Identification of Novel Mutations in Colorectal Cancer Patients Using AmpliSeq Comprehensive Cancer Panel

Molecular pathology of colorectal cancer: The Saudi situation in perspective

Colorectal cancer (CRC) is one of the most common cancers worldwide, and one of the most common causes of cancer deaths. In recent times, significant advancements have been made in elucidating the molecular alterations of the disease, and the results have been an improved understanding of CRC biology, as well as the discovery of biomarkers of diagnostic, prognostic, and therapeutic significance. In this review, an evaluation is carried out of the molecular pathology research of CRC emanating from Saudi Arabia. The verdict is that the data on the molecular alterations in CRC from Saudi patients is at best modest. This dearth of molecular pathology data is aptly reflected in the paucity of molecular markers recommended for testing by the Saudi National Cancer Centre guidelines for CRC management. Large scale multi-institutional and multiregional translational studies are required to generate molecular data that would inform diagnostic, prognostic, and risk-stratification guidelines for Saudi CRC patients.

Identification of Genomic Alterations in Thai Patients With Colorectal Cancer Using Next-Generation Sequencing-Based Multigene Cancer Panel

Introduction Colorectal cancer (CRC) is one of the leading causes of death and illness in the general population. Although the incidence of CRC is steadily decreasing worldwide, it is being diagnosed more in individuals under 50 years of age. Multiple disease-causing variants have been reported to be involved in the development of CRC. This study aimed to investigate the molecular and clinical characteristics of Thai patients with CRC. Methods NGS-based multigene cancer panel testing was performed on 21 unrelated patients. Target enrichment was performed using a custom-designed Ion AmpliSeq on-demand panel. Thirty-six genes associated with CRC and other cancer were analyzed for variant detection. Results Sixteen variants (five nonsense, eight missense, two deletions, and one duplication) in nine genes were identified in 12 patients. Eight (66.7%) patients harboring disease-causing deleterious variants in genes APC, ATM, BRCA2, MSH2, and MUTYH. One of the eight patients also carried additional heterozygous variants in genes ATM, BMPR1A, and MUTYH. In addition, four patients carried variants of uncertain significance in genes APC, MLH1, MSH2, STK11, and TP53. Among all detected genes, APC was the most frequent causative gene observed in CRC patients, which is consistent with previous reports. Conclusion This study demonstrated the comprehensive molecular and clinical characterization of CRC patients. These findings showed the benefits of using multigene cancer panel sequencing for pathogenic gene detection and showed the prevalence of genetic aberrations in Thai patients with CRC.

Next-Generation Sequencing Targeted Panel in Routine Care for Metastatic Colon Cancers

Simple Summary

The place of Next-Generation-Sequencing (NGS) targeted panel in routine practice in digestive oncology should be addressed. The aim of our retrospective study was to assess the results and impact of NGS panel for metastatic colorectal cancer (mCRC) patients. In total, 210 patients with mCRC were included. Based on our findings, a major advantage of the NGS panel over single gene techniques is that, beyond the classical hotspots, it allows for an exhaustive search for molecular abnormalities in routinely recommended genes. In addition, routine NGS is a way to detect amplifications associated with resistance to anti-EGFR therapies and low-prevalence mutations in actionable genes, providing patients with the opportunity to access innovative targeted therapies. In conclusion, NGS targeted panel in mCRC is feasible in routine practice. Nevertheless, panels need to be regularly updated and in-depth studies are needed to better analyse the prognostic factors.

Abstract

In digestive oncology, the clinical impact of targeted next-generation sequencing (NGS) in routine practice should be addressed. In this work, we studied the impact of a 22-gene NGS amplicon-based panel with Ion Torrent Proton Sequencing, prospectively performed in routine practice. We analyzed the results of extended molecular testing, beyond RAS and BRAF, in metastatic colorectal cancer (mCRC) patients in a single-center, retrospective, observational study of consecutive mCRC patients followed up at the Georges Pompidou European Hospital between January 2016 and December 2018. Overall, 210 patients with mCRC were included. Median follow-up was 25.4 months (IQR: 14.9–39.5). The three most frequently mutated genes were: TP53 (63%), KRAS (41%) and PIK3CA (19%). A positive association was found between overall survival and performance status (PS) ≥ 2 (HR: 4.91 (1.84–13.1); p = 0.001) and differentiation (HR: 4.70 (1.51–14.6); p = 0.007) in multivariate analysis. The NGS panel enabled five patients to access a targeted therapy not currently registered for CRC. In conclusion, targeted NGS panels in mCRC are feasible in routine practice, but need to be regularly updated and in-depth studies are needed to better analyze the prognostic factors.