Adjuvant therapy with either tamoxifen or aromatase inhibitors reduces breast cancer recurrence and improves overall survival in patients with hormone receptor-positive breast cancer. However, the benefits achieved with adjuvant endocrine therapy come at a cost. A variety of negative symptoms can substantially impair patients' quality of life and treatment adherence. Sleep disorder, a well-known side effect of endocrine therapy, may compromise treatment effectiveness and serves as relevant behavioral marker of poor prognosis. In order to be able to offer personalized solutions combining conventional pharmacological medicine with non-pharmacological approaches, it is important to understand the impact of the sleep disorders particularly in women with breast cancer on endocrine therapy who present an increased risk of insomnia. The primary aim of this study was to assess sleep quality and its relationship with anxiety, depression and pain. Patients' lifestyle, knowledge on integrative approaches to health and global quality of life were also evaluated.
