Fatigue is one of the most distressing symptoms experienced by cancer patients. The suggested biological mechanism for cancer related fatigue (CRF) includes immune activation triggered by tumor tissue or by anticancer treatment but other mechanisms have also been proposed. Previous large meta-analysis of interventions on fatigue focuses mostly on patients early in the disease trajectory, with only one tenth of included studies performed in palliative cohorts. The aim of this narrative review is therefore to present a background on CRF with focus on the palliative setting. A summary of recent randomized, controlled trials on pharmacological interventions on CRF in palliative care is presented, including studies on psychostimulants, corticosteroids, testosterone and melatonin. Interestingly, in several of these studies there was a positive and similar effect on fatigue in both the intervention and the placebo arm—indicating an important placebo effect for any pharmacological treatment. In addition, studies on dietary supplements and on pharmacological complementary medicines are discussed. To conclude, the evidence is still weak for using pharmacological treatments on CRF in palliative care patients—although methylphenidate and corticosteroids might be considered.

The aim of the ‘Palliative-D’ study was to test the hypothesis that correction of vitamin D deficiency reduces opioid use in cancer patients admitted to palliative care. A multicenter randomized, placebo-controlled, double-blind trial in three home-based palliative care facilities in Sweden was performed. Patients with advanced cancer and 25-hydroxyvitamin D < 50 nmol/L were randomized to vitamin D3 4000 IU/day or placebo for 12 weeks. The primary endpoint was the difference of long-acting opioid use (fentanyl ug/h) between the groups during 12 weeks, based on four time points. Secondary outcomes included changes in antibiotic use, fatigue and Quality of Life (QoL). A total of 244 patients were randomized, and 150 patients completed the 12 weeks. The major reason for drop-out was death due to cancer. The vitamin D-group had a significantly smaller increase of opioid doses compared to the placebo-group; beta coefficient −0.56 (p = 0.03), i.e., 0.56 µg less fentanyl/h per week with vitamin D treatment. Vitamin D-reduced fatigue assessed with ESAS was −1.1 points after 12 weeks (p < 0.01). Antibiotic use or QoL did not differ significantly between the groups. The treatment was safe and well-tolerated. In conclusion, correction of vitamin D deficiency may have positive effects on opioid use and fatigue in palliative cancer patients, but only in those with a survival time more than 12 weeks.

Albumin is an important biochemical marker in palliative cancer care, used for assessment of nutritional status, disease severity and prognosis. Our primary aim was to investigate sex differences in the association between appetite and albumin levels in palliative cancer patients. We also aimed to study associations between appetite and C-reactive protein (CRP), Quality of Life (QoL), pain and fatigue. In the Palliative D-cohort, consisting of 266 men and 264 women, we found a correlation between appetite and albumin; low appetite, measured with the Edmonton Symptom Assessment System, correlated significantly with low albumin in men: (r = −0.33, p < 0.001), but not in women (r = −0.03, p = 0.65). In a regression analysis adjusted for confounding factors, results were similar. Lower appetite was correlated with higher CRP in men (r = 0.27, p < 0.001), but not in women (r = 0.12, p = 0.05). Appetite was correlated with QoL, fatigue and pain in both men and women; those with a low appetite had a low QoL and high fatigue- and pain-scores (p < 0.001). In conclusion, our results indicated possible sex differences in the associations between appetite and albumin, and between appetite and CRP, in palliative care patients. Understanding these associations could provide additional value for clinical practice.

Background According to a small pilot study on palliative cancer patients at our ward, vitamin D supplementation had beneficial effects on pain (measured as opioid consumption), infections and quality of life (QoL) without having any significant side effects. Objective The primary objective of the ‘Palliative-D’ study is to test the hypothesis that vitamin D supplementation for 12 weeks reduces opioid consumption. The secondary objectives are to study if reduction of antibiotic consumption and fatigue as well as improvement in QoL assessments can be observed. Effect on the 25-hydroxy vitamin D (25-OHD) levels in serum after 12 weeks of treatment will be studied, as well as the change in opioid dose in relation to genetic polymorphism in genes involved in the effect and metabolism of vitamin D. Method A randomised, double-blind placebo-controlled multicentre trial has been designed. The trial will include 254 adult palliative cancer patients with 25-OHD levels <50 nmol/L and a life expectancy of more than 3 months recruited from two advanced palliative home care centres in Stockholm. Included patients will be randomly assigned to 12 weeks of treatment with cholecalciferol (vitamin D3) 4000 IU/day or placebo. The study will start in November 2017 and will finish in December 2019. The study is approved by the Regional Ethical Committee, Dnr2017/405-31/1, by the Swedish Medical Products Agency, EudraCT: 2017-000268-14, and is registered at Clinicaltrial.gov: NCT03038516. The study is financed with research grants from the Swedish Cancer Society and the Stockholm County Council.

Background: Fatigue is one of the most distressing symptoms in patients with advanced cancer. Previous studies have shown an association between low vitamin D levels and fatigue. Objectives: The aim of this study was to investigate the association between vitamin D levels and self-assessed fatigue in cancer patients admitted to palliative care, with focus on possible sex differences. Design: This is a cross-sectional study. Subjects: Baseline data from 530 screened patients, 265 women and 265 men, from the randomized placebo-controlled trial “Palliative-D” were analyzed. Measurements: Vitamin D status was measured as 25-hydroxyvitamin D (25-OHD) and fatigue was assessed with EORTC-QLQ-PAL15 and with Edmonton Symptom Assessment System (ESAS). Results: In men, there was a significant correlation between 25-OHD and fatigue measured with the “Tiredness question” (Q11) in EORTC-QLQ-PAL15 (p < 0.05), where higher 25-OHD levels were associated with less fatigue. No correlation between 25-OHD and fatigue was seen for women. Fatigue measured with ESAS did not show any significant association with 25-OHD levels neither in men nor in women. Conclusion: Low vitamin D levels were associated with more fatigue in men but not in women. The study underscores the importance of subgroup analysis of men and women when evaluating the effect of vitamin D in clinical trials since the effect may differ between the sexes. The ongoing “Palliative-D study” will reveal whether vitamin D supplementation may counteract fatigue in both men and women. ClinicalTrial.gov: NCT03038516.

In the randomized, placebo-controlled, double-blind trial ‘Palliative-D’, vitamin D treatment of 4000 IE/day for 12 weeks reduced opioid use and fatigue in vitamin-D-deficient cancer patients. In screening data from this trial, lower levels of vitamin D were associated with more fatigue in men but not in women. The aim of the present study was to investigate possible sex differences in the effect of vitamin D in patients with advanced cancer, with a specific focus on fatigue. A post hoc analysis of sex differences in patients completing the Palliative-D study (n = 150) was performed. Fatigue assessed with the Edmonton Symptom Assessment Scale (ESAS) was reduced in vitamin-D-treated men; −1.50 ESAS points (95%CI −2.57 to −0.43; p = 0.007) but not in women; −0.75 (95%CI −1.85 to 0.36; p = 0.18). Fatigue measured with EORTC QLQ-C15-PAL had a borderline significant effect in men (−0.33 (95%CI −0.67 to 0.03; p = 0.05)) but not in women (p = 0.55). The effect on fatigue measured with ESAS in men remained the same after adjustment for opioid doses (p = 0.01). In conclusion, the positive effect of the correction of vitamin D deficiency on fatigue may be more pronounced in men than in women. However, studies focused on analyzing sex differences in this context must be performed before firm conclusions can be drawn.