Impact of pharmacogenomics on imatinib toxicity in gastrointestinal stromal tumors.

Abstract

11043 Background: Imatinib-induced side effects are common, although most of these side effects are mild, some will be severe and lead to disruption of Imatinib treatment in gastrointestinal stromal tumor (GIST). It is necessary to explore a biological predictors to predict and optimal therapeutic strategy. But there were few studied conducted to explore the mechanisms of Imatinib-induced side effects. The present study comprehensively investigated the effects of genetic polymorphisms of cytokines involved in cell proliferation and metabolic enzymes and transporters involved in Imatinib metabolism on these side effects. Methods: A total of 154 GSIT patients treated with Imatinib were enrolled. 22 SNPs (single nucleotide polymorphisms) in KIT/ PDGFRA/ PDGFRB/ SHC1/ FLT1/ MAPK1/ EGFR/ CCL5/ CXCL14were detected using Agena Massarray matrix-assisted laser desorption / ionization-time of flight (MALDI-TOF) platform. Logistic regression analyses were performed to evaluate their effects on Imatinib-induced toxicities. This study was approved by the ethical committee of Sun Yat-Sen University Cancer Center. Results: Imatinibdose, FLT1 rs9951465, MAPK1 rs13515, PDGFRB rs55712339 and SHC1 rs3766920 were found to be correlated with the incidence of myelosuppression ( P= 0.027, 0.009, 0.002, 0.008, < 0.001, respectively), moreover, FLT1 rs9554314 was correlated with severe myelosuppression (Grade 0,1 vs. 2+, P= 0.009, OR (95%CI) = 3.042 (1.314-7,042)). Meanwhile, EGFR rs10228436 was found to be correlated with the incidence of skin rash ( P= 0.027), moreover, CCL5 rs4796120 and CXCL14 rs7716492 were correlated with severe skin rash (Grade 0,1 vs. 2+), with OR (95%CI) and p value were 8.542 (0.934-78.107), 13.504 (2.308-79.004) and 0.057, 0.020, respectively. Conclusions: This is the first comprehensive report on the biomarkers for Imatinib toxicities. These biomarkers might be able to distinguish patients with mild or more severe forms of Imatinib toxicities, thus enabling the optimization of Imatinib therapy and lead patients benefit from Imatinib treatment in a long-term.