Diet and physical activity behaviors: how are they related to illness perceptions, coping, and health-related quality of life in young people with hereditary cancer syndromes?

Individuals with inherited cancer syndromes, such as Li-Fraumeni syndrome (LFS), may be motivated to adopt health-protective behaviors, such as eating more fruits and vegetables and increasing physical activity. Examining these health behaviors among young people with high lifetime genetic cancer risk may provide important insights to guide future behavioral interventions that aim to improve health-related quality of life (HRQOL). We used a self-regulatory framework to investigate relationships among diet and physical activity behaviors and psychosocial constructs (e.g., illness perceptions, coping, HRQOL) in adolescents and young adults (AYAs; aged 15-39 years) with LFS. This longitudinal mixed-methods study included 57 AYAs aged 16-39 years at enrollment), 32 (56%) of whom had a history of one or more cancers. Participants completed one or two telephone interviews and/or an online survey. We thematically analyzed interview data and conducted regression analyses to evaluate relationships among variables. AYAs described adopting healthy diet and physical activity behaviors to assert some control over health and to protect HRQOL. More frequent use of active coping strategies was associated with greater reported daily fruit and vegetable intake. Greater reported physical activity was associated with better quality of psychological health. Healthy diet and physical activity behaviors may function as LFS coping strategies that confer mental health benefits. Clinicians might emphasize these potential benefits and support AYAs in adopting health behaviors that protect multiple domains of health. Future research could use these findings to develop behavioral interventions tailored to AYAs with high genetic cancer risk.