1208 Surveillance Strategy Following Curative Resection of Colorectal Cancer – What and When?

Aim After curative treatment for colorectal cancer (CRC), recurrence can occur in up to 11% of patients with stage 1-3 disease. Early diagnosis of CRC recurrence is key to improving prognosis. Different follow up strategies such asdetection of carcinoembryonic antigen (CEA) and CT imaging are available and NICE broadly recommends a combination of CEA and CT testing in the first 3 years to look for recurrence. We present our local data for CRC recurrences, when it recurred and the method of detection. Method A retrospective review of all CRC recurrences at our local unit was conducted from 2014 to 2021. Patient demographics, site of primary cancer, staging, surgical procedure for curative treatment, recurrence, surveillance tests and timings were recorded and analysed. Results 66 patients were identified with CRC recurrence in the 7-year period with the earliest detection occurring at 6 months and latest at 60 months. 12%, 35% and 60% of recurrences were detected in the first 6, 12 and 18 monthsrespectively. 80% of patients had positive CT findings, mostly of lung and liver metastases. 77% had abnormal CEA results, but 91% of these were in combination with CT, MRI or PET imaging. Only 9% of recurrences was detected by CEA alone. Conclusions Our data highlights that the majority of CRC recurred within 18 months of initial surgical intervention and CT was the primary modality for detection. Frequent follow up testing is resource intensive and also leads to patient anxiety. We recommend that a follow up CT at 12 months is best placed to detect CRC recurrences.