Validity and screening capacity of the FCR-1r for fear of cancer recurrence in long-term colorectal cancer survivors

PURPOSE: Existing fear of cancer recurrence (FCR) screening measures is being shortened to facilitate clinical use. This study aimed to evaluate the validity and screening capacity of a single-item FCR screening measure (FCR-1r) in long-term colorectal cancer (CRC) survivors with no recurrence and assess whether it performs as well in older as in younger survivors. METHODS: All Danish CRC survivors above 18, diagnosed and treated with curative intent between 2014 and 2018, were located through a national patient registry. A questionnaire including the FCR-1r, which measures FCR on a 0–10 visual analog scale, alongside the validated Fear of Cancer Recurrence Inventory Short Form (FCRI-SF) as a reference standard was distributed between November 2021 and May 2023. Screening capacity and cut-offs were evaluated with a receiver-operating characteristic analysis (ROC) in older (≥ 65 years) compared to younger (< 65 years) CRC survivors. Hypotheses regarding associations with other psychological variables were tested as indicators of convergent and divergent validity. RESULTS: Of the CRC survivors, 2,128/4,483 (47.5%) responded; 1,654 (36.9%) questionnaires were eligible for analyses (median age 76 (range 38–98), 47% female). Of the responders, 85.2% were aged ≥ 65. Ninety-two participants (5.6%) reported FCRI-SF scores ≥ 22 indicating clinically significant FCR. A FCR-1r cut-off ≥ 5/10 had 93.5% sensitivity and 80.4% specificity for detecting clinically significant FCR (AUC = 0.93, 95% CI 0.91–0.94) in the overall sample. The discrimination ability was significantly better in older (AUC = 0.93, 95% CI 0.91–0.95) compared to younger (0.87, 95% (0.82–0.92), p = 0.04) CRC survivors. The FCR-1r demonstrated concurrent validity against the FCRI-SF (r = 0.71, p < 0.0001) and convergent validity against the short-versions of the Symptom Checklist-90-R subscales for anxiety (r = 0.38, p < 0.0001), depression (r = 0.27, p < 0.0001), and emotional distress (r = 0.37, p < 0.0001). The FCR-1r correlated weakly with employment status (r = − 0.09, p < 0.0001) and not with marital status (r = 0.01, p = 0.66) indicating divergent validity. CONCLUSIONS: The FCR-1r is a valid tool for FCR screening in CRC survivors with excellent ability to discriminate between clinical and non-clinical FCR, particularly in older CRC survivors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00520-023-08159-7.