ABSTRACT Background Mindfulness‐based stress reduction (MBSR) has been shown to decrease stress and fear of cancer recurrence among breast cancer (BC) survivors. However, evidence is lacking in exemplifying MBSR as a method to improve positive, psychosocial outcomes, such as optimism and social support. Enhanced mindfulness has been shown to increase optimism and result in healthier coping strategies, however with a lack of research among cancer populations. Aims The aim of this exploratory study was to investigate psychosocial benefits that the MBSR(BC) intervention may impart, as a non‐pharmacological, alternative medicine intervention. Methods Breast cancer survivors ( n = 322, average age 56.6, breast cancer stages 0‐III), post‐treatment, were randomized to a 6‐week MBSR(BC) intervention or usual care as part of a large R01 clinical trial run between 2009 and 2013. Linear mixed models were tested as a secondary data analysis (linear growth curve analysis) to examine the rate of change in optimism and social support between groups at 6 and 12 weeks. Results Self‐report measures of optimism ( p = 0.025) and mindfulness ( p = 0.0001) significantly increased over time for participants randomized to the MBSR group ( n = 152) compared to usual care ( n = 147). Social support did not differ by group ( p = 0.378). Conclusions Enhanced optimism and mindfulness may arise from changes in perceptual biases learned through the MBSR(BC) intervention. MBSR(BC) may therefore impart some psychosocial benefits and encourage adaptive stress responses among breast cancer survivors, ultimately leading to more favorable health outcomes such as improved cancer recovery and quality of life.
Rosenfeld et al. (2026) studied this question.