Trial Information

The Influence of Home-based Aerobic and Resistance Exercise on Cancer-Related Fatigue, Strength, and Muscle Mass in Prostate Patients.

Numerous studies have shown that the vast majority of patients experience cancer-related
fatigue (CRF) during cancer treatments. Research by our group showed that 71% percent of 84
prostate cancer patients reported CRF during radiation. Unlike fatigue caused by
overexertion, CRF is a pervasive, whole-body experience that is not alleviated by rest or
sleep and often lingers long after completing standard treatments like radiation therapy.
It has a detrimental effect on patients' quality of life and can interfere with completion
of prescribed treatment regimens. In addition, lasting fatigue for many patients impedes
the resumption of normal life following treatments. Unfortunately, effective, well-accepted
treatments for CRF are lacking. Although some research suggests that exercise may be a
promising intervention for reducing CRF, physicians are still hesitant to prescribe exercise
for fatigued patients, and, in fact, often encourage them to rest and conserve energy, which
may be in exact opposition to what is needed.

One probable peripheral physiological mechanism that may affect the influence CRF is a loss
of skeletal muscle mass, which, ultimately, effects weakness and strength. This muscle loss
can result from deconditioning effects stemming from reduced physical activity resulting
from cancer and its treatment. It is plausible that patients may enter radiation therapy
with a certain degree of muscle loss, reduced strength and substantially decreased levels of
physical activity as a result of their cancer diagnosis and the associated stress, surgical
and systemic treatments, and/or the subsequent symptomology. Additionally, their physical
activity may decline even further during radiation and escalate the loss of muscle and
decreased strength. Recently, researchers have proposed that these deconditioning
responses, as well as generalized inflammatory responses resulting from the cancer and/or
its treatment result in skeletal muscle loss and strength deficits, which may play a
significant role in the etiology of CRF. Although mild exercise can counteract
deconditioning, current research has shown that cancer patients decrease the amount of
physical activity they engage in after diagnosis as well as during and after treatment.
Additionally, a substantial number of patients never return to prediagnosis levels of
physical exercise and do not meet the minimal ACSM or CDC guidelines for achieving the
health-related benefits (e.g., increased muscle mass, strength, and cardiorespiratory
fitness) thought to be etiologically involved in CRF, suggesting the need for formal
intervention.

We propose to test an individually tailored physical exercise intervention, including both
aerobic and resistance exercise, for reducing CRF in prostate cancer patients receiving
radiation therapy. The proposed research will provide detailed information on the efficacy
and acceptance of a home-based aerobic and resistance exercise program for CRF among
prostate cancer patients receiving radiation. Data regarding the influence of this
intervention on potential factors related to CRF, including loss of strength, muscle atrophy
and inflammatory biomarkers will be gathered. The purpose of the proposed study is to
extend the positive findings from a feasibility study showing that our tailored home-based
aerobic (walking) and progressive resistance exercise program was effective in reducing CRF
and improving strength, skeletal muscle mass, aerobic capacity and quality of life in a
small sample of prostate and breast cancer patients (N=38).

The Primary Aim of the study is to examine the influence of a home-based aerobic and
progressive resistance exercise program on CRF in prostate cancer patients receiving
radiation therapy. The proposed study is a phase II randomized, 2-arm, controlled clinical
trial employing a repeated-measures design (baseline, post intervention, 3-month follow-up)
that will accrue 122 male prostate cancer patients receiving radiation therapy.

This project builds upon very promising pilot data and includes a diverse research team with
substantial experience in exercise interventions, survivorship, and cancer control research.
This grant will allow us to discern the efficacy of a novel, tailored, home-based aerobic
and resistance exercise intervention for reducing CRF among prostate cancer patients during
radiation, and to identify potential factors (e.g., loss of strength, muscle atrophy,
dysregulation of bodily immune function} that may contribute to the development of CRF that,
in turn, can be more effectively targeted through tailoring future exercise interventions to
improve the impact of these exercise interventions on reducing CRF. These results will have
the direct potential to reduce the suffering experienced by prostate cancer patients during
radiation treatments, and to positively impact future research in exercise and cancer
control on side effect management, the practice of evidence-based medicine for the treatment
of CRF, and, eventually, public health policy and oncology practice.