Trends in bone metastasis treatments over recent decades and a historical comparison using the new Katagiri score system: future predictions based on pilot studies

Background In 2016, the Comprehensive Guidelines for the Diagnosis and Treatment of Bone Metastasis was published. Since then, the therapeutic outcomes for patients have gradually improved. As life expectancy is a major determinant of surgical intervention, the strategy should be modified if the prolongation of survival is to be achieved. Methods For advanced cancer patients with bone metastasis who visited the Department of Clinical Oncology at Akita University hospital between 2012 and 2023, parameters including the site and number of bone metastases, laboratory data, and survival time, were extracted from electronic medical records and the Katagiri score was calculated. The association with survival was determined for each factor. Results Data from 136 patients were obtained. The 1-year survival rate for the poor prognosis group with a higher Katagiri score was 20%, which was a significant improvement from 2014 when the scoring system was developed. Other factors significantly affecting survival included thoracic and lumbar metastases, five or more bone metastases, and treatment with chemotherapy and immune checkpoint inhibitors. Conclusions The 1-year survival rate in patients with a poorer score was improved. These patients may be candidates for surgery in the future. Finally, updating the scoring system is required.