The bodily threat monitoring scale: Development and preliminary validation in adult and childhood cancer survivors
Abstract
Objective
Bodily threat monitoring is a core clinical feature of Fear of cancer recurrence (FCR) and is targeted in psycho-oncology treatments, yet no comprehensive self-report measure exists. The aim of this study was the theory-informed development and initial validation of the Bodily Threat Monitoring Scale (BTMS).
Methods
Adult survivors of breast and gynaecological cancers (Study 1: N = 306, age = 37–81 years) and childhood cancer survivors (Study 2: N = 126, age = 10–25 years) completed the BTMS, designed to assess how individuals monitor for and interpret uncertain symptoms as indicating that something is wrong with their body. Participants completed measures to assess construct and criterion validity of the BTMS, and childhood cancer survivors (Study 2) completed the BTMS again 2 weeks later to assess test-retest reliability.
Results
The 19-item BTMS demonstrated excellent internal consistency across adult and childhood cancer samples (α = 0.90–0.96). Factor analyses indicated two subscales capturing 1. Monitoring of bodily sensations and 2. Threatening interpretations of bodily sensations. Two-week stability estimates were acceptable. For construct validity, the BTMS correlated with body vigilance and anxiety sensitivity. The BTMS also demonstrated criterion validity, yielding significant associations with FCR, intolerance of uncertainty, help-seeking behaviours, and quality of life. The BTMS was associated with FCR while controlling for body vigilance and anxiety sensitivity, indicating a unique contribution of this theory-informed measure.
Conclusions
The BTMS shows evidence of sound psychometric properties and could be used to elucidate the role of bodily threat monitoring in the maintenance and management of FCR.
1 INTRODUCTION
Fear of cancer recurrence (FCR), defined as the “fear, worry, or concern that cancer may come back or progress”, is a prevalent concern among adults and young people living with and beyond cancer (i.e., cancer survivors).1 Over half of cancer survivors report moderate or greater FCR2, 3 which is associated with more healthcare utilization4 and poorer quality of life.5 Managing FCR is also the most reported unmet supportive care need in cancer survivors.6 To address this unmet clinical need, several theoretical models of FCR have been proposed over the last decade.7 These theories have led to significant advances in our understanding of FCR and have guided the development of psychological treatments, several of which have demonstrated efficacy in reducing FCR and associated healthcare costs.8, 9 One prominent psychological process that appears across theories10-12 is the tendency to monitor and (mis)interpret uncertain bodily symptoms—hereafter termed ‘bodily threat monitoring’.
Bodily threat monitoring is an understandable response to a cancer diagnosis. As cancer treatment and survivorship are contexts in which there is risk for disease progression, disease recurrence, and late effects of treatment, symptom self-monitoring is often clinically encouraged as part of a ‘better safe than sorry’ strategy.13 Yet, while some degree of bodily threat monitoring may be helpful to respond appropriately to emerging symptoms of concern, persistent and excessive monitoring of bodily sensations and misinterpretation of benign bodily sensations as indicating disease could drive excessive reassurance-seeking, negatively impact mental health, and reduce quality of life.11, 14 A recent Delphi study reported that bodily threat monitoring is a core characteristic that differentiates clinical from nonclinical levels of FCR.15 Accordingly, existing FCR treatments attempt to reduce excessive bodily threat monitoring.8, 16
Yet, there is no comprehensive self-report measure of bodily threat monitoring. This has precluded high-quality empirical research adequately testing FCR theories and thus establishing the role of bodily threat monitoring in the development, maintenance, or remittance of FCR. According to FCR theory, greater bodily threat monitoring should not only be associated with FCR but also with the broader construct of (intolerance of) uncertainty.11 Bodily threat monitoring may emerge as a motivated uncertainty-reducing behaviour, particularly in a context wherein uncertainty lies within the body itself. Critically, without a well-validated measure, bodily threat monitoring has not been adequately assessed as an outcome or mediator of change in FCR treatment studies. We thus do not know whether existing FCR interventions adequately reduce excessive bodily threat monitoring or whether novel treatment approaches are needed to target this core clinical correlate of FCR. Examining whether bodily threat monitoring is associated with healthcare-seeking behaviours and health-related quality of life will also be important to establish its utility as a treatment target.
Bodily threat monitoring is a complex phenomenon. Clinically, the phenomenon appears to comprise both the tendency to persistently attend to the body to detect symptoms of concern as well as the tendency to appraise bodily sensations as symptoms of bodily threat (e.g., as indicating cancer recurrence). Studies to date have typically either conflated these two cognitive processes or have assessed the general cognitive style without the motivational context of detecting bodily threat. For example, the Body Vigilance Scale (BVS)17 which includes items such as “I am the kind of person who pays close attention to the way my body feels” captures attentional focus on the body but does not capture the motivation of this attentional focus. These items could be maladaptive or adaptive depending on whether the motivation for attending is to detect something being wrong with the body, or an accepting awareness and being ‘in tune’ with the body for the purpose of emotion regulation. Other studies have captured a more threat-focused style of relating to bodily sensations through measures such as the Pain Catastrophizing Scale,18 however these are limited in their focus on pain. Sensations such as fatigue may be more relevant signals of threat for many cancer survivors. Lastly, the Symptom Worry Scale19 captures the degree of worry about individual symptoms (e.g., pain, fatigue, itch) as a sign of cancer recurrence, however total scores on this measure are difficult to interpret as they may indicate a high level of worry about an individual symptom or a low level of worry about diffuse symptoms. Thus, we herein define the concept of bodily threat monitoring as comprising both the attending to and appraisal of bodily sensations for the motivational goal of detecting something being wrong with the body. A bodily threat monitoring measure that comprises subscales for both monitoring and appraising could usefully inform treatment approaches, for example, whether strategies to increase attentional control, reduce habitual threat interpretations, or both would be most helpful for FCR management.
The aim of this study is the development and preliminary psychometric assessment of the Bodily Threat Monitoring Scale (BTMS) in two samples of adult and childhood cancer survivors. We aim to examine the internal consistency, preliminary factor structure, and test-retest reliability of the BTMS. We also aim to examine its construct and criterion validity; we hypothesise that greater bodily threat monitoring will be associated, but not entirely overlapping, with greater body vigilance and anxiety sensitivity in adults (construct validity) as well as greater FCR in adults and children, intolerance of uncertainty, help-seeking behaviours, and lower quality of life in children (criterion validity).
2 STUDY 1
2.1 Overview
In Study 1 we examine the BTMS internal consistency, preliminary factor structure, and association with FCR in a sample of women living with and beyond breast or ovarian cancer. The definition of FCR includes both fear of disease recurrence and progression, and FCR is common and impactful in patients receiving active treatment and those who have completed treatment. Moreover, bodily threat monitoring is not limited to the post-treatment phase, as patients may be motivated to detect symptoms of disease progression and spreading within the context of active treatment. Thus, in this first study we employed the BTMS in a mixed sample of patients both on- and off-treatment.
3 METHODS
3.1 Initial development of the Bodily Threat Monitoring Scale
An initial pool of 36 items was developed by compiling and amending items from existing questionnaires and through feedback from an expert panel (see supplemental file S3 for full details).
3.2 Study 1 procedures
3.2.1 Participants
Females (N = 354) with a previous or current diagnosis of breast or ovarian cancer accessed an online survey circulated by Ovarian Cancer Australia and Breast Cancer Network Australia between June and September 2020. Eligible participants were female, fluent in English, aged over 18 years, and diagnosed with breast or ovarian cancer of any stage. Three-hundred and six respondents completed the BTMS and were included in analyses (breast N = 147; ovarian N = 159). Data from subsamples have been reported elsewhere.20, 21 The study received approval from the University of Sydney Human Research Ethics Committee. Participants provided informed consent online. See Table 1 for full demographics.
| Variable | M(SD) |
|---|---|
| Age | 58.81 years (10.77) |
| Frequency (percentage) | |
| Marital status | |
| Married | 191 (62.6%) |
| Widowed | 15 (4.9) |
| Divorced | 43 (14.1%) |
| Separated | 11 (3.6%) |
| Never married | 45 (14.8%) |
| Stage at diagnosis | |
| Stage 1 | 86 (28.1%) |
| Stage 2 | 68 (22.2%) |
| Stage 3 | 101 (33%) |
| Stage 4 | 28 (9.2%) |
| Not known | 23 (7.5%) |
| Cancer type | |
| Breast | 147 (48%) |
| Ovarian | 159 (52%) |
| Current cancer status | |
| On treatment | 108 (35.3%) |
| Off treatment | 198 (64.7%) |
| Cancer recurrence | |
| Yes | 77 (25.2%) |
| No | 229 (74.8%) |
3.2.2 Fear of cancer recurrence inventory—Short form
The Fear of cancer recurrence inventory—Short form (FCRI-SF) is a 9-item questionnaire that assesses the severity of FCR.22 Items are rated on a 5-point scale; a cut-off score of 13 or higher indicates clinically significant levels of FCR.23, 24 Cronbach's alpha for this sample was α = 0.88.
3.2.3 Data analysis
Data were analysed using SPSS v28.0.25 Exploratory maximum likelihood factor analyses (EFA) with oblimin rotation were conducted to examine the BTMS factor structure. Pearson correlations (age), Spearman correlations (cancer stage), and independent-samples t-tests (cancer type, history of recurrence, clinical levels of FCR) were used to inspect demographic and medical correlates of bodily threat monitoring. Pearson correlations were used to assess associations with FCR (<0.3 weak; 0.3–0.5 moderate, >0.5 strong26).
4 RESULTS
4.1 Bodily Threat Monitoring Scale development & factor analyses
There were no items for which >90% of the sample had responses at the extreme ends of the scale (0–1, or 3–4), indicating no issues with ceiling or floor effects. Seven items with skew or kurtosis >2.0 were removed to retain items that approximate a normal distribution. Seventeen items considered as overlapping as identified by a data-driven method (correlations >0.8) and considered to have considerable conceptual overlap were removed. The remaining 19 items were submitted to an unrestricted EFA. Three factors were indicated (Eigenvalues >1); however, the third factor had no unique items. A forced two-factor solution (see Table 2) was a good fit to the data, explaining 65.5% of the variance and with factor loadings >0.5. The two factors corresponded to dimensions of bodily monitoring (6 items, e.g., “I pay attention to my body to check if something is wrong”) and bodily threat appraisals (13 items, e.g., “When I have a bodily sensation that wasn't there before, I immediately think that something is wrong with my body”). The two subscales were strongly associated with each other (r = 0.63, p < 0.001). For parsimony, a one-factor solution was also examined and showed a good fit to the data, explaining 54.9% of the data, with no items loading >0.4 on their factor (see supplemental file S2). The final 19-item BTMS total score and subscales showed excellent internal consistency (see Table 3). The BTMS is freely available to use by research and clinical teams (see S3).
| Items | Factor 1 | Factor 2 |
|---|---|---|
| I monitor my body for signs that something is wrong | 0.893 | |
| I pay attention to my body to check if something is wrong | 0.865 | |
| I think about what my bodily sensations might mean | 0.716 | |
| When I have a new bodily sensation, I pay close attention to it in case it means that something is wrong | 0.604 | 0.353 |
| I take all new bodily sensations seriously | 0.581 | 0.317 |
| I keep track of my bodily sensations to make sure I won't miss if something is wrong | 0.560 | |
| Worrying about something being wrong with my body often stops me from enjoying myself | 0.957 | |
| I worry about bodily sensations even when I've been reassured that there isn't anything wrong | 0.904 | |
| I worry about a lot of different bodily sensations | 0.899 | |
| Worrying about something being wrong with my body often distracts me from other important things | 0.865 | |
| When I have a bodily sensation that wasn't there before, I immediately think that something is wrong with my body | 0.860 | |
| I find it hard to stay calm when I have a bodily sensation that could mean something is wrong | 0.834 | |
| I find it hard to distract myself from thinking about bodily sensations that suggest something is wrong with my body | 0.779 | |
| Worrying about something being wrong with my body often makes me unhappy | 0.729 | |
| My body often seems to send me signals that something is wrong | 0.729 | |
| When I have a bodily sensation I can't explain, I think it means that something is wrong with my body | 0.720 | |
| Even bodily sensations that aren't very intense make me worry that something is wrong | 0.689 | |
| I find it hard to distract myself from looking for signs that something is wrong with my body | 0.642 | |
| When I have a new bodily sensation, I will keep worrying about it until I get it checked out | 0.312 | 0.557 |
- Note: Factor 1 = bodily monitoring; Factor 2 = bodily threat appraisals. Factor loadings greater than 0.4 are bolded. Only factor loadings greater than 0.3 are displayed.
| Study 1 | Study 2 | |||||
|---|---|---|---|---|---|---|
| N = 306 adult survivors of breast & gynaecological cancers | N = 126 survivors of childhood cancers | |||||
| BTMS | Bodily monitoring (6 items) | Bodily threat appraisals (13 items) | BTMS | Bodily monitoring (6 items) | Bodily threat appraisals (13 items) | |
| Total score (19 items) | Total score (19 items) | |||||
| Psychometrics | ||||||
| Mean (SD) | 25.82 (15.91) | 11.18 (5.31) | 14.64 (12.01) | 23.41 (15.64) | 10.56 (6.06) | 12.85 (11.13) |
| Range | 0–76 | 0–24 | 0–50 | 0–74 | 0–24 | 0–50 |
| Cronbach alpha | 0.96 | 0.90 | 0.96 | 0.95 | 0.92 | 0.94 |
| Test-retest reliability | - | - | - | r = 0.76, p < 0.001 | r = 0.63, p < 0.001 | r = 0.79, p < 0.001 |
| Demographics | ||||||
| Age | r = −0.17, p = 0.004 | r = −0.11, p = 0.06 | r = −0.17, p = 0.003 | r = 0.29, p = 0.001 | r = 0.37, p < 0.001 | r = 0.20, p = 0.03 |
| Sex | - | - | - | t = −2.58, p = 0.01 | t = −1.41, p = 0.16 | t = −2.86, p = 0.01 |
| Medical factors | ||||||
| Cancer type | t = −0.09, p = 0.93 | t = −1.30, p = 0.19 | t = 0.46, p = 0.65 | - | - | - |
| Disease status | t = 1.16, p = 0.25 | t = −0.17, p = 0.87 | t = 1.62, p = 0.11 | - | - | - |
| Hx of recurrence | t = 2.22, p < 0.03 | t = 1.52, p = 0.13 | t = 2.26, p = 0.02 | - | - | - |
| Cancer stage | rs = 0.00, p = 0.95 | rs = 0.00, p = 0.94 | rs = 0.02, p = 0.77 | - | - | - |
| Age at diagnosis | - | - | - | r = 0.19, p = 0.04 | r = 0.27, p = 0.003 | r = 0.12, p = 0.19 |
| Time since Tx completion | - | - | - | r = 0.04, p = 0.63 | r = 0.02, p = 0.80 | r = 0.05, p = 0.59 |
| Treatment intensity | - | - | - | rs = 0.03, p = 0.80 | rs = 0.00, p = 0.99 | rs = 0.03, p = 0.75 |
| Construct validity | ||||||
| Body vigilance | - | - | - | r = 0.57, p < 0.001 | r = 0.61, p < 0.001 | r = 0.47, p < 0.001 |
| Anxiety sensitivity | - | - | - | r = 0.64, p < 0.001 | r = 0.36, p < 0.001 | r = 0.70, p < 0.001 |
| Criterion validity | ||||||
| Fear of cancer recurrence | r = 0.48, p < 0.001 | r = 0.31, p < 0.001 | r = 0.51, p < 0.001 | r = 0.56, p < 0.001 | r = 0.35, p < 0.001 | r = 0.59, p < 0.001 |
| Clinical fear of cancer recurrence | t = −5.59, p < 0.001 | t = −4.32, p < 0.001 | t = −5.45, p < 0.001 | - | - | - |
| Intolerance of uncertainty | - | - | - | r = 0.43, p < 0.001 | r = 0.19, p = 0.03 | r = 0.50, p < 0.001 |
| Help-seeking behaviours | - | - | - | r = 0.27, p = 0.002 | r = 0.23, p = 0.01 | r = 0.26, p = 0.003 |
| Health-related quality of life | - | - | - | r = −0.32, p < 0.001 | r = −0.17, p = 0.09 | r = −0.36, p < 0.001 |
4.2 Associations with demographic and medical factors
As seen in Table 3, there were no significant differences in the bodily threat monitoring total score or its subscales according to participants' cancer type (breast or ovarian) or treatment status (on- or off-treatment). Participants who had experienced a recurrence had a significantly higher bodily threat monitoring total score (Mrecurrence = 29.27, SD = 16.45, Mnorecurrence = 24.66, SD = 15.59) and bodily threat appraisals subscale score (Mrecurrence = 17.30, SD = 12.16, Mnorecurrence = 13.74, SD = 11.85). Younger participants yielded a significantly higher bodily threat monitoring total score and bodily threat appraisals subscale score.
4.3 Associations with fear of cancer recurrence
As seen in Table 3, there was a moderate association between FCR and the bodily threat monitoring total and bodily monitoring subscale, and a strong association with the bodily threat appraisals subscale. Participants with clinically significant levels of FCR reported engaging in significantly more bodily threat monitoring than participants with nonclinical levels of FCR (MclinicalFCR = 27.86, SD = 15.84, Mnon-clinicalFCR = 14.28, SD = 10.54); this finding held for both the bodily monitoring subscale (MclinicalFCR = 11.72, SD = 5.16, Mnon-clinicalFCR = 8.15, SD = 5.19) and the bodily threat appraisals subscale (MclinicalFCR = 16.14, SD = 12.06, Mnon-clinicalFCR = 6.13, SD = 7.31).
5 STUDY 2
5.1 Overview
The purpose of Study 2 was the further psychometric investigation of the BTMS in a sample of childhood cancer survivors. Data from a subsample of this sample (U.S. patients only) were reported elsewhere for a study investigating body mindsets and pain after childhood cancer.27 We aimed to examine internal consistency, test-retest reliability, construct validity, and criterion validity of the BTMS. The study protocol received ethical approval by (the Stanford School of Medicine Institutional Review Board #44463) and the Stanford Cancer Institute's Scientific Review Committee.
6 METHODS
6.1 Participants
Survivors of childhood cancer (N = 126; Tables 3 and 4) were recruited from two paediatric cancer centres in the U.S. and Canada between 2019 and 2021. Eligible participants were 10–25 years old, had a prior diagnosis of a childhood cancer, and had completed treatment with curative intent. Participants were required to be fluent in English; a Spanish language consent form was provided for Spanish-speaking parents. Informed consent was obtained via a phone call and using an online REDCap survey for participants aged 18 or older; informed assent and parental consent was obtained from participants aged 17 or younger. Participants were sent a secure REDCap link to complete the surveys and reimbursed $10 in Amazon vouchers. Medical history (age at diagnosis, time off treatment, diagnosis, treatment history) was self-reported and confirmed through medical record review; the intensity of treatment rating scale 3.028 categorised survivor's treatment intensity based on previous diagnosis, stage or risk level of disease, and treatment modality (level 1 = minimally intensive, level 4 = most intensive). Participants were invited to complete the BTMS a second time, two weeks later; 61 participants did so.
| Variable | Full sample | Test-retest sample (n = 61) |
|---|---|---|
| M (SD or %) | M (SD or %) | |
| Age (years) | 17.8 (3.57) | 18.03 (3.82) |
| Age at diagnosis (years) | 10.14 (5.87) | 11.13 (5.42) |
| Time since Tx completion (years) | 6.44 (4.46) | 5.76 (3.83) |
| Sex | ||
| Male | 58 (46%) | 27 (44%) |
| Female | 68 (54%) | 34 (55%) |
| Gender (US sample only) | ||
| Boy/Man | 48 (47%) | 27 (44%) |
| Girl/Woman | 52 (51%) | 34 (55%) |
| Non-binary | 1 (1%) | 0 (0%) |
| Gender fluid/Gender queer | 1 (1%) | 0 (0%) |
| Diagnosis | ||
| ALL | 47 (37%) | 19 (31%) |
| AML | 9 (7%) | 5 (8%) |
| Hodgkin's lymphoma | 17 (14%) | 9 (15%) |
| Non-Hodgkin's lymphoma | 15 (12%) | 8 (13%) |
| Ewing sarcoma | 5 (4%) | 3 (5%) |
| Osteosarcoma | 4 (3%) | 2 (3%) |
| Soft tissue or other sarcoma | 4 (3%) | 3 (5%) |
| Germ cell tumour | 3 (2%) | 3 (5%) |
| Neuroblastoma | 4 (3%) | 1 (2%) |
| Wilms' tumour | 5 (4%) | 1 (2%) |
| Brain/CNS tumour | 2 (2%) | 1 (2%) |
| Carcinoma | 2 (2%) | 1 (2%) |
| Ovarian cancer | 4 (3%) | 2 (3%) |
| Hepatoblastoma | 1 (1%) | 0 (0%) |
| Acute promyelocytic lymphoma | 1 (1%) | 0 (0%) |
| Multiple cancers | 2 (2%) | 2 (3%) |
| Race | ||
| Caucasian/White | 65 (52%) | 23 (38%) |
| Asian America | 30 (24%) | 23 (38%) |
| American Indian/Alaskan Native/Native Canadian | 1 (1%) | 0 (0%) |
| Hawaiian Native or Pacific Islander | 1 (1%) | 0 (0%) |
| Mixed race | 11 (9%) | 5 (8%) |
| Other | 16 (13%) | 8 (13%) |
| Ethnicity (US sample only) | ||
| Not Hispanic or Latino | 69 (68%) | 45 (74%) |
| Hispanic or Latino | 32 (25%) | 16 (26%) |
6.2 Measures
6.2.1 Fear of cancer recurrence—Child version
The FCRI-C is a child version of the FCRI-SF, also comprising 9 items with total scores from 0 to 36 and with higher scores indicating more severe fear of recurrence.29 Cronbach's alpha for this sample was 0.90.
6.2.2 Childhood anxiety sensitivity index (CASI—Autonomic/physical concerns) (U.S. Site only)
The CASI- autonomic/physical concerns subscale comprises 9 items assessing fear of sensations associated with the experience of anxiety and a misinterpretation of anxiety-related sensations as dangerous.30 Total scores range from 9 to 27 and higher scores indicating greater anxiety sensitivity. Cronbach's alpha for this sample was 0.88.
6.2.3 Body Vigilance Scale
The BVS comprises 3 items assessing attentional focus on and perceived sensitivity to bodily changes.31 The BVS comprises total scores from 0 to 30 with higher scores indicating greater body vigilance. Cronbach's alpha for this sample was 0.79.
6.2.4 Intolerance of uncertainty scale (IUS-Revised)
The IUS-R child version32 comprises 12 items for assessing intolerance of uncertainty in adults. Items are summed with total scores ranging from 12 to 60, with higher scores indicating greater intolerance of uncertainty. Cronbach's alpha for this sample was 0.92.
6.2.5 Childhood illness attitudes scale (CIAS-Help seeking)
The help-seeking subscale of the CIAS33 comprises 9 items assessing help-seeking behaviours, including asking to go to the doctor and informing parents about feeling unwell. Scores range from 9 to 27, with higher scores indicating more help-seeking behaviours. Cronbach's alpha for this sample was 0.83.
6.2.6 Health-related quality of life (PROMIS paediatric global health)
The paediatric global health (PGH-7) is a 7-item PROMIS paediatric measure of health-related quality of life.34 Raw scores are rescaled into standardized scores (t-scores) such that a score of 50 represents the average (mean) for the US paediatric population (SD = 10 points). Cronbach's alpha for this sample was 0.77.
6.3 Data analysis
Data were analysed using SPSS v28.0.25 Pearson correlations and paired-samples t-tests were used to examine test-retest reliability. Pearson correlations and Spearman correlations (treatment intensity) were used to inspect demographic and medical correlates of bodily threat monitoring. Partial correlations were used to assess unique associations with FCR.
7 RESULTS
7.1 Psychometric properties of the 19-item Bodily Threat Monitoring Scale in a paediatric sample
The BTMS total score and subscales yielded excellent internal consistency in childhood cancer survivors (see Table 3). All items had responses across the full (0–4) range, with no items showing skew or kurtosis >2.0. Bodily Threat Monitoring Scale total scores (t (124) = 0.86, p = 0.40) and subscale scores (bodily monitoring: t (124) = 0.58, p = 0.28; bodily threat appraisals: t (124) = 0.89, p = 0.38) were not different across the two recruitment sites.
7.2 Test-retest reliability
As seen in Table 3, there was a significant correlation between BTMS total scores, and subscales, at baseline and 2 weeks later. There were no significant differences in BTMS total scores (t (60) = −1.33, p = 0.19) or subscales (bodily monitoring: t (58) = −1.17, p = 0.25; bodily threat appraisals: t (60) = −1.21, p = 0.23) across these two timepoints.
7.3 Associations with demographic and medical factors
As can be seen in Table 3, older participants, those diagnosed at an older age, and females engaged in significantly more bodily threat monitoring. The significant association with age at diagnosis and sex was strongest for the bodily monitoring subscale but did not hold for the bodily threat appraisals subscale. There were no significant differences in bodily threat monitoring according to participants' time since treatment completion or treatment intensity.
7.4 Associations with Fear of cancer recurrence
As seen in Table 3, there was a strong association between FCR and bodily threat monitoring in childhood cancer survivors. The BTMS total score and subscales were significantly, positively correlated with anxiety sensitivity and body vigilance, indicating construct validity. Aligning with theory, body vigilance was more strongly associated with the bodily monitoring subscale, which was expected as these both capture styles of attending. Moreover, anxiety sensitivity was more strongly associated with the bodily threat appraisals subscale as anticipated as these both capture threat-focused appraisals of bodily sensations. Partial correlations revealed that the association between the BTMS total score and the FCRI-SF remained significant when controlling for anxiety sensitivity (r = 0.44, p < 0.001) and body vigilance (r = 0.43, p < 0.001), indicating a unique contribution of this theory-informed measure.
7.5 Association with intolerance of uncertainty, help-seeking behaviours, and quality of life
As seen in Table 3, there were small to moderate positive correlations between the BTMS total score, intolerance of uncertainty, and help-seeking behaviours, and a negative association with health-related quality of life. Intolerance of uncertainty was more strongly associated with the bodily threat appraisals subscale, even more so than the BTMS total score. The bodily threat appraisals subscale was significantly, moderately associated with quality of life.
8 DISCUSSION
The BTMS is a psychometrically promising self-report measure for survivors of adult and childhood cancers aged 10 and above. Following initial pilot work, a large item pool was administered to two samples of adult and childhood cancer survivors across three countries (Australia, United States, Canada). Aligning with theory, exploratory factor analyses in the larger adult sample indicated a two-factor structure; subscales represented ‘bodily monitoring’ and ‘bodily threat appraisals’. The BTMS total score and subscales demonstrated excellent internal consistency across both samples and showed adequate test-retest reliability across a brief 2 week interval in the childhood cancer sample.
As expected, the BTMS total score and its subscales yielded moderate-to-strong correlations with FCR in both adults and young survivors; these significant associations held while controlling for existing constructs of body vigilance and anxiety sensitivity. The effect sizes findings are particularly striking given that the BTMS makes no explicit reference to cancer. Moreover, the BTMS differentiated between those with clinical and subclinical levels of FCR. These findings align with qualitative studies indicating that everyday somatic symptoms (e.g., headache, muscle ache, mild fatigue) can trigger cancer-related fears.35-37 They also align with cross-sectional studies showing that survivors who report more somatic symptoms, including pain and fatigue, are also more fearful of cancer recurrence.5, 19, 38, 39 In addition, these findings align with recent studies showing that FCR is associated with a catastrophic appraisal of pain18 and a tendency to interpret ambiguous health-related information derived from bodily sensations as threatening.21 Fear of recurrence may bias attention towards and motivate monitoring of bodily sensations, lowering the detection thresholds for these sensations, hence fuelling increased fear of recurrence. This indicates that bodily threat monitoring may act as a mechanism maintaining a bi-directional association between FCR and somatic symptoms over time. The current findings provide support that bodily threat monitoring is a core clinical correlate of FCR and further supports its targeting in FCR treatment.
In the childhood cancer survivor sample, we further probed the criterion validity of the BTMS. Greater bodily threat monitoring was associated with elevated intolerance of uncertainty, a dispositional characteristic involving emotional, cognitive, and behavioural responses to an unknown outcome.40 Previous studies have found that intolerance of uncertainty is associated with greater emotional distress and poorer mental health in cancer survivorship.41-43 Yet, intolerance of uncertainty has been inadequately studied in relation to the experience of somatic symptoms. Our findings align with that of Hall and colleagues who found that greater perception of cancer-related uncertainty was associated with more fatigue and insomnia among breast cancer survivors.44 Bodily threat monitoring may emerge as an information-seeking style to reduce uncertainty—this warrants empirical investigation. Lastly, we found that bodily threat monitoring was associated with greater help-seeking behaviours and lower health-related quality of life in childhood cancer survivors. These data provide initial evidence that bodily threat monitoring is related to salient clinical and behavioural outcomes, such as help-seeking, FCR, and HRQoL, that align with higher healthcare costs and morbidity in cancer survivors.4, 45
8.1 Study limitations
This study has limitations, pointing towards directions for future research. First, the adult cancer survivor sample was limited to women living with and beyond breast or gynaecological cancer. Further investigation is needed in other diagnostic groups and in male survivors to assess the utility of the BTMS in these populations. Additionally, several construct and criterion validity measures were only collected in the childhood cancer survivor sample and thus additional inspection of validity in older adults is needed. Second, while we did not observe differences in BTMS total or subscale scores between adult cancer survivors who were on- or off-treatment, further research is needed to probe differences in bodily threat monitoring across the survivorship spectrum. Bodily threat monitoring may ultimately be most impactful after active treatment, wherein opportunities for objective bodily threat assessment (e.g., scans) are less frequent. Third, race/ethnicity data were not available for the adult sample; the childhood cancer survivor sample had representation of Hispanic individuals but greatly under-represented other races including Black survivors. Fourth, the high internal consistency estimates of the BTMS indicates that a briefer measure may be warranted, but creating a brief version of the scale was beyond the scope of this initial validation paper.
8.2 Clinical implications
The current findings are relevant for guiding survivorship care and policy. Less than one third of paediatric oncologists believe that their off-treatment patients worry unnecessarily about symptoms of cancer recurrence or late effects of treatment.13 Oncologists often favour a ‘better safe than sorry’ approach in counselling off-therapy patients to self-monitor for symptoms of disease recurrence and late effects.13 Yet, the current findings add to the growing body of evidence indicating that not only do cancer survivors commonly monitor and worry about their bodily sensations but also that this bodily threat monitoring matters—it is associated with increased healthcare-seeking behaviours and lower health-related quality of life in children. While some degree of self-monitoring is clinically warranted, more discussion is needed within clinical care and policy around striking a balance between mitigating medical risk (e.g., early detection of recurrence) while not unintentionally increasing fear and decreasing quality of life. There may be opportunities within existing clinical care pathways to actively stress the limited utility and mental health consequences of symptom self-monitoring when patients are receiving regular surveillance testing. This may be particularly significant for individuals living with the chronic high threat of cancer associated with cancer predisposition syndromes (e.g., hereditary breast and ovarian cancer). Offering anticipatory guidance as to which symptoms should not be a cause for concern, as well as accessible pathways for patients to report symptoms of concern early to the oncology team, could also be helpful to prevent an escalating cycle of bodily threat monitoring and fear of recurrence.14
9 CONCLUSIONS
In conclusion, the BTMS shows evidence of sound psychometric properties in two samples of adult and childhood cancer survivors. Given that bodily threat monitoring is proposed as a core clinical correlate of FCR and is already targeted in FCR interventions, the BTMS would be useful to include in future studies examining the maintenance and management of FCR.
ACKNOWLEDGEMENTS
We would like to acknowledge participants across both studies who gave their valuable time to complete study measures, the expert panel for their assistance in the initial development of the BTMS, and a previous reviewer of an earlier version of this manuscript who provided insightful feedback. This research was supported by a Postdoctoral Funding Grant from the Stanford Maternal and Child Health Research Institute awarded to LCH.
CONFLICT OF INTEREST STATEMENT
LCH has received consulting fees from Blue Note Therapeutics.
Open Research
DATA AVAILABILITY STATEMENT
Individual, but deidentified participant data and a data dictionary will be made available from publication upon request to researchers who aim to use the data in secondary analyses.
