“…In addition, sleep disturbance has been shown in both healthy women and breast cancer survivors with menopausal symptoms (Carpenter et al., ), and sleep disturbance often accompanies fatigue (Wu et al., ). Cancer patients and survivors with fatigue tend to decrease their daily activity and lengthen their rest by staying in bed, which actually increases fatigue and decreases night‐time sleep quality (Timmerman, Dekker‐van Weering, Tonis, Hermens, & Vollenbroek‐Hutten, ; Winningham et al., ). Furthermore, cancer patients who decrease their activity during the day also decrease their exposure to bright sunlight, which might alter their rest‐activity circadian patterns, leading to increased fatigue, decreased sleep quality and worse quality of life (Berger, Farr, Kuhn, Fischer, & Agrawal, ; Mormont & Waterhouse, ).…”