Recognized as one of the most prevalent and persistent concerns in cancer survivors, fear of cancer recurrence (FCR) is defined as the "fear, worry, or concern relating to the possibility that cancer will come back or progress" (Lebel et al., 2016). Higher FCR severity leads to poor mental health, impaired functioning and reduced quality of life. It is well established that health behaviours can help reduce the risk of cancer recurrence in cancer survivors, but little is known about their relationship with FCR. The overall thesis objectives were: 1) to identify subgroups of cancer survivors by FCR severity and corresponding patient characteristics; 2) to explore the relationship between FCR and health behaviours (physical activity and fruit and vegetable intake) over time; and 3) to further examine the relationship between FCR severity subgroups and health behaviours using the Common-Sense Model (CSM). Data analyses were conducted on 2337 survivors of ten cancer sites who completed the American Cancer Society’s Studies of Cancer Survivorship-I survey at three time points (M =1.3, 2.2, and 8.8 years post-diagnosis). In study 1, group-based trajectory analyses revealed three FCR severity groups: low, moderate, and high. FCR significantly decreased from early to long-term survivorship and remained distinct for each group. Subsequently, repeated measures analysis of variance revealed that patient characteristics prevalent in the high FCR group were being female, of younger age, Hispanic ethnicity, having more advanced cancer stage (II-III) and Non-Hodgkin lymphoma. Across FCR groups, only a minority of survivors adhered to the recommended physical activity and fruit and vegetable intake. Survivors in the high FCR group reported significantly fewer of these health behaviours than other survivors. In study 2, cross-sectional path analyses were conducted to examine the relationship between FCR and health behaviours using the CSM framework across the FCR severity groups. Results indicated good-fitting models for the low, moderate, and high FCR groups. Engaging in physical activity and fruit and vegetable intake did not influence FCR in most participants. Yet, in the low FCR group, survivors reporting more health behaviours had lower FCR severity. In the low and moderate FCR groups, health behaviours were related to control over health and self-efficacy to manage health, suggesting that cancer survivors use health behaviours to manage illness outcomes. For survivors in the high FCR group, results suggest that self-efficacy to manage health is a better predictor of FCR than engaging in physical activity and fruit and vegetable intake In conclusion, most cancer survivors fail to meet the recommended physical activity and fruit and vegetable intake throughout cancer survivorship, with survivors in the high FCR group being at greater risk of engaging in fewer health behaviours. Health behaviours appear unrelated to FCR severity for most cancer survivors, except for survivors with low FCR, who might be experiencing less FCR when engaging in more health behaviours. Findings suggests that clinical interventions should be tailored by FCR severity groups and that health behaviour research among cancer survivors should account for FCR severity groups. Further investigations are required to assess cancer survivors’ perceived usefulness of health behaviours to manage the risk of cancer recurrence by FCR severity group

Parenting is a primary role for many young breast cancer survivors and the combined effect of parenting while coping with this disease can be problematic for many of them. Despite this, little is known about the impact of parenting on the well-being of young breast cancer survivors. This thesis, comprising two studies in article format, explores this question. In the first study, we identified elements of well-being that are salient for all young women with breast cancer, and which also captured some of the unique challenges associated with parenting as a survivor. Using factor analysis techniques, we determined how these elements interrelated in separate groups of young survivors with children and without, and identified differences between the two groups based on the patterns observed. We found that the interrelationship among elements of well-being varied between these two groups: psychological distress (representing mental health and perceived stress), illness intrusiveness, and fear of cancer recurrence were found to co-occur more frequently in mothers than in young survivors without children, thus compromising their well-being. Our second study had two objectives. The first part examined differences in perceived stress, illness intrusiveness, and fear of cancer recurrence between young breast cancer survivors with and without children in two separate timeframes (0-5 and 5-15 years since diagnosis). The second part identified predictors for these elements of well-being in young mothers exclusively. Compared to survivors without children, young mothers reported higher levels of fear of cancer recurrence and illness intrusiveness in intimate life domains during both timeframes, suggesting that disruptions in these areas persist over time. Part two revealed that mothers with adolescent children and high levels of parenting stress were most likely to report perceived stress and illness intrusiveness. A mother’s age and the time since her diagnosis predicted fear of cancer recurrence and illness intrusiveness, respectively. Results from this thesis indicate that young mothers with breast cancer need screening and interventions to manage psychological distress, fear of cancer recurrence, and illness intrusiveness, particularly in intimate life domains. This thesis also identifies the most vulnerable groups of mothers and has important implications for future research.

Fear of cancer recurrence (FCR) is regarded as one of the most common and distressing issues affecting cancer survivors. Observational studies have identified several modifiable characteristics associated with FCR. However, many of the findings are based on post-hoc analyses and come from studies in which FCR was not identified as a primary outcome. This study sought to overcome these limitations by using a model comprised of cognitive, behavioral, and social characteristics as a framework for examining modifiable characteristics associated with FCR. A sample of 120 patients who had been diagnosed with colorectal cancer and completed cancer treatment in the past 6 to 36 months was recruited during routine outpatient visits or by mail for participation in the study. Medical record reviews were conducted to assess clinical variables, and participants filled out a standard demographic questionnaire as well as self-report measures of characteristics resistant to modification (perceived risk of recurrence, neuroticism, conscientiousness), cognitive modifiable characteristics (self-efficacy, positive beliefs about worry, negative beliefs about worry, misinterpretation of symptoms, intolerance of uncertainty and rumination), behavioral modifiable characteristics (reassurance seeking and health-related reassurance seeking), and social modifiable characteristics (social support and social constraints). As hypothesized, results demonstrated that modifiable characteristics (i.e., self efficacy, positive beliefs about worry, negative beliefs about worry, intolerance of uncertainty, rumination, reassurance seeking, health-related reassurance seeking and social constraints) were associated with FCR (all p’s < .05). Multivariable regression analyses demonstrated that modifiable characteristics accounted for 13% of the variance in FCR beyond that accounted for by non-modifiable characteristics (p < .001), with self-efficacy, rumination and health-related reassurance seeking accounting for unique variance in FCR. This study has identified several modifiable characteristics that should be considered as targets for interventions seeking to reduce FCR among cancer survivors.

Fear of cancer recurrence (FCR) is defined as “fear, worry, or concern relating to the possibility that cancer will come back or progress (Lebel et al., 2016, p. 3266). FCR is the most frequently reported concern identified among cancer survivors (Baker, Denniston, Smith, & West, 2005; Lebel, Rosberger, Edgar, & Devins, 2007). Although approximately 50% of cancer survivors experience moderate-to-high levels of FCR (Simard et al., 2013), few psychosocial interventions exist that directly target this construct. The overarching study objectives were: (a) to adapt a manualized, 6-week, cognitive-existential group therapy intervention for FCR to an individual format; (b) to pilot-test the feasibility, acceptability, and satisfaction of this individual intervention on n=3 participants; and (c) to further pilot-test the efficacy of the individual intervention on n=25 participants, via a randomized controlled trial (RCT). In study 1, n=3 cancer survivors (1 male, 2 females) completed the one-on-one therapy intervention for the psychological treatment of FCR. Sessions were 60-90 minutes long, and included cognitive restructuring exercises, behavioural experiments, relaxation techniques, existential processing of the here-and-now, and finding meaning in life post-diagnosis. Participants completed questionnaire packages throughout the intervention and an exit interview to determine their overall feedback on the intervention. Quantitative analyses revealed downwards trends in fear of cancer recurrence and cancer-specific distress across participants. Qualitative analyses of the exit interviews revealed that all participants found the intervention useful, and that the sessions had favourable pacing and length. In study 2, the FCR intervention was further pilot-tested via an RCT. Twenty-five female cancer survivors were randomized to an experimental group or a wait-list control group. Sessions included cognitive restructuring techniques, behavioural experiments, confronting existential distress, and relaxation exercises. Nineteen women (n=9 intervention, n=10 control) completed the 6-week therapy intervention, and completed questionnaire packages at pre-, post- and 3-month follow-up. Between-within ANOVAs revealed significant interactions in the primary outcome measure of FCR, and secondary outcome measures of cancer-specific distress and uncertainty in illness for participants in the experimental group. Repeated measures ANOVAs revealed reductions in FCR, cancer-specific distress, uncertainty in illness, reassurance-seeking, cognitive avoidance, and intolerance of uncertainty, and revealed improvements in positive reinterpretation and growth, use of emotional support and mental health (improved quality of life) for participants in the experimental group, as compared to the wait-list control group. The variables that changed either maintained or improved at follow-up. Results from this study demonstrate promising results in addressing FCR in cancer survivors via a cognitive-existential intervention. Future research should continue investigating the specific therapeutic ingredients that are most effective for the psychological treatment of FCR.

Parenting is a primary role for many young breast cancer survivors and the combined effect of parenting while coping with this disease can be problematic for many of them. Despite this, little is known about the impact of parenting on the well-being of young breast cancer survivors. This thesis, comprising two studies in article format, explores this question. In the first study, we identified elements of well-being that are salient for all young women with breast cancer, and which also captured some of the unique challenges associated with parenting as a survivor. Using factor analysis techniques, we determined how these elements interrelated in separate groups of young survivors with children and without, and identified differences between the two groups based on the patterns observed. We found that the interrelationship among elements of well-being varied between these two groups: psychological distress (representing mental health and perceived stress), illness intrusiveness, and fear of cancer recurrence were found to co-occur more frequently in mothers than in young survivors without children, thus compromising their well-being. Our second study had two objectives. The first part examined differences in perceived stress, illness intrusiveness, and fear of cancer recurrence between young breast cancer survivors with and without children in two separate timeframes (0-5 and 5-15 years since diagnosis). The second part identified predictors for these elements of well-being in young mothers exclusively. Compared to survivors without children, young mothers reported higher levels of fear of cancer recurrence and illness intrusiveness in intimate life domains during both timeframes, suggesting that disruptions in these areas persist over time. Part two revealed that mothers with adolescent children and high levels of parenting stress were most likely to report perceived stress and illness intrusiveness. A mother’s age and the time since her diagnosis predicted fear of cancer recurrence and illness intrusiveness, respectively. Results from this thesis indicate that young mothers with breast cancer need screening and interventions to manage psychological distress, fear of cancer recurrence, and illness intrusiveness, particularly in intimate life domains. This thesis also identifies the most vulnerable groups of mothers and has important implications for future research.

Due to the high survival rates of many young cancer patients and a high risk of second tumors, fear of cancer recurrence (FCR) can cause serious impairment for adolescent and young adult (AYA) cancer patients. The aim of this study is to analyze the structure of the Fear of Disease Progression Questionnaire (FoP-Q-12) to better understand the construct of FCR.We performed a cross-sectional survey on a sample of AYA patients aged 15–39 years with different tumor entities. FCR was measured using the FoP-Q-12, and a network analysis was conducted to examine the relationship of FCR symptoms. The importance of individual items in the network was determined using centrality analyses. A total of 247 AYA patients (81.8% female, median age 31.0 years) participated in the study. The mean FCR score in the sample was 35.9 (SD = 9.9). The majority of patients reported having high FCR (59.5%), according to the established cut-off. The two questionnaire items with the strongest association related to fears about work, and the most central symptom was the fear of serious medical interventions. The centrality of emotional issues in the sample indicates that these symptoms should be prioritized in the development of interventions targeting FCR. Further research should address this topic with larger samples of patients in other age groups and in longitudinal studies.