Abstract
BACKGROUND: Breast cancer causes significant psychological and physical burden, with survivors often reporting persistent psychological symptoms, such as anxiety and depression, along with somatic symptoms like fatigue and pain. Psychological factors may protect from the development of long-term distress and help identify patients with greater needs for supervision and/or care. Here we aimed to study the predictive role of mindfulness as a trait in determining affective and somatic symptoms 12 months after cancer diagnosis. METHODS: Women with a diagnosis of breast cancer were recruited at the onset of systemic treatments and compared with healthy women from the general population. Over a 12-month period, participants were periodically assessed using the Mindfulness Attention Awareness Scale (MAAS), the Hospital Anxiety and Depression Scale, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 and the Positive and Negative Affect Scale. Regression models were employed to assess the predictive associations of baseline mindfulness trait with symptoms after 12 months. RESULTS: The study included 282 participants, 243 of whom contributed complete data for analysis. The Portuguese version of MAAS demonstrated adequate psychometric properties for patients with breast cancer, supporting its use to address our main aim. Mindfulness trait scores remained stable across time, did not differ significantly between patients and healthy participants, and were similarly stable across time for patients undergoing different treatments. Also in the clinical group, MAAS scores at baseline significantly predicted affective, but not somatic symptoms, 12 months later, with higher levels of mindfulness predicting more clinically significant distress. CONCLUSIONS: In women with a recent diagnosis of breast cancer, mindfulness trait appears unaffected by diagnosis or its treatments, serving as a protective factor against affective, but not somatic, symptoms, in the first year following diagnosis.