The "PC-LIGHT" Study

Systematic Light Exposure to Prevent Fatigue in Prostate Cancer Patients

Fatigue due to cancer and its treatment (for example, radiation therapy) can interfere with quality of life and can linger long after treatment has ended, yet research examining preventative approaches has produced limited clinical benefit. The proposed study will provide information about systematic light exposure for the prevention of fatigue in prostate cancer patients undergoing radiation therapy and will investigate how it works. This study would facilitate the development of this potential preventative treatment, giving health care providers and cancer survivors a much-needed tool to help with cancer-related fatigue.

Inclusion Criteria:

• Have been diagnosed with clinical localized prostate cancer,
• Are about to begin external beam radiation therapy (RT) for prostate cancer,
• Are 18 years of age or older,
• Are able to speak or read English,
• Have internet access.

Exclusion Criteria:

• History of light therapy use (e.g. systematic light exposure),
• Active infection
• History of chronic fatigue disorders
• Confounding underlying medical illnesses such as significant pre-existing anemia (Hb<10 gm/dl)
• Diagnosed or suspected psychiatric or medical condition that might contribute to fatigue (other than those caused by the cancer or its treatment)
• Hypothyroidism or documented history of hypothyroidism on thyroid replacement hormone within <3 months of initiating RT
• History of bipolar disorder or mania
• History of seasonal affective disorder
• Diagnosed sleep apnea, restless legs, or other sleep disorders (not including insomnia) known to affect fatigue
• Use of photosensitizing medication
• Plans to travel across more than 2 time zones during the study
• Shift worker
• Adults unable to consent, individuals who are not yet adults, pregnant women, and prisoners will be excluded from the study