Improving Diagnosis and Treatment for Patients With Rectal Cancer

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)

The cancer stage information from scans guides pre-operative treatment and the type of surgery offered. The investigators are studying whether a new Magnetic Resonance Imaging (MRI) staging method can improve the accuracy of prognosis for patients diagnosed with rectal cancer. The investigators will provide consultant radiologists with the know-how to report MRI scans using this new method and compare this with the existing method. This study will test this by comparing how accurately the old versus new method predict the outcomes of patients. The existing method relies on radiologists determining if tumour has spread through the bowel wall or not and whether there are suspected malignant lymph nodes. The new method looks for tumour spread into the veins and whether or not there are tumour deposits. Our previous research has shown that the new method is much more accurate at predicting prognosis, but this finding needs to be verified by a larger multicentre study.

The investigators are also studying the patient journey, so the investigators can better understand patients' experiences and the impact that treatments have on their quality of life. The investigators wish to understand if improvements in the accuracy of prognosis from scans could change treatment decisions in future. The investigators will also compare the radiology scan prediction of prognostic factors by looking carefully at the tumour specimens.

A Retrospective and Prospective Cohort study to improve the prognostic accuracy of preoperative staging in patients diagnosed with primary rectal cancer. The intervention is the training of radiologists to implement specialised MRI reporting using the TDV staging system.

The investigators will collect anonymized scans, clinical and histopathology data from all rectal cancer patients diagnosed in 2019. The central reviewing radiologist will stage the scans by a) mrTDV and b) mrTNM into poor and good prognosis categories. The investigators will compare survival outcomes from original reports as well as the two staging systems using Kaplan-Meier and Cox Proportional-Hazard methods.

The investigators will compare prospectively collected data before and after implementation of the consensus for identifying and treating high-risk and low-risk rectal cancers. The investigators will report on the comparisons of staging, histopathology, MDT treatment decisions, resource utilisation, how patients experienced information provided for shared decision making before and after the intervention changes and quality of life measures.

Inclusion Criteria:

1. Have a rectal cancer proven on biopsy or subsequent surgery
2. Sites able to submit anonymised MRI staging scans, pathology and imaging reports for central review
3. Aged 16 years or over

Exclusion Criteria:

1. Have irresectable metastatic disease at time of initial staging
2. Undergoing palliative treatment for Rectal Cancer
3. Have a biopsy-proven rectal malignancy which is not adenocarcinoma
4. Are contraindicated for MRI staging