# Factors Influencing Mortality in Children with Central Nervous System Tumors: A Cohort Study on Clinical Characteristics and Genetic Markers

## TL;DR

This study identifies genetic variants and a chemotherapy regimen linked to higher mortality in children with brain tumors.

## Contribution

The study links specific genetic markers and treatment schedules to increased mortality in pediatric central nervous system tumor patients.

## Key findings

- The rs1045642 variant in ABCB1 is associated with increased mortality in recessive models.
- The rs3114020 variant in ABCG2 is linked to higher mortality in codominant and dominant models.
- The ICE chemotherapy regimen significantly increases mortality risk in multiple genetic models.

## Abstract

Multidrug resistance (MDR) commonly leads to cancer treatment failure because cancer cells often expel chemotherapeutic drugs using ATP-binding cassette (ABC) transporters, which reduce drug levels within the cells. This study investigated the clinical characteristics and single nucleotide variant (SNV) in ABCB1, ABCC1, ABCC2, ABCC4, and ABCG2, and their association with mortality in pediatric patients with central nervous system tumors (CNST). Using TaqMan probes, a real-time polymerase chain reaction genotyped 15 SNPs in 111 samples. Patients were followed up until death or the last follow-up day using the Cox proportional hazards model. An association was found between the rs1045642 (ABCB1) in the recessive model (HR = 2.433, 95% CI 1.098–5.392, p = 0.029), and the ICE scheme in the codominant model (HR = 9.810, 95% CI 2.74–35.06, p ≤ 0.001), dominant model (HR = 6.807, 95% CI 2.87–16.103, p ≤ 0.001), and recessive model (HR = 6.903, 95% CI 2.915–16.544, p = 0.038) significantly increased mortality in this cohort of patients. An association was also observed between the variant rs3114020 (ABCG2) and mortality in the codominant model (HR = 5.35, 95% CI 1.83–15.39, p = 0.002) and the dominant model (HR = 4.421, 95% CI 1.747–11.185, p = 0.002). A significant association between the ICE treatment schedule and increased mortality risk in the codominant model (HR = 6.351, 95% CI 1.831–22.02, p = 0.004, HR = 9.571, 95% CI 2.856–32.07, p ≤ 0.001), dominant model (HR = 6.592, 95% CI 2.669–16.280, p ≤ 0.001), and recessive model (HR = 5.798, 95% CI 2.411–13.940, p ≤ 0.001). The genetic variants rs3114020 in the ABCG2 gene and rs1045642 in the ABCB1 gene and the ICE chemotherapy schedule were associated with an increased mortality risk in this cohort of pediatric patients with CNST.