[Genetic alterations and chemoresistance].

Molecular targeting agents will likely play an increasing role in the management of cancer.However, resistance to anti-neoplastic drugs remains a serious obstacle to successful cancer treatment. Analysis of SNPs and microarray technologies should enable us to predict toxic responses and sensitivities to anticancer agents of each patient, and the prediction may permit patient-specific anticancer agents and dosages that reduce the risk of acute toxicity and emergence of drug-resistant tumors. The relationships are reviewed between the chemoresistance(chemosensitivity) and polymorphisms, tumor gene expression profiles or mutations of targeted molecules that confer resistance to molecular target therapy.