Disruptions in sleep-wake cycles in community-dwelling cancer patients receiving palliative care and their correlates.

Significant disruptions in sleep-wake cycles have been found in advanced cancer patients in prior research. However, much remains to be known about specific sleep-wake cycle variables that are impaired in patients with a significantly altered performance status. More studies are also needed to explore the extent to which disrupted sleep-wake cycles are related to physical and psychological symptoms, time to death, maladaptive sleep behaviors, quality of life and 24-h light exposure. This study conducted in palliative cancer patients was aimed at characterizing patients' sleep-wake cycles using various circadian parameters (i.e. amplitude, acrophase, mesor, up-mesor, down-mesor, rhythmicity coefficient). It also aimed to compare rest-activity rhythm variables of participants with a performance status of 2 vs. 3 on the Eastern Cooperative Oncology Group scale (ECOG) and to evaluate the relationships of sleep-wake cycle parameters with several possible correlates. The sample was composed of 55 community-dwelling cancer patients receiving palliative care with an ECOG of 2 or 3. Circadian parameters were assessed using an actigraphic device for seven consecutive 24-h periods. A light recording and a daily pain diary were completed for the same period. A battery of self-report scales was also administered. A dampened circadian rhythm, a low mean activity level, an early mean time of peak activity during the day, a late starting time of activity during the morning and an early time of decline of activity during the evening were observed. In addition, a less rhythmic sleep-wake cycle was associated with a shorter time to death (from the first home visit) and with a lower 24-h light exposure. Sleep-wake cycles are markedly disrupted in palliative cancer patients, especially, near the end of life. Effective non-pharmacological interventions are needed to improve patients' circadian rhythms, including perhaps bright light therapy.