WASHINGTON — Patients who wait longer to undergo colonoscopy screening after a positive fecal immunochemical test are at higher risk for developing colorectal cancer, according to research presented at Digestive Disease Week.
“The fecal immunochemical test has been widely used in a nationwide program for the prevention of colorectal cancer,” Yi-Chia Lee, MD, PhD, of National Taiwan University Hospital said in his presentation. “However, in comparison with the primary colonoscopy, there’s a time lag between the positive FIT result and the follow-up colonoscopy.”
To determine how far CRC can progress between a positive FIT test and a follow-up colonoscopy, Lee and colleagues analyzed data from 94,884 patients who had positive FIT tests as part of a biennial FIT screening program in Taiwan between 2004 and 2012. Researchers classified the patients based on their time to colonoscopy: 0–3 months, 3–6 months, 6–9 months, 9–12 and more than 12 months. They determined that 9,033 patients were diagnosed with any kind of CRC, and 2,163 were diagnosed with advanced CRC.
Using 0–3 months — the recommended time for a follow-up colonoscopy — as a baseline, Lee and colleagues determined adjusted odds ratios for any kind of CRC for 3-6 months (aOR = 0.93, 95% CI, 0.85–1.02), 6–9 months (aOR = 0.85: 95% CI, 0.7–1.04), 9–12 months (aOR = 1.01; 95% CI, 0.73–1.4) and more than 12 months (aOR = 1.66; 95% CI, 1.18–2.32).
When accounting for just advanced-stage CRC, they found adjusted odds ratios of 0.84 (95% CI, 0.70-1.01), 1.22 (95% CI, 0.88-1.7), 1.32 (95% CI, 0.76-2.29), and 1.73 (95% CI, 0.94-3.17) for each group, respectively.
Lee and colleagues said their findings show that patients who don’t undergo a follow-up colonoscopy within the recommended three months following a positive FIT test, have a higher risk for developing CRC and advanced CRC.
“After positive FIT results, early colonoscopic follow-up is still required to decrease the stage shifting of already present colorectal cancer even though the overall number of colorectal cancers may increase modestly within one year,” Lee said. - by Alex Young
Lee Y, et al. Abstract 98. Presented at: Digestive Disease Week; June 2-5, 2018; Washington, D.C.
Disclosures: Lee reports no relevant financial disclosures. Please see the DDW faculty disclosure index for a list of all other authors’ relevant financial disclosures.