Pharmacogenetic markers of chemotherapy toxicity in gastrointestinal tumors: a preliminary analysis

Abstract

Aim. To assess the association between the carriage of minor allelic variants of 8 genes that encode key enzymes involved in the metabolism of anticancer drugs (DPYD, GSTP1, MTHFR, UGT1A1) and cell repair (XPC, ERCC1, TYMP, NQO1) and the severity of adverse drug events in patients with common gastrointestinal tumors. Tasks. To study the frequency of minor allelic variants of the DPYD, GSTP1, MTHFR, UGT1A1, XPC, ERCC1, TYMP, NQO1 genes; to assess the frequency and severity of adverse drug events of chemotherapy treatment in the study population. Materials and methods. For the period from October 2020 to April 2021, 56 patients (women 29, men 27) with verified malignant tumors of the gastrointestinal tract were included in a prospective clinical study as a part of the RSF grant No. 20-75-10158. The mean age was 62.311.4 years. Colon cancer was detected in 24 patients, tumors of the esophagus and stomach in 19 patients, tumors of pancreas and biliary tract in 13 patients. First-line palliative chemotherapy was given to 27 patients, adjuvant 19 patients, neoadjuvant 10 patients. All patients had not previously received cytotoxic or radiation treatment. Point nucleotide variants of genes DPYD, XPC, GSTP1, MTHFR, ERCC1, UGT1A1, TYMPS, NQO1 were determined by hybridization analysis on biological microchips. Differences in the tolerance of cytotoxic therapy (5-fluorouracil, platinum preparations, irinotecan) depending on the genotype were assessed using Fishers exact test. Results. The average number of chemotherapy courses received was 4.22.6 (112). There was a statistically significant difference in the tolerability of chemotherapy in patients with minor allelic variants of the GSTP1 rs1695 (p=0.03), ERCC1 rs11615 (p=0.01), and UGT1A1 rs8175347 (p=0.003) genes. Conclusion. The use of hybridization analysis on biological microchips to assess allelic variants responsible for the tolerability of cytotoxic therapy is reasonable and requires further prospective assessment.