To correlate the molecular profile of a series of defined CRCs with prognosis and toxicity.

Inclusion Criteria:

• All patients participating in the RMHNHST study of infusional versus bolus 5FU (Saini et al. 2003).

The GI unit Royal Marsden Hospital NHS trust (RMHNHST) has co-ordinated and published results from a large multicentre randomised clinical trial of patients with locally advanced CRC (Saini et al. 2003). A total of 716 patients Dukes' B and C CRC operated with curative intent were randomised to receive either bolus or infusional 5FU regimes. Patients treated at the RMHNHST made up the majority of the total sample cohort (n=550). Analysis of results after a median of 19.8 months follow-up showed that infused 5-FU given over 12 weeks resulted in similar survival to bolus 5-FU and FA over a six-month period (log rank p=0.764). There was, however, significantly less toxicity associated with the infusional regime.