Incidence and Risk of Secondary Malignancy in Patients with Waldenström Macroglobulinemia: A Population-Based Analysis.

Waldenström macroglobulinemia (WM) is a rare lymphoplasmacytic lymphoma which may predispose individuals to development of secondary malignancies (SMs). The Surveillance, Epidemiology, and End Results (SEER) database is a comprehensive registry of cancer patients in the United States reporting on a wide set of demographic variables. Using the SEER-18 dataset, analyzing patients from 2000 to 2018, we aimed to assess the incidence of SMs in WM patients. Patient characteristics such as gender, age, race, and latency were identified, and respective standardized incidence ratios (SIRs) and absolute excess risks (AERs) were calculated to compare to the general population. Of the 4,112 eligible WM patients identified, SMs were reported in 699 (17%) patients. The overall risk of developing SM, second primary malignancy, and secondary hematological malignancy was significantly higher in WM patients compared to the general population. Our findings show that WM patients had a 53% higher risk of SMs relative to the general population, and an AER of 102.69 per 10,000. Although the exact mechanism is unclear, the risk of SM development may be due to genetic predisposition, immune dysregulation, or treatment-induced immune suppression.