Effects of Exercise on the Immune Function of Pediatric Patients With Solid Tumors: Insights From the PAPEC Randomized Trial

The effects of exercise training on inflammatory markers in children and adolescents: A systematic review and meta-analysis

INTRODUCTION AND AIM

Exercise training is effective for improving cardiometabolic health in children and adolescents, but less is known about its impact on inflammatory markers. We therefore, undertook a systematic review and meta-analysis to investigate the role of exercise training on pro-inflammatory cytokines including interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) in children and adolescents.

METHOD

A comprehensive search was conducted in three electronic databases including PubMed, Web of Science, and Scopus, from inception to December 2023 to identify exercise trials with and without control groups, involving participants with mean ages ranging from ≥ 6 to < 18 years, of age with measurements of at least one of the following pro-inflammatory cytokines IL-6, TNF-α, or CRP. Standardized mean differences (SMD) and 95 % confidence interval (ICs) were calculated using random effects models.

RESULTS

Thirty-eight studies involving 2043 children and adolescents were included. The results show that exercise training resulted in significant reductions in IL-6 [SMD: -0.44; 95 % CI: -0.68, -0.21; P = 0.001] and CRP [SMD: -0.28; 95 % CI: -0.41, -0.16; P = 0.001], but not TNF-α [SMD: -0.15; 95 % CI: -0.38, -0.07; P = 0.19]. Subgroup analyses showed that IL-6 and CRP were reduced with aerobic training in adolescents, as was CRP with high-intensity interval training.

CONCLUSION

These results provide evidence that exercise training is effective for reducing IL-6 and CRP in adolescents, but not in children, and any benefits may be modulated by the type of exercise performed.

Exercise Immunology Applied to Pediatric Sport and the Importance of Monitoring Stages of Puberty and Biological Maturation

CONTEXT

Exercise immunology is aimed at understanding how exercise sessions can affect the immune system in athletic subjects of different age groups. The objective of the current study was to discuss in which stage of biological maturation (BM) young athletes may be more vulnerable in relation to the immune system, and whether there is a BM range in which it is safer to perform sports training with strenuous exercise loads.

EVIDENCE ACQUISITION

Evidence from scientific research from several scientific disciplines (eg, immunology, sport immunology, pediatrics, sports medicine, human development) was gathered to holistically examine the main particularities of exercise immunology as applied to pediatric sport.

STUDY DESIGN

Narrative review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

In pediatric patients, lymphoid tissue expands during puberty and involutes after puberty until it returns to pre-expansion values. This suggests that there is a specific period in which the immune system may be stronger, which may provide opportunities for strenuous exercise in pediatric athletes. However, the chronological period when puberty occurs will be determined by BM, which is the rate at which the biological systems of the human body improves. This may affect the period of lymphoid tissue expansion and, consequently, the behavior of the immune system in pediatric subjects of the same age category.

CONCLUSION

During puberty, there is a significant increase in the proinflammatory profile; to compensate for this, there is an expansion of lymphoid tissue that may favor the efficiency of the immune system. The period in which puberty is reached may vary according to the stages of BM. Therefore, in exercise immunology applied to pediatric sports, in addition to external and internal training loads, it is necessary to consider BM and puberty, which have been shown to be safer biomarkers than chronological age for determining immune system behavior in pediatric athletes.

STRENGTH-OF-RECOMMENDATION TAXONOMY (SORT)

Evidence B level 3.

Effects of Exercise and Physical Activity Levels on Childhood Cancer: An Umbrella Review

Patients and survivors of childhood cancer experience adverse effects related to the disease and its treatment. These adverse effects are associated with both physiological and psychological health. Exercise helps manage the side effects and improve the health outcomes. The objective of this umbrella review is to search the current literature in the context of exercise and physical activity as complementary interventions on pediatric cancer and to provide comprehensive information about the derived health outcomes. A literature search was conducted on the Cochrane, PubMed, and Embase databases for systematic reviews published up to January 2023. Moreover, a hand search of reference lists was performed. We included participants under 19 years of age at diagnosis of any type of childhood cancer, without restriction on the type or phase of treatment, who participated in exercise interventions. The results showed a beneficial impact on fatigue, muscle strength, aerobic capacity, activity and participation levels, psychosocial health, cardiovascular/cardiorespiratory fitness, physical function, bone mineral density, and brain volume and structure, with limited and not serious adverse effects. These findings documented that exercise interventions had a positive effect on many physiological and psychological health outcomes in pediatric cancer patients and survivors.

Physiological and mental health changes in cancer patients during the COVID-19 state of emergency

Backgrounds

Due to the COVID-19 pandemic that we are currently facing, many governments across the world have declared a state of emergency and even confinements. This stressful situation, in addition to prolonged stays at home, may imply a radical change in lifestyle behavior and physical activity (PA). The aim of this study is to evaluate the physiological and psychological effects in cancer patients who changed their PA habits during the COVID-19 state of emergency in Spain.

Methods

Thirty-three participants were evaluated pre- and post-state of emergency. A series of questionnaires was used to assess cancer-specific quality of life.

Results

The most relevant results revealed significantly lower walking time (p < 0.001) and sitting time (p = 0.014). Upper and lower body strength also decreased significantly (p = 0.009 and 0.012, respectively) and oxygen consumption (VO2 peak) (p = 0.023). None of the parameters analysed showed significant differences for psychological aspects (QLQ-C-30 and SF-36) and body composition.

Conclusion

Lower physical activity leads to negative physiological adaptation, particularly affecting cardiovascular and strength levels. While it is important to maintain the general population's amount and intensity of exercise, this particularly vulnerable group's physical capacity is vital to their health and well-being.

Therapeutic exercise interventions in pediatric survivors of brain cancer and other solid tumors: A scoping review

Background

Improved survival rates for children with solid tumors presents an ongoing challenge of how to maximize quality of survivorship and effectively manage the short- and long-term complications of disease and treatment. To gain an understanding of the extent and nature of research pertaining to therapeutic exercise interventions and identify knowledge gaps, we conducted a scoping review of exercise training studies conducted in pediatric survivors of brain cancer and other solid tumors.

Method

A systematic literature search was performed across four electronic databases. Papers were selected for full-text review if they included participants treated for brain cancer or other solid tumors, with at least 50% of participants aged ≤ 21 years, evaluated an exercise intervention ≥2-weeks in duration, and were published in an English, peer-reviewed journal. We included the following quantitative study designs; randomized controlled trials, non-randomized trials, and single-arm pre-test-post-test.

Results

Of the 7,482 citations identified, 17 papers met the inclusion criteria (presenting findings from eleven studies). Two studies were randomized controlled trials, five studies were non-randomized controlled trials, and four studies were a single-arm pre-test post-test design. Average age of participants ranged from 7.3-15.5 years, and time since diagnosis ranged from 3 to 70 months. Five studies included participants with brain tumors exclusively, three studies included other solid tumors, and three studies included a mixed sample (brain and other solid tumors). A wide range of exercise modalities were employed, including cycle ergometry, resistance training, sport, yoga, and active gaming. The length of the exercise program ranged from 3-40 weeks and frequency from 3-11 sessions per week. Exercise session duration ranged from 15-180 min, with most studies reporting 30-90-min sessions. Adherence ranged from 77 to 100%, with none of the studies reporting adverse events. Studies reported improvements in cardiorespiratory fitness, functional strength, physical activity, and quality of life.

Conclusions

A small number of mostly low methodological quality studies have examined the effects of therapeutic exercise in pediatric survivors of solid tumors. Although limited, the extant literature supports the feasibility and safety of therapeutic exercise interventions for pediatric survivors of brain cancer and other solid tumors.

NK and cells with NK-like activities in cancer immunotherapy-clinical perspectives

Natural killer (NK) cells are lymphoid cells of innate immunity that take important roles in immune surveillance. NK cells are considered as a bridge between innate and adaptive immunity, and their infiltration into tumor area is related positively with prolonged patient survival. They are defined as CD16⁺ CD56⁺ CD3^- cells in clinic. NK cells promote cytolytic effects on target cells and induce their apoptosis. Loss of NK cell cytotoxic activity and reduction in the number of activating receptors are the current issues for application of such cells in cellular immunotherapy, which resulted in the diminished long-term effects. The focus of this review is to discuss about the activity of NK cells and cells with NK-like activity including natural killer T (NKT), cytokine-induced killer (CIK) and lymphokine-activated killer (LAK) cells in immunotherapy of human solid cancers.

Supervised Exercise Interventions in Childhood Cancer Survivors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Childhood cancer survivors (CCSs) may suffer from a multitude of health impairments, resulting in a compromised quality of life (QoL). This review’s objective was to examine CCSs’ adherence to supervised exercise training interventions and the impact of these interventions on health outcomes. Methods: The following databases were searched in May 2022: PubMed, Embase, Cochrane Library, and Web of Science. The included studies were limited to randomized controlled trials (RCTs), published in English involving CCSs aged 18 years and below. Results: Nine RCTs (n = 642 participants) were included in the systematic review, and seven of them (n = 551 participants) were included in the meta-analysis. Both the mean retention rate and adherence to the supervised exercise interventions were 87%. Supervised exercise interventions significantly improved muscle strength (standardized mean difference (SMD) = 1.42, p = 0.03), level of daily physical activity (SMD = 1.05, p < 0.001), body mass index (BMI) (mean difference (MD) = 1.06, p = 0.03), and fatigue (SMD = −0.44, p < 0.001), while there was no statistical significance in the quality of life (QoL) (SMD = 0.21, p = 0.20). Conclusions: The adherence of CCSs to supervised exercise interventions is high, and supervised exercise interventions are safe and effective.

Recommendations for Resuming PA after Prolonged Rest in Children and Adolescents: A Systematic Integrative Review of Relevance for Immunity

This systematic integrative review aims to summarize the protective effect of PA on children and adolescents, with special reference to the immune system. Periods of prolonged inactivity in children and adolescents are rare and due to exceptional events, such as illness or environmental circumstances, e.g., natural disasters, wars, or epidemics. The recent COVID-19 pandemic forced billions of children in developmental ages into inactivity. This exceptional event was the reason for studying the compensational behavioral strategies adopted by children and adolescents to counteract physical inactivity. Several studies showed the rise of spontaneous physical activity (PA) among children and adolescents to compensate for sedentarism. However, for some children, sedentarism could in turn foster other sedentarism. With the restart of "normal daily life" worldwide, a question is posed on both how to resume PA without causing damage and how to improve the immune response. Some key points emerged from the literature. Children must resume PA gradually using different methods, considering age, sex, health status, and the presence of overweight conditions. Immunity can be stimulated with PA by aerobic exercise, resistance training, flexibility exercise, relaxation, and coordinative exercises.

Exercise Training and Natural Killer Cells in Cancer Survivors: Current Evidence and Research Gaps Based on a Systematic Review and Meta-analysis

Background

Exercise training can positively impact the immune system and particularly natural killer (NK) cells, at least in healthy people. This effect would be of relevance in the context of cancer given the prominent role of these cells in antitumor immunity. In this systematic review and meta-analysis, we aimed to summarize current evidence on the effects of exercise training on the levels and function of NK cells in cancer survivors (i.e., from the time of diagnosis until the end of life).

Methods

Relevant articles were searched in PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials (until January 11, 2022). Randomized controlled trials (RCT) of exercise training (i.e., non-acute) interventions vs usual care conducted in cancer survivors and assessing NK number and/or cytotoxic activity (NKCA) before and upon completion of the intervention were included. Methodological quality of the studies was assessed with the PEDro scale, and results were meta-analyzed using a random effects (Dersimoian and Laird) model.

Results

Thirteen RCT including 459 participants (mean age ranging 11–63 years) met the inclusion criteria. Methodological quality of the studies was overall fair (median PEDro score = 5 out of 10). There was heterogeneity across studies regarding cancer types (breast cancer, non-small cell lung cancer and other solid tumors), treatment (e.g., receiving vs having received chemotherapy), exercise modes (aerobic or resistance exercise, Tai Chi, Yoga) and duration (2–24 weeks). No consistent effects were observed for NK number in blood (mean difference [MD]: 1.47, 95% confidence interval [CI] − 0.35 to 3.29, p = 0.113) or NKCA as assessed in vitro (MD: − 0.02, 95%CI − 0.17 to 0.14, p = 0.834). However, mixed results existed across studies, and some could not be meta-analyzed due to lack of information or methodological heterogeneity.

Conclusions

Current evidence does not support a significant effect of exercise training intervention on NK cells in blood or on their ‘static response’ (as assessed in vitro) in cancer survivors. Several methodological issues and research gaps are highlighted in this review, which should be considered in future studies to draw definite conclusions on this topic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00419-w.

Exercise and Childhood Cancer-A Historical Review

Simple Summary

Childhood cancer survivors are at risk of developing important adverse effects, but there is growing evidence that physical exercise could help in this regard. The present review summarizes the history of pediatric exercise oncology and the main milestones achieved along the way. Overall, physical exercise appears to be safe and beneficial even during the most aggressive phases of pediatric cancer treatment and can represent an effective coadjuvant therapy for attenuating cancer-related adverse effects.

Abstract

Childhood cancer survivors are at risk of developing important adverse effects, many of which persist for years after the end of treatment. The implementation of interventions aiming at attenuating tumor/treatment-associated adverse effects is therefore a major issue in pediatric oncology, and there is growing evidence that physical exercise could help in this regard. The present review aims to summarize the main milestones achieved in pediatric exercise oncology. For this purpose, we conducted a systematic review of relevant studies written in English in the electronic database PubMed (from inception to 14 August 2021). This review traces the field of pediatric exercise oncology throughout recent history based on three fundamental pillars: (i) exercise during childhood cancer treatment; (ii) exercise during/after hematopoietic stem cell transplantation; and (iii) exercise after childhood cancer treatment. Accumulating evidence––although still preliminary in many cases––supports the safety and potential benefits of regular exercise (with no major contraindications in general) in the childhood cancer continuum, even during the most aggressive phases of treatment. Exercise can indeed represent an effective coadjuvant therapy for attenuating cancer-related adverse effects.

Effects of Exercise Interventions on Immune Function in Children and Adolescents With Cancer and HSCT Recipients - A Systematic Review

Background

Pediatric cancer patients are at high risk for life-threatening infections, therapy associated complications and cancer-related side effects. Exercise is a promising tool to support the immune system and reduce inflammation. The primary objective of this systematic review was to evaluate the effects of exercise interventions in pediatric cancer patients and survivors on the immune system.

Methods

For this systematic review (PROSPERO ID: CRD42021194282) we searched four databases (MEDLINE, Cochrane Library, ClinicalTrials.gov, SPORTDiscus) in June 2021. Studies with pediatric patients with oncological disease were included as main criterion. Two authors independently performed data extraction, risk of bias assessment, descriptive analysis and a direction ratio was calculated for all immune cell parameters.

Findings

Of the 1448 detected articles, eight studies with overall n = 400 children and adolescents with cancer and n = 17 healthy children as controls aged 4-19 years met the inclusion criteria. Three randomized, four non-randomized controlled trials and one case series were analyzed descriptively. The exercise interventions had no negative adverse effects on the immune system. Statistically significant results indicated enhanced cytotoxicity through exercise, while changes in immune cell numbers did not differ significantly. Interventions further reduced days of in-hospitalization and reduced the risk of infections. Several beneficial direction ratios in immune parameters were identified favoring the intervention group.

Interpretation

Exercise interventions for pediatric cancer patients and survivors had no negative but promising beneficial effects on the immune system, especially regarding cytotoxicity, but data is very limited. Further research should be conducted on the immunological effects of different training modalities and intensities, during various treatment phases, and for different pediatric cancer types. The direction ratio parameters given here may provide useful guidance for future clinical trials.

Systemic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021194282, Prospero ID: CRD42021194282.

The low cytotoxic activity of peripheral blood NK cells may relate to unexplained recurrent miscarriage

PROBLEM

Unexplained recurrent miscarriage (uRM) is defined as two or more spontaneous abortions prior to 20 weeks of gestation with unknown etiology. Peripheral blood natural killer (pNK) cells contact with the villus and exert important role in normal pregnancy. However, it is still controversial about the association between pNK cytotoxicity and uRM, and the underlying mechanism remains unknown so far.

METHOD OF STUDY

In this study, we aim to compare the percentage, immunophenotype, and function of pNK cells between patients with uRM and fertile controls. The peripheral blood was collected from 49 patients with uRM and 11 fertile women in their middle luteal phase of the menstrual cycle. pNK cells were co-cultured with K562 cells at different cell ratios to measure the cytotoxicity. The percentage of CD3^- CD56⁺ , CD3^- CD56^bright , and CD3^- CD56^dim pNK was analyzed by flow cytometry and quantified to evaluate the expression of cytotoxic granules (granzyme B, granulysin, and perforin), and the cell surface receptors related to pNK cell cytotoxicity (NKG2D, NKp30, NKp46, CD158a, and CD158b) were also detected.

RESULTS

The general linear model analysis showed that pNK cell cytotoxicity in patients with uRM was significantly lower than that in fertile controls. In addition, the ratios of NKG2D/CD158a, NKp30/CD158a, and NKp46/CD158a in CD3^- CD56^bright pNK subsets were significantly lower in uRM group than that in fertile control. The logistical regression analysis showed that the reduced NKp30/CD158a, NKp46/CD158a ratios in CD3^- CD56^bright pNK subsets were significantly associated with uRM.

CONCLUSION

Our results suggested that a low pNK cytotoxicity, which is mediated by inhibitory signals, might be associated with uRM.

Tailored Exercise during Hematopoietic Stem Cell Transplantation Hospitalization in Children with Cancer: A Prospective Cohort Study

We assessed the clinical effects of a supervised exercise (aerobic + resistance) intervention performed during inpatient hospitalization for pediatric hematopoietic stem cell transplantation (HSCT). Patients were placed in an exercise (n = 65 (47 and 18 with allogeneic (allo-) and autologous (auto-) HSCT, respectively)) or a control (n = 53 (39 and 14)) group. Exercise interventions were performed in isolated hospital patient rooms. Patients were followed-up from the beginning of the conditioning phase up to 6 years. We assessed survival, risk of graft-versus-host disease (GvHD) or graft failure (primary outcomes), and engraftment kinetics, supportive care, toxicity profile, and immune reconstitution for auto-HSCT and allo-HSCT. The exercise intervention was safe and did not affect the risk of mortality, acute/chronic GvHD, or graft failure (all p > 0.05). No between-group differences (p > 0.05) were found for the remainder of clinical endpoints, except for a reduced number of total and viral infections in the exercise group after allo-HSCT (unadjusted p = 0.005 for both total and viral infections, and adjusted p = 0.023 and 0.083, respectively). In conclusion, exercise performed during inpatient hospitalization for pediatric HSCT is safe and well tolerated during both auto and allo-HSCT and tends to decrease the risk of infection after allo-HSCT. These findings provide additional support to the notion that a multidisciplinary approach (i.e., including the work of exercise specialists) is suitable in the management of children undergoing HSCT. Further studies are needed to determine whether applying a different training stimulus (notably, higher exercise intensities) exerts positive effects on HSCT prognosis in these patients.

EFFECTS OF PHYSICAL EXERCISE DURING HOSPITALIZATION IN CHILDREN AND ADOLESCENTS WITH CANCER: A SYSTEMATIC REVIEW

Objective:

To identify the effects of exercise programs during hospitalization on children and adolescents with cancer.

Data source:

This is a systematic review, carried out in PubMed/ Medical Literature Analysis and Retrieval System Online (MEDLINE), Latin American and Caribbean Health Sciences Literature (LILACS), Scientific Electronic Library Online (SciELO), Latin American and Caribbean Center on Health Sciences Information (BIREME), and Physiotherapy Evidence Database (PEDro). We selected studies that included children and adolescents diagnosed with cancer (solid or hematologic) and submitted to exercise protocols during hospitalization. Studies involving patients with other pathologies or with a medical contraindication for exercise were excluded. We used the following search strategy: Neoplasm OR Leukemia OR Cancer OR Tumor OR Medical Oncology AND Hospitalization OR Inpatient Care Units OR Intrahospital AND Exercise. The methodological quality of the studies was analyzed by the PEDro scale.

Data synthesis:

Among the 626 articles found, only 9 fulfilled the inclusion criteria, obtaining a regular methodological quality. The samples had 172 participants, aged 4 to 18 years. Only 6 studies presented both intervention group and control group. The intervention group received strength, aerobic, and muscle stretching exercises, and games, among others. The control group received the standard treatment. The studies varied regarding time, frequency, intensity, and type of exercise. Most studies showed an increase in muscle strength (4/5), followed by an improvement in physical fitness (2/3) and functional capacity (2/4). No adverse events were reported during the interventions. The methodological quality was considered regular.

Conclusions:

The findings suggest that. during hospitalization of children and adolescents with cancer, exercise improves muscle strength, physical fitness, and functionality.

Social ecological interventions to increase physical activity in children and young people living with and beyond cancer: a systematic review

Objective: To identify the behaviour change techniques and intervention components associated with the promotion of physical activity (PA) for children and young people living with and beyond cancer. Design and main outcome measures: A systematic review and narrative synthesis was conducted on the evidence on PA interventions for children and young people (up to 30 years of age) living with and beyond cancer using a social ecological framework. Results: Out of 12 studies, 8 were shown to change PA. Intervention components included (1) behavioural (Instruction on how to perform the behaviour, credible source, behavioural demonstration and rehearsal), (2) cognitive-emotional (targeting attitude, perceived behavioural control, intentions, resilience and achievement) (3) socio-cultural (family and peer support for PA), (4) environmental (providing access to resources, environmental restructuring, safety), (5) demographic (child, adolescent, young adult or mixed) and (6) medical (tailored exercise depending on age and cancer stage). Conclusions: Interventions designed to increase physical activity participation and adherence during and beyond cancer treatment for young people should integrate psychosocial (behavioural, cognitive-emotional, social), environmental and medical intervention components. Our conceptual model can be used to inform the development of interventions and guides future research objectives and priorities.

Effects of a group-based physical activity program for pediatric patients with cancer on physical activity and symptom experience: A quasi-experimental study

AIMS

To examine the effects of a group-based physical activity intervention on improvement in physical activity and mitigation of symptom distress among pediatric patients with cancer.

METHODS

Based on convenience sampling, 57 pediatric patients with cancer admitted to the cancer center were included in the intervention group. The control group included 57 pediatric patients with cancer from two other hospitals matched to the patients in the intervention group by age, sex, and diagnosis. A group-based physical activity program was implemented among the children in the intervention group, whereas the children in the control group received standard care. Physical activity and symptoms were measured using the Children's Leisure Time Activities Study Survey-Chinese and using the Memorial Symptom Assessment Scale 10-18 at baseline and after the 12^th exercise session in both the intervention and control groups.

RESULTS

The repeated-measures analysis of variance showed that the main intervention effects on the decrease in light-intensity physical activity and increase in moderate-to-vigorous physical activity were significant between the two groups (P < .001). The group-based physical activity intervention could decrease the scores of psychological symptoms (P < .001), Global Distress Index (P < .001), and physical symptoms (P = .01) when comparing the difference between the two groups before and after the intervention. There was no significant difference in the number of symptoms or the total symptom experience score between the two groups.

CONCLUSION

These findings suggest that a group-based physical activity intervention can promote physical activity and relieve psychological and physical symptom distress among pediatric patients with cancer.

Dietary and Exercise Interventions for Pediatric Oncology Patients: The Way Forward

This review focuses on diet and exercise interventions that have been conducted in pediatric cancer and pediatric stem cell transplant patients. It examines the different reasons for conducting lifestyle interventions with attention to the different outcome measurements and feasibility of these measures with an argument toward a need for standardization to move the field forward.

The number and cytotoxicity and the expression of cytotoxicity-related molecules in peripheral natural killer (NK) cells do not predict the repeated implantation failure (RIF) for the in vitro fertilization patients

Natural killer (NK) cells are thought to play a key role in the successful establishment of a pregnancy by facilitating immunological adaptation of the semi-allogeneic developing embryo. The aim of this study was to explore the cell number, immunophenotypic characteristics, and activities of peripheral blood NK cells in women with repeated implantation failure (RIF). Peripheral blood was obtained from 27 women with RIF and 11 healthy, fertile controls during the middle luteal phase of the menstrual cycle. CD3^- CD56⁺ NK cells were quantified and analyzed by flow cytometry for the expression of cytolytic molecules (granzyme B, granulysin, and perforin) as well as cell surface receptors responsible for NK cell activation or inhibition (NKG2D, NKp30, NKp46, CD158a, CD158b). NK cytotoxicity was measured at three effector-to-target cell ratios. Women with RIF and fertile controls did not differ significantly in the percentage of circulating CD3⁻CD56⁺ NK cells, or in the proportions of these cells that expressed granzyme B, granulysin, or perforin. The two groups also did not differ significantly in the proportions of NK cells expressing the receptors NKG2D, NKp30, NKp46, CD158a or CD158b. General linear model analysis showed that NK cytotoxicity increased with effector-to-target cell ratio. However, NK cytotoxicity did not differ significantly between patients with RIF and fertile controls. These results suggest that RIF is not associated with significant alterations in the number or function of peripheral blood NK cells.

Exercise training in childhood cancer: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Physical capacity and quality of life (QoL) are typically impaired in children/adolescents with cancer. Our primary objective was to examine the effects of exercise training performed after diagnosis of any type of pediatric cancer on physical capacity-related endpoints, survival, disease relapse and adverse effects.

METHODS

(a) Search and selection criteria: Systematic review in Pubmed and Web of Science (until August 2018) of randomized controlled trials (RCTs) of exercise interventions in children with cancer during treatment or within one year after its end. (b) Data collection: Two authors independently identified studies meeting inclusion criteria, extracted data, and assessed risk of bias using standardized forms. When needed, we contacted authors to request clarifications or additional data. (c) Statistical Analysis: The pooled standardized mean differences (SMD) were calculated for those endpoints for which a minimum of three RCTs used the same assessment method. We also calculated the pooled odds ratio (OR) of dying or having a tumor relapse.

RESULTS

Eight RCTs (n = 283 patients) were included in the systematic review. Of these, five studies (n = 173) could be meta-analyzed. Exercise training during pediatric cancer treatment significantly improves patients' functional mobility, as assessed with the timed up and down stairs test (SMD: -0.73, p < 0.001) and does not affect mortality (OR: 0.85, p = 0.76) or relapse risk (OR: 0.96, p = 0.94).

CONCLUSIONS

Exercise training in children with cancer improves functional mobility. More RCTs analyzing the effects of supervised exercise interventions are needed, as well as the development of a core-set of outcomes in pediatric oncology exercise research.

Inhospital Exercise Training in Children With Cancer: Does It Work for All?

Purpose: Physical exercise training might counteract the weakening effects of both pediatric cancer and anti-cancer treatment. We aimed to analyze the prevalence of "responders" and "non-responders" to inhospital exercise training in children with cancer and to identify the factors that could influence responsiveness, which might help personalize exercise interventions for this patient population. Methods: We performed an ancillary analysis of the randomized controlled trial "Physical activity in Pediatric Cancer" (NCT01645436), in which 49 children with solid tumors were allocated to an inhospital exercise intervention or control group. The present study focused on the children in the former group (n = 24, 10 ± 4 years), who performed 3 weekly training sessions (aerobic + strength exercises). The intervention lasted 19 ± 8 weeks (i.e., from the start to the end of neoadjuvant chemotherapy treatment). A responder-vs-non-responder analysis was performed for physical capacity-related endpoints (five-repetition maximum strength, functional mobility tests, and cardiorespiratory fitness [CRF]). Only those participants showing improvements in a given test of a magnitude greater than both the random error and the threshold for clinically meaningful changes were considered responders. Results: Most participants improved their performance in the strength tests, with 80, 88, and 93% of total showing a positive response for seated bench press, lateral row, and leg press, respectively (p < 0.001). No significant improvements were observed for the functional mobility tests or CRF (p > 0.05, rate of responsiveness ≤ 50%). No differences between responders and non-responders were observed for sex, age, type of cancer, or treatment (i.e., including or not anthracyclines/radiotherapy). However, significant differences (p < 0.05) were observed between responders and non-responders for baseline performance in all the tests, and a significant (p < 0.05) inverse relationship was found between baseline performance and relative improvement for most endpoints. Conclusions: Although most children improved their muscle strength after the exercise intervention, a considerable individual variability was observed for the training responsiveness of functional mobility and CRF. A lower baseline performance was associated with a higher responsiveness for all the study endpoints, with the fittest children at the start of treatment showing the lowest responses. Efforts to individualize exercise prescription are needed to maximize responsiveness in pediatric cancer patients.