Cancer is largely a disease of older people; the median age for cancer diagnosis in industrialised countries is approaching 70 years of age and is expected to increase. The morbidity and mortality rates of various tumors increase with age, and thus, malignant tumors are generally defined as aging diseases. The immune system has an ambiguous role in cancer, as it plays an important immune surveillance role in the antitumor response but is also closely associated with the initiation and progression of tumors. With aging we assist to the erosion of the immune response called immunosenescence. This deregulation particularly affects the T cell compartment of the adaptive immune response. In addition to the accumulation of genetic mutations, many researchers believe that immunosenescence may also play an important role in the tumoral process. In the future, targeting immune senescent cells may be a novel interventional opportunity in cancer patients.