UGT1A1 Polymorphism in Patients With Colorectal Cancer Treated With CPT-11 (Irinotecan)

OBJECTIVES:

• Determine the frequency of genetic polymorphisms of UGT1 in Hispanics with colorectal cancer.
• Determine if pharmacokinetics of irinotecan and its metabolites, SN38 and SN38G, are associated with the genotype of UGT1 and clinical toxicity.
• Determine whether the genetic polymorphisms of UGT1 are associated with clinical toxicity and pharmacokinetics/pharmacodynamics of irinotecan in patients with unresectable colorectal cancer treated with irinotecan.
• Determine the response, time to progression, and survival in patients with UGT1A1 polymorphisms treated with irinotecan.

OUTLINE: Genomic DNA is isolated from blood samples from patients and analyzed for UGT1 polymorphisms. Patients are stratified according to UGT1 genotype (homozygous for wild type vs heterozygous for abnormal allele vs homozygous for abnormal allele).

Patients receive irinotecan over 90 minutes weekly for 4 weeks. Treatment repeats every 6 weeks in the absence of disease progression or unacceptable toxicity.

PROJECTED ACCRUAL: Approximately 28 patients will be accrued for this study.