568P - The impact of antithrombotics on immunochemical fecal occult blood testing for colorectal cancer screening

Date 09 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Aetiology, epidemiology, screening and prevention
Colon and Rectal Cancer
Gastrointestinal Cancers
Basic Scientific Principles
Presenter Véronique Van der Voort
Citation Annals of Oncology (2017) 28 (suppl_5): v158-v208. 10.1093/annonc/mdx393
Authors V. Van der Voort1, L. Wauters2, P. Dobbels1, K. Hendrickx1, V. Casneuf1, J. Vandervoort1
  • 1Gastroenterology, OLV Aalst, 9300 - Aalst/BE
  • 2Gastroenterology, KU Leuven, Leuven/BE



The impact of antithrombotics on immunochemical fecal occult blood testing (iFOBT) for colorectal cancer (CRC) screening in the general population remains unclear.


A prospective cohort of patients undergoing endoscopy for positive iFOBT in 2015 at 3 centers in Belgium was analyzed. Medical records were reviewed for demographic and clinical variables: gastro-intestinal (GI) symptoms, family history of polyps/CRC, use of antithrombotics (including Aspirin and/or Clopidogrel, Dipyridamole, Ticagrelor, novel anticoagulants or vitamin K antagonists). Endoscopy reports were checked for colorectal pathology. Significant findings were defined as CRC or advanced adenomas. Rates of false positive iFOBT and detection of CRC or advanced adenomas were compared in patients with and without antithrombotics or Aspirin. Finally a distinction was made between patients who had a iFOBT through programmatic or opportunistic screening.


A total of 510 patients (64% male, median (IQR) age 63.2 years) with positive iFOBT were included. Colorectal pathology was confirmed in 73% of the patients; more commonly in males and family history. Significant findings were present in 220/371 (59%) patients with colorectal pathology. Antithrombotics were used in 25% of the patients and associated with male gender, older age and lower GI symptoms. Aspirin alone was used in 17% and associated with male gender and older age. Rates of false positive iFOBT, detection of advanced adenoma and CRC were similar in patients with or without antithrombotics and in patients with Aspirin alone compared to no antithrombotics. iFOBT was mainly used in programmatic screening (91%), with no differences in demographic or clinical variables between these two groups.


Although antithrombotic drugs were mostly prescribed in male and older patients with an inherent higher cancer risk, detection rates of CRC and advanced adenoma’s were similar. Despite the higher rate of lower GI symptoms, antithrombotics or Aspirin alone did not lead to more false positive iFOBT. Use of antithrombotics or Aspirin alone does not seem to impact the performance of iFOBT for screening of CRC in the general population.

Clinical trial identification

Legal entity responsible for the study

OLV Aalst




All authors have declared no conflicts of interest.