Pharmacogenomics in chemotherapy for GI tract cancer.

The study of pharmacogenomics (PGx) has recently been intensively applied to gastrointestinal tract cancer. It has become clear that there are genetic differences in the activities of enzymes that influence the kinetics of chemotherapeutic agents. Moreover, genetic differences related to cellular sensitivity to anti-cancer agents have also been elucidated. In GI-tract cancer chemotherapy, 5-FU, gemcitabine, taxanes (docetaxel and paclitaxel), platinum (cisplatin and oxaliplatin) and irinotecan are often used, and molecular targeting therapy has also been developed. The respective PGx markers to such agents have been reported. Of the candidate PGx markers, K-ras mutation and UGT1A1 polymorphisms have sufficient evidence to justify routine clinical assessment for the selection of anti-cancer regimens. Progress in this field would facilitate the further development of PGx-guided individualized therapy, which could be expected to increase therapeutic efficacy and decrease the risk of adverse events.