Improvement of fatigue due to placebo in blinded and open labeled cancer fatigue treatment trials.

Background: The purpose of this study was to compare the placebo response i.e., improvement of cancer-related fatigue (CRF) between cohorts of advanced cancer patients who received placebo as part of CRF clinical trials in a blinded fashion, and as open-label for treatment of CRF.

Materials and methods: In this study, data of advanced cancer patients from randomized controlled CRF clinical treatment trials who received placebo in a blinded, and as an open labeled design at a tertiary cancer center were reviewed. Demographic data, Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), and Edmonton Symptom Assessment Scale (ESAS) scores were pooled, and changes in FACIT-F (placebo response), from baseline to day 8 in the two cohorts were compared. We also examined the association of placebo response with demographics factors, FACT-G, and its sub scales, ESAS symptoms, and ESAS symptom distress scores.

Results: We found no significant differences in placebo response between the blinded and open label cohorts [6.6 vs 7.9, -1.3 (P =0.87)]. We found significant association between placebo response and baseline FACIT-F -3.5 (P=0.0001), gastrointestinal cancers 5.2 (P=0.02), ESAS- pain 0.70 (P=0.04), ESAS anxiety 1.3 (P=0.003), and ESAS-Symptom Distress Score -0.53 (P=0.012).

Conclusions: In this study we found placebo response was not significantly different between patients receiving placebo in a blinded and open-labeled design in randomized controlled CRF clinical trials. In this study we found a significant association between placebo response and baseline CRF, gastrointestinal cancers, ESAS- pain, anxiety and ESAS-Symptom Distress Score. Further research is needed.