Incidence of Skeletal-Related Events Among Multiple Myeloma Patients: A Nationwide Population-Based Cohort Study

Background: Multiple myeloma (MM) patients are at high risk of skeletal-related events (SREs), including spinal cord compression, pathologic fractures, surgery to bone, and radiation to bone. Given the limited data on the real-world incidence of SREs in MM, we performed a large-scale, retrospective, nationwide, cohort study.

Methods: The population data were extracted from the Health Insurance Review and Assessment Service (HIRA) of Korea database from January 1, 2007 to Dec 31, 2018. HIRA databases include patient demographic information, diagnoses, procedures, and prescriptions obtained from inpatient and outpatient records of approximately 50 million Koreans. Patients identified were aged ≥ 19 years and newly diagnosed with MM (ICD-10: C90.00), had received anti-MM therapy, and had at least 1 year of follow-up after MM diagnosis.

Results: 6,717 patients were included, 43.9% of whom had a baseline history of any SRE. During a median follow-up of 35.1 months, 43.6% of patients experienced SREs after diagnosis. Median time to SRE was 9.6 months (IQR, 1.2-25.8). The median time to first SRE was 3.0 months for patients who had a history of any SRE and 19.8 months for patients who did not have a history. Among patients experiencing an SRE, 55.0% had an SRE within the first year. Among the patients with SREs, 51.1% had 3 or more SREs. The proportion of patients with spinal cord compression, pathologic fracture, radiation to bone, and surgery to bone during follow-up were 0.6%, 33.4%, 7.9%, and 1.6%, respectively. A total of 2,838 (42.3%) of patients received a bone-targeting agent (BTA) during the follow-up period. Pamidronate was the predominant BTA (80.9% of patients received ≥1 administration). The median time from MM diagnosis until first BTA was 313 days (IQR, 30-1075).

Conclusions: This population-based study is the first to describe incidence of SREs for MM in Korea, and the findings can be used to assess the actual bone health status of MM patients.

No relevant conflicts of interest to declare.