Abstracts
2000 Digestive Disease Week

# 2245 Serological Pre-Hospital Detection of Colorectal Neoplasia in a Symptomatic Cohort - the Next Step Towards a Population Screening Programme.
Nicholah G. Hurst, Darren M. Williams, Michael J. Wakelam, Tariq Ismail, Birmingham, United Kingdom

Colorectal cancer (CRC) is well suited to a dedicated screening programme although none exists in the Western World. The absence of a sensitive, specific, palatable and affordable test confounds efforts to establish such a scheme. Traditional imaging techniques of the colorectal mucosa remain hitherto largely invasive with associated morbidity and mortality, and may still overlook significant lesions. Serological evaluation for detection of primary disease has not previously been applied in colorectal cancer. Referrals for specialist coloproctological opinion are traditionally triaged by general practitioners as urgent or non-urgent. Failing such designation, hospital prioritisation occurs via evaluation of symptoms and signs described in the referring communiqué. The classical tetrad of an altered bowel habit, rectal bleeding, abdominal pain and weight loss are currently used to identify patients with a perceived higher risk of neoplastic pathology. Critical analysis of patients attending our Colorectal Clinic has cast doubt on the usefulness of symptom patterns in eliciting high-risk patients. Multi-variant analysis of presenting symptoms versus eventual diagnosis failed to detect a consistent relationship between presenting symptoms and the presence of colorectal neoplasia, except for age >50 years and family history of >1 first degree relative with CRC. It is clear from our observations that triaging patients on the basis of symptoms alone is inefficient and may cause delay in consulting a specialist. Serum Matrix Metalloproteinase (MMP) estimation offers early indication of adenoma and carcinoma development. Analysis of serum MMPs, from patients presenting at a colorectal clinic, identifies patients who would benefit from traditional colonic imaging. A 240 patient cohort had serum MMP9 levels measured, corrected for age, and predictions of colorectal neoplasia were made based on the results. Comparison of our forecasts, with diagnoses achieved by conventional investigations, showed detection of 67/70 (95.7%) significant lesions by serum analysis. Further improvement by comparative analysis of other MMPs may prove possible in future assays. Referral of patients with an accompanying serum sample could provide an objective means of classifying patients as at high or low risk of CRC, enabling prioritisation of appointments. Its extended application in the asymptomatic population as a screening tool is under development.