The Role of suPAR Biomarker in Blood Samples of Breast Cancer Patients During and Post Doxorubicin Chemotherapy: Causative vs. Predictor
Condition: Doxorubicin Adverse Reaction; Cardiomyopathies, Secondary; Breast Cancer
MeSH terms: Breast Neoplasms; Cardiomyopathies
Study type: Observational

Summary: 
      This study looks to find a causative or predictive aspect of the suPAR biomarker for heart
      failure in breast cancer patients receiving Doxorubicin drug chemo regimen.

      suPAR is a circulating protein which can be found in blood and/or urine and is associated
      with both kidney and heart disease.

        -  Hypothesis 1: Higher suPAR at baseline will predispose to Doxorubicin-induced
           cardiomyopathy or heart failure, observed by histology (under the microscope and other
           lab techniques) in mouse models, and tested using heart ultrasound techniques in humans.

        -  Hypothesis 2: suPAR is a marker of Doxorubicin-induced cardiomyopathy or heart failure
           after exposure to Doxorubicin, observed by histology (under the microscope and other lab
           techniques) in mouse models, and tested in humans.

      The study will look at suPAR's association with three other biomarkers called troponin,
      B-Type Natriuretic Peptide (BNP) and C- Reactive Protein (CRP) that are also associated with
      heart disease.

      In this study, the patient will have blood drawn as a routine part of the cancer treatment.
      That is prior to starting the cancer therapy, then after the first 2 and last 2 doxorubicin
      cycles (4 cycles altogether); as well as at 3, 6, & 12 months after doxorubicin treatment. (6
      Visits in total) The patient will also have an echocardiogram (echo, heart ultrasound) at
      each of these time points. The first of the six study echos is considered part of the routine
      care.
    

Detailed description: 
      -  Hypothesis 1: Higher suPAR at baseline will predispose to DOX-induced cardiomyopathy to
           be observed by histology in mouse models, and tested using LVEF (Left Ventricular
           Ejection Fraction) assessment, and surrogate cardiovascular outcome measures as
           described in humans.

        -  Hypothesis 2: suPAR is a marker of DOX-induced cardiomyopathy after exposure to DOX, to
           be observed by histology in mouse models, and tested using surrogate cardiovascular
           outcome measures as described in humans.

             1. Patients meeting outlined eligibility criteria are identified by breast cancer
                physicians working in the Rush Cancer Center. After eligibility is verified,
                patients are approached by the study coordinators or research fellow to discuss
                participation in the trial while patients were being seen by their provider within
                the cancer center and given the informed consent form for review. Patients are
                contacted approximately one week later to answer questions and plan for baseline
                visit if interested in enrolling.

             2. After signing the informed consent form, patients are officially enrolled. The
                research nurse, study coordinator, or research fellow will conduct research visits
                at each of the six study time points outlined in the protocol: pre-chemo, post-2
                cycles of doxorubicin, post-4 cycles of doxorubicin, 3 months post-doxorubicin, 6
                month post-doxorubicin and 12 months post-doxorubin

             3. Each study visit consists of collecting lab work via blood draw as detailed in the
                protocol as well as an echocardiogram performed with strain.

             4. Results from each test are collected, reviewed by the PI and documented in the
                patient's study binder.

             5. Preliminary human results have not been analyzed at this time as there is currently
                insufficient data collected.

      In the laboratory approach of the study, the investigators aimed to establish the role of
      suPAR in DOX induced cardiomyopathy. The risk for DOX induced cardiomyopathy is known to
      increase with an increase of the accumulative dose. The investigators therefore used two
      doses of DOX. One group of mice received weekly injections of DOX at 3mg/kg bodyweight for 6
      week (accumulative dose of 18mg/kg: DOX18) whereas another group received an accumulative
      dose of 25mg/kg bodyweight (DOX25: 5 weeks, at 5 mg/kg bodyweight). Blood samples were taken
      before the first injection, in the middle of treatment and at the end of treatment or at the
      day of sacrifice. The bodyweight of the animals was constantly monitored throughout the
      study.

      At time of sacrifice, the heart weight and tibia length of the mice were quantified and cells
      were isolated to determine cellular levels of reactive oxygen species (ROS), contractility
      and Ca handling properties.

      DOX induced cardiomyopathy can manifest years after treatment. Tissue samples from hearts of
      the DOX18 and DOX25 treatment group were obtained and quantitative PCR (Polymerase Chain
      Reaction amplification) of the ventricular tissue will help us determine the changes in
      protein expression and cellular signaling that underlie these DOX induced changes in cellular
      function.

      Blood samples obtained from the DOX18 and DOX25 mice will be analyzed for their level of
      suPAR to determine changes in suPAR over the duration of treatment and potential correlations
      of [suPAR] with the degree of cardiac dysfunction.

      The data collected will be analyzed using a descriptive analysis with means and standard
      deviations for continuous variables and percentages for categorical variables. A paired
      t-test comparing the pre-post difference will be used to compare the differences in the
      groups comparing pre to post measures of myocardial damage based on histology for mouse
      models, and LVEF (Left Ventricular Ejection Fraction) for human data. Analysis will be
      performed using SAS (statistical analysis software).

      The expected results from the data collected in this study aim to both gain an understanding
      of and describe the relationship of various covariates to primary outcomes.

      It is expected to have 50 participants by the study end date. There is a trained team working
      on the study, insuring quality of data gathering, recruitment and enrollment of patients.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Female patients aged between 18 and 64, recently diagnosed with non metastatic breast
        cancer, and will be receiving doxorubicin containing chemo regimen.

        All patients are being treated at Rush University Medical Center, Chicago, IL, and Rush Oak
        Park Hospital, Oak Park, IL.
      
Biospecimen description: 
      Blood samples are put in a Centrifugation machine to separate the plasma. The plasma is then
      kept in -70 to -80 degrees Fahrenheit. Each sample will be studied for suPAR levels.
    
Keywords: Doxorubicin; suPAR; Cardiomyopathy; Heart Failure; Breast Cancer