Multicenter, randomised controlled trial comparing endoscopic Mucosal resection (EMR) And endoscopic submucosal dissecTIon (ESD) for resection of Large Distal non-pedunculated colorectal Adenomas

Endoscopic resection of polyps in the colon is a cornerstone of effective CRC
prevention, because it allows the removal of precursor lesions that may
progress to cancer. Two modalities are available for the endoscopic resection
of lateral spreading polyps (LSTs), including endoscopic mucosal resection
(EMR) and endoscopic submucosal dissection (ESD). EMR is quick, easy to perform
and associated with a low number of complications. However, polyps larger than
2 cm often cannot be removed in one piece (en-bloc) and are removed in pieces
(piecemeal (p)EMR), resulting in high recurrence rates. For this reason ESD was
developed, which enables high en-bloc resection rates even in large polyps, and
is associated with low recurrence rates. As a disadvantage, ESD is much more
difficult to perform and associated with higher complication rates and a longer
procedure time. Currently, a direct randomized comparison between ESD and EMR
(with APC or tipping in adjunct to pEMR) is lacking and therefore current
guidelines are not able to guide practice on this topic.

The aim of this study is to perform a randomized comparison between ESD and EMR
in large (>20 mm) distal non-pedunculated polyps in a Western population. We
aim to compare both procedures with regard to recurrence rates and radical (R0)
resection rate, and to put this into perspective against the costs and
complication rates of both strategies and the burden perceived by patients on
long term-term (36 months).

Multicenter randomized controlled trial.
Due to the nature of the treatment, neither patients nor endoscopists
participating in this study will be blinded.

In the EMR-arm, endoscopic resection will be performed using the EMR technique
(with APC or tipping in adjunct to pEMR), whereas patients randomized to the
ESD-arm will undergo resection using the ESD technique.

The two endoscopic resection techniques investigated in this study are standard
care in the Netherlands. A follow-up colonoscopy is performed 6 and 36 months
after the procedure, which is standard care in the Netherlands. In case of
macroscopic residual disease this will be resected, which is standard care. If
not, biopsies of the scar and surrounding area will be taken, which is optional
and recommended in standard care and fixed care in this study. With regard to
the quality of life questionaires, we aimed to minimize questionnaire length
and density of sampling to the highest necessary in order to balance the effort
required by the patient to answer the questionnaires with the estimated goal of
quality of life analysis for this study. Taken this together, neither an
unacceptable risk nor a direct benefit is expected for patients participating
in this study.
This study will increase the knowledge on the preferred endoscopic method in
Western countries that is currently unknown. This is important, as the
detection rate of large distal non-pedunculated adenomas is expect to further
increase with the introduction of the Dutch CRC screening program. The study
will therefore support an optimal use of health resources in the future.