Introduction Bowel cancer screening has resulted in a greater incidence of early colorectal cancers, or malignant polyps (MPs). Increasingly MPs are being resected endoscopically, hence avoiding the associated risks of major surgery. There remains, however, concern regarding local cancer recurrence and residual loco-regional lymph node disease, along with the future risk of metachronous disease in the remaining bowel. Detection of these adverse outcomes of endoscopic resection suggests a need for regular surveillance, though this has to be contrasted with the risks of unnecessary surveillance; e.g. morbidity, false negatives, and cost. The ACPGBI position statement¹gives guidance on post-resection colonoscopies, though there is little guidance on other surveillance modalities. This study aimed to review post-MP excision surveillance practice in a single NHS Trust.

Method All excised MPs were identified from a prospective consecutive database of all colorectal cancers with a date of diagnosis 01/04/10 – 31/03/14 diagnosed in a UK NHS Foundation Trust. Electronic records were reviewed to ascertain the number of endoscopic and radiological tests that patients underwent post-MP excision (excluding initial staging scans). Primary outcomes were tumour recurrence, metastases or detection of metachronous disease. Investigations for reasons other than surveillance (e.g. emergency admission) were excluded.

Results There were 130 MPs excised over a four year period, 96 of which were excised initially endoscopically (28 underwent further formal resection, in which there were four cases of residual disease: 3 nodal diseases and 1 local disease). Median follow-up was 34 months (range 3–58). A total of 106 surveillance CT scans were performed and eight surveillance MRI scans (range 0 to 5 CTs, and 0–3 MRIs per patient). 194 surveillance endoscopies were performed (98 colonoscopies, 96 flexible sigmoidoscopies), ranging from zero to seven per patient. There was no association with duration of follow-up for either scans or endoscopies, though on average, surgically managed patients had more surveillance scans, whereas those managed endoscopically had more surveillance endoscopies. In total there were no recurrences, 1 case of metastases and 2 detected metachronous tumours.

Conclusion Surveillance of patients following MP excision remains controversial; this experience highlights a wide variation in practice, and low yield from surveillance tests. Although each case should be managed individually according to a local multi-disciplinary team, there appears to be a requirement for a larger evidence base and subsequent guidance on optimal surveillance for these patients.

Disclosure of interest None Declared.

Reference

1. Williams JG, et al. Management of the malignant colorectal polyp: ACPGBI position statement. Colorectal Dis.2013;15(Suppl 2):1–38