Time to Colonoscopy After Positive Fecal Testing and Colorectal Cancer Outcomes

Colonoscopy technology concept
Colonoscopy is required following a positive fecal screening test for CRC. It remains unclear to what extent time to colonoscopy is associated with CRC-related outcomes, so study authors performed a systematic review.

A longer time delay to colonoscopy after positive fecal-based colorectal cancer (CRC) screening is associated with an increased incidence of CRC, more advanced cancer stage at diagnosis, and higher CRC-specific mortality, according to a study published in Clinical Gastroenterology and Hepatology.

Colonoscopy is required following a positive fecal screening test for CRC, however, it remains unclear to what extent time to colonoscopy is associated with CRC-related outcomes. Therefore, researchers performed a systematic review to determine this relationship.

Out of 1612 initial studies, 8 were included in the systematic review, with 5 reporting outcomes for fecal immunochemical testing (FIT). Although a meta-analysis was not possible, the researchers observed consistent trends between longer time delays and worse outcomes in all studies. Specifically, colonoscopy performed beyond 9 months from a positive FIT compared to within 1 month was significantly associated with a higher incidence of CRC, with adjusted odds ratios (AORs) of 1.75 and 1.48 in the two largest studies.

These studies also reported significant associations between colonoscopy performed beyond 9 months and a higher incidence of advanced stage CRC (stage III or IV) at diagnosis, with AORs of 2.79 and 1.55, respectively. Thus, given the additional time required for urgent referrals and surgical planning for CRC, colonoscopy should ideally be performed well in advance of 9 months following a positive FIT.

“In conclusion, our study demonstrates clear associations between time from positive fecal screening test to colonoscopy and worse CRC outcomes,” stated the authors. They added, “Further research is urgently needed to elucidate the optimal timeframe within which those with positive fecal testing should undergo colonoscopy.”

Reference

Forbes N, Hilsden RJ, Martel M, et al. Association between time to colonoscopy after positive fecal testing and colorectal cancer outcomes: a systematic review. Clin Gastroenterol Hepatol. Published online September 20, 2020. doi: 10.1016/j.cgh.2020.09.048