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

Imperial College London

Status: Enrolling

Conditions: Colo-rectal Cancer; Rectal Cancer

Treatments: Diagnostic Test: MRI scan; Other: Radiologist training

Study type: Interventional

Funder types: Other

Identifiers

NCT04103372

DOCUMAS 24HH8769

Details and patient eligibility

About

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.

Full 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%.

Enrollment: 200 estimated patients

Sex: All

Ages: 16 to 100 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. 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
2. Be aged 16 years or over

Exclusion criteria

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

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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200 participants in 2 patient groups

Control Arm Schedule

No Intervention group

Description:

All sites will begin in the Control arm, with patients recruited to the Control Arm Schedule. Clinical investigations prior to treatment, during treatment, after surgery and during further treatment should be performed as per standard clinical practice and as clinically indicated. Each site will transition to the Intervention arm at a month prescribed by their randomised cluster, and from that point patients are recruited to the Intervention Arm Schedule . Patients will be recruited to either the Control or Intervention arms dependent on which arm is in progress at the site at the time of recruitment. There will be no crossover of patients between the arms at any point.

Intervention Arm Schedule

Experimental group

Description:

Each site will transition to the Intervention arm at a month prescribed by their randomised cluster, and from that point patients are recruited to the Intervention Arm Schedule . The transition period lasts one month during which recruitment is halted and two interventions implemented: 1. 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. 2. Radiologist training in the use of the PRESERVE mrSRT for suspected Early Rectal Cancer. Patients will be recruited to either the Control or Intervention arms dependent on which arm is in progress at the site at the time of recruitment. There will be no crossover of patients between the arms at any point.

Treatment:

Other: Radiologist training

Diagnostic Test: MRI scan