FIT Tests, Direct Mailed, Increase Initiation of CRC Screening in Adults Aged 45 to 49

A randomized clinical trial of more than 20,000 adults aged 45 to 49 found that unsolicited mailing of fecal immunochemical test (FIT) kits directly to individuals without requiring active choice significantly outperformed 3 other strategies for initiating colorectal cancer (CRC) screening.1

The study, published online August 4 in JAMA, highlights a practical and effective population health approach to improving early CRC detection in younger adults, a group at increasingly greater risk for the disease2 and for whom screening rates remain suboptimal despite recent guideline changes lowering the recommended starting age from 50 to 45.3

Artin Galoosian, MD, MA Courtesy of University of Southern California

The trial was conducted at UCLA Health between May and November 2022 and included 20,509 average-risk adults from primary care settings who were randomly assigned to one of 4 outreach strategies:

1. fecal immunochemical test (FIT)–only active choice
2. colonoscopy-only active choice
3. dual-modality (FIT or colonoscopy) active choice
4. usual care default mailed FIT outreach

Mean age of participants was 47.4 years, approximately half were women (54%) and half (50.8%) self-identified as non-Hispanic White. First author Artin Galoosian, MD, MA, assistant professor of Medicine at the University of Southern California, and colleagues measured screening uptake over 6 months following the intervention. Overall screening participation was 18.6%, according to the study.1

Galoosian et al reported that screening participation was highest (26.2%) in the group that received unsolicited mailed FIT kits. In contrast, they found significantly lower rates in the 3 “active choice” arms: 16.4% for FIT-only, 14.5% for colonoscopy-only, and 17.4% for those offered a choice between FIT or colonoscopy. All comparisons with the mailed FIT group were statistically significant (all P <.001).1

Compared with usual care, the absolute differences in screening rates were −9.8% for FIT-only, −11.7% for colonoscopy-only, and −8.9% for dual-modality (all P <.001). Among participants offered dual-modality active choice, colonoscopy was more frequently completed than FIT (12.0% vs 5.6%; P <.001), and there was notable crossover in the FIT-only arms, with nearly 10% ultimately opting for colonoscopy.1

“This study highlights that health systems can effectively engage adults aged 45 to 49 years with mailed FIT outreach, a practice already adopted by health systems for adults aged 50 years and older,” the authors wrote. They noted that the mailed FIT strategy eliminates the need for individuals to log into electronic portals or make a choice, reducing friction in the screening process.1

While active choice strategies allow for personalization, they may pose barriers to action, the authors wrote, and particularly in younger adults who are less accustomed to preventive care engagement. “This study offers robust evidence for how to engage this age group in CRC screening,” Galoosian and colleagues stated.1

A First for the Efficacy of Outreach

According to the authors, the study is the first to demonstrate the effectiveness of direct outreach to increase CRC screening in a younger cohort less likely to be aware of recommendations. In 2021, the US Preventive Services Task Force issued a grade B recommendation to begin colorectal cancer (CRC) screening at age 45 for average-risk adults, expanding eligibility under the Affordable Care Act.3 This change followed a nearly 15% rise in CRC incidence among adults under 50 over the past 30 years.4 Despite CRC now being a leading cause of cancer death in younger adults, participation remains low. Galoosian and team cite a recent claims-based study that found screening uptake among 45- to 49-year-olds was just 1.51% within 20 months of the updated guidelines. While proven effective in older adults, evidence for mailed outreach in the younger, newly eligible population was lacking, authors stated.1

Among the study's limitations the researchers acknowledged limited generalizability due to a sample restricted to average-risk individuals with low to medium social vulnerability as well as investigators' reliance on robust EHR and patient portal systems to gather data, not available in some areas. They also noted that colonoscopies performed outside the system may have been missed, and the 6-month follow-up may have favored FIT due to easier access. Additional concerns included COVID-19 disruptions, lack of cost-effectiveness analysis, and challenges replicating the study without a waiver of consent.

Nonetheless, the findings point to default mailed FIT as an effective, scalable tool for increasing CRC screening rates among adults in their mid to late 40s. “Future research should explore further optimization and tailoring of mailed FIT outreach to enhance screening participation across diverse populations and in other health care settings,” the researchers concluded.1

References

1. Galoosian A, Dai H, Croymans D, et al. Population health colorectal cancer screening strategies in adults aged 45 to 49 years: a randomized clinical trial. JAMA. Published online August 4, 2025. doi: 10.1001/jama.2025.12049

2. Halsey G. Early colorectal cancer screening at ages 40–49 reduces long-term incidence and mortality. Patient Care. June 18, 2025. https://www.patientcareonline.com/view/early-colorectal-cancer-screening-at-ages-40-49-reduces-long-term-mortality-and-incidence

3. Davidson KW, Barry MJ, Mangione CM, et al; US Preventive Services Task Force. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(19):1965-1977. doi:10.1001/jama.2021.6238

4. Siegel RL, Wagle NS, Cercek A, Smith RA, Jemal A. Colorectal cancer statistics, 2023. CA Cancer J Clin. 2023;73(3):233-254. doi:10.3322/caac.21772