There Are Now 5 Randomized Controlled Trials of Flexible Sigmoidoscopy Screening, and They All Show It Works
Douglas K. Rex, MD, MASGE, reviewing Senore C, et al. Ann Intern Med 2021 Nov 9.
Four previous randomized controlled trials of flexible sigmoidoscopy (FS) have shown reductions in at least distal colorectal cancer (CRC) incidence and mortality after FS screening.
The fifth trial is from Italy and involved persons aged 55 to 64 years who expressed interest in having FS screening. They were recruited from 1995 to 1999 and followed until 2012 for incidence and 2014 to 2016 for mortality. The control group had usual care.
There were more than 17,000 patients randomized to a single FS screening, and 58% of those randomized to FS had the procedure. At median follow-up periods of 15.4 years for incidence and 18.8 years for mortality, CRC incidence dropped by 19% and mortality by 22% in the intervention group in the intention-to-treat analysis. In the per-protocol analysis, there were reductions of 33% in incidence and 39% in mortality among the screened patients in the intervention group compared with control group participants. The incidence reduction was statistically significant in both men and women, but the mortality reduction reached significance only in men.
Patients underwent colonoscopy if they had at least 1 distal polyp >5 mm and any polyp if the bowel preparation was inadequate. Colonoscopy was also performed for >2 diminutive polyps or any advanced adenoma.
There were trends toward proximal colon mortality reduction in the per-protocol analyses, but they did not reach significance. The benefit of the single sigmoidoscopy was sustained throughout the follow-up period.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
CITATION(S)
Senore C, Riggi E, Armaroli P, et al. Long-term follow-up of the Italian Flexible Sigmoidoscopy Screening Trial. Ann Intern Med 2021 Nov 9. (Epub ahead of print) (https://doi.org/10.7326/m21-0977)