Colorectal cancer is the second leading cause of cancer mortality in Western countries after breast cancer among women and lung cancer among men. About 5.000 new cases are diagnosed each year in Austria. This represents an annual incidence of 50-60 per 100.000 inhabitants. In patients with colorectal cancer stage III and in certain situations even in stage II adjuvant chemotherapy is indicated after R0 resection. Despite recent advances in adjuvant chemotherapy 20-30% of these patients still relapse. About 80% of recurrences occur in the first three years.~There is consistent evidence from several observational epidemiologic studies that physical activity reduces the risk of developing colon cancer. In recent years several observational studies even showed a reduction in relapse rate, colon cancer-specific mortality and overall mortality by physical activity in patients with colon and breast cancer. Colon cancer survivors who engaged in higher levels of physical activity experienced a 50-60% improvement in long-term outcomes compared to inactive patients. Different mechanisms for the protective effect of physical activity on colon cancer have been proposed and it is believed that the same mechanisms of physical activity are also involved in the improvement of disease outcomes in gastrointestinal cancer survivors. Physical activity leads to decrease of inflammation, decreased levels of insulin-like growth factor (IGF) and insulin, reduced transit time through the gut and increased levels of vitamin D. Factors, that are associated with a reduced risk of colon polyps, colon cancer and colon cancer mortality.~A review on the impact of various exercise programs on fatigue, found good evidence that exercise not only decreased levels of fatigue, but also increased quality of life, mood and functioning.~While there is evidence supporting the beneficial effects of exercise programs during chemotherapy, the results across studies are not entirely consistent. Additional studies are needed to determine the optimal content, intensity, and form of training programs.~Recently ABCSG has investigated the feasibility of endurance exercise after adjuvant chemotherapy in patients with locally advanced colorectal cancer in the investigator's study group (ABCSG C07 Exercise - pilot study). Results concerning compliance of patients have been considered for sample size estimations and study planning.
ABCSG C08 is a randomized, two-arm, multicenter trial to investigate the efficacy of endurance exercise following adjuvant chemotherapy in patients with colorectal cancer.~Indication: Locally advanced colorectal cancer after adjuvant chemotherapy. Evidence supporting the beneficial effects of exercise programs during chemotherapy are available, the results across studies are not entirely consistent. Additional studies are needed to determine the optimal content, intensity, and form of training programs.