Cancer continues to be a major global health concern, with improving patient outcomes becoming an increasingly urgent priority worldwide.1–3 In Switzerland, this problem is considerable, with around 60,500 new cases reported annually4 and about a quarter of a million people living five years post-diagnosis.4 Breast cancer is the most common cancer type in Switzerland, with yearly reports of 7,292 new cases.3 Although advancements in precision oncology and other innovative treatments are crucial to improving patient outcomes and quality of life for cancer patients, integrating behavior-based approaches into everyday clinical practice is equally vital.5,6

Psychological coaching has emerged as a crucial component in promoting overall health and positively impacting the immune system, especially in the context of breast cancer.7–10 A breast cancer diagnosis brings with it a host of emotional and mental challenges that can profoundly impact a patient’s overall health, especially their immune responses.11,12 Psychological coaching aims to manage and alleviate stress, anxiety, and depression, which are prevalent emotional reactions to facing cancer.13 Research indicates that persistent stress can weaken the immune system, potentially impairing the body’s capacity to combat cancer cells.7 By offering emotional support, strategies for dealing with stress, and fostering a positive mindset, psychological coaching can counteract the adverse impact of stress on immune health.13,14 This may lead to enhanced immune functionality and better patient outcomes in breast cancer, underscoring the critical link between mental and physical health in cancer treatment and recovery.14