Hiromichi Yamane, Toshiyuki Kunisada, Toshifumi Ozaki, Nobuaki Ochi, Yoshihiro Honda, Yasunari Nagasaki, Nozomu Nakagawa, Tomoko Yamagishi, Hidekazu Nakanishi, Nagio Takigawa

"Rare cancer" is defined as malignancy with a disease prevalence (age-adjusted incidence rate) of less than six per 100,000 population. Proper treatments which these patients need cannot always be performed unless they find dedicated facilities. Patients tend to be desperate, searching for advice and care. Thus, they are called "cancer refugees". Osteosarcoma and soft tissue sarcoma (OS/STS) are representative rare cancers in Japan. We conducted a retrospective analysis of patients with OS/STS to improve the current treatment modalities in a Japanese regional city. Twenty-one patients with OS/STS who were hospitalized to receive standard chemotherapy or palliative treatment were enrolled between October 2011 and January 2017. Patients with non-Hodgkin's lymphoma (NHL) and advanced cancer who were treated in the palliative care unit (PCU) of the Kawasaki Medical School General Medical Center were recruited as the control groups. We analyzed the difference in residential area between patients with OS/STS and the control groups. Approximately one-third of patients with OS/STS were referred from hospitals outside of Okayama prefecture. The ratio of patients with OS/STS referred from Okayama city and/or the same medical administration area of Okayama prefecture was lower than that of patients with NHL and advanced cancer who were treated in the PCU. Because the medical environment of patients with OS/STS in Japanese local cities has not been consolidated, completing medical care within the patient's own medical administration area is difficult. Thus, some patients with OS/STS may become "cancer refugees" who are unable to receive standard therapy near their residence.