Mailed FIT-DNA Outreach Boosted Screening in Community Health Centers

Key Takeaways

• Screening participation remained higher with mailed FIT-DNA than with mailed FIT at both 90 and 180 days.
• The comparison paired mailed FIT with automated text outreach against mailed FIT-DNA with a manufacturer-supported outreach and patient assistance workflow.
• Colonoscopy completion within 180 days remained limited among patients with abnormal stool tests despite navigation support in randomized sites.

Community health centers using mailed outreach in the CARES trial saw higher 90-day colorectal cancer screening participation with FIT-DNA than with mailed FIT outreach. At 90 days, 751 of 2692 patients in the FIT-DNA group had screened versus 550 of 2435 in the FIT group. That corresponded to 27.9% versus 22.6%, with a 4.7-point adjusted difference, a 95% CI of 0.8 to 8.6, and P = .02. Follow-up colonoscopy after abnormal stool tests still lagged, leaving higher screening participation with FIT-DNA but incomplete diagnostic follow-up.

Randomized sites included community health centers in greater Boston and Los Angeles County, while Rapid City, South Dakota, participated through a parallel descriptive protocol without randomization. Eligible participants were English- or Spanish-speaking primary care patients aged 45 to 75 years who were due for colorectal cancer screening. The randomized cohort included 5127 participants, with 2435 assigned to FIT and 2692 assigned to FIT-DNA. The primary outcome was screening participation by any modality within 90 days of screening test mailing, and secondary outcomes were 180-day participation and time to screening. The comparison was mailed FIT with automated text outreach versus mailed FIT-DNA through the manufacturer outreach program.

By 180 days, 854 of 2692 FIT-DNA participants had screened versus 649 of 2435 FIT participants, or 31.7% versus 26.7%. The adjusted difference was 4.5 percentage points, with a 95% CI of 0.5 to 8.5, and time to screening was shorter with FIT-DNA. Per-protocol and as-treated analyses were also reported, and subgroup patterns varied by region, age, race and ethnicity, language, and insurance status. Regional heterogeneity was evident, with similar completion between groups in Boston and a wider gap favoring FIT-DNA in Los Angeles. The participation advantage was therefore accompanied by differing regional patterns.

Among 1435 screened participants in randomized sites, 100 had an abnormal stool test result, representing 7.0% of those screened. Only 36 of those 100 completed colonoscopy within 180 days. Standardized navigation was offered in Boston and Los Angeles, yet completion still differed by region, with 23 of 33 in Boston and 13 of 67 in Los Angeles. Incomplete diagnostic follow-up remained a key limitation of the outreach pathways.

In the FIT-DNA arm, the manufacturer outreach protocol used letters, telephone calls, text messages, and emails, with a median of 10 attempts overall. The authors did not assess cost or cost-effectiveness, and the trial did not include a usual care group. They also noted that FIT kits differed by region, and the relative effects of outreach intensity and test type could not be separated. Rapid City data remained descriptive only, and the trial paired higher screening participation with FIT-DNA outreach and persistently incomplete colonoscopy follow-up after abnormal stool tests.