Early Detection of Colorectal Cancer Following Changes to Screening Guidelines: A Population-Based Analysis of Adults...

Colorectal cancer (CRC) is the third most common cancer, with millions of new cases and deaths annually. There is an increasing incidence of CRC among patients <50 years, leading to recommendations for CRC screening initiation at age 45 by the American Cancer Society (ACS) in May 2018. However, it is unclear if CRC screening at ages 45 to 49 has increased the detection of early-stage CRC (ES-CRC).

We conducted a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) database from 2015 to 2022, including individuals aged 45 to 49 diagnosed with CRC. The primary outcome was the diagnosis of ES-CRC (stages 1 and 2). The exposure was the time of diagnosis, categorized as preguideline (2015 to 2018) and postguideline (2019 to 2022). Multivariable logistic regression assessed the association between time period and ES-CRC diagnosis, adjusting for demographic and socioeconomic factors.

Among 28,532 individuals, 47.0% were diagnosed preguideline and 53.0% postguideline. The proportion of ES-CRC increased significantly postguideline (31.1%) compared with preguideline update (29.8%, P=0.012). Notably, a decline in ES-CRC diagnoses was observed in 2020, likely due to disruptions in cancer screening during the COVID-19 pandemic. The adjusted odds of ES-CRC diagnosis was higher postguideline compared with preguideline update (AOR: 1.068; 95% CI: 1.004-1.137). Subgroup analyses revealed higher odds of ES-CRC diagnosis among females, Asians and Black individuals postguideline update.

Following the 2018 ACS guideline change, ES-CRC diagnoses increased among adults aged 45 to 49. These findings suggest the updated screening recommendations may have facilitated earlier detection in this age group.