Polymorphisms in EGFR, GSTP1, XPD, DPD, ERCC1, and UTG1A1 of colorectal cancer patients treated with 5-fluorouracil plus oxaliplatin or irinotecan chemotherapy

As chemotherapy causes severe and harmful drug reactions in most of the colorectal cancer patients, predictive biomarkers for treatment efficacy are needed for these patients. In the present study, we investigated the prevalence of single nucleotide polymorphisms related to genes associated with chemotherapeutic agents, 5-fluorouracil plus oxaliplatin or irinotecan, in 255 colorectal cancer patients in southern Taiwan. EGFR codon 497G>A, GSTP1 codon 105 A>G, XPD codon 751 A>C, DPD IVS14 + 1G>A, ERCC1 codon 118 C>T, and UTG1A1 3156 G>A were amplified by polymerase chain reaction and then sequenced. The prevalence of genotypes EGFR codon 497 A/A, GSTP1 codon 105 G/G, XPD codon 751 C/C, DPD IVS14 + 1 A/A, ERCC1 codon 118 T/T, and UGT1A1 3156 AA was 33.73%, 3.01%, 0.39%, 0%, 2.88%, and 1.18%, respectively. However, the correlation between the results of 5-fluorouracil plus oxaliplatin or irinotecan therapy and the frequencies of these single nucleotide polymorphisms needs further investigation.