An observational study in Muscle Weakness, Low Muscle Mass and Sarcopenia, sponsored by St. Jude Children's Research Hospital. Recruiting at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-16.
Sponsored by St. Jude Children's Research Hospital · Observational
Childhood cancer survivors experience premature declines in muscle mass, strength, and physical function that contribute to morbidity and early mortality. The biological mechanisms driving these impairments are heterogeneous and poorly understood. This observational study aims to characterize distinct muscle health endotypes in adult survivors of childhood cancer using advanced imaging, neuromuscular testing, and functional assessment. Survivors with reduced muscle health and community controls will undergo multimodal magnetic resonance imaging and spectroscopy, nerve conduction studies, surface electromyography, body composition assessment, and physical performance testing during a single study visit integrated into an ongoing cohort evaluation. Identifying mechanistic endotypes of impaired muscle health will support development of targeted interventions to preserve function and improve long-term outcomes in childhood cancer survivors.
Primary Objective:
- Characterize reduced muscle health endotypes in childhood cancer survivors.
Secondary Objective:
- Identify specific treatment and lifestyle related risk factors for each reduced muscle health endotype.
Exploratory Objective:
- Host germline genetics will be associated with specific muscle endotypes.
Survivors of childhood cancer are at increased risk for early-onset frailty characterized by low lean mass, muscle weakness, and impaired physical function. Prior studies in the St. Jude Lifetime Cohort (SJLIFE) demonstrate that the prevalence of these impairments increases with age and is associated with a significantly higher risk of mortality. Traditional lifestyle and resistance training interventions have yielded only modest benefits, suggesting that superficially similar muscle phenotypes may be driven by distinct biological mechanisms.
Potential contributors to impaired muscle health in this population include peripheral nervous system dysfunction, altered motor unit activation, mitochondrial dysfunction, and muscle fat infiltration, resulting from cancer therapies, chronic health conditions, and lifestyle factors. Advanced imaging and neuromuscular phenotyping provide an opportunity to define distinct mechanistic "endotypes" that underlie reduced muscle health and to inform future precision interventions.
477 studies on the registry are indexed under Muscle Weakness; 73 are open to participants now.
This study's planned enrollment of 533 is above the median of 68 across 108 observational studies indexed under Muscle Weakness.
Browse Muscle Weakness studies →St. Jude Children's Research Hospital is the lead sponsor of 440 studies on the registry; 102 are open to participants now.
Of its 61 completed or terminated interventional studies of FDA-regulated products, 37 (61%) have results posted.
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The study population includes adults aged 18 years or older enrolled in the St. Jude Lifetime Cohort (SJLIFE) who are childhood cancer survivors and community control participants without a cancer history. Eligible survivors are at least five years from primary cancer diagnosis and have reduced muscle mass and/or muscle strength based on age- and sex-specific z-scores. Survivors are categorized by prior exposure to peripheral neurotoxic cancer therapies. Community controls are frequency-matched by age and sex. All participants complete neuromuscular, imaging, and physical function assessments during a single study visit.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults with no history of cancer recruited from the community or non-first-degree relatives of St. Jude patients.
Other: Multimodal Muscle Imaging and Functional Assessment
Adult childhood cancer survivors with low lean mass and/or muscle weakness and documented exposure to peripheral neurotoxic therapies.
Other: Multimodal Muscle Imaging and Neuromuscular Assessment
Adult childhood cancer survivors with low lean mass and/or muscle weakness and no history of exposure to peripheral neurotoxic therapies.
Other: Comprehensive Muscle Phenotyping
Adult childhood cancer survivors meeting criteria for both low lean mass and muscle weakness, irrespective of treatment exposure.
Other: Integrated Neuromuscular and Imaging Evaluation
Participants undergo comprehensive muscle phenotyping, including magnetic resonance imaging (MRI) to assess muscle cross-sectional area and fat fraction; magnetic resonance spectroscopy (¹H MRS and ³¹P MRS) to evaluate skeletal muscle mitochondrial energetics; body composition assessment using dual energy X ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA); nerve conduction velocity testing; surface electromyography (EMG); and standardized physical performance testing.
Participants complete advanced neuromuscular and imaging assessments, including MRI-based evaluation of muscle structure and fat infiltration; magnetic resonance spectroscopy to assess mitochondrial oxidative metabolism; DXA and BIA for lean mass measurement; nerve conduction studies; surface electromyography during submaximal and maximal muscle activation; and physical function testing, performed during a single study visit.
Participants undergo protocol-defined observational assessments including MRI and MRS of skeletal muscle, body composition analysis via DXA and BIA, neuromuscular testing with nerve conduction velocity and surface electromyography, and functional performance evaluations to characterize muscle health and underlying biological mechanisms.
Participants receive integrated phenotyping of muscle health using multimodal MRI and MRS imaging, neuromuscular testing with EMG and nerve conduction velocity, body composition assessment, and standardized physical performance measures to identify muscle aging endotypes.
Nerve conduction velocity (NCV) at rest and Electromyography (EMG) during submaximal and maximal force generation
Nerve conduction velocity (NCV) of sural sensory and tibial motor nerves will be performed using electromyography with standard landmarks for electrode placement. Compound Muscle Action Potential (CMAP) and Sensory Nerve Action Potential (SNAP) amplitudes are measured from negative to positive peak, and velocities calculated based on onset latency. NCV testing at rest and EMG during submaximal and maximal force generation will allow us to characterize the impact of the peripheral nervous system and the motor unit on muscle health.
Time frame: Baseline
Creatinine recovery post exercise with magnetic resonance imaging (MRI)
The plantar flexion motion is performed during the dynamic CrCEST MRI and 31P MRS acquisitions to provide a standardized in scanner exercise stimulus that perturbs skeletal muscle energy metabolism in the calf muscles. We will perform Cr-weighted CEST MRI to map calf muscle Cr recovery kinetics following plantar flexion exercise using an ergometer device. MATLAB scripts will be used for post-processing CEST data. 31P-MRS is performed with 1H/31P dual-tuned surface/volume coil. PCr is determined by fitting the signal intensity of PCr following plantar flexion exercise to a mono-exponential function. We will acquire a steady state 31P-MR spectra for phosphorylated metabolite quantification.
Time frame: Baseline
Intramyocellular and extramyocellular fat fraction in muscle during magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS)
Multiparametric MRI, 1H-MRS and Fat fraction MRI will be performed. 1H-MRS is a unique tool for studies of lipid metabolism because it is the only noninvasive method that separately quantifies Intramyocellular and extramyocellular lipids (IMCL and EMCL). Fat fraction is a metric for fat accumulation in healthy muscle tissue because of perturbed fatty acid oxidation. Dixon MRI sequence will be used to measure intramuscular fat fraction in legs and abdomen. MATLAB scripts are used for post- processing Dixon data. We will perform multiparametric quantitative MRI (PMID: 40172709). 1H-MRS is performed on a Siemens 3T scanner using Point RESolved Spectroscopy (PRESS) sequence (PMID: 3326459). A water-suppressed 1H spectrum will be acquired from a voxel positioned in gastrocnemius and soleus muscles. 1H- MRS data will be processed using LCModel (PMID: 8139448).
Time frame: Baseline
Plan to share: Yes — Individual participant de-identified datasets containing the variables analyzed in the published article will be made available (related to the study primary or secondary objectives contained in the publication). Supporting documents such as the protocol, statistical analyses plan, and informed consent are available through the CTG website for the specific study. Data used to generate the published article will be made available at the time of article publication. Investigators who seek access to individual level de-identified data will contact the computing team in the Department of Biostatistics (ClinTrialDataRequest@stjude.org) who will respond to the data request.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: Data will be made available at the time of article publication.
Access criteria: Data will be provided to researchers following a formal request with the following information: full name of requestor, affiliation, data set requested, and timing of when data is needed. As an informational point, the lead statistician and study principal investigator will be informed that primary results datasets have been requested.
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