Statistics of soft-tissue sarcoma in Japan: Report from the Bone and Soft Tissue Tumor Registry in Japan

Background: No previous reports to date have characterized the national profiles of soft-tissue sarcomas (STSs). In the present study, we reviewed current practice for STSs in Japan using data from a nationwide organ-specific cancer registry for bone and soft-tissue tumors in Japan, the Bone and Soft Tissue Tumor (BSTT) Registry. Methods: In the registry, we identified 8228 patients with STSs during the period 2006-2012, and extracted data on patient demographics, treatment, and outcome at the last follow-up for each patient. Disease-specific survival was analyzed using the Cox proportional hazards model. Results: STSs showed a slight male predilection. The age distribution had a single peak in the seventh decade, the proportion of elderly patients aged >60 years being approximately 53%. For most of the histologic subtypes, the most frequent tumor location was the lower extremity, whereas it was the trunk in patients with malignant peripheral nerve sheath tumor, dedifferentiated liposarcoma, and primitive neuroectodermal tumor. Based on data for 2432 patients with STSs, we found significant associations between disease-specific survival and age, sex, histologic subtype, tumor size, tumor depth, tumor location, additional surgery, limb salvage status, and surgical margin; elderly patients showed the poorest disease-specific survival. Conclusions: Using the BSTT Registry, this study has clarified the epidemiology, treatment, and prognosis of patients with STSs in Japan. Our experiences with the BSTT Registry will be of help to other countries where aging of the population is occurring. Continuous accumulation of clinical data in the BSTT Registry should provide more informative data on STSs, thus improving both the level of medical care offered by clinicians and the outcomes for patients through sharing of such data and promotion of clinical research. (C) 2017 The Authors. Published by Elsevier B.V. on behalf of The Japanese Orthopaedic Association.