Causes of Death Among Waldenström Macroglobulinemia Patients: A Population-Based Study.

Background: Waldenström macroglobulinemia (WM) is a rare, indolent lymphoma, and death from non-WM causes has become increasingly important in treatment decisions. This study explored the causes of death in WM patients.

Methods: The data from 8894 patients diagnosed with WM in the Surveillance, Epidemiology, and End Results (SEER) database from 1980 to 2016 were included. Standardized mortality ratios (SMRs) were used to assess the relative risk of death compared with that of the general US population.

Results: Considering other competing events, the 5-year cumulative incidences of death from the index cancer, SMNs and noncancer causes were 8.6% (SD: 1.00e-05), 10.02% (SD: 1.17e-05) and 16.14% (SD: 1.79e-05), respectively, among WM patients. WM patients had the highest SMR for index cancer-related death, at 121.84 (95% CI, 103.8-142.11) in the first year after diagnosis, which declined thereafter. Among nonindex cancer-related deaths, hematological malignancy-related deaths were notably increased, whereas solid neoplasm deaths were elevated only 10 years after diagnosis (SMR, 1.43; 95% CI, 1.06-1.9). Among noncancer causes of death, infection, particularly among patients <50 years old, had the highest SMR (SMR, 19.01; 95% CI, 10.12-32.5). There were decreasing trends in the SMRs of index cancer-related deaths, all nonindex cancer-related deaths and many noncancer disease-related deaths from 1980 to 2001 and 2002 to 2016.

Conclusions: Currently, the risk of noncancer-related deaths (mainly cardiovascular disease-related deaths) exceeds that of cancer-related deaths among WM patients. These findings may provide improved guidance regarding future health risks for WM patients.