Abstract
IMPORTANCE: Despite the availability of effective interventions, fear of cancer recurrence (FCR) remains a prevalent concern among cancer survivors, underscoring the need for approaches that balance accessibility (eg, an online program with asynchronous therapist guidance) with engagement and effectiveness. OBJECTIVE: To evaluate the efficacy of a 10-week therapist-guided (TG) e-health intervention, TG-iConquerFear, to reduce FCR in colorectal cancer (CRC) survivors. DESIGN, SETTING, AND PARTICIPANTS: This single-site, Danish population-based randomized clinical trial enrolled cancer-free adult CRC survivors aged 18 years or older from May 8, 2023, to April 8, 2024, with clinical FCR (FCR Inventory-Short Form [FCRI-SF] score ≥22). Eligible participants had completed curative-intent CRC treatment between March 1, 2014, and December 31, 2018. Follow-up was 6 months. INTERVENTIONS: Participants were randomized 1:1 (stratified by age and sex) to receive TG-iConquerFear or augmented control. TG-iConquerFear comprised 6 modules with written therapist guidance delivered remotely, individually, and asynchronously as needed over 10 weeks. Augmented control was a diagnostic interview and referral to a webpage with self-help mindfulness exercises. MAIN OUTCOMES AND MEASURES: The primary outcome was change in FCRI total score at 3 months postintervention, analyzed according to intention-to-treat. RESULTS: Of 9946 eligible CRC survivors, 103 with clinically significant FCR were randomized. Prior to the intervention, 2 were excluded due to cancer and 6 dropped out. Of the remaining 95 participants (median age, 63 [IQR 57-72] years; 60 [63%] female; median time since diagnosis, 7 [IQR 6-9] years), 42 were analyzed in the TG-iConquerFear group and 53 in the augmented control group. Intervention participants completed a mean (SD) of 4.5 (1.9) of 6 modules. Total FCRI score decreased significantly from baseline to 3 months in the TG-iConquerFear group (mean change, -21.7 [95% CI, -30.1 to -13.3] points) but not in the control group (mean change, -2.6 [95% CI, -7.8 to 2.6] points). This represents a between-group difference of 19.1 (95% CI, 10.0-28.3) points (P < .001) and a standardized effect size (Cohen d) of 0.62 (95% CI, 0.13-1.10). A significantly higher proportion of TG-iConquerFear participants had FCRI-SF scores below the cutoff for clinical FCR at 3 months postintervention compared with self-help participants (22 of 27 [81%] vs 18 of 42 [43%]; P = .002). The number needed to treat was 3. CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, TG-iConquerFear intervention participants reported a significant and clinically meaningful reduction in FCR compared with the control group, suggesting an e-health intervention may expand the range of FRC treatment options beyond face-to-face interventions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04287218.