A genetic signature of relapse in stage II colorectal cancer derived from formalin fixed paraffin embedded tissue (FFPE) tissue using a unique disease specific colorectal array

3519 Background: We have developed the first disease specific microarray for colorectal cancer using a transcriptome-based approach. This unique tool has been specially designed and optimised for analysis of gene expression profiles from formalin fixed paraffin embedded tissues (FFPE). To evaluate this tool we are conducting a study in patients with Dukes B (stage II) colorectal cancer (CRC) using FFPE tissues to determine a prognostic genetic signature predicting disease recurrence. Methods: The colorectal array was developed using a high-throughput transcriptome-based approach and encodes over 52,500 transcripts expressed in normal and diseased colorectal tissue. To date, tumours from 32 patients have been selected (mean FFPE tissue block age - 10.4 years) from the stage II CRC cohort of a phase III randomized trial comparing 5-FU/Leucovorin versus no adjuvant treatment (NI240). The patients were from the observation alone arm;19 of whom were disease-free for 5 years post-randomisation, while 13 suffere...