Decreased health-related quality of life in women with breast cancer is associated with poor sleep.

This study examined the longitudinal relation between health-related quality of life (HR-QOL) and subjective and objective sleep quality in 166 women with newly diagnosed Stage-1 through Stage-3 breast cancer, who were scheduled to receive ≥ 4 cycles of adjuvant/neoadjuvant chemotherapy. HR-QOL was assessed with the Medical Outcomes Study 36-item Short Form, Physical Component Scale (PCS), and Mental Component Scale (MCS) scores; subjective sleep was assessed with the Pittsburgh Sleep Quality Index; and objective sleep was measured with actigraphy. Data were collected before starting chemotherapy and during the last week of Cycle 4 of chemotherapy. Patients reported poor HR-QOL and poor sleep quality before and during chemotherapy. Short sleep time and long naps were recorded at both time points. The MCS score was related to reports of poor sleep, but not to recorded sleep; worse PCS scores were associated with reports of poor sleep and less recorded naptime, suggesting sleep plays an important role in cancer patients' HR-QOL.