Abstract 7361: The prognostic value of TP53 and tumor suppressor gene mutations in temozolomide-treated IDH1 mutant low-grade glioma

Abstract Background: Temozolomide has been extensively utilized in the treatment of gliomas across various grades, offering significant therapeutic benefits. However, the impact of concurrent mutations in TP53 and other tumor suppressor genes (TSG) on treatment outcomes in patients with IDH1 mutant low-grade glioma (LGG) treated with temozolomide remains to be fully understood. This study aims to explore the influence of these genetic factors on the response to temozolomide therapy, focusing on identifying potential genetic markers that can predict therapeutic outcomes. Methods: Our study exclusively analyzed The Cancer Genome Atlas (TCGA) LGG PanCancer dataset from cBioPortal, focusing on IDH1 mutant cases treated with temozolomide. Data analysis was carried out using Python 3. 11. The cohort was categorized based on genetic alterations: TP53 mutation with additional TSGs (ATRX, CIC, FUBP1, NOTCH1) mutations (TP53mut/TSGmut), TP53 mutation without additional TSG mutations (TP53mut/TSGwt), and no TP53 mutations (TP53wt). Results: In our study, 178 LGG samples with IDH-1 mutation treated with temozolomide were selected. Of these, 113 samples had a mutation in TP53, and 88 had an additional mutation in a TSG. For TP53mut/TSGmut compared to TP53wt, the analysis revealed significant differences in clinical outcomes (PFS: HR 1. 95, CI: 1. 17-3. 26, p=0. 011; OS: HR 1. 6, CI: 1. 13-2. 26, p=0. 008). When comparing TP53mut/TSGwt with TP53mut/TSGmut, the findings were (PFS: HR 1. 36, CI: 0. 63-2. 92, p=0. 432; OS: HR 0. 93, CI: 0. 31-2. 79, p=0. 896). Finally, the comparison between TP53wt and TP53mut/TSGwt showed (PFS: HR 1. 45, CI: 0. 62-3. 39, p=0. 397; OS: HR 2. 31, CI: 0. 64-8. 3, p=0. 200). Conclusion: The presence of concurrent mutations in TP53 and other TSGs in IDH1 mutant LGG patients (TP53mut/TSGmut) is indicative of a more aggressive disease course and reduced response to temozolomide treatment, as evidenced by significantly worse clinical outcomes. In contrast, the TP53mut/TSGwt group did not exhibit significant differences in treatment outcomes. These findings underscore the importance of detailed genetic profiling in developing personalized treatment strategies for this patient population. Citation Format: Yahia E. Salem, Bayan O. Abu Alragheb. The prognostic value of TP53 and tumor suppressor gene mutations in temozolomide-treated IDH1 mutant low-grade glioma abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 7361.