Laurien M Buffart

• Amsterdam University Medical Center

Purpose Maintaining exercise behavior is crucial for cancer survivors, yet adherence to exercise recommendations remains low. This study explores the experiences and perspectives of community-working physical therapists and survivors of cancer regarding barriers and facilitators that support the maintenance of exercise behavior post-treatment. Met...

Pre-clinical studies have shown that exercise can decrease tumour growth through mobilisation, activation, and increased tumour infiltration of natural killer (NK) and CD8⁺ T cells. It is currently unclear whether this can be extrapolated to patients. Therefore, a pilot study was set up to examine the feasibility of obtaining an additional study bi...

Aim Advanced-stage ovarian cancer survivors often have compromised muscle morphology (muscle mass and density), muscle function (muscle strength and physical function), and health-related quality of life (HRQoL). We recently reported improvements in these outcomes following resistance training. Information on the resistance exercise dose required t...

Pre-clinical studies have shown that exercise can decrease tumour growth through mobilisation, activation, and increased tumour infiltration of natural killer (NK) and CD8+ T cells. It is currently unclear whether this can be extrapolated to patients. Therefore, a pilot study was set up to examine the feasibility of obtaining an additional study bi...

Purpose Patients with metastatic colorectal cancer (mCRC) undergoing systemic treatment often experience toxicities. Although exercise may improve physical fitness and quality of life and counteract treatment toxicity, knowledge in patients with mCRC is limited. The ongoing randomized controlled AMICO trial evaluates the effects of supervised exerc...

Knowledge of muscle contractile properties, physical fitness, and their associations with perceived fatigue may provide insights into mechanisms inducing fatigue and treatment targets. We aimed to identify differences in contractile properties and physical fitness between populations, and examine associations with perceived fatigue. We pooled data...

Purpose This study examined the associations of device-measured moderate-to-vigorous physical activity (MVPA) and sedentary time as well as self-reported MVPA with health-related quality of life (HRQoL) in patients with localized renal cell cancer (RCC) in the recovery phase after surgery. Methods At 3 months post-surgery, 341 patients with stage...

Samenvatting Enzalutamide is een sterke remmer van de androgeenreceptor. Behandeling met enzalutamide is effectief bij verschillende stadia van prostaatkanker. De behandeling kan echter gepaard gaan met bijwerkingen, zoals vermoeidheid, cognitieve achteruitgang en depressie, die een grote impact kunnen hebben op de kwaliteit van leven. In dit onder...

Objective Chemotherapy treatment modifications can impact survival in patients with ovarian cancer, particularly when the relative dose intensity falls below 85%. Exercise and dietary interventions may benefit treatment tolerability. This study aimed to explore the effects of a combined exercise and dietary intervention on secondary outcomes of the...

Background: A decline in physical function may be an early predictor for complications of cancer treatment. This study examined whether repeated objective smartphone measurements of physical activity and exercise capacity in patients with cancer are feasible during early-phase clinical trials (EPCTs) and whether a decline in physical function is as...

Background: Guidelines recommend to include exercise and dietary advice in standard care for patients with cancer, based on evidence primarily derived from patients with breast cancer. Its applicability to patients with ovarian cancer is uncertain due to differences in patient characteristics and treatments. The PADOVA trial examined the effective...

Background There is a growing population of survivors of colorectal cancer (CRC). Fatigue and insomnia are common symptoms after CRC, negatively influencing health-related quality of life (HRQoL). Besides increasing physical activity and decreasing sedentary behavior, the timing and patterns of physical activity and rest over the 24-h day (i.e. diu...

Background : To better understand physical activity behavior and its health benefits in people living with health conditions, we studied people with and without 20 different self-reported health conditions with regard to (1) their physical activity levels, (2) factors correlated with these physical activity levels, and (3) the association between p...

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...

Cancer-related fatigue (CRF) is a common and debilitating long-term side effect of cancer and its treatment. While exercise has been shown to effectively reduce CRF, the underlying mechanisms are not fully clear. Therefore, the aim of this study was to explore the effects of a 4-month walking exercise program on fatigue severity and to explore pote...

Background: As physical inactivity and poor sleep quality may impose additional risk for cancer recurrence and overall mortality in postmenopausal breast cancer (PMBC) survivors, it is important to gain insight into the effect of the COVID-19 pandemic on their physical activity (PA) and sleep level. Objective: This study aimed to assess the cour...

Purpose Growing recognition of the gut microbiome as an influential modulator of cancer treatment efficacy and toxicity has led to the emergence of clinical interventions targeting the microbiome to enhance cancer and health outcomes. The highly modifiable nature of microbiota to endogenous, exogenous, and environmental inputs enables interventions...

Purpose. We aimed to evaluate the potential for implementing exercise interventions for patients with breast cancer in the Netherlands, based on findings of the Dutch randomized controlled trials in this population. Methods. We evaluated the implementation of four Dutch exercise trials retrospectively, using the five dimensions of the RE-AIM framew...

Debate is ongoing on the efficacy of cognitive behavior therapy (CBT) for myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS). With an individual patient data (IPD) meta-analysis we investigated whether the effect of CBT varied by patient characteristics. These included post-exertional malaise (PEM), a central feature of ME/CFS according...

Purpose: This study aims to capture the complex clinical reasoning process during tailoring of exercise and dietary interventions to adverse effects and comorbidities of patients with ovarian cancer receiving chemotherapy. Methods: Clinical vignettes were presented to expert physical therapists (n = 4) and dietitians (n = 3). Using the think alo...

Background: Maintaining a sufficient health-related quality of life (HRQoL) is important in the palliative treatment of patients with metastatic colorectal cancer (mCRC). The ORCHESTRA trial (ClinicalTrials.gov identifier: NCT01792934) is designed to prospectively evaluate overall survival benefit and impact on HRQoL of tumor debulking when added...

Background: The minimal and optimal daily step counts for health improvements remain unclear. Objectives: A meta-analysis was performed to quantify dose-response associations of objectively measured step count metrics in the general population. Methods: Electronic databases were searched from inception to October 2022. Primary outcomes include...

Purpose The aim of this prospective cohort study was to estimate the relationship between the course of HRQOL in the first 2 years after diagnosis and treatment of head and neck cancer (HNC) and personal, clinical, psychological, physical, social, lifestyle, HNC-related, and biological factors. Methods Data were used from 638 HNC patients of the N...

Introduction: Older men with prostate cancer are commonly affected by reductions in lean mass and physical function following androgen deprivation therapy (ADT). Resistance-based exercise programs are critical to counteract the musculoskeletal toxicities derived from prostate cancer treatment and aging. However, there is significant variability in...

Purpose This individual participant data meta-analysis (IPD-MA) assesses exercise effects on self-reported cognitive functioning (CF) and investigates whether effects differ by patient-, intervention-, and exercise-related characteristics. Methods IPD from 16 exercise RCTs, including 1987 patients across multiple types of non-metastatic cancer, wa...

Objective: Adaptive designs may reduce trial sample sizes and costs. This study illustrates a Bayesian adaptive decision-theoretic design applied to a multi-arm exercise oncology trial. Study design and setting: In the PACES trial, 230 breast cancer patients receiving chemotherapy were randomized to supervised resistance and aerobic exercise (On...

Purpose: To examine the effects and moderators of exercise effects on cardiometabolic outcomes in men with prostate cancer previously or currently undergoing androgen deprivation therapy (ADT). Results: Seven trials including 560 patients were examined. Exercise resulted in significant effects on whole-body and regional fat mass (P≤0.001). For w...

Purpose Resistance exercise is a well-established intervention to counteract musculoskeletal and metabolic toxicities from prostate cancer treatment. In this study, we reported resistance exercise attendance and compliance, and examine if these variables can influence changes in outcomes of interest in men with localised or locally advanced prosta...

Background: The emerging study of wearable devices (WDs) in patients with cancer provides opportunities to harness real-time patient data for predicting clinical outcomes. We conducted a systematic review with best evidence synthesis to examine the association between WD metrics and clinical outcomes in patients with cancer. Methods: MEDLINE and...

Immune checkpoint inhibitors, including anti-PD-1 and anti-CTLA-4 therapies, are used to (re)activate the immune system to treat cancer. Despite promising results, a large group of patients does not respond to checkpoint inhibition. In the vulnerability-stress model of behavioral medicine, behavioral factors, such as stress, exercise and classical...

We examined the effect of a COVID-19 infection on changes in exercise levels in recreational athletes in the first three months after infection, and identified personal factors associated with a larger change in exercise level and recovery time. Recreational athletes (n=4360) completed an online questionnaire on health and exercise levels. 601 Athl...

Objective: Non-adherence to adjuvant endocrine therapy (AET) for breast cancer leads to increased recurrence and mortality risk and healthcare costs. Evidence on feasible, effective AET adherence interventions is scarce. This paper describes the systematic adaptation of the cost-effective adherence improving self-management strategy (AIMS) for pat...

Background: This systematic review and meta-analysis synthesized evidence in patients with ovarian cancer at diagnosis and/or during first-line treatment on; (i) the association of body weight, body composition, diet, exercise, sedentary behavior, or physical fitness with clinical outcomes; and (ii) the effect of exercise and/or dietary interventi...

Background: There is much evidence to implement physical activity interventions for medical reasons in healthcare settings. However, the prescription of physical activity as a treatment, referring to as 'Exercise is Medicine' (E = M) is currently mostly absent in routine hospital care in The Netherlands. To support E = M prescription by clinicians...

Background Knowledge regarding adherence is necessary to improve the specificity of exercise interventions during cancer treatment. We aimed to determine adherence to resistance and endurance training interventions in parallel; identify subgroups with similar adherence characteristics; and examine determinants of these subgroups. Methods In the Ph...

Introduction The results from the physical training and cancer randomized controlled trial (Phys-Can RCT) indicate that high intensity (HI) strength and endurance training during (neo-)adjuvant cancer treatment is more beneficial for cardiorespiratory fitness (CRF, measured as peak oxygen uptake [VO2peak]) than low-to-moderate intensity (LMI) exerc...

e13610 Background: Wearable activity trackers offer possibilities to harness real-time patient data for predicting clinical outcomes in patients with cancer during treatment with immune checkpoint inhibitors (ICIs). As a first step towards this purpose, we aimed to assess the feasibility of using wearable activity trackers to objectively measure ph...

Objective: To investigate the construct validity of the Steep Ramp Test by longitudinally comparing the correlation between Maximum Short Exercise Capacity (MSEC) of the Steep Ramp Test (SRT) and direct measurements of VO2peak during or shortly after treatment in patients with breast cancer and the potential impact of chemotherapy-induced symptom...

Purpose: To perform a systematic review and network meta-analysis to investigate the most effective intervention for improving body composition outcomes in prostate cancer patients during or following treatment. Methods: A systematic search was undertaken in multiple databases from inception to December 2020. Randomized clinical trials examining th...

Aims and Objectives The self‐performance of a Five‐Times‐Sit‐To‐Stand (FTSTS)‐test, without the usual supervision by a medical professional, provides valuable opportunities for clinical practice and research. This study aimed: (1) to determine the validity of the self‐performed FTSTS test in comparison to a supervised reference test and (2) to dete...

Objectives Despite the many proven advantages of a physically active lifestyle in patient populations, prescription of exercise is currently not widely implemented in routine clinical practice. The aims of this study were twofold: (1) to assess perceptions of clinicians on the current practice of exercise is medicine (E=M) prescription in two Dutch...

Background Identification of characteristics of individuals that are related to decreases in physical activity (PA) levels during lockdown is needed to develop targeted-interventions. This study aims to evaluate changes in domain-specific (i.e. leisure time, transportation, occupational, and household) and total PA due to the Dutch COVID-19 lockdow...

Purpose The expanding armamentarium of wearable activity monitors (WAMs) offers new opportunities to supplement physician-assessed performance status (PS) with real-life patient activity data. These data could guide clinical decision making or serve as a measure of treatment outcome. However, information on the association between physical activity...

Background To systematically review and analyse the associations between fat and muscle mass measures with overall survival in men with prostate cancer. Methods A systematic search was conducted in CINAHL, Cochrane Library, EMBASE, PubMed, and Web of Science databases from inception to December 2020, while abstracts from the American Society of Cl...

Background The majority of postmenopausal breast cancer (PMBC) survivors do not adhere to lifestyle recommendations and have excess body weight. In this group, this is associated with poorer health-related quality of life and an increased risk of type II diabetes mellitus, cardiovascular disease, second primary cancers, cancer recurrences, and mort...

Background Patients, who discontinue early, do not benefit from phase I/II clinical trials (early-phase clinical trials (EPCT)). In this study, associations between objective smartphone measurements of physical activity and fitness and early trial discontinuation in patients with cancer participating in EPCT were investigated. Methods Before start...

Background: A uniform treatment strategy for patients suffering from early recurrence after local treatment of CRLM is currently lacking. The aim of this observational cohort study was to assess the potential survival benefit of repeat local treatment compared to systemic therapy in patients suffering from early recurrence of CRLM. Patients and m...

Natural killer (NK) cells are a population of innate immune cells known to play a pivotal role against tumor spread. In multiple murine models, it was shown that physical exercise had the potential to increase NK cell antitumor activity through their mobilization and tissue redistribution in an interleukin (IL)‐6 and epinephrine‐dependent manner. T...

Background Active treatments for prostate cancer are well known to result in several adverse effects such as fatigue, depression and anxiety symptoms, impacting the overall quality of life (QoL) and wellbeing of a considerable proportion of patients. Resistance-based exercise interventions have shown positive effects to reduce or mitigate these tre...

Despite stringent eligibility criteria for trial participation, early discontinuation often occurs in phase I trials. To better identify patients unlikely to benefit from phase I trials, we investigated predictors for early trial discontinuation. Data from 415 patients with solid tumors who participated in 66 trials were pooled for the current anal...

Exercise during cancer treatment improves cancer-related fatigue (CRF), but the importance of exercise intensity for CRF is unclear. We compared the effects of high vs. low-to-moderate intensity exercise with or without additional behaviour change support (BCS) on CRF in patients undergoing (neo-)adjuvant cancer treatment. This was a multicentre, 2...

Background A 2019 review concluded that spinal manipulative therapy (SMT) results in similar benefit compared to other interventions for chronic low back pain (LBP). Compared to traditional aggregate analyses individual participant data (IPD) meta-analyses allows for a more precise estimate of the treatment effect. Purpose To assess the effect of...

Objective Psychosocial interventions can reduce cancer‐related fatigue effectively. However, it is still unclear if intervention effects differ across subgroups of patients. These meta‐analyses aimed at evaluating moderator effects of (1) sociodemographic characteristics, (2) clinical characteristics, (3) baseline levels of fatigue and other sympto...

Background This pilot trial explores the feasibility of measuring muscle contractile properties in patients with cancer, effects of exercise during chemotherapy on muscle contractile properties and the association between changes in contractile muscle properties and perceived fatigue. Method Patients who received (neo)adjuvant chemotherapy for bre...

Purpose The level of daily physical activity in patients with cancer is frequently assessed by questionnaires, such as the Physical Activity Scale for the Elderly (PASE). Objective assessments, with for example accelerometers, may be a good alternative. The aim of this study was to investigate the agreement between the PASE questionnaire and accele...

Purpose This study evaluated the effects of coping skills training (CST) on symptoms of depression and anxiety in cancer patients, and investigated moderators of the effects. Methods Overall effects and intervention-related moderators were studied in meta-analyses of pooled aggregate data from 38 randomized controlled trials (RCTs). Patient-relate...

Purpose In this study, we investigated factors associated with program adherence and patient satisfaction with a home-based physical activity program (Onco-Move, N = 77) and a supervised exercise program with a home-based component (OnTrack, N = 76). Methods We assessed adherence via self-report (home-based program) and attendance records (supervi...

Background The prescription of physical activity (PA) in clinical care has been advocated worldwide. This “exercise is medicine” (E=M) concept can be used to prevent, manage, and cure various lifestyle-related chronic diseases. Due to several challenges, E=M is not yet routinely implemented in clinical care. Objective This paper describes the rati...

Introduction: Objective measurements of levels of physical activity and fitness in patients with head and neck cancer (HNC) are lacking. Furthermore, demographic, clinical and lifestyle-related correlates of low levels of physical activity and fitness in patients with HNC are unknown. This study aims to investigate the levels of accelerometer that...

Background Patients with cancer who are refractory to standard treatments may participate in phase I clinical trials. Despite stringent eligibility criteria for trial participation, early discontinuation often occurs. These patients do not benefit from study treatment and may experience additional burden from participation, while adequate evaluatio...

Background The expanding armamentarium of wearable devices offers new opportunities to supplement physician-assessed performance status (PS) with continuously acquired real-life patient data. It is relevant to identify and characterize the level of association between wearable device physical activity (PA) metrics and PS in cancer patients as a fir...

Background: Fatigue is one of the most common and distressing long-term effects of cancer treatment. Cognitive behavioral therapy (CBT) is an evidence-based intervention for patients with severe post-cancer fatigue. CBT for fatigue is a complex intervention consisting of multiple elements like a graded activity program, regulation of the sleep-wake...

Objectives: We aimed to investigate accelerometer output corresponding to physical activity intensity cut-points based on percentage of peak oxygen consumption (%VO2peak) and Metabolic Equivalent of Task (MET) value in women treated for breast cancer. Design: Laboratory study. Methods: Fifty female patients shortly after completion of treatmen...

Purpose: Fatigue is a common and potentially disabling symptom in patients with cancer. It can often be effectively reduced by exercise. Yet, effects of exercise interventions might differ across subgroups. We conducted a meta-analysis using individual patient data of randomized controlled trials (RCTs) to investigate moderators of exercise interv...

Background: Physical activity has beneficial effects on the health of cancer survivors. We aimed to investigate accelerometer-assessed physical activity and sedentary time in cancer survivors, and describe activity profiles. Additionally, we identify demographic and clinical correlates of physical activity, sedentary time and activity profiles. M...

Purpose This qualitative study aimed to identify hematopoietic stem cell transplantation (HSCT) survivors’ (1) work perceptions; (2) barriers to and facilitators of return to work (RTW); and (3) possible solutions to improve RTW. Method Fifteen patients treated with HSCT 1–5 years ago participated in face-to-face semi-structured interviews. Interv...

Purpose To evaluate the long-term effectiveness and cost-effectiveness of a supervised 18-week high-intensity exercise program compared with usual care in patients treated with autologous stem cell transplantation. Methods One hundred nine patients were randomly assigned to the exercise intervention (n = 54) or the usual care control group (n = 55...

Objectives: To evaluate the effects of exercise interventions on sleep disturbances and sleep quality in patients with mixed cancer diagnoses, and identify demographic, clinical, and intervention-related moderators of these effects. Methods: Individual patient data (IPD) and aggregated meta-analyses of randomized controlled trials (RCTs). Using...

Patiënten met kanker ondergaan vaak een of meer behandelingen zoals chirurgie, chemotherapie, radiotherapie en/of immunotherapie. Door deze behandelingen hebben zij te maken met verminderde fysieke fitheid, vermoeidheid en verminderde kwaliteit van leven. Fysieke training kan hierbij uitkomst bieden, zowel tijdens als na de behandeling.

The aims of the present systematic review and meta‐analysis were to investigate the effect of exercise on maximal oxygen uptake (VO2max) and to investigate whether exercise frequency, intensity, duration and volume are associated with changes in VO2max among adult patients with cancer undergoing treatment. Medline and Embase through OvidSP were sea...

Introduction: Ecological momentary assessment (EMA) is an emerging method to assess an individual's current thoughts, affect, behaviour, physical states and contextual factors as they occur in real-time and in their natural environment. Whereas EMA is frequently used in mental health, little is known about the added value of EMA in oncology resear...

Objective Harmonizing individual patient data (IPD) for meta-analysis has clinical and statistical advantages. Harmonizing IPD from multiple studies may benefit from a flexible data harmonization platform (DHP) that allows harmonization of IPD already during data collection. This paper describes the development and use of a flexible DHP that was in...

Background Physical fitness and psychosocial function is often reduced in children during or shortly after cancer treatment. This study evaluates the effect of a combined physical exercise and psychosocial intervention on cardiorespiratory fitness, muscle strength, body composition, psychosocial function and health-related quality of life (HrQoL)....

Background: Current toxicity evaluation is primarily focused on high-grade adverse events (AEs) reported by clinicians. However, the cumulative effect of multiple lower-grade AEs may also impact patients’ quality of life (QoL). Further, patient-reported toxicity may be more representative of patients’ treatment experiences. This study aimed to dete...

Background Previous systematic reviews and meta-analyses demonstrated beneficial effects of exercise during or following cancer treatment on quality of life (QoL). Aiming to understand how exercise contributes to a patient's QoL, we examined patients' perspectives via a process called concept mapping. This unique method provides structure and objec...

Background Physical function is important for defining treatment strategies in patients with cancer and can be estimated using patient-reported outcomes (pros). Although pros are subjective, physical activity and fitness can be tested objectively with adequate, but more labour-intensive methods that are rarely used in daily clinical practice. To de...

Background A patient’s physical function plays a leading role in the treatment prescription for patients with cancer. Objective assessments of physical function may be more predictive for treatment tolerability and survival than frequently used subjective measures, such as the Eastern Cooperative Oncology Group/World Health Organization (ECOG/WHO)...