European Polyp Surveillance Trials (EPoS)

Patients with adenomas in the colon are considered to be at increased risk of colorectal cancer even following adenoma removal. Surveillance of this rapidly growing group of patients consumes substantial resources for colonoscopy. But due to a severe lack of evidence, the algorithms for follow-up vary widely between countries and centers. Our hypothesis is that surveillance is unnecessary intense/frequent.

This is unfortunate because substantial health care resources are consumed and colonoscopy is an invasive procedure with rare but severe complications.

To fill this problematic knowledge gap, a large group of investigators in Sweden, Norway, Poland, the Netherlands and Spain have decided to undertake a large-scale series of randomized trials. In these trials, we will compare the most widely surveillance algorithms with a more conservative one. The study has a non-inferiority design and is based on the hypothesis that costs and adverse effects can be minimized without jeopardizing the benefits of surveillance to detect and remove precursor lesions and also diagnose invasive cancers at an early stage. The study has three components whereof the first two are randomized trials. In EPoS I, low risk adenomas are included whilst in EPoS II high risk adenomas are enrolled. EPoS III is an observational study of serrated polyps that have recently been identified also as a marker of excess risk of colorectal cancer. Altogether, the goal is to enroll approximately 30,000 patients totally into the three components of this large-scale initiative.

As of late 2017, over 9,000 patients have been included in the EPoS trials and enrollment is accelerating as new centers join the collaboration. Productive meetings are held regularly, most recently in Barcelona in October 2017. The expanding group of investigators is also discussing two new components of EPoS whereof the first (EPoS V) would be an observational study of patients in whom malignant polyps have been removed endoscopically.

Besides two randomized trials, EPoS also includes two observational cohort studies; one that studies cancer risk following removal of serrated polyps, and another cancer risk after removal of malignant polyps.

Participants Sweden: Hans-Olov Adami (PI in Sweden) and Stefan Willmarsson (Project Leader Karlstad)

Collaborators in Norway: Mette Kalager, Michael Bretthauer, et al.

Financing: The Swedish Research Council, The Research Council of Norway, Helse SørØst, Norway

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Hans-Olov Adami

Professor Emeritus/Emerita
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