Inclusion Criteria:

- Histologically confirmed colorectal cancer

- Age 18-75

- Eastern Cooperative Oncology Group (ECOG) performance status 0-1

- Life expectancy of at least 12 months

- Full recovery from any post operative sequelae

- Adequate hepatic function as documented by a serum bilirubin < 18 umol/L, and liver
function tests (LFTs) within 1.5X normal range

- Informed consent

Exclusion Criteria:

- Any major pre-existing psychiatric history or dementia, alcohol abuse, or currently
using a psychotropic medication that might lead to cognitive problems, other than
short acting benzodiazepines for nausea or sleep

- Any evidence of metastatic disease other than group C who may have limited metastatic
disease. If there is clinical suspicion of central nervous system (CNS) involvement
patients must have brain imaging (MRI or CT scan) prior to recruitment.

- Ongoing sepsis or uncontrolled infection, including HIV infection

- Pre-existing neurological condition likely to interfere with ability to perform
cognitive testing

- Any other severe co-morbidity which, in the judgement of the investigator, would make
the patient inappropriate for entry into this study

- Active cancer within the last 5 years other than squamous or basal cell carcinoma of
the skin or cervical cancer in situ (except for CRC)

- Previous history of chemotherapy, other than adjuvant chemotherapy for group C
metastatic group > 1 year previously

- Minimal English skills such that subjects would be unable to follow simple, written
English instructions and to read questionnaires of a grade 8 standard with the help
of a research assistant.