Background: Cancer is a leading cause of death worldwide, the leading cause of death in Canada, and a significant burden for Canadians. Cancer survivors and their partners have unique healthcare needs. In particular, anxiety is pervasive and impairs quality of life. In order to improve care in cancer survivors and their partners, it is vital that greater efforts are made to understand, measure, and evaluate therapies that can ameliorate anxiety. Objectives: This study will adapt the Dot-Probe Paradigm (DPP) to measure anxiety in breast cancer survivors. The DPP is a feasible, 15-minute, computer-based test of experimental cancer-relevant words and control words that are ideographically matched and presented at random. Using this tool, I will identify whether anxiety is characterized by attentional capture (i.e. longer 'looking time' on threat words) or avoidance (i.e. shorter 'looking time' on threat words). This study will then test the predictive power of the DPP by examining the effects of Mindfulness-Based Stress Reduction (MBSR) therapy on anxiety in breast cancer survivors and their partners. Methods: Two studies will be conducted. In the first study, I will adapt the DPP for breast cancer survivors and assess the convergent and divergent validity of this tool using established questionnaires. In the second study, I will use the DPP to measure the decrease of breast cancer survivors' and their partners' anxiety after MBSR, compared to control groups. Research Implications: Therapeutically, this project will determine whether MBSR mitigates anxiety in breast cancer survivors, and, for the first time, whether this therapy diminishes anxiety in the partners of survivors. Theoretically, this project will also identify the underlying coping style of cancer anxiety in survivors and partners, and the aspect of anxiety (i.e. avoidance or attentional capture) that is improved after MBSR.