Aims: Evidence supporting exercise post-cancer is largely derived from studying cancer types with 5-year survival rates typically higher than the 69% 5-year survival rate for all-cancers combined. Cancer types with poorer prognosis are associated with later-stage at diagnosis, more invasive/intensive treatment and more severe treatment-related side effects; factors which may influence exercise safety, feasibility and efficacy. The purpose of this work was to compare the results of two independent meta-analyses conducted to assess the safety, feasibility and effects of exercise following colorectal cancer (CRC) and lung cancer (LC), with these two common cancers being associated with 5-year survival rates of 70% and 18%, respectively.
Methods: A database search (protocols registered on PROSPERO) was undertaken to identify eligible randomised, controlled, exercise trials. The PEDro scale was used to assess risk of bias, and the Adverse Events (AE) Common Terminology Criteria was used to classify AE. Feasibility was assessed by calculating retention and exercise attendance rates. Meta-analyses were undertaken to evaluate AE risk between exercise and usual care (risk difference; RD), and effects on health outcomes (standardised mean difference; SMD).
Results: 32 LC (n=2109) and 19 (n=1293) CRC trials were included. AE risk for both cancer types was low (LC: RD=-0.01 [91% CI=–0.02, 0.01], p=0.31; CRC: RD=0.00 [95% CI:–0.01, 0.01], p=0.92). Feasibility appeared slightly better for CRC vs LC: median withdrawal rate - 12% (0-22%) vs 14% (0-50%); adherence rate - 86% (42-91%) vs 80% (44-100%), respectively. Significant effects (p<0.05) of exercise compared to usual care were observed for quality of life (SMD: LC=0.31; CRC=0.21), aerobic fitness (SMD LC=0.54; CRC=0.57), strength (SMD: LC=0.59; CRC=0.39), depression (SMD: LC=0.49; CRC=0.35) and sleep (SMD: LC=0.31; CRC=0.66).
Conclusion: These results support the COSA statement which recommends embedding exercise as part of standard care for all cancers patients, including those associated with poor prognosis.