Bone-targeting agent utilization among lung cancer patients with bone metastasis in Taiwan.

Abstract

e24111 Background: Bone is a common metastatic site among patients with advanced lung cancer. With new treatments available to improve survival of lung cancer and in all likelihood to change the natural history of disease, the diagnosis and management of bone metastasis (BM) may be of increasing clinical relevance. This study aimed to describe the management of BM using bone targeting agents (BTA) among lung cancer patients in Taiwan. Methods: A retrospective cohort of lung cancer patients with BM from 2004 through 2016 was identified using Taiwan National Health Insurance (NHI) data and Taiwan Cancer Registry. Diagnosis codes of International Classification of Disease 9th revision (ICD-9: 198.5) and ICD-10 (C79.51 and C78.03) were used to define BM. Patients were followed from the time of BM diagnosis till death or the end of study period (2017/12/31). We ascertained demographic information and BTA use among these patients. Two classes of BTAs were included: bisphosphonates (zoledronic acid (ZA), pamidronate, and clodronate) and denosumab. Results: A total of 44,800 patients with lung cancer and incident BM diagnosis were identified during the study period. Median age at the time of BM diagnosis was 67 years (25th and 75th percentile: 57-76), with 58.2% male (n = 26,058). The annual number of lung cancer patients with incident BM increased from 2,814 in 2004 to 3,829 in 2016, while the proportion of these patients receiving any BTA during the follow-up ranged from 25.2% to 34.8% annually. Clodronate and pamidronate were the common BTA prescriptions, whereas denosumab became the most frequently prescribed BTA after reimbursement by NHI since 2015. Among patients who initiated BTA after BM diagnosis (n = 10,879), the median time from BM diagnosis to BTA initiation ranged from 31 to 152 days by initial BTA type. More than half of them received more than one dose (56.3%, n = 6,126), with median numbers of doses received as 3, 4, 6 and 6 for ZA, pamidronate, clodronate and denosumab, respectively. Conclusions: A large population of patients with lung cancer were diagnosed with BM every year. However, overall, we observed only a small proportion of eligible patients receiving a BTA and a delayed initiation of BTA, indicating suboptimal treatment for lung cancer patients with BM in Taiwan.[Table: see text]