Prediction of efficacy and side effects of chemotherapy in colorectal cancer.

Treatment of gastrointestinal cancers has significantly advanced over the last several years with the introduction of effective chemotherapeutic and targeted drugs. Providing individual treatment with low toxicity but maximum benefit is still an unsolved problem. Inter-individual variation of drug toxicity and efficacy is mainly determined by genetic polymorphisms. The genetic approach of pharmacogenetics and pharmacogenomics is developing as a valuable tool to design tailored therapy. This review focuses on clinically significant polymorphisms in genes involved in metabolism of chemotherapy used in gastrointestinal cancer: fluoropyrimidines, irinotecan, and platinum. In addition, the first results of pharmacogenetics in targeted therapy including cetuximab and bevacizumab are discussed.