Optimizing Urgent Suspected Colon Cancer Referrals and Reducing Colonoscopy Wait Times in Wales

Aim: To assess recent colonoscopies and CT scans in conjunction with the feacal immunochemical test (FIT) for possibly downgrading urgent suspected cancer (USC) referrals.

Methods: A retrospective single-centre study was conducted, including all USC referrals for colonoscopy in 2022, excluding anal cancers. The CT and colonoscopy findings for a two-year period prior to the referral, along with the FIT result (if done), were noted. Combinations of tests were used to ascertain if any such combination would predict a negative colonoscopy (no cancer detected).

Results: Out of 500 USC referrals made, 160 were positive for colorectal cancer (CRC). Twelve cases had prior negative CT scans and colonoscopies, and none showed cancer (three were FIT and nine FIT not performed). A total of 54 cases had a prior CT with no FIT, four of which showed cancer. Fifteen cases had a prior CT with a negative FIT, and none showed cancer. Sixteen cases had prior negative colonoscopies, and all were negative for cancer (five negative FIT, one positive FIT, and 10 FIT not done ). Combining the categories where no cancer was missed, potentially 40 referrals could have been downgraded safely (8%).

Conclusions: The above data indicate that, among the patients being considered for a colorectal USC referral, a combined prior negative colonoscopy and CT scan warrants a downgrading of the referral (irrespective of the FIT result). Referrals with a prior negative CT (abdomen) with a negative FIT or normal colonoscopy within the last two years can be safely downgraded. This will have a positive impact on waiting times and monetary expenditure on the USC pathway, but larger studies would be required to prove the external validity of these findings.