Pre-therapeutic MRI Assessment of Early-Stage Rectal Cancer and Significant Rectal Polyps to Avoid Major Resectional Surgery

Overview

When a patient is diagnosed with a rectal (bowel) polyp or cancer, radiology doctors read MRI scans to describe how deeply the cancer invades into the bowel wall (this is the 'stage' of the cancer). In this project, we will teach radiologists to find more early-stage rectal cancers. These are cancers that have only grown partially into the bowel wall. If we succeed, more patients could have these lesions removed by a local procedure that preserves the bowel and avoids the risks and complications of major surgery. We have developed a new method for radiology doctors to read MRI scans, which is more accurate than current practice. Currently only 3/10 of early rectal cancers are found by radiologists but by using our MRI reading system, 9/10 patients can be accurately identified as having early rectal cancer. We have proven that we can teach this method to other radiology doctors whose reports help to accurately inform patients of all possible treatment options, so they can be offered the option of a local procedure. In this initial work we will train radiology doctors in our MRI reading method in 20 hospitals. We will compare MRI reports before and after training to see if an accurate reading method improves treatments choices for patients. We will also determine whether more patients have local procedures after our training. The results of this initial work will help us to apply for national funding for a trial that we can quickly roll out to all NHS hospitals.

Detailed description

Many patients diagnosed with Early Rectal Cancer (ERC) are currently over-treated. Most patients with confirmed ERC will undergo an MRI, but some are not correctly identified in endoscopy and immediately removed. Of those who undergo MRI, 69% are over-staged and undergo major surgery or unnecessary radiotherapy when local excision surgery to preserve the patients rectum, and quality of life, would have been possible. \<10% of patients with ERC are staged accurately and offered local excision, with the majority who are staged as ERC on MRI still undergoing major surgery, likely due to uncertainty in the staging report.

Prof Gina Brown developed a more accurate radiological staging system (PRESERVE) or ERC, whereby T2 tumours are identified and classified according to the degree of preservation of the individual layers of the rectal wall. It has been shown that PRESERVE enabled better identification of ERC suitable for local excision from the expected 30% to 89% accuracy. This improved accuracy was replicated in a further study by training a cohort of 12 radiologists. It is predicted that wider adoption of PRESERVE will result in increased organ-preserving surgery from the current rates of 10% to \>50%.

Interventions

• Diagnostic test MRI scan
  MRI scans will be recommended for all rectal polyps ≥20mm in size, or with other features suspicious of malignancy, prior to removal. This is designed to reduce the numbers of Early Rectal Cancers missed in endoscopy.
• Other Radiologist training
  Radiologist training in the use of the PRESERVE mrSRT for suspected Early Rectal Cancer.

Primary outcome measures

• Impact of a training intervention on the accuracy of the tumour staging diagnosis through systematic reporting approach to MRI scans against current (pre intervention) practice. [Time frame: 1 year]

Secondary outcome measures (12)

• Proportion of patients with technically adequacate scans before and after intervention [Time frame: 1 year]
• Proportion of primary tumour characterised by morphology and other features associated with malignancy before and after intervention [Time frame: 1 year]
• Proportion of MRI reports with T substage given before and after intervention [Time frame: 1 year]
• Number of patients identified on imaging as suitable for rectal preservation by local excision [Time frame: 1 year]
• Number of patients identified by MDT as suitable for rectal preservation by local excision [Time frame: 1 year]
• Correlation of accuracy in the identification of safe plane of excision for rectal preservation by the radiologist [Time frame: 1 year]
• Numebr of patients with R0 by local excision or TME as appropriate [Time frame: 1 year]
• Qualitative EORTC QLQ-CR29 Questionnaire on Quality of Life of patients undergoing local excision vs major surgery [Time frame: 1 year, 3 years, 5 years]
• Qualitative EORTC QLQ-CR30 Questionnaire on Quality of Life of patients undergoing local excision vs major surgery [Time frame: 1 year, 3 years, 5 years]
• Qualitative LARS Questionnaire on Quality of Life of patients undergoing local excision vs major surgery [Time frame: 1 year, 3 years, 5 years]
• Qualitative Questionnaire on Quality of Life of patients undergoing local excision vs major surgery [Time frame: 1 year, 3 years, 5 years]
• Comparison of total costs of procedures performed between patients undergoing local excision surgery to those undergoing major surgery [Time frame: 1 year]

Eligibility criteria

Inclusion criteria

• Have a rectal tumour or suspected tumour less than or equal to T3b on MRI stage or pT2 or less after excision, or 20mm or more on endoscopy with suspicion of malignancy
• Be aged 16 years or over

Exclusion criteria

• Have metastatic disease at time of initial staging
• Have a biopsy-proven rectal malignancy which is not adenocarcinoma
• Are contraindicated for MRI

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Crossover

Masking

Open label

Primary purpose

Diagnostic

Study locations

United Kingdom · 23 centers

• Royal Berkshire Hospital — Reading
• Buckinghamshire Healthcare Nhs Trust — Amersham
• University College London Hospitals Nhs Foundation Trust — London
• King'S College Hospital Nhs Foundation Trust — London
• West Middlesex Hospital — London
• Imperial College Healthcare Nhs Trus — London
• The Hillingdon Hospitals Nhs Foundation Trust — Uxbridge
• Hampshire Hospitals Nhs Foundation Trust — Basingstoke
• … and 15 more centers

Publications

• Detering R, van Oostendorp SE, Meyer VM, van Dieren S, Bos ACRK, Dekker JWT, Reerink O, van Waesberghe JHTM, Marijnen CAM, Moons LMG, Beets-Tan RGH, Hompes R, van Westreenen HL, Tanis PJ, Tuynman JB; Dutch ColoRectal Audit Group*. MRI cT1-2 rectal cancer staging accuracy: a population-based study. Br J Surg. 2020 Sep;107(10):1372-1382. doi: 10.1002/bjs.11590. Epub 2020 Apr 16. PMID 32297326
• Balyasnikova S, Read J, Wotherspoon A, Rasheed S, Tekkis P, Tait D, Cunningham D, Brown G. Diagnostic accuracy of high-resolution MRI as a method to predict potentially safe endoscopic and surgical planes in patients with early rectal cancer. BMJ Open Gastroenterol. 2017 Aug 14;4(1):e000151. doi: 10.1136/bmjgast-2017-000151. eCollection 2017. PMID 29259791

Identifiers

NCT: NCT04103372 · DOCUMAS 24HH8769

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗