Exercise modulation of tumour perfusion and hypoxia to improve radiotherapy response in prostate cancer

Exercise medicine as adjunct therapy during RADIation for CAncer of the prostaTE to improve treatment efficacy - protocol for the ERADICATE study: a phase II randomised controlled trial

BACKGROUND

Tumour hypoxia resulting from inadequate perfusion is common in many solid tumours, including prostate cancer, and constitutes a major limiting factor in radiation therapy that contributes to treatment resistance. Emerging research in preclinical animal models indicates that exercise has the potential to enhance the efficacy of cancer treatment by modulating tumour perfusion and reducing hypoxia; however, evidence from randomised controlled trials is currently lacking. The 'Exercise medicine as adjunct therapy during RADIation for CAncer of the prostaTE' (ERADICATE) study is designed to investigate the impact of exercise on treatment response, tumour physiology, and adverse effects of treatment in prostate cancer patients undergoing external beam radiation therapy (EBRT).

METHODS

The ERADICATE study is a two-arm, parallel group, phase II randomised controlled trial. Fifty patients diagnosed with prostate cancer will be randomised (1:1) to either an exercise intervention group (EBRT + exercise) or a usual care control group (EBRT only) for the duration of treatment (i.e., 2 to 8 weeks of EBRT). The exercise intervention will be clinic-based and supervised by exercise physiologists. Exercise sessions will include moderate- to vigorous-intensity aerobic and resistance exercise conducted two to three times per week for 60 min per session. Treatment response (primary outcome) will be assessed by change in tumour apparent diffusion coefficient derived from magnetic resonance imaging. Secondary outcomes will include acute and chronic changes in tumour perfusion and hypoxia, treatment-related toxicity, body composition, physical function, and quality of life. Survival outcomes will be assessed as exploratory endpoints. Study measurements will be conducted at baseline (i.e., prior to commencing EBRT), immediately after completion of EBRT, and during follow-up at 3 months as well as 2 years and 5 years post treatment. The study was approved by the Human Research Ethics Committee at Edith Cowan University.

DISCUSSION

The ERADICATE study will investigate exercise as a novel therapeutic approach for sensitising prostate cancer to EBRT by targeting a known mechanism of treatment resistance. Improving treatment efficacy of EBRT with exercise may result in better patient outcomes clinically, while also addressing adverse effects of treatment and quality of life in prostate cancer patients.

TRIAL REGISTRATION

The study was registered on the Australian New Zealand Clinical Trials Registry (ACTRN12624000786594) on 26/06/2024.

Hypoxia-inducible transcription factors: architects of tumorigenesis and targets for anticancer drug discovery

Hypoxia-inducible factors (HIFs) play a pivotal role as master regulators of tumor survival and growth, controlling a wide array of cellular processes in response to hypoxic stress. Clinical data correlates upregulated HIF-1 and HIF-2 levels with an aggressive tumor phenotype and poor patient outcome. Despite extensive validation as a target in cancer, pharmaceutical targeting of HIFs, particularly the interaction between α and βsubunits that forms the active transcription factor, has proved challenging. Nonetheless, many indirect inhibitors of HIFs have been identified, targeting diverse parts of this pathway. Significant strides have also been made in the development of direct inhibitors of HIF-2, exemplified by the FDA approval of Belzutifan for the treatment of metastatic clear cell renal carcinoma. While efforts to target HIF-1 using various therapeutic modalities have shown promise, no clinical candidates have yet emerged. This review aims to provide insights into the intricate and extensive role played by HIFs in cancer, and the ongoing efforts to develop therapeutic agents against this target.

Cardiovascular adverse events-related to GnRH agonists and GnRH antagonists: analysis of real-life data from Eudra-Vigilance and Food and Drug Administration databases entries

INTRODUCTION AND OBJECTIVES

GnRH agonists and GnRH antagonists are two of the mainstays of hormonal therapy (HT) for prostate cancer (PCa). These drugs are at increased risk of cardiovascular (CV) adverse events (AEs). Aim of our study was to compare real-life data on AEs associated with GnRH agonists and GnRH antagonists based on Eudra-Vigilance (EV) and Food and Drug Administration (FDA) reported AEs.

MATERIALS AND METHODS

EV and FDA databases were queried and the number of CV adverse events (AEs) for degarelix, buserelin, goserelin, leuprorelin, triptorelin until September 2021 were recorded. Specific CV AEs were recorded and data were analyzed per age and severity. pooled relative risk (PRR) was used to compare data between drugs.

RESULTS

CV events were reported in 315/5128 (6%) for Degarelix, in 55/628 for Buserelin (9%), in 843/12,145 (7%) for Goserelin, in 3395/71,160 (5%) for Leuprorelin and in 214/4969 (5%) for Triptorelin. In terms of specific CV disorders, Degarelix presented lower risk of hypertension (PRR 0.60 (95% CI 0.37-0.98), p = 0.04), of myocardial infarction (PRR 0.05 (95% CI 0.01-0.39), p < 0.01) and thrombosis (PRR 0.14 (0.02-1.07), p = 0.06) when compared to GnRH agonists. Overall, younger patients (<65 years) presented a very low risk of CV AEs. Side effects were classified as serious in 90-96% of the cases. Fatal AEs were 5-20% over the CV AEs and 0.2-1% over the total AEs.

CONCLUSIONS

Real-life data are consistent with registry studies regarding side effects related to HT. Real-life data suggest GnRH agonists are associated with higher CV AEs when compared to GnRH antagonists. Clinicians should consider these data when prescribing HT especially in patients with CV comorbidities.

Aerobic physical exercise modifies the prostate tumoral environment

Exercise is recognized for its potential role in reducing the risk of certain cancers. However, the molecular mechanisms behind this risk reduction are not fully understood. Here, we hypothesized that aerobic physical exercise induces cancer attenuating effects through the modulation of oxidative stress and inflammation. To test this hypothesis, twenty male Sprague Dawley rats with chemically induced prostate tumors were divided into two groups: Prostate cancer (PC) in the absence and presence of exercise (PC + Ex). Rats in the PC + Ex group performed exercises on a treadmill for 8 weeks, 5 sessions per week, at an intensity of 60 % of maximum capacity. Weight and feed efficiency, Ki-67, apoptosis, prostatic inflammation, and markers of oxidative stress were analyzed. We found that aerobic physical exercise significantly decreased prostate cell proliferation (p < 0.05) across modulation, tumor size, and prostate weight. The PC + Ex group also significantly reduced anti-apoptosis protein expression (p < 0.05) and increased pro-apoptotic protein expression. Furthermore, physical exercise increased enzymatic antioxidant defenses in the prostate, plasma, and whole blood. Moreover, PC + Ex reduced lipid peroxidation and protein carbonyl levels (p < 0.05). In the prostate, there was an increase in anti-inflammatory cytokines (IL-10), and a reduction in pro-inflammatory cytokines (IL-6, TNF-α, and NF-κB) after 8 weeks of physical exercise. In conclusion, we found that aerobic physical exercise is a functional, beneficial, and applicable approach to control PC progression, because it modifies the systemic environment, including the regulation of glucose and circulating lipids. This modification of the cancer cells environment has anti-inflammatory and antioxidant effects that attenuate tumor growth.

Regular Voluntary Running is Associated with Increased Tumor Vascularization and Immune Cell Infiltration and Decreased Tumor Growth in Mice

Tumors present dysfunctional vasculature that limits blood perfusion and hinders immune cells delivery. We aimed to investigate if regular voluntary running promotes tumor vascular remodelling, improves intratumoral immune cells infiltration and inhibits tumor growth. Tumors were induced in C57BL/6 male mice (n=28) by subcutaneous inoculation in the dorsal region with a suspension of RM1 cells (1.5×10⁵ cells/500 µL PBS) and randomly allocated into two groups: sedentary (n=14) and voluntarily exercised on a wheel (n=14). Seven mice from each group were sacrificed 14 and 28 days after cells' inoculation to evaluate tumor weight, microvessel density, vessels' lumen regularity and the intratumoral quantity of NKG2D receptors, CD4⁺and CD8⁺T cells, by immunohistochemistry. The statistical inference was done through a two-way ANOVA. Exercised mice developed smaller tumors at 14 (0.17±0.1 g vs. 0.48±0.2 g, p<0.05) and 28 (0.92±0.7 g vs. 2.09±1.3 g, p<0.05) days, with higher microvessel density (21.20±3.2 vs. 15.86±4.0 vessels/field, p<0.05), more regular vessels' lumen (1.06±0.2 vs. 1.43±0.2, p<0.05), and higher CD8⁺T cells (464.95±48.0 vs. 364.70±49.4 cells/mm², p<0.01), after 28 days. NKG2D expression was higher in exercised mice at 14 (263.27±25.8 cells/mm², p<0.05) and 28 (295.06±56.2 cells/mm², p<0.001) days. Regular voluntary running modulates tumor vasculature, increases immune cells infiltration and attenuates tumor growth, in mice.

EffectiveNess of a multimodal preHAbilitation program in patieNts with bladder canCEr undergoing radical cystectomy: protocol of the ENHANCE multicentre randomised controlled trial

INTRODUCTION

Radical cystectomy (RC) is the standard treatment for patients with non-metastatic muscle-invasive bladder cancer, as well as for patients with therapy refractory high-risk non-muscle invasive bladder cancer. However, 50-65% of patients undergoing RC experience perioperative complications. The risk, severity and impact of these complications is associated with a patient's preoperative cardiorespiratory fitness, nutritional and smoking status and presence of anxiety and depression. There is emerging evidence supporting multimodal prehabilitation as a strategy to reduce the risk of complications and improve functional recovery after major cancer surgery. However, for bladder cancer the evidence is still limited. The aim of this study is to investigate the superiority of a multimodal prehabilitation programme versus standard-of-care in terms of reducing perioperative complications in patients with bladder cancer undergoing RC.

METHODS AND ANALYSIS

This multicentre, open label, prospective, randomised controlled trial, will include 154 patients with bladder cancer undergoing RC. Patients are recruited from eight hospitals in The Netherlands and will be randomly (1:1) allocated to the intervention group receiving a structured multimodal prehabilitation programme of approximately 3-6 weeks, or to the control group receiving standard-of-care. The primary outcome is the proportion of patients who develop one or more grade ≥2 complications (according to the Clavien-Dindo classification) within 90 days of surgery. Secondary outcomes include cardiorespiratory fitness, length of hospital stay, health-related quality of life, tumour tissue biomarkers of hypoxia, immune cell infiltration and cost-effectiveness. Data collection will take place at baseline, before surgery and 4 and 12 weeks after surgery.

ETHICS AND DISSEMINATION

Ethical approval for this study was granted by the Medical Ethics Committee NedMec (Amsterdam, The Netherlands) under reference number 22-595/NL78792.031.22. Results of the study will be published in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05480735.

Physical Activity as the Best Supportive Care in Cancer: The Clinician's and the Researcher's Perspectives

Multidisciplinary supportive care, integrating the dimensions of exercise alongside oncological treatments, is now regarded as a new paradigm to improve patient survival and quality of life. Its impact is important on the factors that control tumor development, such as the immune system, inflammation, tissue perfusion, hypoxia, insulin resistance, metabolism, glucocorticoid levels, and cachexia. An increasing amount of research has been published in the last years on the effects of physical activity within the framework of oncology, marking the appearance of a new medical field, commonly known as "exercise oncology". This emerging research field is trying to determine the biological mechanisms by which, aerobic exercise affects the incidence of cancer, the progression and/or the appearance of metastases. We propose an overview of the current state of the art physical exercise interventions in the management of cancer patients, including a pragmatic perspective with tips for routine practice. We then develop the emerging mechanistic views about physical exercise and their potential clinical applications. Moving toward a more personalized, integrated, patient-centered, and multidisciplinary management, by trying to understand the different interactions between the cancer and the host, as well as the impact of the disease and the treatments on the different organs, this seems to be the most promising method to improve the care of cancer patients.

The effect of aerobic exercise on tumour blood delivery: a systematic review and meta-analysis

PURPOSE

Tumour blood vessels are structurally and functionally abnormal, resulting in areas of hypoxia and heterogeneous blood supply. Aerobic exercise may modulate tumour blood flow and normalise the tumour microenvironment to improve chemotherapy delivery. This systematic review and meta-analysis aimed to evaluate the effect of the aerobic exercise mode on tumour hypoxia, vascularisation and blood flow.

METHODS

Four online databases were searched. Preclinical and clinical randomised controlled trials examining the effects of aerobic exercise training on hypoxia, vascularisation or blood flow in solid tumours were included. The risk of bias was assessed and a meta-analysis performed.

RESULTS

Seventeen preclinical studies and one clinical study met criteria. Eleven studies assessed hypoxia, 15 studies assessed vascularisation and seven evaluated blood flow. There was large variability in measurement methods, tumour types and exercise program designs. The overall risk of bias was unclear in clinical and preclinical studies, owing to poor reporting. There was no significant effect of aerobic exercise on hypoxia (SMD = -0.17; 95% CI = -0.62, 0.28; I2 = 60%), vascularisation (SMD = 0.07; 95% CI = -0.40, 0.55; I2 = 71%) or blood flow (SMD = 0.01; 95% CI = -0.59, 0.61; I2 = 63%).

CONCLUSION

There is heterogeneity in methodology, resulting in evidence that is inconsistent and inconclusive for the effects of aerobic exercise on hypoxia, vascularisation and blood flow. Most evidence of aerobic exercise effects on tumour blood flow is in animal models, with very limited evidence in humans.

Peroxide mediated oxygen delivery in cancer therapy

Hypoxia is a serious obstacle in cancer treatment. The aberrant vascular network as well as the abnormal extracellular matrix arrangement results in formation of a hypoxic regions in tumors which show high resistance to the curing. Hypoxia makes the cancer treatment challengeable via two mechanisms; first and foremost, hypoxia changes the cell metabolism and leads the cells towards an aggressive and metastatic phenotype and second, hypoxia decreases the efficiency of the various cancer treatment modalities. Most of the cancer treatment methods including chemotherapy, radiotherapy, photodynamic therapy, sonodynamic therapy and immunotherapy are negatively affected by the oxygen deprivation. Therefore, the regional oxygenation is requisite to alleviate the negative impacts of the hypoxia on tumor cells and tumor therapy modalities. A great deal of effort has been put forth to resolve the problem of hypoxia in tumors. Peroxides have gained tremendous attention as oxygen generating components in cancer therapy. The concurrent loading of the peroxides and cancer treatment components into a single delivery system can bring about a multipurpose delivery system and substantially encourage the success of the cancer amelioration. In this review, we have tried to after the description of a relation between hypoxia and cancer treatment modalities, discuss the role of peroxides in tumor hyperoxygenation and cancer therapy success. Thereafter, we have summarized a number of vehicles for the delivery of the peroxide alone or in combination with other therapeutic components for cancer treatment.

Effects of acute exercise training on tumor outcomes in men with localized prostate cancer: A randomized controlled trial

Postdiagnosis physical activity is associated with improved cancer outcomes, but biological mechanisms mediating anticancer effects remain unclear. Recent findings suggest that physiological adaptations to acute exercise comprise potential anticancer effects, but these remain poorly explored in clinical settings. The objective of this study was to explore the effects of a single exercise bout on tumor oxygenation and immune cell infiltration in patients with prostate cancer. Thirty patients with localized prostate cancer were randomized (2:1) to either one high-intensity interval training bout or no exercise on the day before radical prostatectomy. Immunohistochemical analyses were performed on prostatic tissue from surgery and assessed for tumor hypoxia, natural killer (NK) cell infiltration, and microvessel density (MVD). Acute systemic response in blood lymphocytes, epinephrine, norepinephrine, IL-6, tumor necrosis factor, cortisol, lactate, and glucose was also evaluated. We did not find between-group differences in tumor hypoxia (Mann-Whitney U test, U = 83.5, p = 0.604) or NK cell infiltration (U = 77.0, p = 0.328). Also, no significant correlation was found between MVD and tumor hypoxia or NK cell infiltration. One exercise bout is likely insufficient to modulate tumor hypoxia or NK cell infiltration. Future studies may elucidate if an accumulation of several exercise bouts can impact these outcomes (NCT03675529, www.clinicaltrials.gov).

Muscle-to-tumor crosstalk: The effect of exercise-induced myokine on cancer progression

Physical exercise has gradually become a focus in cancer treatment due to its pronounced role in reducing cancer risk, enhancing therapeutic efficacy, and improving prognosis. In recent decades, skeletal muscles have been considered endocrine organs, exerting their biological functions via the endocrine, autocrine, and paracrine systems by secreting various types of myokines. The amount of myokines secreted varies depending on the intensity, type, and duration of exercise. Recent studies have shown that muscle-derived myokines are highly involved the effects of exercise on cancer. Multiple myokines, such as interleukin-6 (IL-6), oncostatin M (OSM), secreted protein acidic and rich in cysteine (SPARC), and irisin, directly mediate cancer progression by influencing the proliferation, apoptosis, stemness, drug resistance, metabolic reprogramming, and epithelial-mesenchymal transformation (EMT) of cancer cells. In addition, IL-6, interleukin-8 (IL-8), interleukin-15 (IL-15), brain-derived neurotrophic factor (BDNF), and irisin can improve obesity-induced inflammation by stimulating lipolysis of adipose tissues, promoting glucose uptake, and accelerating the browning of white fat. Furthermore, some myokines could regulate the tumor microenvironment, such as angiogenesis and the immune microenvironment. Cancer cachexia occurs in up to 80% of cancer patients and is responsible for 22%-30% of patient deaths. It is characterized by systemic inflammation and decreased muscle mass. Exercise-induced myokine production is important in regulating cancer cachexia. This review summarizes the roles and underlying mechanisms of myokines, such as IL-6, myostatin, IL-15, irisin, fibroblast growth factor 21 (FGF21) and musclin, in cancer cachexia. Through comprehensive analysis, we conclude that myokines are potential targets for inhibiting cancer progression and the associated cachexia.

Physical Exercise and Tumor Energy Metabolism

Evidence supports the antitumoral effects of physical activity, either in experimental animal models or humans. However, the biological mechanisms by which physical exercise modulates tumoral development are still unclear. An important feature of the tumor cells is the altered energy metabolism, often associated with definitions of tumor aggressiveness. Nevertheless, exercise can cause global metabolic changes in the body, as well as modulate tumor metabolism. Here we specifically discuss the metabolic changes found in tumors and how exercise can contribute to anti-tumoral effects by modulating the mitochondrial function, and tricarboxylic acid cycle-related metabolites of cancer cells. The effect of physical exercise on tumor metabolism is a new possibility for comprehension of cancer biology and developing therapies focused on tumor energy metabolism.

Modulating Tumour Hypoxia in Prostate Cancer Through Exercise: The Impact of Redox Signalling on Radiosensitivity

Prostate cancer is a complex disease affecting millions of men globally. Radiotherapy (RT) is a common treatment modality although treatment efficacy is dependent upon several features within the tumour microenvironment (TME), especially hypoxia. A hypoxic TME heightens radioresistance and thus disease recurrence and treatment failure continues to pose important challenges. However, the TME evolves under the influence of factors in systemic circulation and cellular crosstalk, underscoring its potential to be acutely and therapeutically modified. Early preclinical evidence suggests exercise may affect tumour growth and some of the benefits drawn, could act to radiosensitise tumours to treatment. Intracellular perturbations in skeletal muscle reactive oxygen species (ROS) stimulate the production of numerous factors that can exert autocrine, paracrine, and endocrine effects on the prostate. However, findings supporting this notion are limited and the associated mechanisms are poorly understood. In light of this preclinical evidence, we propose systemic changes in redox signalling with exercise activate redox-sensitive factors within the TME and improve tumour hypoxia and treatment outcomes, when combined with RT. To this end, we suggest a connection between exercise, ROS and tumour growth kinetics, highlighting the potential of exercise to sensitise tumour cells to RT, and improve treatment efficacy.

Effect of acute aerobic exercise before immunotherapy and chemotherapy infusion in patients with metastatic non-small-cell lung cancer: protocol for the ERICA feasibility trial

INTRODUCTION

Patients with metastatic non-small cell lung cancer (mNSCLC) suffer from numerous symptoms linked to disease and treatment which may further impair the patient's overall condition. In addition to its benefits on quality of life and fatigue, physical exercise may improve treatment response, notably due to its known effects on the immune system. The ERICA study is designed to assess the feasibility of a supervised acute physical exercise therapy realised immediately prior immune-chemotherapy infusion in patients with mNSCLC. Secondary objectives will examine the effects of acute exercise combined with an unsupervised home-walking programme on clinical, physical, psychosocial and biological parameters.

METHODS AND ANALYSIS

ERICA is a prospective, monocentric, randomised controlled, open-label feasibility study conducted at the Centre Léon Bérard Comprehensive Cancer Center (France). Thirty patients newly diagnosed with mNSCLC will be randomised (2:1 ratio) to the 'exercise' or the 'control' group. At baseline and during the last treatment cycle, participants in both groups will receive Physical Activity recommendations, and two nutritional assessments. In the exercise group, participants will receive a 3-month programme consisting of a supervised acute physical exercise session prior to immune-chemotherapy infusion, and an unsupervised home-based walking programme with an activity tracker. The acute exercise consists of 35 min interval training at submaximal intensity scheduled to terminate 15 min prior to infusion. Clinical, physical, biological and psychosocial parameters will be assessed at baseline, 3 and 6 months after inclusion. Biological measures will include immune, inflammatory, metabolic, oxidative stress biomarkers and molecular profiling.

ETHICS AND DISSEMINATION

The study protocol was approved by the French ethics committee (Comité de protection des personnes Ile de France II, N°ID-RCB 20.09.04.65226, 8 December 2020). The study is registered on ClinicalTrials.gov (NCT number:NCT04676009) and is at the pre-results stage. All participants will sign an informed consent form. The findings will be disseminated in peer-reviewed journals and academic conferences.

Alternatives for MRI in Prostate Cancer Diagnostics-Review of Current Ultrasound-Based Techniques

The purpose of this review is to present the current role of ultrasound-based techniques in the diagnostic pathway of prostate cancer (PCa). With overdiagnosis and overtreatment of a clinically insignificant PCa over the past years, multiparametric magnetic resonance imaging (mpMRI) started to be recommended for every patient suspected of PCa before performing a biopsy. It enabled targeted sampling of the suspicious prostate regions, improving the accuracy of the traditional systematic biopsy. However, mpMRI is associated with high costs, relatively low availability, long and separate procedure, or exposure to the contrast agent. The novel ultrasound modalities, such as shear wave elastography (SWE), contrast-enhanced ultrasound (CEUS), or high frequency micro-ultrasound (MicroUS), may be capable of maintaining the performance of mpMRI without its limitations. Moreover, the real-time lesion visualization during biopsy would significantly simplify the diagnostic process. Another value of these new techniques is the ability to enhance the performance of mpMRI by creating the image fusion of multiple modalities. Such models might be further analyzed by artificial intelligence to mark the regions of interest for investigators and help to decide about the biopsy indications. The dynamic development and promising results of new ultrasound-based techniques should encourage researchers to thoroughly study their utilization in prostate imaging.

Circadian rhythms and cancers: the intrinsic links and therapeutic potentials

The circadian rhythm is an evolutionarily conserved time-keeping system that comprises a wide variety of processes including sleep-wake cycles, eating-fasting cycles, and activity-rest cycles, coordinating the behavior and physiology of all organs for whole-body homeostasis. Acute disruption of circadian rhythm may lead to transient discomfort, whereas long-term irregular circadian rhythm will result in the dysfunction of the organism, therefore increasing the risks of numerous diseases especially cancers. Indeed, both epidemiological and experimental evidence has demonstrated the intrinsic link between dysregulated circadian rhythm and cancer. Accordingly, a rapidly increasing understanding of the molecular mechanisms of circadian rhythms is opening new options for cancer therapy, possibly by modulating the circadian clock. In this review, we first describe the general regulators of circadian rhythms and their functions on cancer. In addition, we provide insights into the mechanisms underlying how several types of disruption of the circadian rhythm (including sleep-wake, eating-fasting, and activity-rest) can drive cancer progression, which may expand our understanding of cancer development from the clock perspective. Moreover, we also summarize the potential applications of modulating circadian rhythms for cancer treatment, which may provide an optional therapeutic strategy for cancer patients.

Therapeutic approach for digestive system cancers and potential implications of exercise under hypoxia condition: what little is known? a narrative review

BACKGROUND

Cancer, like other chronic pathologies, is associated with the presence of hypoxic regions due to the uncontrolled cell growth. Under this pathological hypoxic condition, various molecular signaling pathways are activated to ensure cell survival, such as those that govern angiogenesis, erythropoiesis, among others. These molecular processes are very similar to the physiological response caused by exposure to altitude (natural hypobaric systemic hypoxia), the use of artificial hypoxia devices (systemic normobaric simulated hypoxia) or the delivery of vascular occlusion to the extremities (also called local hypoxia by the blood flow restriction technique). "Tumor hypoxia" has gained further clinical importance due to its crucial role in both tumor progression and resistance to treatment. However, the ability to manipulate this pathway through physical exercise and systemic hypoxia-mediated signaling pathways could offer an important range of therapeutic opportunities that should be further investigated.

METHODS

This review is focused on the potential implications of systemic hypoxia combined with exercise in digestive system neoplasms prognosis. Articles included in the review were retrieved by searching among the three main scientific databases: PubMed, Scopus, and Embase.

FINDINGS

The findings of this review suggest that exercise performed under systemic hypoxic conditions could have a positive impact in prognosis and quality of life of the population with digestive system cancers.

CONCLUSIONS

Further studies are needed to consider this paradigm as a new potential intervention in digestive oncological population.

Plausible conditions and mechanisms for increasing physical activity behavior in men with prostate cancer using patient education interventions: sequential explanatory mixed studies synthesis

PURPOSE

This mixed studies synthesis sought to evaluate structured patient education interventions (PEIs) to elucidate relevant conditions and mechanisms for increasing physical activity behavior in men with prostate cancer (PCa).

METHODS

Studies that randomized men diagnosed with PCa, assessed PEIs, and reported (1) between-group changes in the outcome measures of exercise self-efficacy, PA level, or patient-centered outcomes (cancer-related fatigue, aerobic fitness, and quality of life) at baseline and post-intervention, and/or (2) men's perceptions of structured PEIs were synthesized. Results from five RCTs reporting data on 895 men and qualitative reports from four studies were respectively and sequentially analyzed with narrative and thematic syntheses. Findings from both syntheses were further integrated using the context-mechanism-outcome configuration (CMO) to elucidate potential "contextual factors" or "conditions" that may support plausible PEI mechanisms.

RESULTS

Structured PEIs were associated with a beneficial increase in task self-efficacy, vigorous-intensity PA, minutes/week of resistance exercise, the proportion of men meeting ≥ 150 minutes/week of moderate-vigorous intensity aerobic exercise, and overall PA. No effects were found on patient-centered outcomes. Drawing upon the CMO configuration, the inclusion of a referral process, access to "credible influence" (e.g., involving former patients as program facilitators), and adopting hybrid service delivery are likely critical conditions that may explain the success of PEIs in men with PCa.

CONCLUSION

PEIs can increase PA behavior in men with PCa. The likelihood of success is higher for multicomponent interventions that prioritized credible influence and exercise referral as critical components besides offering access to interventions within hospital settings, with home-based sessions in addition.

Obesity and prostate cancer: A narrative review

Overweight and obese men with prostate cancer are at an increased risk of disease recurrence, exacerbated treatment-related adverse effects, development of obesity-related comorbidities, earlier progression and development of metastatic disease, and higher all-cause and prostate cancer-specific mortality. The physiological mechanisms associating obesity with poor prostate cancer outcomes remain largely unknown; however, an increased inflammatory environment and metabolic irregularities associated with excess fat mass are commonly postulated. Although research is limited, fat loss strategies using exercise and nutrition programmes may slow down prostate cancer progression and improve a patient's prognosis. This review is an overview of: 1) the association between obesity and poor prostate cancer prognosis; 2) potential physiological mechanisms linking obesity and prostate cancer progression; 3) the effect of obesity on treatments for prostate cancer; and 4) the potential for weight loss strategies to improve outcomes in patients with prostate cancer.

Voluntary Wheel Running Does Not Enhance Radiotherapy Efficiency in a Preclinical Model of Prostate Cancer: The Importance of Physical Activity Modalities?

Physical activity is increasingly recognized as a strategy able to improve cancer patient outcome, and its potential to enhance treatment response is promising, despite being unclear. In our study we used a preclinical model of prostate cancer to investigate whether voluntary wheel running (VWR) could improve tumor perfusion and enhance radiotherapy (RT) efficiency. Nude athymic mice were injected with PC-3 cancer cells and either remained inactive or were housed with running wheels. Apparent microbubble transport was enhanced with VWR, which we hypothesized could improve the RT response. When repeating the experiments and adding RT, however, we observed that VWR did not influence RT efficiency. These findings contrasted with previous results and prompted us to evaluate if the lack of effects observed on tumor growth could be attributable to the physical activity modality used. Using PC-3 and PPC-1 xenografts, we randomized mice to either inactive controls, VWR, or treadmill running (TR). In both models, TR (but not VWR) slowed down tumor growth, suggesting that the anti-cancer effects of physical activity are dependent on its modalities. Providing a better understanding of which activity type should be recommended to cancer patients thus appears essential to improve treatment outcomes.

Exercise-induced myokines and their effect on prostate cancer

Exercise is recognized by clinicians in the field of clinical oncology for its potential role in reducing the risk of certain cancers and in reducing the risk of disease recurrence and progression; yet, the underlying mechanisms behind this reduction in risk are not fully understood. Studies applying post-exercise blood serum directly to various types of cancer cell lines provide insight that exercise might have a role in inhibiting cancer growth via altered soluble and cell-free blood contents. Myokines, which are cytokines produced by muscle and secreted into the bloodstream, might offer multiple benefits to cellular metabolism (such as a reduction in insulin resistance, improved glucose uptake and reduced adiposity), and blood myokine levels can be altered with exercise. Alterations in the levels of myokines such as IL-6, IL-15, IL-10, irisin, secreted protein acidic risk in cysteine (SPARC), myostatin, oncostatin M and decorin might exert a direct inhibitory effect on cancer growth via inhibiting proliferation, promoting apoptosis, inducing cell-cycle arrest and inhibiting the epithermal transition to mesenchymal cells. The association of insulin resistance, hyperinsulinaemia and hyperlipidaemia with obesity can create a tumour-favourable environment; exercise-induced myokines can manipulate this environment by regulating adipose tissue and adipocytes. Exercise-induced myokines also have a critical role in increasing cytotoxicity and the infiltration of immune cells into the tumour.

The antitumor mechanisms of aerobic exercise: A review of recent preclinical studies

Aerobic exercise is an important non‐pharmacological means of antitumor intervention, but related mechanisms are poorly understood. In this review, previous studies are summarized from the aspects of tumor oxygenation, autophagy versus apoptosis, and organismal immunity. Current findings on the antitumor effects of aerobic exercise involve AMPK signaling, PI3K/Akt signaling, Th1/Th2 cytokine balance related to immunity, PD‐1/PD‐L1 immunosuppressive signaling, and related cytokine pathways. Several directions for further research are proposed, including whether newly discovered subgroups of cytokines influence the effects of aerobic exercise on tumors, tailoring corresponding exercise prescriptions based on the bidirectional effects of certain cytokines at different stages, identifying the potential effects of exercise time and intensity, and elucidating details of the unclear mechanisms. Through the discussion of the existing data, we hope to provide new ideas for the future research of exercise therapy.

The Effects of Physical Exercise on Tumor Vasculature: Systematic Review and Meta-analysis

A wealth of evidence supports an association between physical exercise, decreased tumor growth rate, and reduced risk of cancer mortality. In this context, the tumor vascular microenvironment may play a key role in modulating tumor biologic behavior. The present systematic review and meta-analysis aimed to summarize the evidence regarding the effects of physical exercise on tumor vasculature in pre-clinical studies. We performed a computerized research on the PubMed, Scopus, and EBSCO databases to identify pre-clinical studies that evaluated the effect of physical exercise on tumor vascular outcomes. Mean differences were calculated through a random effects model. The present systematic review included 13 studies involving 373 animals. From these, 11 studies evaluated chronic intratumoral vascular adaptations and 2 studies assessed the acute intratumoral vascular adaptations to physical exercise. The chronic intratumoral vascular adaptations resulted in higher tumor microvessel density in 4 studies, increased tumor perfusion in 2 studies, and reduced intratumoral hypoxia in 3 studies. Quantitatively, regular physical exercise induced an increased tumor vascularization of 2.13 [1.07, 3.20] (p<0.0001). The acute intratumoral vascular adaptations included increased vascular conductance and reduced vascular resistance, which improved tumor perfusion and attenuated intratumoral hypoxia. In pre-clinical studies, physical exercise seems to improve tumor vascularization.

Anti-carcinogenic effects of exercise-conditioned human serum: evidence, relevance and opportunities

Regular physical activity reduces the risk of several site-specific cancers in humans and suppresses tumour growth in animal models. The mechanisms through which exercise reduces tumour growth remain incompletely understood, but an intriguing and accumulating body of evidence suggests that the incubation of cancer cells with post-exercise serum can have powerful effects on key hallmarks of cancer cell behaviour in vitro. This suggests that exercise can impact tumour biology through direct changes in circulating proteins, RNA molecules and metabolites. Here, we provide a comprehensive narrative overview of what is known about the effects of exercise-conditioned sera on in vitro cancer cell behaviour. In doing so, we consider the key limitations of the current body of literature, both from the perspective of exercise physiology and cancer biology, and we discuss the potential in vivo physiological relevance of these findings. We propose key opportunities for future research in an area that has the potential to identify key anti-oncogenic protein targets and optimise physical activity recommendations for cancer prevention, treatment and survivorship.

Highly Stable Silica-Coated Bismuth Nanoparticles Deliver Tumor Microenvironment-Responsive Prodrugs to Enhance Tumor-Specific Photoradiotherapy

Radiosensitizers are agents capable of amplifying injury to tumor tissues by enhancing DNA damage and fortifying production of radical oxygen species (ROS). The use of such radiosensitizers in the clinic, however, remains limited by an insufficient ability to differentiate between cancer and normal cells and by the presence of a reversible glutathione system that can diminish the amount of ROS generated. Here, to address these limitations, we design an H₂O₂-responsive prodrug which can be premixed with lauric acid (melting point ∼43 °C) and loaded around the surface of silica-coated bismuth nanoparticles (BSNPs) for cancer-specific photoradiotherapy. Particularly, silica coating confers BSNPs with improved chemical stability against both near-infrared light and X-rays. Upon photothermal heating, lauric acid is melted to trigger prodrug release, followed by its transformation into p-quinone methide via H₂O₂ stimulation to irreversibly alkylate glutathione. Concurrently, this heat boosts tumor oxygenation and helps relieve the hypoxic microenvironment. Following sequential irradiation by X-rays, BSNPs generate plentiful ROS, which act in combination with these events to synergistically induce cell death via DNA breakage and mitochondria-mediated apoptosis pathways, ultimately enabling effective inhibition of tumor growth in vivo with high tumor specificity and reduced side effects. Collectively, this work presents a promising approach for the improvement of other ROS-responsive proalkylating agents, while simultaneously highlighting a robust nanosystem for combining these prodrugs with photoradiosensitizers to realize precision photoradiotherapy.

Effects of Exercise During Radiation Therapy on Physical Function and Treatment-Related Side Effects in Men With Prostate Cancer: A Systematic Review and Meta-Analysis

PURPOSE

Radiation therapy is a commonly used treatment for prostate cancer; however, the side effects may negatively affect quality of life and cause patients to be less physically active. Although exercise has been shown to mitigate radiation therapy-related fatigue in men with prostate cancer during radiation therapy, other adverse effects of treatment such as physical deconditioning, urinary symptoms, or sexual dysfunction have not been systematically reviewed in this patient population. Thus, the purpose of this review was to investigate the effect of exercise on physical function and treatment-related side effects in men with prostate cancer undergoing radiation therapy.

METHODS

A systematic literature search was conducted in the PubMed, Embase, CINAHL Plus, SPORTDiscus, and Web of Science databases in December 2020. Included studies were randomized controlled trials examining the effects of aerobic and/or resistance exercise interventions on measures of physical function and treatment-related side effects in prostate cancer patients undergoing radiation therapy. Meta-analysis was performed on outcomes that were reported in 2 or more studies.

RESULTS

Seven publications from 6 randomized controlled trials involving 391 prostate cancer patients were included. Patients had stage I to IV cancer with a Gleason score of ≤6 to 10. Exercise resulted in consistent significant benefits for physical function in terms of cardiovascular fitness (standardized mean difference [SMD], 0.83; 95% confidence interval [CI], 0.31-1.36; P < .01) and muscle function (SMD, 1.30; 95% CI, 0.53-2.07; P < .01). Furthermore, there was a significant positive effect of exercise on urinary toxicity (SMD, -0.71; 95% CI, -1.25 to -0.18; P < .01), but not on intestinal (P = .21) or hormonal toxicity (P = .41), depression (P = .45), or sleep symptoms (P = .88).

CONCLUSION

Based on the current evidence, exercise in men with prostate cancer undergoing radiation therapy improves physical function and mitigates urinary toxicity. The effect of exercise on other treatment-related side effects are less clear and require further investigation.

Anti-carcinogenic effects of exercise-conditioned human serum: evidence, relevance and opportunities

Regular physical activity reduces the risk of several site-specific cancers in humans and suppresses tumour growth in animal models. The mechanisms through which exercise reduces tumour growth remain incompletely understood, but an intriguing and accumulating body of evidence suggests that the incubation of cancer cells with post-exercise serum can have powerful effects on key hallmarks of cancer cell behaviour in vitro. This suggests that exercise can impact tumour biology through direct changes in circulating proteins, RNA molecules and metabolites. Here, we provide a comprehensive narrative overview of what is known about the effects of exercise-conditioned sera on in vitro cancer cell behaviour. In doing so, we consider the key limitations of the current body of literature, both from the perspective of exercise physiology and cancer biology, and we discuss the potential in vivo physiological relevance of these findings. We propose key opportunities for future research in an area that has the potential to identify key anti-oncogenic protein targets and optimise physical activity recommendations for cancer prevention, treatment and survivorship.