Effects of Bright Light on Co-occurring Cancer-related Symptoms in Breast Cancer Survivors

Effects of Bright Light on Co-occurring Cancer-related Symptoms in Breast Cancer Survivors: A Personalized Intervention

This study will implement therapeutic bright light that is tailored to the individual's circadian typology and will estimate its effects on circadian rhythms, 4 common cancer-associated symptoms, and impact on quality of life in survivors living with cancer. Examining a selected phase marker (core body temperature) in relation to the associated clinical features (symptoms) is the starting point for future investigation of the biological mechanisms of symptoms.

The purpose of this pilot study is to evaluate the feasibility of implementing a home-based, personalized bright light intervention, and to estimate the effects of bright light on 4 common long-term or late effects of cancer (sleep disturbance, fatigue, depression, cognitive dysfunction) and on quality of life in post-treatment survivors of breast cancer. The three specific aims include:

Aim #1: To assess the feasibility of implementing a home-based, personalized bright light intervention and the proposed data collection plan in post-treatment survivors of breast cancer.

Aim #2: To estimate the effects of the personalized bright light intervention on sleep disturbance, fatigue, depression, cognitive dysfunction, and quality of life in survivors of breast cancer.

Aim #3: To estimate the effects of a personalized bright light intervention on circadian rhythms in survivors of breast cancer.

The participants of this randomized, controlled pilot study will be randomized to either 30-minute blue-green light therapy at 12,000 lux or dim red light control at 5 lux. Light will be self-administered using a light visor cap at home for 14 consecutive days. Tailored to the individual's circadian pattern, light will be delivered either within 30 minutes of waking in the morning or between 1900-2000 hours in the evening. The nocturnal sleep patterns will be monitored by all-night in-lab polysomnography; sleep quality, fatigue, depression, and quality of life will be self-reported; cognition will be objectively assessed before and after the intervention. Circadian rhythm will be indexed by nocturnal core body temperature before and after the intervention. Feasibility will be determined by the proportion of contacted, recruited, and retained subjects, and completeness of the data collected. Subjective feedback and burden will be assessed at study exit.

Inclusion Criteria:

• Females
• 21 years of age or older 1-3 years post-completion of chemotherapy or/and radiation therapy for stage I-III breast cancer
• Experience ≥ 2 concurrent symptoms (fatigue, sleep disruption, depressive symptoms, and/or cognitive dysfunction as measured by 4 screening instruments)
• Be either phase advanced or delayed (morning or evening types by the Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ) ≥59 or ≤41)
• Sighted
• Mentally competent to consent
• Able to understand English.

Exclusion Criteria:

• Undergoing cancer treatment for another malignancy
• Have metastatic cancer
• Engaged in shift work or travel across more than three time zones within 2 weeks prior to study
• Current diagnosis of seasonal affective disorder or substance abuse Current diagnosis of major Axis I psychiatric disorders (e.g. depressive disorders), neurological impairments, or muscular dystrophies
• Report severe depressive mood (Center for Epidemiological Studies Depression Scale (CES-D) >24)
• Take prescribed sedative hypnotics or steroids Have eye conditions (glaucoma or retinal disease), problems triggered by bright light (e.g., migraine), or take photosensitizing medications (e.g., some porphyrin drugs, antipsychotics, antiarrhythmic agents)