Risk of second cancers in Waldenström macroglobulinemia

Background: An increased incidence of second cancers has been reported in lymphoproliferative disorders. Patients and methods: We assessed the frequency, characteristics and predictive factors of second cancers in 230 patients with Waldenström macroglobulinemia (WM) and compared the incidence of second cancers in WM with that of an age- and sex-matched control population. Results: Twenty-two patients (10%) developed solid cancers and 10 (4%) second hematologic malignancies. In a competing risk model, the cumulative incidence of solid cancers was 12% at 10 years and 17% at 15 years while the incidence of hematologic malignancies was 6% and 8%, respectively. The overall risk of second cancer in WM was 1.69 times higher than expected (P = 0.002). WM patients were at increased risk for diffuse large B-cell lymphoma [standardized incidence ratio (SIR) 9.24, P <0.0001], myelodisplastic syndrome/acute myeloid leukemia (SIR 8.4, P <0.0001), brain cancer (SIR 8.05, P = 0.0004). The risk of a second hematologic malignancy was fourfold higher in patients previously treated, though not reaching statistical significance (P = 0.19). Conclusions: WM patients are at higher risk of second cancers as compared with the general population. The sample size does not allow firm conclusions about the effect of therapy on the development of second cancers.