Relationship of Mitochondrial Enzymes to Fatigue Intensity in Men With Prostate Cancer Receiving External Beam Radiation Therapy

Determinants of Cancer-Related Fatigue among Cancer Patients: A Systematic Review

Objectives: This systematic review aims to assess and explore various determinants of cancer- related fatigue. Methods: A systematic search of various determinants of Cancer-related fatigue (CRF) was performed in different databases like PubMed, Google Scholar, Science Direct and Clinical Key dating from 1990 to September 2020. Results: A total of 6115 studies were screened and 95 articles related to determinants of fatigue were retained. Various modifiable and non-modifiable determinants including socio-demographic, clinical, treatment related, plasma biomarker related, genetic, behavioural, concurrent symptoms related and psychological determinants were identified. Depression was one of the significant factors reported in 28% of studies, followed by pain, (17%), performance status (16%), chemotherapy and anxiety (15%). Conclusion: It is recommended that nurses and clinicians should anticipate, identify and take appropriate interventions to manage those modifiable factors. Ultimately, managing the modifiable factors helps in the comprehensive care of cancer patients.

The Effects of a Mediterranean Diet Intervention on Cancer-Related Fatigue for Patients Undergoing Chemotherapy: A Pilot Randomized Controlled Trial

Cancer-related fatigue is a common, burdensome symptom of cancer and a side-effect of chemotherapy. While a Mediterranean Diet (MedDiet) promotes energy metabolism and overall health, its effects on cancer-related fatigue remain unknown. In a randomized controlled trial, we evaluated a rigorous MedDiet intervention for feasibility and safety as well as preliminary effects on cancer-related fatigue and metabolism compared to usual care. Participants had stage I−III cancer and at least six weeks of chemotherapy scheduled. After baseline assessments, randomization occurred 2:1, MedDiet:usual care. Measures were collected at baseline, week 4, and week 8 including MedDiet adherence (score 0−14), dietary intake, and blood-based metabolic measures. Mitochondrial respiration from freshly isolated T cells was measured at baseline and four weeks. Participants (n = 33) were 51.0 ± 14.6 years old, 94% were female, and 91% were being treated for breast cancer. The study was feasible, with 100% completing the study and >70% increasing their MedDiet adherence at four and eight weeks compared to baseline. Overall, the MedDiet intervention vs. usual care had a small-moderate effect on change in fatigue at weeks 4 and 8 (ES = 0.31, 0.25, respectively). For those with a baseline MedDiet score <5 (n = 21), the MedDiet intervention had a moderate-large effect of 0.67 and 0.48 at weeks 4 and 8, respectively. The MedDiet did not affect blood-based lipids, though it had a beneficial effect on fructosamine (ES = −0.55). Fatigue was associated with mitochondrial dysfunction including lower basal respiration, maximal respiration, and spare capacity (p < 0.05 for FACIT-F fatigue subscale and BFI, usual fatigue). In conclusion, the MedDiet was feasible and attenuated cancer-related fatigue among patients undergoing chemotherapy, especially those with lower MedDiet scores at baseline.

Exploratory Analysis of Associations Between Whole Blood Mitochondrial Gene Expression and Cancer-Related Fatigue Among Breast Cancer Survivors

BACKGROUND

Cancer-related fatigue is a prevalent, debilitating, and persistent condition. Mitochondrial dysfunction is a putative contributor to cancer-related fatigue, but relationships between mitochondrial function and cancer-related fatigue are not well understood.

OBJECTIVES

We investigated the relationships between mitochondrial DNA (mtDNA) gene expression and cancer-related fatigue, as well as the effects of fish and soybean oil supplementation on these relationships.

METHODS

A secondary analysis was performed on data from a randomized controlled trial of breast cancer survivors 4-36 months posttreatment with moderate-severe cancer-related fatigue. Participants were randomized to take 6 g fish oil, 6 g soybean oil, or 3 g each daily for 6 weeks. At pre- and postintervention, participants completed the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire and provided whole blood for assessment of mtDNA gene expression. The expression of 12 protein-encoding genes was reduced to a single dimension using principal component analysis for use in regression analysis. Relationships between mtDNA expression and cancer-related fatigue were assessed using linear regression.

RESULTS

Among 68 participants, cancer-related fatigue improved and expression of all mtDNA genes decreased over 6 weeks with no effect of treatment group on either outcome. Participants with lower baseline mtDNA gene expression had greater improvements in cancer-related fatigue. No significant associations were observed between mtDNA gene expression and cancer-related fatigue at baseline or changes in mtDNA gene expression and changes in cancer-related fatigue.

DISCUSSION

Data from this exploratory study add to the growing literature that mitochondrial dysfunction may contribute to the etiology and pathophysiology of cancer-related fatigue.

Cancer-related fatigue: an overview

A diagnosis of cancer is a major life stressor that can affect the physiological, psychological and physical state of the person concerned. Fatigue is a particularly common and troubling symptom that has a negative impact on quality of life throughout all phases of treatment and stages of the illness. The aim of this review is to provide background information on cancer-related fatigue. This review discusses cancer-related fatigue (CRF) in terms of the definition, prevalence, risk factors, aetiology, and the measurement scales used. The differences between definitions of symptoms and relevant theories will be explored and discussed to help explain the variety of instruments used in its measurement. The prevalence of fatigue will be assessed by looking critically at the evidence of fatigue and the factors that affect it. Potential treatment and management strategies for CRF will also be discussed. Finally, there will be an overview of the instruments used to measure fatigue. This review also provides important evidence for measuring and managing CRF that can help nurses to understand fatigue among patients with cancer. Assessing CRF should be routinely undertaken in clinical settings to help identify the proper interventions, treatments and management to reduce fatigue among cancer patients.

A study protocol for HEalth-Related quality of life-intervention in survivors of Breast and other cancers experiencing cancer-related fatigue using TraditionAL Chinese Medicine: the HERBAL trial

BACKGROUND

Cancer-related fatigue (CRF) is a debilitating condition which commonly affects cancer survivors. The management of CRF remains a challenge due to the lack of effective pharmacological interventions. Traditional Chinese medicine (TCM) could be a potential therapeutic option for CRF. The modified Xiang Bei Yang Rong Tang (XBYRT) is a TCM herbal decoction, formulated to improve fatigue symptoms in cancer survivors. This clinical trial aims to evaluate the efficacy and safety of XBYRT in improving CRF and quality of life (QOL) of cancer survivors.

METHODS

This is a single centre, randomized, double-blind, placebo-controlled, parallel trial. Eighty cancer survivors will be recruited and randomized to receive the XBYRT or placebo decoction, in a ratio of 1:1. Participants will consume the XBYRT/placebo decoction daily for 8 weeks and undergo assessments at baseline and 4, 8 and 10 weeks after baseline. The participants will be assessed for patient-reported outcomes (PRO), blood biomarkers and adverse events at each time point. The primary outcome is the overall health and QOL status, at 8 weeks follow-up. The secondary outcomes are the effects of XBYRT on fatigue levels, cancer-related cognitive impairment and QOL, as assessed by PRO. The incidence of adverse events and the effects of the XBYRT decoction on blood biomarkers associated with CRF will also be evaluated.

DISCUSSION

Efficacy and safety outcomes from this trial will provide important clinical data to guide future large-scale randomized controlled trials, and the evaluation of the objective blood biomarkers can help to delineate the biological mechanisms of CRF.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT04104113 . Registered on 26 September 2019.

Exploring Biologic Correlates of Cancer-Related Fatigue in Men With Prostate Cancer: Cell Damage Pathways and Oxidative Stress

The pathobiology of cancer-related fatigue (CRF) remains elusive, hindering the development of targeted treatments. Radiation therapy (RT), a common treatment for men with prostate cancer, induces cell damage through the generation of free radicals and oxidative stress. We hypothesized that disruption in cellular responses to this surge of nonphysiological oxidative stress might contribute to CRF in men with prostate cancer treated with RT. We evaluated the potential role of three cell damage pathways (apoptosis, autophagy, necrosis) and oxidative stress in CRF in men with prostate cancer receiving RT. Fatigue was measured by the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) questionnaire. Gene expression was measured in whole blood using RT² profiler™ PCR arrays. Data were collected at two time points: either baseline or Day 1 of treatment (T1) and completion of treatment (T2). Participants were grouped into either the fatigued or nonfatigued phenotype at T2 using the recommended FACT-F cut-off score for clinical significance. We observed significant upregulation of seven genes related to three cell damage pathways in the fatigued group from T1 to T2 and no significant changes in the nonfatigued group. We also observed significant downregulation of two genes related to oxidative stress in the fatigued group compared to the nonfatigued group at T2. These collective results provide preliminary evidence that cell damage might be upregulated in the CRF phenotype. Validation of these findings using a larger and more diverse sample is warranted.

Consortium Building for Nurse Scientists Interested in Symptoms Research in the Era of Precision Health

PURPOSE

This article aims to provide perspectives on the establishment of a consortium for nurse scientists with similar career trajectories interested in cancer-related symptoms (CRS) research. Hereby, we describe the development of and recent outcomes from the CRS consortium, the lessons learned in establishing the consortium, and future directions to advance the science of CRS.

MODEL AND METHODS

New and innovative strategies are needed to address the complexity of CRS research. A CRS consortium was created to allow a mechanism for oncology nurse scientists with varying expertise to collaborate to advance CRS research. The National Institutes of Health (NIH) Symptom Science Model (SSM) guides the research of the CRS Consortium.

DISCUSSION AND CONCLUSIONS

A need for improved CRS assessment and management has been identified. The CRS consortium was created as a collaborative think tank to begin to address this need. Guided by the NIH SSM, CRS consortium members have worked to define symptom phenotypes, enhance understanding of the biologic mechanisms that can contribute to symptom phenotypes, and develop tailored interventions to improve symptom management. Dissemination of the CRS consortium efforts involve publications and presentations.

CLINICAL IMPLICATIONS

Nurse scientists interested in symptom science and biobehavorial research face many challenges on how to initiate and sustain independent programs of research. Through the formation of a CRS consortium, oncology nurse scientists can work together to address identified issues in symptom measurement and management.

Assessment and predictors of fatigue in men with prostate cancer receiving radiotherapy and androgen deprivation therapy

INTRODUCTION

Fatigue is a commonly reported symptom in men receiving radiation therapy and androgen deprivation therapy (ADT) for prostate cancer. Despite this, the complex mechanisms remain unclear. This study aims to investigate factors which correlate with development of fatigue.

METHODS

Twenty-seven men with high-risk prostate cancer undergoing radiation therapy and 18 months of ADT were assessed for fatigue, haemoglobin (Hb), testosterone, magnetic resonance imaging (MRI) fat fraction (FF) and apparent diffusion coefficient (ADC), at baseline and at intervals after radiotherapy. Changes from baseline were analysed using paired t-tests. Linear time trends were assessed using linear mixed effect models.

RESULTS

Overall, mean fatigue score increased from baseline to the 18-month time interval (difference 4.5, P = 0.0114). The mean value for Hb significantly decreased (P < 0.001) from baseline to 18 months. The mean value for testosterone significantly decreased (P < 0.001) from baseline to 12 months, and remained low. Mean for MRI FF showed a significant increase (P < 0.001) from baseline to 6 months. MRI ADC showed a non-significant decrease from baseline to 6 months (P = 0.4416).

CONCLUSION

Radiotherapy and ADT resulted in a significant increase in fatigue scores. Statistically significant changes were noted in Hb, testosterone and MRI FF and ADC, however, none were shown to have a strong association with worsening fatigue. Further investigation in a larger cohort is required to assess the interaction between fatigue and possible biological factors.

The High Costs of Low-Grade Inflammation: Persistent Fatigue as a Consequence of Reduced Cellular-Energy Availability and Non-adaptive Energy Expenditure

Chronic or persistent fatigue is a common, debilitating symptom of several diseases. Persistent fatigue has been associated with low-grade inflammation in several models of fatigue, including cancer-related fatigue and chronic fatigue syndrome. However, it is unclear how low-grade inflammation leads to the experience of fatigue. We here propose a model of an imbalance in energy availability and energy expenditure as a consequence of low-grade inflammation. In this narrative review, we discuss how chronic low-grade inflammation can lead to reduced cellular-energy availability. Low-grade inflammation induces a metabolic switch from energy-efficient oxidative phosphorylation to fast-acting, but less efficient, aerobic glycolytic energy production; increases reactive oxygen species; and reduces insulin sensitivity. These effects result in reduced glucose availability and, thereby, reduced cellular energy. In addition, emerging evidence suggests that chronic low-grade inflammation is associated with increased willingness to exert effort under specific circumstances. Circadian-rhythm changes and sleep disturbances might mediate the effects of inflammation on cellular-energy availability and non-adaptive energy expenditure. In the second part of the review, we present evidence for these metabolic pathways in models of persistent fatigue, focusing on chronic fatigue syndrome and cancer-related fatigue. Most evidence for reduced cellular-energy availability in relation to fatigue comes from studies on chronic fatigue syndrome. While the mechanistic evidence from the cancer-related fatigue literature is still limited, the sparse results point to reduced cellular-energy availability as well. There is also mounting evidence that behavioral-energy expenditure exceeds the reduced cellular-energy availability in patients with persistent fatigue. This suggests that an inability to adjust energy expenditure to available resources might be one mechanism underlying persistent fatigue.

Exploring Genetic Attributions Underlying Radiotherapy-Induced Fatigue in Prostate Cancer Patients

CONTEXT

Despite numerous proposed mechanisms, no definitive pathophysiology underlying radiotherapy-induced fatigue (RIF) has been established. However, the dysregulation of a set of 35 genes was recently validated to predict development of fatigue in prostate cancer patients receiving radiotherapy.

OBJECTIVES

To hypothesize novel pathways, and provide genetic targets for currently proposed pathways implicated in RIF development through analysis of the previously validated gene set.

METHODS

The gene set was analyzed for all phenotypic attributions implicated in the phenotype of fatigue. Initially, a "directed" approach was used by querying specific fatigue-related sub-phenotypes against all known phenotypic attributions of the gene set. Then, an "undirected" approach, reviewing the entirety of the literature referencing the 35 genes, was used to increase analysis sensitivity.

RESULTS

The dysregulated genes attribute to neural, immunological, mitochondrial, muscular, and metabolic pathways. In addition, certain genes suggest phenotypes not previously emphasized in the context of RIF, such as ionizing radiation sensitivity, DNA damage, and altered DNA repair frequency. Several genes also associated with prostate cancer depression, possibly emphasizing variable radiosensitivity by RIF-prone patients, which may have palliative care implications. Despite the relevant findings, many of the 35 RIF-predictive genes are poorly characterized, warranting their investigation.

CONCLUSION

The implications of herein presented RIF pathways are purely theoretical until specific end-point driven experiments are conducted in more congruent contexts. Nevertheless, the presented attributions are informative, directing future investigation to definitively elucidate RIF's pathoetiology. This study demonstrates an arguably comprehensive method of approaching known differential expression underlying a complex phenotype, to correlate feasible pathophysiology.

Symptoms predicting health-related quality of life in prostate cancer patients treated with localized radiation therapy

Objective

Patient-reported health-related quality-of-life (HRQOL) measures can provide guidance for treatment decision making, symptom management, and discharge planning. HRQOL is often influenced by the distress experienced by patients from disease or treatment-related symptoms. This study aimed to identify symptoms that can predict changes in HRQOL in men undergoing external beam radiation therapy (EBRT) for nonmetastatic prostate cancer (NMPC).

Methods

Fifty-one men with NMPC scheduled for EBRT were assessed at the baseline, at the midpoint of EBRT, and at the end of EBRT. All participants received 38–42 daily doses of EBRT (five times a week), depending on the stage of their disease. Validated questionnaires were administered to evaluate depressive symptoms, urinary and sexual functions, bowel issues, symptom-related distress, fatigue, and HRQOL. Pearson correlations, repeated-measures ANOVA, and multiple regressions examined the relationships among variables.

Results

Intensification of symptoms and increased symptom-related distress, with a corresponding decline in HRQOL, were observed during EBRT in men with NMPC. Changes in symptoms and symptom distress were associated with changes in HRQOL at the midpoint of EBRT (r=−0.37 to −0.6, P=0.05) and at the end of EBRT (r=−0.3 to −0.47, P=0.01) compared with the baseline. The regression model comprising age, body mass index, Gleason score, T category, androgen-deprivation therapy use, radiation dose received, symptoms (urinary/sexual/bowel problems, fatigue), and overall symptom distress explained 70% of the variance in predicting HRQOL. Urinary problems and fatigue significantly predicted the decline in HRQOL during EBRT.

Conclusion

Identifying specific symptoms that can influence HRQOL during EBRT for NMPC can provide feasible interventional targets to improve treatment outcomes.

How Exercise Can Benefit Patients With Cancer

Thirty years ago, the first article on exercise for patients with cancer appeared in the cancer research literature. The time from that first article to the present has included oncology nurses taking the lead in investigations related to exercise and cancer-related symptoms, most notably cancer-related fatigue (CRF). The Oncology Nursing Society (ONS) has been instrumental in publishing much of the research on exercise and cancer and continues in that tradition by issuing this supplement to the Clinical Journal of Oncology Nursing. In addition, ONS has facilitated the translation of research findings to practicing oncology nurses by convening meetings, participating in expert opinion consensus groups, and disseminating evidence through Putting Evidence Into Practice resources.