Breast cancer survivors often experience chronic psychological and physiological stress after completing treatment​. Prolonged stress can dysregulate the hypothalamic-pituitary-adrenal axis, leading to elevated levels of cortisol and inflammatory cytokines like interleukin-6 (IL-6), which have been linked to poorer health outcomes (e.g., fatigue, depression, and even cancer progression)​. Mindfulness-Based Stress Reduction (MBSR) is a meditation-based program shown to alleviate stress, anxiety, fatigue, and other symptoms in cancer survivors​ . However, prior to this study it was unclear whether MBSR produces measurable changes in objective stress biomarkers such as salivary cortisol and IL-6​. Lengacher et al. (2019) address this gap by investigating the effects of a tailored MBSR program for breast cancer survivors on these biomarkers in a large randomized controlled trial (RCT). The authors also examined how changes in cortisol and IL-6 relate to patients’ symptoms and quality of life​

Participants were recruited from the Moffitt Cancer Center and the Morsani clinics at the University of South Florida, located in Tampa, FL. Participation selection criteria was: (1) female sex; (2) age >= 21 years; (3) a diagnosis of Stage 0, I, II, or III BC; (4) treatment with a lumpectomy and/or mastectomy; (5) completion of adjuvant radiation and/or chemotherapy at least 2 weeks prior to enrollment and within 2 years from end of primary treatment; and (6) the ability to read and speak English at an eighth-grade level. Exclusion criteria included: (1) diagnosis of Stage IV cancer, (2) a severe current psychiatric diagnosis, and (3) a cancer recurrence.