Study of Genetic Polymorphisms of Drug Transporters and Orphan Nuclear Receptors on Treatment Effects of Irinotecan

From 100 colorectal cancer patients being treated with FOLFIRI regimen or any kind of irinotecan containing regimen, blood samples for irinotecan and its metabolites levels and genotypes related with its metabolism will be collected. The association of their levels and genotypes and treatment effects will be evaluated.