Role of physical activity and sport in oncology: scientific commission of the National Federation Sport and Cancer CAMI.

This overview reports published data about the interaction between physical activity and sport during and after cancer on one hand and improvement in psychological parameters, survival and biological mechanisms underlying this effect on the other hand. Practising physical activity and sport during cancer modifies parameters assessing fatigue and quality of life and reduces symptoms of depression. An association also exists between the practise of physical activity and sport and overall and cancer-specific survivals, especially after breast cancer, colon cancer and prostate cancer. These benefits seem to be mediated by a modification of circulating levels of estrogens, insulin, IGF-1 and by a decrease in insulin-resistance, by alterations in the secretion of adipokines, and by a reduction in chronic inflammation through decreased levels of cytokines. There exist some obstacles to the practise of physical activity. These obstacles are mainly related to a fear of pain induced by physical activity and to overweight. These programmes of physical activity and sport cannot be offered to all patients since there are several contra-indications, with some being present since the initial visit and others appearing during cancer management either due to disease progression or related to iatrogenic effects. Whereas benefits from physical activity and sport among cancer patients seem obvious, there are still several pending clinical and biological issues.