Due to the aging of the population, in 70% of cases, a new cancer diagnosis equals a cancer diagnosis in a geriatric patient. In this population, beyond the concept of mortality and morbidity, functional capacity, disability, and quality of life remain crucial. In fact, when the functional status is preserved, the pathogenetic curve towards disability will stop or even regress. The present systematic review investigated the effectiveness of physical exercise, as part of a holistic assessment of the patient, for preventing disability and improving the patient's quality of life, and partially reducing all-cause mortality. This evidence must point towards decentralization of care by implementing the development of rehabilitation programs for elderly cancer patients either before or after anticancer therapy.