A Randomized, Controlled, Parallel-Group, Trial on the Long-term Effects of Melatonin on Fatigue Associated With Breast Cancer and Its Adjuvant Treatments

Objective: Cancer related fatigue is a distressing condition and correlated with decrease in quality of life of patients with malignant conditions. In continuation of our previous research, we assessed long term anti-fatigue effects of melatonin in patients with the breast cancer. Material and methods: In this clinical trial, 92 breast cancer patients were randomly assigned to receive either melatonin (18 mg/day) or placebo from 1 week before the adjuvant treatments until 2 years after their completion. The levels of fatigue were assessed before and after intervention using Brief Fatigue Inventory (BFI) and were compared at a significance level of P <= .05. Results: The BFI scores were similar between the 2 groups at the baseline (placebo group: 5.56 +/- 1.59 and melatonin group: 5.72 +/- 1.68, P =.67). After the intervention, not only the mean fatigue score was significantly lower in melatonin group (2.93 +/- 1.04 vs 1.99 +/- 1.02, P <.001, P <= .05), but also a greater reduction in fatigue score in intervention group was evident over time (P =.001). Conclusion: Long-term usage of melatonin even after completion of adjuvant therapies in women with breast cancer decreased the levels of fatigue associated with the malignant condition and its treatments.