Correlation of Genetic Polymorphism of CYP3A5 to Cyclophosphamide Efficacy and Toxicity in Rhabdomyosarcoma Pediatric Egyptian Cancer Patients
Correlation of Genetic Polymorphism of CYP3A5 to Cyclophosphamide Efficacy and Toxicity in Rhabdomyosarcoma Pediatric Egyptian Cancer Patients

Correlation of Genetic Polymorphism of CYP3A5 to Cyclophosphamide Efficacy and Toxicity in Rhabdomyosarcoma Pediatric Egyptian Cancer Patients

Asian Pac J Cancer Prev. 2024 Jul 1;25(7):2445-2455. doi: 10.31557/APJCP.2024.25.7.2445.

ABSTRACT

OBJECTIVES: Rhabdomyosarcoma (RMS) accounts for 50% of soft tissue sarcomas and 7% of pediatric malignancies. Cyclophosphamide (CPA) is the cornerstone of therapy and is a prodrug that is activated by the highly polymorphic drug-metabolizing enzyme CYP3A5. We aim to examine the possible CYP3A5 polymorphism association with CPA efficacy, survival outcomes, and toxicity in Egyptian pediatric RMS patients.

METHODS: The three non-functional SNPs, CYP3A5*3 rs776746 (C_26201809_30), CYP3A5*6 rs10264272 (C_30203950_10), and CYP3A5*7 rs41303343 (C_32287188_10) were genotyped by real-time PCR. We conducted a cohort retrospective study of 150 pediatric RMS patients treated with CPA-based first-line treatment to analyze the association between these genotypes and CPA efficacy/toxicities in RMS patients.

KEY FINDINGS: The frequency of having normal, intermediate, and poor metabolizers was 4.7%, 34%, and 61.3%, respectively. There was an association between these different phenotypes, genotypes, and CPA efficacy/toxicity. Hemorrhagic cystitis and pancytopenia were present in all patients, while nephrotoxicity incidence was 87.3%. There was a notable difference in the occurrence of hemorrhagic cystitis among CYP3A5 intermediate metabolizers *1/*3, *1/*6, and poor metabolizers *3/*3, *3/*6 with a significance level of p<0.05. Neither CYP3A5*7 polymorphism nor *6/*6 genotype was identified in our study.

CONCLUSION: Our results demonstrate that CYP3A5*3 (rs776746) and CYP3A5*6 (rs10264272) have a great association with CPA efficacy and toxicity in RMS patients.

PMID:39068579 | DOI:10.31557/APJCP.2024.25.7.2445