P026 - EXAMINING THE CORRELATION OF FAECAL IMMUNOCHEMICAL TESTING WITH COLORECTAL FINDINGS: A SINGLE CENTRE RETROSPECTIVE STUDY

P026

EXAMINING THE CORRELATION OF FAECAL IMMUNOCHEMICAL TESTING WITH COLORECTAL FINDINGS: A SINGLE CENTRE RETROSPECTIVE STUDY

M. Gabriel^1,*, E. Rezkallah¹, A. Chokkaligam¹

¹General Surgery, Wye Valley NHS Trust, Hereford, United Kingdom

Rationale: Faecal Immunochemical Testing (FIT) is a widely used screening test for colorectal cancer (CRC) detection. Early detection of CRC can improve the outcomes of treatment. Currently, FIT is not used for CRC risk stratification in the UK and remains an adjunct to referral or diagnostic decision making. This study aims to evaluate the diagnostic accuracy of the FIT test in detecting colorectal cancer, assessing its correlation with tumour size and location.

Methods: A retrospective review was conducted on 881 patients who had FIT results available and colorectal investigations to exclude/confirm malignancy. We conducted our diagnostic accuracy analysis using two cut off values of 9.9 and 38ug/g, with 95% confidence intervals (CIs). We calculated the test sensitivity for T stage and location of the tumor.

Results: Using a cut off value of 9.9 ug/g, the sensitivity of FIT test for detecting CRC was 91.8% with diagnostic accuracy of 42.8%, while with a cut off value of 38 ug/g, the sensitivity was 83.9%, with diagnostic accuracy of 64.9%. We found the sensitivity of FIT for detecting CRC for the right colon was 89.8%, for left colon 96.6%, while for the rectum was 96.6%. The T stage–specific sensitivity rates were 36.7% for T1 tumors, 68.7 % for T2, 85.7% for T3 and 71% for T4. We found no significant correlation between the FIT level and the tumor size or stage.

Conclusion: FIT is a valuable tool for guiding referrals for suspected colorectal cancer in adults presenting with colorectal symptoms. Despite the high sensitivity of FIT for CRC detection, it should not be solely relied upon to triage patients for further costly and invasive investigations, due to false negative and false positive cases. Therefore, FIT testing should be used in conjunction with other clinical assessments and diagnostic tools to optimise patient outcomes. 

Disclosure of Interest: None declared