Contactless Device Reveals Timing of Sleep Disturbances Due to Breast Cancer Treatment

Sleep disturbances in breast cancer patients undergoing neoadjuvant chemotherapy – designed to shrink the tumours prior to surgery – are one of the common side effects of these treatments, which can not only exacerbate other side effects, but also impact prognosis. One of the possible, non-pharmacological strategies to mitigate these disturbances is thought to be physical exercise.

However, to advance the research on the potential benefits of exercise, more accurate, more detailed, less subjective methods for quantifying sleep in patients are needed. In a preliminary study, a team of scientists in Portugal used a sensor-based, non-wearable device to measure various parameters of sleep including sleep duration, quality, and sleep timing.

Their results were recently published in the journal Scientific Reports. Carla Malveiro, an exercise physiologist and the coordinator of the Oncology Exercise Programme at the Champalimaud Foundation (CF), and Pedro Saint-Maurice, group leader of the Physical Activity and Quality of Life Lab, also at the CF, are, respectively, lead and senior author of this new study, which was done in collaboration with the University of Lisbon’s Faculdade de Motricidade Humana.

“While much research has focused on chemotherapy's impact on overall sleep quality through subjective measures, less attention has been given to its effects on specific sleep metrics such as duration, timing, continuity, and naps”, the authors write in their paper. “This preliminary study addresses this gap.” 

Usually, in sleep assessment studies in cancer research, subjects are asked to self-evaluate their sleep relative to the previous few days using standard questionnaires. However, contactless, sensor-based sleep devices are becoming more prominent since this technology can collect sleep information passively and for long periods of time without disrupting cancer patients sleep routines.

In this new study, the team used a contactless device, placed under the mattress, which can assess not only sleep duration, but timing and regularity of sleep as well. “[We used] the Emfit QS device over 100 consecutive days in 24 breast cancer patients undergoing neoadjuvant chemotherapy”, the authors write. Also included was a subjective quality of sleep assessment, using the Pittsburgh Sleep Quality Index (PSQI), a self-report questionnaire that generates an overall score for sleep quality and insomnia-related symptoms.

The researchers identified the periods in which sleep disturbances in the cancer patients were most pronounced. As measured by the device, time spent in bed “decreased over the first seven weeks (e.g., 9.3 hours/day at week 1 vs. 8.5 hours/day at week 8), and increased thereafter to similar amounts as those recorded in week 1 (9.0 hours/day at week 15)”. Sleep timing and regularity did not change.

As to the statistical analysis of the subjective assessment score, it corroborated the results obtained with the device: “Approximately, 33%, 63%, and 73% [of patients] reported having insomnia symptoms at week 1, 8, and 15”, highlighting “critical periods during treatment when patients are vulnerable to disrupted sleep”. 

“Future research should focus on interventions to mitigate sleep disturbances, improving patient well-being and overall quality of life”, the authors conclude.

“Physical exercice has been identified as one potential strategy to attenuate disrupted sleep patterns”, says Malveiro. However, she points out, “one barrier to advancing our understanding of sleep among cancer patients is the lack of more objective measures that can provide more accurate and detailed information about sleep”. This study is a first step in surmounting that barrier. 

Original paper here.
 

Text by Ana Gerschenfeld, Health & Science Writer of the Champalimaud Foundation.