In Japan, the population aged 65 and over accounts for 29% of the total population, and the number of elderly cancer patients is increasing. Geriatric oncology is an academic area that considers the characteristics of the elderly and provides appropriate cancer care. The International Society of Geriatric Oncology considers education, medical care, research, and partnership formation as priority areas and has set them as policy goals. In Japan, the content related to”cancer in the elderly”has been added to the 3rd-term Basic Plan to Promote Cancer Control Programs, aiming to formulate cancer treatment guidelines for the elderly. So far, the”Guidelines for Cancer Chemotherapy for the Elderly”have been published. With the aging of the population, social security costs will increase significantly after 2022, when the baby boomer generation will be 75 years old. Currently, reforms of social security systems such as pensions, medical care, and long-term care are underway. In order to promote geriatric oncology, it is important to enhance cooperation between oncology and geriatrics and to support the cooperation system between families and medical staff. In Japan, where the working-age population and the total population have begun to decline, we are facing many challenges. The experience of Japan, a top runner in a super- aged society, has the potential to be shared on a global scale and should be addressed from a long-term perspective.