Effect of Bright Light on Fatigue in Breast Cancer

Institution: University of California, San Diego
Investigator(s): Sonia Ancoli-Israel, Ph.D. -
Award Cycle: 2005 (Cycle 11) Grant #: 11IB-0034 Award: $141,282
Award Type: IDEA
Research Priorities
Community Impact of Breast Cancer>Sociocultural, Behavioral, and Psychological Issues: the human side



Initial Award Abstract (2005)
Introduction: Patients treated with chemotherapy complain of poor sleep, fatigue and depression. In addition, chemotherapy disrupts the body's internal "biological clock", which may make sleep, fatigue and depression all worse. Women with breast cancer undergoing chemotherapy are not exposed to much bright light and this may also contribute to the disruption of their body's internal "biological clock," because bright light is necessary for a strong biological clock. One of the easiest ways to strengthen the biological clock is by increasing bright light exposure. The correct timing of the light exposure will help the women feel more alert during the day.

Hypotheses: Fatigue is described as a general tiredness or an overwhelming lack of energy that is often associated with a need to rest, inability to regain energy even with rest, and lack of interest in events. The principal focus of this proposal is to examine the effect of bright light exposure on fatigue, sleep, mood, and daily functioning in women with breast cancer undergoing chemotherapy. The three main hypotheses are that increased bright light exposure during chemotherapy will: 1) decrease fatigue and improve mood and daily functioning; 2) improve both the quality and quantity of sleep, and 3) strengthen the body's internal "biological clock," particularly the sleep/wake rhythm.

Methodology: Fatigue, mood, daily functioning, sleep and the sleep/wake cycle will be measured with questionnaires and with sleep recordings before chemotherapy begins in women with breast cancer. Women will be assigned to either bright light treatment or dim light treatment. The light will be administered with special light boxes during cycles 1-4 of chemotherapy. Fatigue, mood, daily functioning, sleep and the sleep/wake cycle will be re-measured during the first and last weeks of cycle 1 and of cycle 4 of chemotherapy to evaluate the effect of light treatment.

Innovative elements: This proposal is innovative because it is one of the first to look at how fatigue might be improved with non-drug therapy. It also looks to see if the non-drug therapy will improve the women's sleep, mood and daily functioning. Understanding how the sleep/wake cycle can be strengthened to reduce fatigue is a relatively new topic within the field of breast cancer. Finding ways to reduce fatigue without drugs may help women tolerate their chemotherapy better, and be able to function better each day. All of these findings should help health professionals be more effective in the treatment of fatigue.

Advocacy involvement: The Y-ME National Breast Cancer Organization and Susan G. Koman Breast Cancer Foundation list fatigue as one of the most common side effects of cancer treatment, making it an important area for research. Symptoms of fatigue include weakness, difficulty thinking, and tiredness and lead to a decreased ability to perform everyday activities, like eating or visiting with family and friends. Treatments listed for fatigue include resting, getting enough sleep, exercising, eating right and conserving energy. But none of these treatments is wholly effective. Dr. Ancoli-Israel and Dr. Sadler are members of the UCSD Cancer Center's Outreach Program, which has also identified fatigue and poor sleep as common complaints among breast cancer patients and facilitates research in this area. Women have reported a desire for non-pharmacological ways to improve both sleep and fatigue and have promised support in helping with the project.


Final Report (2007)
Women with breast cancer undergoing chemotherapy often report disturbed sleep and increased symptoms of fatigue and depression. These patients also exhibit a disrupted circadian rhythm, also known as the “biological clock.” This internal clock is driven by exposure to bright light. In a previous study we found that women with breast cancer are exposed to less bright light during chemotherapy, and that less light exposure is related to increased fatigue.

The aims of this study were to explore the effect of increased bright light exposure on decreasing fatigue, improving sleep and improving mood. Women undergoing chemotherapy were assigned to self-administer either bright white light (BWL) or dim red light (DRL) for 30 minutes on each morning of their first four cycles of chemotherapy. Sleep/wake activity was recorded with an actigraph for 72-hours before the start of chemotherapy and during the first and last weeks of cycle 1 and cycle 4. The actigraph is a device worn on the wrist which records activity levels from which sleep and wake can be estimated. Patients also completed questionnaires on fatigue, mood, daily function, menopause, and sleep quality. Both groups had good compliance, with the average duration of each session being 33 minutes (SD=17) for the BWL group and 30 minutes for the DRL group.

The initial pace of recruitment was slower than expected, causing us to enroll three patients fewer than projected. We addressed this issue by introducing the study to several community oncologists, asking for their help in referring patients to our study. These referrals also gave us access to patients from the communities who are largely underrepresented in academic research studies. In total, 27 women agreed to participate and 7 of them then withdrew from the study. Most of the women who discontinued the study chose to do so before their second cycle of chemotherapy, stating their reason for withdrawal as being “overwhelmed” with their diagnosis.

Twenty patients, 10 in each treatment group, completed the study. Results suggest that increased light exposure during chemotherapy results in less fatigue and better sleep at the end of four cycles of chemotherapy compared to before chemotherapy. Specifically, total sleep time increased by 22 minutes and wake time during the night decreased by 12 minutes with increased light exposure, and general fatigue, as measured by a fatigue questionnaire, was reduced. The quality of sleep was also improved, although with this small group we did not reach a statistical significance for this measure.

We have received addition funding from Litebook Inc to continue this line of research. In the continuation of this study, we aim to repeat the protocol in a greater number of patients to continue testing the effect of bright light on sleep, fatigue and mood, as well as to test whether improved sleep and fatigue result in less cognitive impairment (“chemobrain”). Each participant will have a complete neuropsychological test battery, administered prior to chemotherapy and during the last week of cycle 4. A larger sample size will help us further address the original aims, and to elucidate the clinical value of light as a non-pharmacological approach to improving the quality of life in breast cancer patients.


Symposium Abstract (2007)
Background: Studies have shown that women with breast cancer undergoing chemotherapy report disturbed sleep. Studies have also suggested that these women have very little bright light exposure, yet it is known that bright light may improve sleep. This study examined whether increasing exposure to bright light will improve fatigue in women with breast cancer.

Methods: 11 women (mean age=50.3 yrs, SD=8.4, range: 35-70 yrs) diagnosed with stage I-III breast cancer, scheduled to receive at least 4 cycles of adjuvant or neoadjuvant anthracycline-based chemotherapy participated. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) and objective measures of sleep were assessed with 72-hours of actigraphy (Ambulatory Monitoring, Inc. and Respironics) at baseline (pre-chemotherapy) and during the last week of cycle 4 (C4). An actigraph is a device worn on the wrist which measure sleep/wake patterns. Participants were randomized into two treatment groups: bright white light (BWL) and dim red light (DRL). Both groups were instructed to self-administer light therapy for 30 minutes every morning throughout 4 cycles of chemotherapy.

Results: In the BWL group, total sleep time (TST) increased by 41 min (SD=69), while wake time during the night stayed approximately the same. In the DRL group TST decreased by 32 minutes (SD=30), while wake time increased by 27 minutes (SD=39). Subjectively, PSQI sleep latency subscale for BWL was reduced from 2.6 (SD=3.0, range=0-5) at baseline to 1.9 (SD=2.3, range=0-6) at C4, while for DRL, mean sleep latency increased from 2.7 (SD=2.5, range=0-5) at baseline to 3.0 (SD=3.0, range=0-6) at C4. PSQI total score for BWL decreased from 12.0 (SD=4.7, range=7-19) at baseline to 10.9 (SD=4.2, range=5-16) at C4 while for DRL it decreased from 8.3 (SD=3.1, range=5-11) at baseline to 7.7 (SD=5.1, range=2-12) at C4.

Conclusions: Preliminary results suggest that bright white light may increase the number of hours of sleep in women undergoing chemotherapy, as well as decreasing the amount of time it takes to fall asleep and improving sleep quality

The relative importance of specific risk factors for insomnia in women treated for early-stage breast cancer.
Periodical:Psycho-oncology
Index Medicus:
Authors: Bardwell WA, Profant J, Casden DR, Dimsdale JE, Ancoli-Israel S, et al.
Yr: 2008 Vol: 17 Nbr: 1 Abs: Pg:9-18

Taking fatigue seriously, II: variability in fatigue levels in cancer patients.
Periodical:Psychosomatics
Index Medicus: Psychosomatics
Authors: Dimsdale JE, Ancoli-Israel S, Ayalon L, Elsmore TF, Gruen W
Yr: 2007 Vol: 48 Nbr: 3 Abs: Pg:247-52

Sleep dysfunction in patients with cancer.
Periodical:Current Treatment Options in Neurology
Index Medicus: Curr Treat Options Neurol
Authors: Fiorentino L, Ancoli-Israel S
Yr: 2007 Vol: 9 Nbr: Abs: Pg:337-346

Predictors of inflammation in response to anthracycline-based chemotherapy for breast cancer.
Periodical:Brain, Behavior, and Immunity
Index Medicus: Brain Behav Immun
Authors: Mills PJ, Ancoli-Israel S, Parker B, Natarajan L, Hong S, Jain S, Sadler GR, von Känel R
Yr: 2008 Vol: 22 Nbr: 1 Abs: Pg:98-104