Genetic Trial to Study Diarrhea in Patients With Stage III Colon Cancer Who Are Receiving Chemotherapy

OBJECTIVES:

- Determine whether the presence of a 7 allele at the UGT1A1 locus is associated with
either grade 3-4 diarrhea or grade 4 neutropenia in patients with stage III colon
cancer after treatment with irinotecan, fluorouracil, and leucovorin calcium.

- Determine whether polymorphisms in the TS enhancer and/or MTHFR gene are associated
with grade 3-4 diarrhea in these patients after treatment with fluorouracil and
leucovorin calcium.

- Determine whether polymorphisms in UGT1A1, TS, MTHFR, CYP3A4, or CYP3A5 are associated
with either grade 3-4 diarrhea or grade 4 neutropenia in these patients after treatment
with irinotecan, fluorouracil, and leucovorin calcium.

OUTLINE: Patients are stratified according to prior therapy (irinotecan, fluorouracil, and
leucovorin calcium vs fluorouracil and leucovorin calcium) and prior toxic effects (grade
3-4 diarrhea vs grade 4 neutropenia vs grade 1 or lower diarrhea AND grade 2 or lower
neutropenia).

Patients undergo collection of blood specimens for polymerase chain reaction and restriction
fragment length polymorphism analysis. Genotyping assays are performed to determine UGT1A1
promoter genotyping, UGT1A1 coding polymorphisms, TS promoter polymorphisms, and MTHFR
polymorphisms.

DISEASE CHARACTERISTICS:

- Histologically confirmed stage III adenocarcinoma of the colon

- Enrolled on CALGB-89803 and must fall into 1 of the following categories:

- Received irinotecan, fluorouracil, and leucovorin calcium and experienced at
least 1 of the following:

- Grade 3-4 diarrhea

- Grade 4 neutropenia

- Grade 1 or lower diarrhea AND grade 2 or lower neutropenia

- Received fluorouracil and leucovorin calcium and experienced at least 1 of the
following:

- Grade 3-4 diarrhea

- Grade 1 or lower diarrhea AND grade 2 or lower neutropenia

PATIENT CHARACTERISTICS:

Age

- 18 and over