Surveillance Colonoscopy Following Colorectal Cancer Resection: Are we Doing it Right?

Background: There is dispute among surgeons with regard to interval between surveillance colonoscopies following colorectal cancer resection. Our objective was to assess the incidence of metachronous cancers and recurrence in our less intensive surveillance programme and compare with intensive programmes elsewhere.

Methods: Colonoscopic records of patients who had surveillance colonoscopy between 1^st April 1998 to 31^st March 2003 for colorectal cancer were available from the endoscopy department computer data base. Following curative resection, patients undergo colonoscopy at two, five and ten years. Patients who had colonoscopy within the first postoperative year were not considered as surveillance and thus excluded. The tumour site, Duke's stage, follow-up details, number of recurrences, number of metachronous tumours, size and number of polyps and their biopsy results were reviewed. Six patients who had endoscopic resection of tumour were classified as unknown stage.

Results: Table 1. Incidence of polyps and tumours in relation to stage of disease

Stage	Total	Adenomas	>2 Adenomas	>1cm Adenomas	Metachronous tumours	Recurrence
Duke's A	19	3	1	0	0	0
Duke's B	54	15	8	6	2	1
Duke's C	26	5	0	0	0	0
Unknown	6	1	0	0	0	2

The incidence of metachronous tumours and recurrence were 1.9% and 2.8% respectively

Conclusions: The incidence of metachronous tumours and recurrence were low. The results are comparable to intensive colonoscopic surveillance programmes elsewhere. Large trials may be required to assess if there is any survival advantage for intensive programmes.