A structured group exercise program for patients with metastatic cancer receiving chemotherapy and CTNNB1 (β-catenin) as a biomarker of exercise efficacy

INTRODUCTION Exercise can improve the symptoms of cancer. However, is it a cancer treatment? We tested the feasibility of group exercise for metastatic cancer patients while on chemotherapy. A biomarker for exercise efficacy in colorectal cancer (CRC), β-catenin, was tested. METHODS Patients undergoing palliative chemotherapy were eligible for a pre-post, single-arm study comprising an indefinite, weekly group exercise intervention using strength and aerobic training. The Functional Assessment of Chronic Illness Therapy (FACIT) and Piper Fatigue Scale (PFS) questionnaires were administered, and aerobic capacity assessed using the 6-minute walk test. Selection bias, as measured by invitation rate, as well as participation, compliance, and attrition rates, was measured. CRC patients had surgical sections stained for β-catenin and correlated to survival. The statistical analysis was primarily exploratory and hypothesis generating. RESULTS Of the 124 eligible patients, 53 (43%) patients were invited and 35 (28%) patients participated. The median number of classes attended was 16, the compliance rate was 73.1% (95% confidence interval [CI] 67.0-79.4), and the modified attrition rate was 24%. There were no injuries. No significant improvements were seen in the FACIT or PFS at 30 weeks. Aerobic capacity significantly improved at 30 weeks. Participation of CRC patients in the exercise pilot vs nonparticipation was not associated with a change in survival (hazard ratio [HR] =0.98, 95% CI 0.32-2.97). For all CRC patients, strong nuclear staining for β-catenin, compared to weak, suggested a lower risk of mortality (HR =0.54, 95% CI 0.14-1.96). However, CRC participants in the exercise program with weak nuclear staining for β-catenin had a trend to lower mortality (HR =0.39, 95% CI 0.025-6.1). CONCLUSION Exercise for patients with metastatic cancer receiving chemotherapy is feasible and safe. β-Catenin is a potential biomarker for exercise anticancer effect in CRC.