For Doctors in a Hurry
- Researchers investigated whether mailed FIT-DNA kits increase colorectal cancer screening rates compared to standard fecal immunochemical tests in underresourced community settings.
- This pragmatic cluster randomized trial enrolled 5,127 primary care patients aged 45 to 75 years across multiple community health center sites.
- Screening participation at 90 days was 27.9 percent for FIT-DNA versus 22.6 percent for fecal immunochemical tests (p = .02).
- The researchers concluded that mailed FIT-DNA outreach achieved higher screening uptake than mailed fecal immunochemical tests among diverse, low-income patient populations.
- Despite higher initial uptake, only 36 percent of patients with abnormal results completed follow-up colonoscopies, indicating a need for better diagnostic adherence.
Bridging the Screening Gap in High-Risk Populations
Colorectal cancer remains the second leading cause of cancer-related mortality in the United States, despite the proven efficacy of early detection in reducing both incidence and death [1, 2, 3]. Meta-analysis data indicate that screening with colonoscopy or sigmoidoscopy can reduce colorectal cancer incidence by 20 percent (RR: 0.80, 95% CI: 0.77 to 0.83) and cancer-specific mortality by 26 percent (RR: 0.74, 95% CI: 0.69 to 0.80) [4]. While visual examinations are primary tools for prevention through the removal of precancerous lesions, stool-based modalities like the fecal immunochemical test (a diagnostic assay that uses antibodies to detect human hemoglobin in stool) offer a less invasive alternative with a pooled sensitivity of 75 percent and specificity of 89 percent for cancer detection [5, 6]. Current guidelines emphasize that any screening is better than none [7], yet adherence remains suboptimal in underresourced settings where patients face significant socioeconomic barriers [8]. Patient navigation (a strategy using trained personnel to identify and overcome individual barriers to care) has emerged as a vital tool to improve participation and reduce the time from a positive screen to diagnostic follow-up [9]. A new study evaluates how different mailed outreach protocols and stool-based testing technologies influence screening uptake within community health centers, providing actionable data for clinicians managing high-risk populations.
Comparing Mailed Outreach Strategies in Diverse Settings
The researchers conducted a pragmatic cluster randomized clinical trial (a study design implemented in real-world clinical settings to evaluate the effectiveness of interventions in routine practice rather than highly controlled environments). Between June 7, 2023, and October 24, 2023, the trial enrolled English- or Spanish-speaking primary care patients aged 45 to 75 years who were due for colorectal cancer screening. The study took place across eight community health centers and one additional site using a nonrandomized parallel protocol. These sites were located in the greater Boston area in Massachusetts, Los Angeles County in California, and Rapid City, South Dakota. Among the 5127 participants in the randomized regions, 2435 (47.5%) were assigned to the fecal immunochemical test (FIT) group and 2692 (52.5%) were assigned to the FIT-DNA group.
The study cohort reflected a high-risk, diverse population with a mean age of 54.5 years (SD 8.1). The group included 3018 (58.9%) female and 2109 (41.1%) male participants. Racial and ethnic representation was notably high for minority groups, with 3818 Hispanic individuals (74.5%), 369 non-Hispanic Black individuals (7.2%), 763 non-Hispanic White individuals (14.9%), and 58 individuals of another race (1.1%). Language and socioeconomic barriers were also prominent, as 3363 individuals (65.6%) preferred the Spanish language, while 2540 (49.5%) were insured by Medicaid and 614 (12.0%) were uninsured.
The trial compared two distinct outreach strategies to determine which better facilitated screening adherence. Participants in the FIT intervention group received a mailed fecal immunochemical test accompanied by automated text message outreach from study personnel. In contrast, the FIT-DNA group received a mailed fecal immunochemical test-DNA (a multi-target stool test that combines hemoglobin detection with DNA biomarkers for cancer) managed through the manufacturer’s specific outreach protocol. By utilizing these two different modalities, the researchers aimed to identify whether the more complex FIT-DNA test and its associated commercial outreach could improve participation rates compared to standard FIT and automated text reminders in underresourced community health center environments.
FIT-DNA Shows Higher Participation Rates at 90 and 180 Days
The researchers defined the primary outcome as colorectal cancer screening participation using any available modality, including fecal immunochemical test (FIT), fecal immunochemical test-DNA (FIT-DNA), or colonoscopy, within 90 days of the intervention. In the randomized controlled trial regions, screening participation at 90 days was significantly higher in the FIT-DNA group compared to the FIT group, with 27.9% (751 of 2692) of participants completing a test versus 22.6% (550 of 2435) in the FIT group (P = .02). This 5.3 percentage point difference indicates that the combination of the multi-target DNA test and the manufacturer's specific outreach protocol resulted in higher initial engagement within these community health center populations.
Secondary outcomes for the trial included screening participation within 180 days, the time to screening participation, and the completion of follow-up colonoscopy within 180 days of an abnormal stool test result. The data at 180 days demonstrated a sustained advantage for the multi-target DNA test, as screening participation reached 31.7% (854 of 2692) in the FIT-DNA group compared to 26.7% (649 of 2435) in the FIT group. Despite the higher rates of initial screening uptake in the FIT-DNA arm, the transition from a positive stool test to diagnostic confirmation remained a clinical challenge. Among the 100 individuals who received an abnormal stool test result across both groups, only 36.0% (36 individuals) completed a follow-up colonoscopy within the 180-day window, even with the provision of standardized patient navigation.
The study also identified notable geographic variations in screening adherence between the two primary randomized sites. At the 90-day mark, screening participation in Boston was 28.4% (628 of 2208), which was higher than the 23.1% (673 of 2919) observed in Los Angeles. These regional differences in screening participation remained similar at the 180-day follow-up. For practicing physicians, these findings suggest that while mailed FIT-DNA outreach can increase the number of patients who initiate screening, local health center factors and regional barriers continue to play a significant role in overall participation and the successful completion of the screening continuum.
The Persistent Challenge of Diagnostic Follow-Up
While the study demonstrated that mailed outreach can effectively initiate the screening process, the transition from a positive stool test to diagnostic confirmation remains a significant clinical bottleneck. Colorectal cancer prognosis depends heavily on the timely identification and removal of precancerous lesions or early stage malignancies. To support this transition, participants in Boston and Los Angeles who received an abnormal stool test result were offered standardized navigation to colonoscopy (a process involving dedicated personnel who assist patients with scheduling, preparation instructions, and addressing logistical barriers to care).
Despite the availability of these navigation services, the researchers found that the completion of the diagnostic loop was remarkably low. Among the 100 individuals with an abnormal stool test result, only 36 (36.0%) completed a colonoscopy within 180 days. This finding suggests that while mailed fecal immunochemical test-DNA (FIT-DNA) increases the number of patients who engage with initial screening, it does not necessarily translate to a completed diagnostic workup. For clinicians, this highlights a critical gap in the care continuum where nearly two-thirds of patients with potentially high-risk results did not receive the definitive imaging required to rule out or diagnose malignancy.
The suboptimal follow-up rate underscores the complexity of managing colorectal cancer screening in underresourced community health center populations. Even with the increased sensitivity of FIT-DNA and the provision of patient navigation, systemic barriers likely continue to impede access to specialist procedures. These results indicate that primary care practices and health systems must look beyond initial screening uptake and develop more robust interventions to ensure that patients with abnormal stool tests successfully navigate the path to colonoscopy, as the clinical benefit of any non-invasive screening modality is entirely dependent on the subsequent diagnostic step.
References
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9. Chan RJ, Milch V, Crawford‐Williams F, et al. Patient navigation across the cancer care continuum: An overview of systematic reviews and emerging literature. CA A Cancer Journal for Clinicians. 2023. doi:10.3322/caac.21788
