Sense of coherence and its relationship to participation, cancer-related fatigue, symptom burden, and quality of life in women with breast cancer participating in the OptiTrain exercise trial

PURPOSE: This study examined the Sense of Coherence (SOC) of patients participating in the randomized controlled 'Optimal Training for Women with Breast Cancer' (OptiTrain) study and assessed how patient characteristics were associated with SOC. Secondary aims were to assess the association between SOC and patients' participation in this study and to determine whether SOC moderates the effect of the 16-week exercise intervention on fatigue, quality of life (QoL), and symptom burden in women with breast cancer undergoing chemotherapy. METHODS: Modified Poisson regression analyses were conducted to determine the relative risk of weak-normal SOC versus strong SOC in terms of exercise session attendance, study and intervention dropout, and long absence rates. Analyses of covariance were performed to assess whether SOC moderated the effect of the exercise intervention (pinteraction ≤ 0.10). RESULTS: Two hundred and forty women with early breast cancer (mean age 53 ± 10) participated in the OptiTrain study. Women with strong SOC reported less fatigue, lower symptom burden, and higher QoL. Women with weak-normal SOC were significantly more likely to drop out from the OptiTrain study and tended to have slightly poorer exercise session attendance. Women with breast cancer and weaker SOC benefitted as much from the exercise intervention, in terms of fatigue and QoL, as those with stronger SOC (pinteraction > 0.10). CONCLUSIONS: Strong SOC appears to be associated with a more positive subjective state of health. Women with weak-normal SOC may need additional support to encourage participation and adherence in exercise trials. Assessing SOC may assist clinicians to identify and provide extra support for participants with weak SOC, who may be less inclined to participate in exercise programs

Doxorubicin-induced skeletal muscle atrophy:Elucidating the underlying molecular pathways

AIM: Loss of skeletal muscle mass is a common clinical finding in cancer patients. The purpose of this meta-analysis and systematic review was to quantify the effect of doxorubicin on skeletal muscle and report on the proposed molecular pathways possibly leading to doxorubicin-induced muscle atrophy in both human and animal models. METHODS: A systematic search of the literature was conducted in PubMed, EMBASE, Web of Science and CENTRAL databases. The internal validity of included studies was assessed using SYRCLE's risk of bias tool. RESULTS: Twenty eligible articles were identified. No human studies were identified as being eligible for inclusion. Doxorubicin significantly reduced skeletal muscle weight (ie EDL, TA, gastrocnemius and soleus) by 14% (95% CI: 9.9; 19.3) and muscle fibre cross-sectional area by 17% (95% CI: 9.0; 26.0) when compared to vehicle controls. Parallel to negative changes in muscle mass, muscle strength was even more decreased in response to doxorubicin administration. This review suggests that mitochondrial dysfunction plays a central role in doxorubicin-induced skeletal muscle atrophy. The increased production of ROS plays a key role within this process. Furthermore, doxorubicin activated all major proteolytic systems (ie calpains, the ubiquitin-proteasome pathway and autophagy) in the skeletal muscle. Although each of these proteolytic pathways contributes to doxorubicin-induced muscle atrophy, the activation of the ubiquitin-proteasome pathway is hypothesized to play a key role. Finally, a limited number of studies found that doxorubicin decreases protein synthesis by a disruption in the insulin signalling pathway. CONCLUSION: The results of the meta-analysis show that doxorubicin induces skeletal muscle atrophy in preclinical models. This effect may be explained by various interacting molecular pathways. Results from preclinical studies provide a robust setting to investigate a possible dose-response, separate the effects of doxorubicin from tumour-induced atrophy and to examine underlying molecular pathways. More research is needed to confirm the proposed signalling pathways in humans, paving the way for potential therapeutic approaches

Socio-ecological correlates of physical activity in breast and colon cancer survivors 4 years after participation in a randomized controlled exercise trial (PACT study)

Having a physically active lifestyle after cancer diagnosis is beneficial for health, and this needs to be continued into survivorship to optimize long-term benefits. We found that patients, who participated in an 18-week exercise intervention, reported significant higher physical activity (PA) levels 4 years after participation in a randomized controlled trial of supervised exercise delivered during chemotherapy (PACT study). This study aimed to identify social-ecological correlates of PA levels in breast and colon cancer survivors 4 years after participation in the PACT study. Methods Self-reported PA levels and potential correlates (e.g. physical fitness, fatigue, exercise history, and built environment) were assessed in 127 breast and colon cancer survivors shortly after diagnosis (baseline), post-intervention and 4 years later. Multivariable linear regression analyses were performed to identify social-ecological correlates of PA 4 years postbaseline. Results The final model revealed that lower baseline physical fatigue (β =-0.25, 95% CI-0.26;-0.24) and higher baseline total PA (0.06, 95% CI, 0.03; 0.10) were correlated with higher total PA levels 4 years post-baseline. Higher baseline leisure and sport PA (0.02, 95% CI 0.01; 0.03), more recreational facilities within a buffer of 1 km (4.05, 95% CI = 1.28; 6.83), lower physical fatigue at 4-year follow-up (-8.07, 95% CI-14.00;-2.1,3), and having a positive change in physical fatigue during the intervention period (0.04, 95% CI 0.001; 0.07) were correlates of sport and leisure PA levels 4 years post-baseline. Conclusions This study suggests that baseline and 4-year post-baseline physical fatigue, and past exercise behaviour, were significant correlates of PA 4 years after participation in an exercise trial. Additionally, this study suggests that the built environment should be taken into account when promoting PA. Understanding of socio-ecological correlates of PA can provide insights into how future exercise interventions should be designed to promote long-term exercise behaviour

Perspectives of patients with metastatic breast cancer on physical exercise programs: results from a survey in five European countries

Background: To successfully implement exercise programs for patients with metastatic breast cancer (MBC), services and patient education should consider patients’ knowledge, preferences, values, and goals. Hence, gaining insight into their perspectives on exercise and exercise programming is important. Method: In this cross-sectional survey, we recruited patients with MBC from the Netherlands, Germany, Poland, Spain, and Sweden. We collected data on patients’ knowledge and skills about exercise and outcome expectations. We identified barriers to and facilitators of participation in exercise programs, and patients’ preferences for program content and modes of exercise delivery. Results: A total of 420 patients participated in the survey. Respondents were, on average, 56.5 years old (SD 10.8) and 70% had bone metastases. Sixty-eight percent reported sufficient skills to engage in aerobic exercise, but only 35% did so for resistance exercise. Respondents expected exercise to have multiple physical benefits, but a few patients expected exercise to worsen their pain (5%). Not having access to an exercise program for cancer patients (27%), feeling too tired (23%), and/or weak (23%) were the most often reported barriers. Facilitators for exercising regularly were previous positive physical (72%) and emotional (68%) experiences with exercising, and receiving personalized advice from a physiotherapist or sport/fitness instructor (62%). Patients were most interested in walking and preferred exercising at a public gym, although there were differences by country. Fifty-seven percent did not know whether their insurance company reimburses exercise programs and only 9% would be willing to pay more than €50 per month to participate. Conclusion: A large percentage of patients with MBC lack the skills to engage in regular exercise as recommended by exercise guidelines for people with cancer. Patients may benefit from personalized advice and appropriate training facilities to overcome barriers. When implementing exercise interventions, attention should be given to reimbursement and the relatively low willingness-to-pay

Perceived facilitators and barriers by esophageal cancer survivors participating in a post-treatment exercise program

Purpose: Participation in a post-treatment exercise program improves cardiorespiratory fitness and aspects of quality of life for esophageal cancer survivors. For optimal effects, high adherence to the exercise intervention is important. We assessed which facilitators and barriers to exercise adherence are perceived by esophageal cancer survivors, who participate in a post-treatment exercise program. Methods: The current qualitative study was performed within the randomized controlled PERFECT trial, in which we investigated effects of a 12-week supervised exercise program with moderate-to-high intensity and daily physical activity advice. Semi-structured interviews were conducted with patients randomized to the exercise group. A thematic content approach was used to derive perceived facilitators and barriers. Results: Thematic saturation was reached after inclusion of sixteen patients. Median session attendance was 97.9% (IQR 91.7–100%), and relative dose intensity (compliance) to all exercises was ≥90.0%. Adherence to the activity advice was 50.0% (16.7–60.4%). Facilitators and barriers were captured in seven themes. The most important facilitators were patients’ own intention to engage in exercise and supervision by a physiotherapist. Barriers were mainly experienced in completion of the activity advice, and included logistic factors and physical complaints. Conclusions: Esophageal cancer survivors are well capable to attend a moderate-to-high intensity post-treatment exercise program, and to fulfill the exercises according to protocol. This is facilitated by patients’ own intention to engage in exercise and supervision of the physiotherapist, and only minimally affected by barriers as logistic factors and physical complaints. Implications for cancer survivors: When implementing postoperative exercise programs in clinical care, it can be useful to be aware of perceived facilitators and barriers of cancer survivors in order to achieve optimal exercise adherence and maximize beneficial exercise effects

Circulating inflammatory biomarkers, adipokines and breast cancer risk—a case-control study nested within the EPIC cohort

Background Inflammation has been hypothesized to play a role in the development and progression of breast cancer and might differently impact breast cancer risk among pre and postmenopausal women. We performed a nested case-control study to examine whether pre-diagnostic circulating concentrations of adiponectin, leptin, c-reactive protein (CRP), tumour necrosis factor-alpha, interferon-gamma and 6 interleukins were associated with breast cancer risk, overall and by menopausal status. Methods Pre-diagnostic levels of inflammatory biomarkers were measured in plasma from 1558 case-control pairs from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. We used conditional logistic regression to estimate the odds ratios (ORs) of breast cancer at blood collection, per one standard deviation increase in biomarker concentration. Results Cases were diagnosed at a mean age of 61.4 years on average 8.6 years after blood collection. No statistically significant association was observed between inflammatory markers and breast cancer risk overall. In premenopausal women, borderline significant inverse associations were observed for leptin, leptin-to-adiponectin ratio and CRP [OR= 0.89 (0.77-1.03), OR= 0.88 (0.76-1.01) and OR= 0.87 (0.75-1.01), respectively] while positive associations were observed among postmenopausal women [OR= 1.16 (1.05-1.29), OR= 1.11 (1.01-1.23), OR= 1.10 (0.99-1.22), respectively]. Adjustment for BMI strengthened the estimates in premenopausal women [leptin: OR = 0.83 (0.68-1.00), leptin-to-adiponectin ratio: OR = 0.80 (0.66-0.97), CRP: OR = 0.85 (0.72-1.00)] but attenuated the estimates in postmenopausal women [leptin: OR = 1.09 (0.96-1.24), leptin-to-adiponectin ratio: OR = 1.02 (0.89-1.16), CRP: OR = 1.04 (0.92-1.16)]. Conclusions Associations between CRP, leptin and leptin-to-adiponectin ratio with breast cancer risk may represent the dual effect of obesity by menopausal status although this deserves further investigation

Dropout from exercise trials among cancer survivors—An individual patient data meta-analysis from the POLARIS study

Introduction: The number of randomized controlled trials (RCTs) investigating the effects of exercise among cancer survivors has increased in recent years; however, participants dropping out of the trials are rarely described. The objective of the present study was to assess which combinations of participant and exercise program characteristics were associated with dropout from the exercise arms of RCTs among cancer survivors. Methods: This study used data collected in the Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS) study, an international database of RCTs investigating the effects of exercise among cancer survivors. Thirty-four exercise trials, with a total of 2467 patients without metastatic disease randomized to an exercise arm were included. Harmonized studies included a pre and a posttest, and participants were classified as dropouts when missing all assessments at the post-intervention test. Subgroups were identified with a conditional inference tree. Results: Overall, 9.6% of the participants dropped out. Five subgroups were identified in the conditional inference tree based on four significant associations with dropout. Most dropout was observed for participants with BMI &gt;28.4 kg/m2, performing supervised resistance or unsupervised mixed exercise (19.8% dropout) or had low-medium education and performed aerobic or supervised mixed exercise (13.5%). The lowest dropout was found for participants with BMI &gt;28.4 kg/m2 and high education performing aerobic or supervised mixed exercise (5.1%), and participants with BMI ≤28.4 kg/m2 exercising during (5.2%) or post (9.5%) treatment. Conclusions: There are several systematic differences between cancer survivors completing and dropping out from exercise trials, possibly affecting the external validity of exercise effects.</p

Dropout from exercise trials among cancer survivors-An individual patient data meta-analysis from the POLARIS study

INTRODUCTION: The number of randomized controlled trials (RCTs) investigating the effects of exercise among cancer survivors has increased in recent years; however, participants dropping out of the trials are rarely described. The objective of the present study was to assess which combinations of participant and exercise program characteristics were associated with dropout from the exercise arms of RCTs among cancer survivors. METHODS: This study used data collected in the Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS) study, an international database of RCTs investigating the effects of exercise among cancer survivors. Thirty-four exercise trials, with a total of 2467 patients without metastatic disease randomized to an exercise arm were included. Harmonized studies included a pre and a posttest, and participants were classified as dropouts when missing all assessments at the post-intervention test. Subgroups were identified with a conditional inference tree. RESULTS: Overall, 9.6% of the participants dropped out. Five subgroups were identified in the conditional inference tree based on four significant associations with dropout. Most dropout was observed for participants with BMI >28.4 kg/m 2 , performing supervised resistance or unsupervised mixed exercise (19.8% dropout) or had low-medium education and performed aerobic or supervised mixed exercise (13.5%). The lowest dropout was found for participants with BMI >28.4 kg/m 2 and high education performing aerobic or supervised mixed exercise (5.1%), and participants with BMI ≤28.4 kg/m 2 exercising during (5.2%) or post (9.5%) treatment. CONCLUSIONS: There are several systematic differences between cancer survivors completing and dropping out from exercise trials, possibly affecting the external validity of exercise effects