Can Exercise Improve Cancer Associated Cognitive Dysfunction?
Condition: Breast Cancer
MeSH terms: Cognitive Dysfunction
Study type: Interventional
Phase: Phase 2

Summary: 
      Following chemotherapy, some breast cancer survivors report alterations in their ability to
      remember, concentrate, or think, which can have significant emotional, psychological, and
      economic impact on their lives. Survivors have also reported feeling frustrated by the
      response of the medical community, who either may not acknowledge their symptoms or have no
      treatment options to suggest. Exercise may be a promising treatment, as improvements in
      cognitive function with exercise have been demonstrated in older adults and other clinical
      populations.

      The investigators will recruit women who have completed chemotherapy for breast cancer
      (within the past 2 years) and report cognitive changes. Women will be randomly assigned to
      either a 24-week aerobic exercise intervention or delayed exercise control (offered the same
      exercise program following the study). At the start and end of the study the investigators
      will measure: i) performance on four standard neuropsychological tests that measure working
      memory, learning, and problem solving; ii) a questionnaire on cognitive function and its
      impact on quality of life; iii) functional magnetic resonance imaging (fMRI) during two of
      the standard neuropsychological tests which provides information on how the brain is working
      during the tests.

      To knowledge of the investigators this is the first study to examine the effect of an
      exercise intervention on cognitive function in breast cancer survivors. In addition, the use
      of fMRI imaging is a new way to approach this research question, and may be more sensitive to
      change than traditional measures of cognitive function.
    

Detailed description: 
      Objective 1:

      Conduct a randomized trial to test the effectiveness of a 24-week aerobic exercise
      intervention in adult, female breast cancer survivors with self-reported cognitive changes
      following chemotherapy.

      The investigators will test the following hypotheses:

        1. A) The exercise intervention will improve performance on neuropsychological tests of
           specific cognitive domains of executive function, namely i)selective attention and
           response inhibition, ii)processing speed and mental flexibility, and iii) verbal memory
           and learning in exercisers (EX; n=15) versus delayed exercise controls (CON; n=15).

           B) The exercise intervention will reduce self-reported cognitive dysfunction and its
           impact of function and quality of life, in EX compared to CON, measured as a decreased
           score on the Functional Assessment Cancer Therapy-Cognition Scale (FACT-Cog).

           Objective 2:

           Conduct analyses on the effect of the intervention on brain activation patterns using
           functional magnetic resonance imaging (fMRI).

           The investigators will test the following hypotheses:

        2. A) At baseline, brain activation patterns will differ in breast cancer survivors
           reporting cognitive difficulties following chemotherapy compared to breast cancer
           survivors who have not received chemotherapy (who serve as breast cancer/no chemotherapy
           controls; not enrolled in the exercise intervention) during neuropsychological tests
           completed in the scanner.

      B) The exercise intervention will result in a decrease in regions of cortical activation,
      particularly in regions that show higher activation in breast cancer survivors following
      chemotherapy, compared with no change in controls.
    

Intervention name(s): Exercise
Intervention type(s): Behavioral
Intervention description(s): 150 minutes/week of aerobic exercise at 60-70% of heart rate reserve (individualized based on baseline VO2 peak test). The intervention is 24 weeks with an exercise progression to reach the full exercise prescription by week 8. Participants are required to attend two 45 minute supervised sessions per week and complete two additional 30 minute sessions independently at home.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment