1. RECTAL CARCINOMA AND PREOPERATIVE MRI: USING A NATIONAL DATASET FOR REGIONAL AUDIT South West Cancer Intelligence Service www.swpho.nhs.uk J Weeks (jenny.weeks@swpho.nhs.uk) 1, A Miles 2 on behalf of SWCIS Colorectal Tumour Paneljenny.weeks@swpho.nhs.uk 1 Cancer Intelligence Service, South West Public Health Observatory (SWCIS), 2 Royal Hampshire Hospital Objective To assess the availability and use of Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) in decision making for the management of rectal cancer. The revised Improving Outcomes Guidance (1) specifies that all patients with invasive rectal cancer should have a preoperative MRI scan. To determine the incidence of tumour involvement at circumferential margins after potentially curative surgery for rectal cancer. To assess the use of a national dataset, Association of Coloproctology dataset (ACP) now the National Bowel Cancer Audit Project, for regional audit. Method A subset of the ACP dataset was requested from all hospitals in 4 Cancer Networks in SWCIS region for the year April 2004 to March 2005, via colorectal lead clinicians and cancer information managers. Results Analysable data was received from 12 hospitals for 416 cases. Two Trusts declined to take part as MRI was not available at the time. Preoperative MRI was received by 58% of patients (individual hospitals ranging from 3 to100%) and MRI and/or CT imaging by 84% (range 66 to100%). Preoperative MRI by Hospital Conclusions The use of MRI and CT for preoperative imaging in rectal carcinoma is very variable in the SWCIS region, partially due to variation in its availability. This can affect whether the patient receives optimal treatment for their condition. Not all high stage patients had preoperative chemotherapy or radiotherapy but usage will also be affected by patient choice and co-existing morbidity. The audit demonstrates that data routinely collected as part of a national dataset can be effectively used for regional audit. The results can be used to stimulate changes. This method of data collection avoids the need for additional manpower and can encourage local ownership and participation in national audit. Key Guideline (1) Patients with invasive rectal cancers for whom surgery is being considered should have MRI scans before treatment begins to determine the precise location and extent of the tumour and clarify who is likely to be adequately treated by surgery alone. Patients having MRI had more: preoperative staging recorded (91% versus 27%) preoperative stage T3 or T4 preoperative chemo-radiation treatment. (Table on left) Background: Involved circumferential margins Patients with rectal carcinoma having tumour extending beyond the mesorectal fat at operation (ie an involved circumferential margin) have a poor prognosis. Preoperative chemo- radiation can reduce the tumour and improve survival. Staging MRI can assist in predicting those patients likely to have involved circumferential margins. Patients havingMRINo MRI Preop T stage recorded91%27% Preop Stage T3 or T457%20% Preop Chemo-radiation22%11% Involved circumferential margin at surgery 5%9% Total patients having surgery 214150 Involved margins were recorded in 23 of the 364 patients who underwent surgery. Of these fewer than half had had MRI (10/32) Of these 10 patients most (8/10) were predicted T stage of preT3 or preT4, but only 3/8 had preoperative radiotherapy or chemotherapy. T3/T4 indicates a likelihood of circumferential margins being involved at surgery. Preoperative chemo and or radiotherapy may be given to try to reduce the tumour size. References 1.Guidance on Cancer Services. Improving Outcomes in Colorectal Cancers. Manual Update. National Institute for Health and Clinical Excellence, 2004. 2.Minimum dataset for colorectal cancer histopathology reports. Royal College of Pathologists, 1998. Cross-section of rectum to show tumour extending towards circumferential margin (2)