGFR therapy and prognosis are affected by the presence of KRAS mutations. However, whether primary CRC or metastatic tissues are appropriate in the analysis is still unclear. In the present study, we assessed the concordance of KRAS/BRAF mutation status and microsatellite instability (MSI) in primary CRC and corresponding metastases. This study enrolled 457 patients with surgically resected primary and corresponding metastatic CRC (499 synchronous metastases and 57 metachronous metastases) and seven local recurrences, and KRAS/BRAF mutation and MSI status were analysed for these tumours. The concordance rates of KRAS mutation, BRAF mutation, wild-type, MSI-H and MSS between primary CRC and corresponding metastases were 93.9% (214/228), 100% (30/30), 99.3% (304/306), 87.5% (21/24) and 100% (137/137), respectively. These high concordance rates were not different between synchronous and metachronous metastases. In conclusion, a high concordance of KRAS/BRAF mutation status and MSI status was observed between primary CRC and corresponding metastases in this study. Either primary CRC or metastatic tissues can be used for testing KRAS/BRAF mutation status and MSI status.

High Concordance and Negative Prognostic Impact of RAS/BRAF/PIK3CA Mutations in Multiple Resected Colorectal Liver Metastases

“…Also, among the few patients with mutation heterogeneity, the temporal nature of the disease had no effect, in line with the findings from previous studies. [43][44][45] Nevertheless, heterogeneity in CRC beyond driver gene mutations has been demonstrated and is likely to affect tumor progression and the response to treatment. A large number of subclones in the primary tumor, which correlated with a high degree of heterogeneity, 46 and the heterogeneity of genome-wide copy number aberrations 18 have both been associated with a poor prognosis.…”

Comparison of Mismatch Repair Status Between Primary and Matched Metastatic Sites in Patients With Colorectal Cancer

“…Change in MSI status is important because studies have shown that only patients with deficient MMR (dMMR) or MSI-high tumors benefit from anti-PD-1 therapy. 17,18 Haraldsdottir et al 19 reported a 100% concordance rate in MMR status between the primary tumor and corresponding metastatic tissue in 25 patients with CRC, whereas Fujiyoshi et al 20 found a discordance in 3 patients and Jung et al 21 found a concordance rate of only 77%.…”

The RAS mutation status predicts survival in patients undergoing hepatic resection for colorectal liver metastases: The results from a genetic analysis of all‐RAS

“…It is desirable that all‐ RAS analysis is performed early in the surgical management of CLM patients. Because the all‐ RAS mutation status of the primary tumor and CLM usually showed >95% concordance, endoscopic biopsy, or surgical specimens of primary tumor can be confidently used for the all‐ RAS mutation analysis to predict the prognosis and for clinical decision‐making in relation to anti‐EGFR antibody therapy before hepatic resection in CLM patients …”

“…| 753 prognosis and for clinical decision-making in relation to anti-EGFR antibody therapy before hepatic resection in CLM patients. 25,[43][44][45]…”