0696 EFFECTS OF MORNING BRIGHT LIGHT THERAPY ON CIRCADIAN ACTIVITY RHYTHMS IN LUNG CANCER SURVIVORS

Abstract

Introduction: Robustness and stability in circadian rhythms indicate well-entrained circadian function. Cancer patients and survivors often experience dampened circadian activity rhythms (CAR) that are associated with, insomnia, fatigue and poor quality of life. Lung cancer survivors (LCS) have the worse patterns for CAR among cancer survivorship. Chronobiological interventions such as bright light therapy (BLT) have been implemented to re-entrain circadian rhythms, and prevent the worsening of fatigue in breast and gynecological cancer patients. However, this intervention is yet to be tested in LCS. Methods: A randomized controlled trial to explored the effects of morning BLT on CAR in LCS. Fourteen non-small cell lung cancer survivors (NSCLC), stage I-III were randomly assigned into experimental (green-blue) and attention control (red-yellow) light intervention groups. Individuals with macular degeneration, glaucoma, bipolar disease, seizure disorder or other psychiatric conditions were excluded. Demographic information and chronotype (Morningness and Eveningness Questionnaire) were assessed at pre-test. Pre and posttest comparison on visual acuity (Snellen visual acuity chart), fatigue (Brief Fatigue Inventory), and insomnia (Insomnia Severity Index) were performed along with a fiveweek assessment of CAR with wrist actigraphy (2-week pre-test, 1-week of intervention, and 2-week posttest). Data were analyzed using a t-test, ANCOVA, and non-parametric analysis as appropriate. Results: Preliminary data on four participants shows predominance of female 83.3% (n=3), older age 66.03.5 (SD 7.8, range=53-82), Caucasian-non-Hispanic 100% (n=4) with evening chronotype (100%, n=4), moderate to severe fatigue 66.7% (n=3) and clinically significant insomnia 66.7% (n=3). Participants had CAR patterns similar to free-running rhythms at pre-test but exhibited entrainment when exposure to morning green-blue light. No changes in visual acuity and no side effects were reported. Conclusion: This study in ongoing. Disrupted patterns of CAR may be associated with decreased light exposure. Morning BLT may be effective to re-entrain and strengthen circadian rhythms leading to better quality better sleep quality and overall quality of life.