Background: Single-nucleotide polymorphisms (SNPs) in enzyme-coding genes play a role in susceptibility to anti-cancer therapy.
Materials & methods: A prospective study was performed of the relationship between enzyme activity and treatment response, drug toxicity and hypersensitivity reactions in 51 patients with colorectal cancer treated with fluoropyrimidine-based chemotherapy. SNP analysis was performed in 22 enzyme-coding genes with a previously described role in treatment efficacy.
Results: SLC6 and MTHR enzyme activity was related with rates of progressive disease, GSTP1 activity with anti-EGFR antibodies-related skin toxicity, CYP3A5 and MTHR with chemotherapy dose reduction, CYP2B6, IL10, MTHR and TYMS activity with the risk of drug hypersensitivity reactions.
Conclusion: Pharmacogenetics is a valuable predictive marker in oncology, related to chemotherapy treatment response, toxicity and hypersensitivity.
Keywords: Polymorphisms; SNPs; chemotherapy; colorectal cancer; hypersensitivity; toxicity.
This study looked at specific changes in 22 genes from 51 people with colorectal cancer, who were treated with a type of chemotherapy and targeted cancer drugs. These gene changes, called SNPs, affected how certain enzymes work in the body. Changes in the SLC6 and MTHR genes were linked to faster cancer growth. The GSTP1 gene was connected to skin rashes caused by one of the cancer drugs. Some patients needed lower doses of chemotherapy due to changes in the CYP3A5 and MTHR genes, while other changes increased the chance of allergic reactions to the treatment. These gene changes can help doctors predict how patients will respond to treatment and what side effects they might experience.