The high rate of recurrent disease is a critical barrier to promote the health and longevity of colon cancer (CC) survivors. An approach to reduce this barrier is to develop interventions to minimize recurrence that CC survivors can accomplish autonomously, such as lifestyle and behavioral modification. Epidemiologic evidence suggests that increasing levels of post-diagnosis physical activity is associated with a 42% improvement in disease-free survival, 40% reduction in recurrence, and 45-71% reduction in CC-specific mortality. However, the underlying molecular mechanisms of this association remain unidentified. Characterizing biomarkers that promote existing tumor growth and dissemination of circulating tumor cells (CTCs) may advance knowledge of CC recurrence and progression. Cell-adhesion molecules play a pivotal role in the development and progression of CC recurrence. Cell-adhesion molecules, such as soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular adhesion molecule-1 (sVCAM-1), promote the growth and progression of existing micro-metastases, and promote the formation of additional metastatic foci by enabling CTC invasion of the extracellular matrix, infiltration and dissemination throughout the blood stream, and extravasation into distant organs. This pilot study will randomize 39 CC survivors to three equal-sized groups: low dose (150 min?wk-1) moderate-intensity aerobic exercise, high-dose (300 min?wk-1) moderate-intensity aerobic exercise, or a control group, for 26-weeks. Participants will be provided with in-home treadmills to support the achievement of these exercise goals. Our research team has demonstrated success in prescribing these volumes of aerobic exercise. The primary aims of this trial are to quantify and describe the feasibility, incidence of healthcare events requiring dose-reduction or cessation of exercise and to gather preliminary evidence regarding the biologic efficacy of two distinct doses of aerobic exercise on two cell-adhesion biomarkers associated with CC recurrence and metastasis (sICAM-1 and sVCAM-1). We will then explore the relationship between cell-adhesion molecules and CTCs. This line of investigation aligns with the current mission of the National Cancer Institute PAR-12-229, and provocative question PQA-5, which aim to elucidate the optimal exercise prescription to improve molecular pathways hypothesized to underlie the association between physical activity and cancer prognosis.
Despite the success of surgery and chemotherapy among people with colon cancer (CC), 30-50% of patients develop recurrent disease. Physical activity has emerged as a potential lifestyle intervention to reduce cancer recurrence and improve survival among people with CC. This pilot study aims to identify the dose-response effects of exercise on molecular and cellular pathways associated with physical activity and CC outcomes.