INTRODUCTION: Virtual reality (VR) has garnered increasing attention in oncology due to its potential to enhance patient care by alleviating anxiety and emotional distress. The present work evaluates the hypothesis proposed by a recent theoretical model that engagement and the sense of presence are key mediators that impact the degree of beneficial effects that VR may have on the emotional well-being of breast cancer patients. METHODS: This study draws on data from three previous studies comprising 156 breast cancer patients. The psychological variables of well-being studied included emotional dimensions measured before and after exposure to a virtual environment, as well as factors related to immersive qualities. Correlation and mediation analyses were conducted to explore relationships among said variables, namely, one's tendency to be immersed in an activity, engagement, spatial presence, and emotional well-being (i.e., valence and arousal) of the patients. RESULTS: Engagement plays a crucial mediating role between tendency of immersion, spatial presence, and positive emotional responses. Patients with a greater tendency toward immersion and higher engagement in the virtual environment showed significant emotional improvements. However, tendency of immersion and spatial presence alone did not directly lead to more positive emotional experiences
their influence was primarily exerted through engagement. CONCLUSIONS: Engagement emerges as a fundamental lever for maximizing the psychological benefits of VR in oncology. Clinical interventions using VR should prioritize optimizing engagement in immersive environments to improve patients' emotional state throughout their cancer treatment journey.