[History of the Japanese Society of Medical Oncology].

The Japanese Society of Medical Oncology(JSMO)was founded in 1993 by the Research Society of Clinical Oncology, the predecessor of the Society. Twenty years have passed since the transition to JSMO in 2003. During this time, JSMO has contributed to the establishment of the academic field of medical oncology in Japan for many years. On the other hand, over the last 20 years, cancer treatment by anti-cancer agents, which forms the basis of medical oncology, has made significant progress, prolonging the survival period of many advanced cancers. In the last 5 years in particular, there have been remarkable advances in the development and clinical introduction of immune checkpoint inhibitors, cancer molecular targeted agents based on genetic abnormalities, and cancer genomic medicine. Furthermore, in addition to conventional multidisciplinary treatment with surgery, radiology, and palliative medicine, collaboration with cancer-related interdisciplinary fields has become extremely important in recent years. For this reason, there is an increasing need for medical oncologists who specialize in organ(cancer type)cross-sectional treatment including cancer genomic medicine, and treat advanced cancer as a systemic disease as a specialist in internal medicine. In this article, we review the history of the Japanese Society of Medical Oncology and the history of medical oncology in Japan and look forward to the future of medical oncology.