Incidence, Prevalence, Mortality, and Causes of Death in Waldenström Macroglobulinemia in South Korea: A Nationwide, Population-Based Study

Backgroud: Studies investigating the epidemiology of Waldenström macroglobulinemia (WM) in Asia are scarce. The aim of this study was to provide the epidemiological and clinical features of WM in South Korea at a national level, including incidence, prevalence, mortality, survival with competing risks, and causes of death.

Methods: We used a national, population-based database maintained by the Health Insurance Review and Assessment Service, which includes information on all WM patients, diagnosed based on uniform criteria from 2003 to 2016.

Results: The total number of patients newly diagnosed with WM was 429 during study period with a female to-male ratio of 3.2. The incidence from 2003 to 2016 increased from 0.03 to 0.11 per 10⁵, and the prevalence in 2016 was 0.42 per 10⁵. A total of 217 WM patients died during the study period (standardized mortality ratio =22.07) and the overall survival (OS) of WM patients was 47.5%. In the multivariate analysis, a significant factor associated with a worse OS was older age, whereas stem cell transplantation showed a better outcome (hazard ratio = 0.163; P = 0.0109). WM was the most common cause of death (n = 173; 79.7%), followed by other malignant neoplasms (n= 21; 9.7%).

Conclusions: The national incidence of WM in Korea, a racially homogeneous country of Asia, was lower than that in previous reports from other countries, reflecting ethnic disparities. However, the incidence increased and mortality was the highest ever reported. The main cause of death was WM itself and stem cell transplantation was considerably effective. This study reflects the need for greater awareness of WM, particularly in Asian countries.