Research published in this month's Journal of Clinical Oncology found that pre-op MRI assessment is crucial in helping to inform a more advanced treatment approach for rectal patients by predicting local recurrence and disease-free survival.

Rectal cancer currently accounts for one third of all colorectal cancers and is a leading cause of cancer death in the Western World. The 5 year study was conducted across 11 hospitals and research institutes across the UK1, following-up on 374 patients diagnosed and being treated for rectal cancer.

The research aimed to qualify the prognostic relevance of high-resolution magnetic resonance imaging (MRI) assessment of circumferential resection margin (CRM) - its usefulness in assessing the risk of local recurrence has not been previously shown.

The benefits were clearly noticeable, rates of recurrence for patients with MRI-clear CRM were only 7% compared to 20% in the case of MRI-involved CRM. In addition, a 5-year overall survival rate of 62% was showed in patients with MRI-clear CRM, compared to 42% in patients with MRI-involved CRM, independent of the type of treatment received by patients. From this, it is possible to conclude that by using this pre-op assessment method, patients could be identified who have a significant risk of local recurrence, which can in turn be prevented by preoperative down-staging of MRI identified high risk tumours and improved surgery.

The study aimed to compare the prognostic importance of using pre-operative MRI assessment of CRM compared with the existing and widely used 'staging' systems such as the American Joint Committee on Cancer (AJCC) TNM stage model and other clinical variables. The pre-op MRI assessment proved to be superior to TNM in predicting local recurrence, disease free survival and overall survival. The researchers believe that MRI CRM status rather than assessing the AJCC TNM should be used when informing patients regarding the risks of local recurrence and treatment decisions such as pelvic radiotherapy.

Furthermore, although computed tomography (CT) scan, endoluminal ultrasound (EUS) and MRI have all shown to be acceptable in terms of tumour and node 'staging' - neither a CT nor EUS is capable of assessing the potential circumferential margin.

Dr Gina Brown, Report Author, Consultant Radiologist & Reader in Gastrointestinal Cancer Imaging at The Royal Marsden NHS Foundation Trust, comments; "The research found that it is highly beneficial in terms of patient outcome to predict local recurrence by adopting MRI pre-operative imaging 1 helping to inform treatment decisions both amongst multi-disciplinary teams and patients. If an MRI predicts that complete removal of the tumour can be achieved with at least 1 millimetre of clear margin, this should largely eliminate the risk of local recurrence in patients."

Professor Bill Heald, Pelican Cancer Foundation comments; "Predicting recurrence by pre-operative imaging would enable more intensive pre-operative treatments as well as providing a surgical 'roadmap' to avoid breaching the tumour. This is a significant breakthrough and reinforces our belief here at the Pelican Cancer Foundation that investment in research is vital - advances in diagnosis and treatments are making a real difference to bowel cancer patients and helping to save thousands of lives each year in the UK alone."

The study was jointly funded by The Pelican Cancer Foundation, Siemens Medical, the Croydon Colorectal Charity, Yorkshire Cancer Research & Experimental Cancer Medicine Centre and the National Institute for Health Research Specialist Biomedical Research Centre for Cancer.