Soft-tissue sarcoma in Japan: National Cancer Registry-based analysis from 2016 to 2019.

Background: No previous reports have characterized national profiles of soft-tissue sarcoma overall. We examined the nationwide statistics for soft-tissue sarcoma in Japan using data from the population-based National Cancer Registry.

Methods: We identified 23 522 soft-tissue-sarcoma patients who were entered in the National Cancer Registry during 2016-19 using International Classification of Diseases-Oncology, Third Edition codes for cancer topography and morphology.

Rare cancers in Japan: definition, clinical features and future perspectives.

This review introduces the definition, epidemiology and therapeutic challenges of rare cancers and describes the establishment of the Rare Cancer Center at the National Cancer Center, Japan. Rare cancers are defined as malignant tumors with an incidence rate of less than 6 cases per 100 000 individuals. Due to their low incidence rate, medical treatment for rare cancers is more challenging than for more common cancer types.

[Sarcoma].

Challenges in the treatment of sarcoma as a rare cancer include(1)inexperience of sarcoma physicians due to the small number of patients,(2)insufficient information due to the lack of evidence,(3)lack of opportunities to provide information to non-specialists and to educate young physicians,(4)low adherence to standard treatments presented in clinical practice guidelines,(5)insufficient number of researchers engaged in basic research on rare cancers and their research funds, and(6) low number of clinical trials for the development of orphan drugs. This paper describes the current status and future prospects for the centralization and networking of sarcoma treatment, problems in pathological diagnosis, clinical evidence creation, information provision and human resource development, and information dissemination and consultation support to sarcoma patients.