Universidad Pedro Henriquez Ureña Santo Domingo, Distrito Nacional, Dominican Republic
Introduction: An increase in incidence and mortality associated with early-age onset colorectal cancer (CRC) prompted the American Cancer Society to recommend the beginning of CRC screening at age 45. This has prompted studies to calculate adenoma detection rate (ADR) in this age group to support these new guidelines, also leading many to wonder whether the minimum acceptable ADR threshold, which according to the U.S. Preventive Services Task Force currently stands at >25% (30% for men and 20% for women), will need adjustments.
Methods: A prospective observational study was conducted on 924 patients who underwent colonoscopies from January 2021 through June 10th, 2022 in a single, non-academic, outpatient Gastroenterology center in the Dominican Republic. The procedures were performed by 2 endoscopists. The patients were divided into two groups, the first one including all patients aged 45-49 undergoing screening colonoscopies, and the other all patients aged >50 undergoing screening colonoscopies. The primary outcome of this study was the adenoma detection rate (ADR). Secondary outcomes included polyp detection rate (PDR), adenomas per colonoscopy (APC), and adenomas per positive participant (APP).
Results: The ADR in the group aged 45-49 was 36.3%, while the ADR in the group aged >50 was 57%. The PDR in the group aged 45-49 was 54.7%, while PDR in the group aged >50 was 71.7%. The APC in patients aged 45-49 was 0.59, while APC in patients aged >50 was 1.1. Finally, the APP in patients aged 45-49 was 1.62, while APP in patients >50 was 1.87.
Discussion: The ADR was lower in the 45-49 age group with a 36.3%, compared to the 57% ADR in the >50 age group. The same could be said when it comes to PDR, this is related to the fact that polyps are more prevalent with increasing age. This data supports the new guidelines, as the adenoma detection rates in the 45-49 age group were above the current standards for ADR in patients above the age of 50. Further studies will be needed to forecast the full impact of the new screening guidelines on the ADR, however, the need to lower the current ADR threshold would be unlikely. Then again, further studies are still needed to learn how these new standards will impact not only ADR but also CRC detection and prevention in the following years.
