Chrono-behavioral Therapy for Chronic Fatigue in Cancer

Cancer-related fatigue (CRF) is frequently reported as the most severe and distressing side effect of cancer and its treatment. Among cancer patients, up to 40% will experience CRF that can last months or even years after treatment and it is also deleterious to quality of life. However, there is still no established CRF treatment. Underlying mechanisms of CRF are likely multi-factorial and recently, circadian rhythm disruption has been implicated as a possible related pathophysiological mechanism underlying CRF. Circadian rhythms are endogenous 24-hour cycles of rhythmicity in physiology and behavior orchestrated by the suprachiasmatic nuclei (SCN) in the brain. They are entrained to the environment via time-giving cues called "zeitgebers". Thus, improving circadian rhythm robustness by strengthening modifiable zeitgebers is one potential way to ameliorate CRF. The overarching goal of the proposed project is to conduct an optimization trial of a home-based, low-burden multicomponent chrono-behavioral therapy (ChronoBT) that aims to strengthen the effects of 3 zeitgebers to treat CRF - light/dark exposure, physical activity and eating - all of which individually have shown promise in strengthening circadian rhythms and reducing fatigue. The study will include two work packages: In Work Package 1 (WP1), the investigators will pilot test candidate intervention components in prostate and female breast cancer survivors. In Work Package 2 (WP2), a fully powered optimization trial will be undertaken using the framework - the Multiphase Optimization Strategy (MOST), to test the optimal combination of ChronoBT components.

Inclusion criteria

• prostate or female breast cancer survivors
• completed local and/or adjuvant cancer therapy (with the exception of hormonal therapy) ≥ 1 year previously
• ≥18 years of age
• able to speak and read Danish
• experiencing CRF (score ≤36 on FACT-F)

Exclusion criteria

• use of light therapy in the last year
• confounding underlying medical/psychiatric disorders or use of medications associated with fatigue (e.g., a central nervous system cancer, untreated hypothyroidism, anemia, chronic fatigue syndrome, insomnia, major depression)
• non-cancer related factor likely to be a driver of fatigue (e.g., shift work, pregnancy, recent travel across time zones)
• recurrence of cancer or new cancer
• physical or psychological conditions that could prevent participation in intervention components
• use of photosensitizing medications