Association of TP53 mutation with decreased prevalence of MSI-high, RAS and PI3KCA mutations in metastatic colorectal cancer.

Authors

Minggui Pan

Minggui Pan

Kaiser Permanente, Dept of Medical Oncology, Santa Clara, CA

Minggui Pan , Chen Jiang , Pamela Tse , Aleyda V Solorzano-Pinto , Elaine Chung , Thach-Giao Truong , Amit Arora , Tilak Kumar Sundaresan , Jennifer Marie Marie Suga , Laurel A. Habel , Sachdev P. Thomas

Organizations

Kaiser Permanente, Dept of Medical Oncology, Santa Clara, CA, Kaiser Permanente, Division of Research, Oakland, CA, Kaiser Permanente, Oakland, CA, Kaiser Permanente, Dept of Medical Oncology, Vallejo, CA, Kaiser Permanente, Fremont, CA, San Francisco Medical Center, Kaiser Permanente Northern California, San Francisco, CA, NSABP/NRG Oncology, and Kaiser Permanente NCI Community Oncology Research Program, Vallejo, CA

Research Funding

No funding received
None

Background: TP53 tumor suppressor gene is mutated in approximately 50% of colorectal cancer (CRC). How TP53 mutations are associated with the prevalence of the other common genomic alterations such as RAS (KRAS/NRAS), BRAF, PI3KCA, as well as microsatellite stability (MSI) is not clear. Methods: We investigated the impact of TP53 mutations on other common genomic alterations and survival in patients with metastatic CRC using the NGS data within Kaiser Permanente Northern California (KPNC). Results: From November 2017 to January 2021, genomic profiling was performed on 1056 patients with metastatic CRC, of whom 740 patients harbored a TP53 mutation (TP53mut) and 316 patients had wild-type TP53 (TP53wt). We found that median overall survival (OS) was similar between the TP53wt and TP53mut patients (50.1 vs 47.5 months, p = 0.9), however, the percent with a Ras mutation was significantly higher in patients with TP53wt compared to TP53mut (63.2 vs 45.2%, p = 0.0001). Interestingly, the percent with MSI-high was also significantly higher in TP53wt than TP53mut patients (11.1 vs 1.4%, p = 0.0001), however, the response rate of the MSI-high patients to immune checkpoint inhibitor (ICI) was similar (40 vs 37.5%). In addition, a significantly higher percent of patients with TP53wt had PI3KCA mutations and a significantly lower percent had c-Myc amplifications compared to patients with TP53mut (PI3KCA, 32 vs 10.7%, p = 0.0001; c-Myc, 1.26 vs 4.6%, p = 0.008). There was no significant difference in the percent of BRAF mutations between the two patient populations (6.2 vs 9.8%). A significantly higher percent of patients with TP53wt and a PI3KCA mutation had a Ras mutation compared to patients with TP53mut and a PI3KCA mutation (81.2 vs 57%, p = 0.0004). However, TP53 mutation status was not significantly associated with the OS of patients with either a Ras, or BRAF, or PI3KCA mutation, or combination of Ras and PI3KCA mutations. Conclusions: TP53 mutation is associated with decreased prevalence of Ras, PI3KCA mutation and MSI-high in patients with metastatic CRC, however, without impacting the OS or response rate to ICI.

Disclaimer

This material on this page is ©2024 American Society of Clinical Oncology, all rights reserved. Licensing available upon request. For more information, please contact licensing@asco.org

Abstract Details

Meeting

2021 ASCO Annual Meeting

Session Type

Publication Only

Session Title

Publication Only: Gastrointestinal Cancer—Colorectal and Anal

Track

Gastrointestinal Cancer—Colorectal and Anal

Sub Track

Colorectal Cancer–Advanced Disease

Citation

J Clin Oncol 39, 2021 (suppl 15; abstr e15578)

DOI

10.1200/JCO.2021.39.15_suppl.e15578

Abstract #

e15578

Abstract Disclosures