Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02957058 |
| Other study ID # |
AU RED HREC/16/WMEAD/130 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 2017 |
| Est. completion date |
April 2023 |
Study information
| Verified date |
June 2023 |
| Source |
Western Sydney Local Health District |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
To prospectively validate the SERT (Sydney EMR Recurrence Tool) scoring system for adenoma
recurrence rates around the endoscopic mucosal resection (EMR) scar after wide field-EMR with
thermal treatment applied to the defect margin. The primary aim of the study will be to
ensure the safety of this approach and there will be constant monitoring to ensure that this
is the case.
Description:
Colonoscopy and polypectomy reduces the anticipated incidence of colorectal malignancy in
patients with significant adenomatous polyps by approximately 80% in long term follow up.
Most endoscopists routinely perform removal of small polyps. However, removal of flat colonic
neoplasia 20mm in size or larger is more complex and requires specific endoscopic techniques,
one such technique being termed wide field endoscopic mucosal resection (WF-EMR).
Traditionally these lesions were treated surgically at significant expense to the healthcare
system. Endoscopic treatment of large colonic polyps reduces health care costs by
approximately $11,000 per patient treated, saves bed days and avoids surgery in more than 90%
of patients.
EMR describes the endoscopic technique of treating colorectal adenomatous polyps with
submucosal lifting and careful piecemeal snare resection. This procedure has been shown to be
safe and effective at resecting lesions limited to the mucosa. Clearly the importance of
predicting lesions that are unlikely to have invaded the deeper layers is of the utmost
importance here, and significant improvements in our ability to assess this have been made in
large volume centres such as Westmead
An important longer-term complication of EMR of large flat colonic neoplasia is the
phenomenon of residual polyp tissue or polyp recurrence, which will be the focus of the
proposed research study. Recurrence is detected by surveillance colonoscopies (SC), which are
performed at defined intervals after the index procedure. Our current standard for safe
surveillance interval at Westmead after >= 20mm EMR is 5 months (SC1). In the largest study
to date, the Australian Colonic EMR (ACE) study, recurrence at SC1 stands at 16.5% for all
patients.
We have recently come to the end of a randomised trial (SCAR) of thermal treatment (snare tip
soft coagulation, STSC) of the EMR defect margin (SCAR technique), with the findings to be
presented at the Digestive Diseases Week in San Diego. The results of this trial (n=353) are
promising with a risk of adenoma recurrence in the treated group of 6.4% vs 20.7% in the
non-treated group (relative risk 0.3, p < .001). There have been no adverse events related to
this treatment. The investigators plan to perform this intervention on all patients in the
proposed study.
In addition, there is increasing evidence, both in the scientific literature and at our
institution, that there are identifiable factors at the initial EMR that predict recurrence
at SC1. Current data from the ACE cohort suggests that increasing size of lesion (>=40mm),
presence of high grade dysplasia (HGD) in the resection specimen and intra-procedural
bleeding requiring endoscopic control predict greater likelihood of recurrence. The
investigators have created, and have submitted for publication, a risk score for recurrence
after EMR known as the Sydney EMR Recurrence Tool (SERT), (figure 1). SERT was created by
binomial logistic regression analysis (figure 2) on 692 patients (model cohort) from the ACE
study and validated on the remaining 691 patients (validation cohort) who had undergone SC1.
Kaplan Meier curves (figure 3) were used to determine the predicted incidence of recurrence
at various points in time after EMR on the validation cohort (figure 4). The strength of SERT
lies in predicting the absence of recurrence, with negative predictive value of 92.6% at
first surveillance colonoscopy. While this score was not derived from patients treated with
SCAR technique, it is expected that the stratification of lesions by SERT will continue to be
valid with lower overall rates.
Crucial in ensuring the absence of polyp recurrence in the long term is surveillance
colonoscopy. In the endoscopy department at Westmead the current standard of follow-up is SC1
at 5 months. This short interval is costly and inconvenient for patients, but has been
thought necessary due to previous anxiety over recurrence rates.
The investigators therefore propose a study to prospectively evaluate recurrence after WF-EMR
by triaging follow up based on SERT, with all lesions treated by SCAR technique. Patients
with SERT 0 lesions would be triaged to first follow up at 18 months (the usual time for SC2)
since their rate of recurrence until this point is predicted to be very low (8.5%) and such
recurrence is likely to be easily treated endoscopically after this time (in the validation
cohort recurrence was commonly diminutive (<5mm, 67%), uni-focal (75%), with no high grade
dysplasia (HGD). All recurrences were treatable endoscopically. This compares favourably to
the 90.3% successful endoscopic treatment of recurrence rate in a recent meta-analysis.
Higher risk lesions (SERT 1-4) would be triaged to earlier follow up at 6 then 18 months,
since their predicted risk of recurrence at 6 months is 14.8% and at 18 months is 31.8%. All
lesions would require a follow up procedure at approximately 36 months after the original EMR
since both groups rate of recurrence increases by this time (figure 4) and this will be
suggested to the referring specialist.
Risk factor Score Laterally Spreading lesion Size >= 40, score 2 Intraprocedural bleeding
requiring endoscopic control, score 1 High grade dysplasia, score 1
