AB193. SOH26AB_0118. “Does imaging surveillance frequency of patients post treatment for non-metastatic (stage II/III) colorectal cancer affect survival outcomes?”—a systematic review of the current literature

Background: Colorectal cancer is the 3^rd most commonly diagnosed cancer worldwide. Current surveillance regimens include combinations of imaging, circulating tumour markers, and colonoscopy to detect early recurrence. Follow-up after completed non-metastatic Colorectal cancer therapy is based on tradition more than evidence, and there are currently no Irish guidelines to guide follow-up practices. There is conflicting evidence pertaining to the frequency of follow-up and its impact on overall survival.

Methods: A systematic search using PubMed, Cochrane, Epistemonikos, Turning Research into Practice (TRIP), and Google Scholar databases was undertaken, and relevant research papers, systematic reviews, and guidelines published in the last 10 years were considered for review. Articles excluding imaging surveillance, or that included endoscopic or tumour marker follow-up only post curative treatment for colorectal cancer, were excluded. Using a validated critical appraisal tool, the most relevant articles were evaluated.

Results: The systematic search returned approximately 30 articles for review, and the most recent, relevant literature was considered for appraisal. The majority of relevant, up-to-date research articles and guidelines contradict more dated research and now support a less-frequent surveillance regimen. This has implications not only for patients but also on hospital costs and for the redistribution of already limited resources.

Conclusions: Recent research increasingly encourages a shift from more- to less-frequent follow-up testing (i.e., 5 to 2 occasions in the 1^st 5 years) post treatment because there is no significant reduction in 5–10 years overall mortality or colorectal cancer-specific mortality in this cohort with more intense follow-up protocols.

Keywords: Colorectal cancer; follow-up; mortality; surveillance; survival