Testing the Effects of Exercise on Colorectal Cancer Development After Treatment With Pelvic Radiation Therapy for Prostate Cancer

PRIMARY OBJECTIVE: I. Determine the effects of exercise on mitigating molecular features in collected normal mucosa sample and any polyps identified. SECONDARY OBJECTIVES: I. Study longitudinal changes in predictors of colon cancer risk. II. Evaluate accrual and retention rates, as well as exercise compliance and safety. EXPLORATORY OBJECTIVE: I. Bank tissue from standard of care colonoscopies/flex sigmoidoscopies for exploratory biological analyses (e.g., immune cell infiltration, mutational signature analysis). OUTLINE: STAGE 1: Patients undergo standard of care (SOC) colonoscopy/flex sigmoidoscopy with tissue biopsy, have their Apple Health physical activity data collected and analyzed, and complete a survey. Patients determined to have low physical activity over the previous 12 months may proceed to Stage 2. STAGE 2: Patients participate in individualized walking sessions over 10-70 minutes each, 5 times per week (225 minutes total per week), for 6 months. Patients also undergo collection of a blood sample on study and undergo SOC colonoscopy/flex sigmoidoscopy with tissue biopsy during follow-up. After completion of study intervention, patients are followed up within 2 weeks, or up to 3 months, for completion of follow-up SOC colonoscopy/flex sigmoidoscopy.