Recent Trends in Bone Metastasis Treatments: A Historical Comparison Using the New Katagiri Score System

BACKGROUND Bone metastasis has various negative impacts. Activities of daily living (ADL) and quality of life (QOL) can be significantly decreased, survival may be impacted, and medical expenses may increase. It is estimated that at least 5% cancer patients might be suffering from bone metastases. In 2016, we published the Comprehensive Guidelines for the Diagnosis and Treatment of Bone Metastasis. 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. AIM To monitor how bone metastasis treatment has changed before and after launch of our guidelines for bone metastasis. 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 20.0% in this study, which was 6% and an apparent improvement from 2014 when the scoring system was developed. Other factors significantly affecting survival included five or more bone metastases than less (P = 0.0080), and treatment with chemotherapy (P < 0.001), bone modifying agents (P = 0.0175) and immune checkpoint inhibitors (P = 0.0128). In recent years, advances in various treatment methods have extended the survival period for patients with advanced cancer. It is necessary not only to simply extend survival time, but also to maintain ADL and improve QOL. CONCLUSION Various therapeutic interventions including surgical approach for bone metastasis, which is a disorder of locomotor organs, are increasingly required. Guidelines and scoring system for prognosis need to be revised promptly.