Impact of somatic genomic alterations in patients with metastatic colorectal cancer in a minority-rich academic medical center.

Abstract

215 Background: Genomic alterations in metastatic colorectal cancer (mCRC) play a pivotal role in the clinical manifestations of the disease. Mutations have been associated with the age of onset of mCRC, tumor location, and metastatic sites. We conducted a retrospective study to explore the relationship between the genomic profile and clinical phenotype in a distinct patient population predominantly comprised of Hispanic and Black patients with mCRC. Methods: Patients with mCRC with available next-generation sequencing (NGS) treated at Montefiore Einstein Comprehensive Cancer Center (MECCC) who were diagnosed from January 2000 - January 2023 were included. Molecular testing was collected from: Perthera, Guardant, Caris, and Foundation One. The following parameters were collected: race, ethnicity, age of CRC diagnosis, age of metastatic diagnosis, metastatic sites, NGS profile, tumor location, and lines of treatment. Mutations were categorized into one of eight distinct pathways: cell cycle, MAP Kinase, WNT, homologous recombination, DNA damage repair, epigenetic modifications, transcription, & cell death. The primary endpoint was to examine the relationship between individual genetic alterations or any of these eight pathways and the clinical parameters. Results: 169 patients with microsatellite stable (MSS) mCRC were included (median age at diagnosis 59 years, 42% Hispanic, 38% Black). 148 distinct genetic alterations were discovered across our population, of which roughly half fit into one of eight clinical pathways. In concordance with previously published data, we found a significant association between PTEN and right-sided tumors (38% mutated in right-sided vs. 16% mutated in left-sided, p<.001). Cell cycle pathway mutations and SMAD4 mutations were associated with an earlier age of both primary CRC (p=.001 & p=.042, respectively) and metastatic diagnosis (p=<.001 & p=.013, respectively). CDK8 mutations were associated with atypical sites of metastases (p=.045). Conclusions: This analysis sought to deepen the understanding of how genomic alterations impacted the clinical phenotype in our population of mCRC patients. We identified previously undescribed associations between mutations in the cell cycle pathway and SMAD4 versus age of CRC diagnosis. As molecular sequencing in CRC continues to advance, these relationships may be further elucidated, which can potentially help guide treatment and identify higher-risk patients.