MERCURY 3 v1.0
Research type
Research Study
Full title
Improving the Prognostic Accuracy of Staging Rectal Cancer using Magnetic Resonance Imaging (MRI) - Detected Tumour Deposits and Vascular Invasion (mrTDV) instead of Tumour Nodal Metastasis (mrTNM)
IRAS ID
348532
Contact name
Gina Brown
Contact email
Sponsor organisation
Imperial College London
Clinicaltrials.gov Identifier
MERCURY3 funding award, AMRC funder Pelican Cancer Foundation; 2024112, Red Trouser Day
Duration of Study in the UK
5 years, 11 months, 31 days
Research summary
This study seeks to prove that a different staging system of mrTDV will improve the care and survival rates compared with the current practice of using TNM.
Our research discovered that MRI scans show that tumour often spreads by extending into veins outside the bowel wall in rectal and colon cancers, this is known as extramural venous invasion(EMVI); we showed this was a powerful predictor of the risk of metastatic disease and is the hallmark of lethal colorectal cancers. This feature is visible on radiology scans in 30 to 40% of newly diagnosed patients with bowel cancer. We also observed that tumours can then spread and “seed” along the vessels close to the tumour forming discrete deposits, which have a completely different appearance to lymph nodes on high resolution scans but have been mistaken for lymph nodes. Together with EMVI, these radiologically identified tumour deposits (TDs) are independently associated with a higher risk of recurrence. In contrast using the traditional the TNM classification for rectal cancer fails to identify the patients who are truly at risk of metastases because of over-reliance on lymph nodes. Over 90% of patients with EMVI or TDs develop recurrence but in the absence of EMVI or TDs, survival of patients is the same regardless of whether the lymph nodes are involved by cancer cells (published by our group in Lancet Oncology 2022 and Annals of Surgery 2020).
MERCURY 3 aims to prove that when radiologists look for Tumour Deposits or EMVI (mrTDV staging) on MRI scans, this improves the accuracy of the cancer prognosis compared with using traditional TNM staging. Therefore oncologists and surgeons can use the information to plan the right kinds of treatment before surgery takes place.REC name
East Midlands - Derby Research Ethics Committee
REC reference
25/EM/0105
Date of REC Opinion
29 May 2025
REC opinion
Further Information Favourable Opinion