RESUMEN
The role of self-efficacy to cope with breast cancer as a mediator and/or moderator in the relationship of trait resilience to quality of life and psychological symptoms was examined in this study. Data from the BOUNCE Project ( https://www.bounce-project.eu/ ) were used. Women diagnosed with and in treatment for breast cancer (N = 484), from four countries, participated in the study. Trait resilience and coping self-efficacy were assessed at baseline (soon after the beginning of systemic treatment), and outcomes (quality of life, psychological symptoms) 3 months later. Hierarchical regression, mediation, moderation, and conditional (moderated) mediation and moderation analyses were performed to examine the study hypotheses. Coping self-efficacy mediated the impact of trait resilience. In addition, higher levels of resilience in combination with higher levels of coping self-efficacy were associated with better outcomes. Country of origin had no impact on these results. Overall, it seems that coping self-efficacy is a key factor that should be taken into account for research and intervention efforts in cancer.