A real-world retrospective analysis found old age, low platelet count, low albumin, high β-2 microglobulin, high lactate dehydrogenase (LDH), and secondary amyloidosis were associated with worse prognosis in patients with Waldenstrom macroglobulinemia (WM).
The researchers, led by Xin-xin Cao, MD, of the Chinese Academy of Medical Sciences and Peking Union Medical College in Beijing, retrospectively evaluated outcomes in 1,141 patients with WM who were treated across 35 academic hospitals in China between 2003 and 2019. Patient data were obtained from the database of the China WM Registration.
Approximately 72.7% of patients in the study were male. Overall, the median age at time of WM diagnosis was 64 years, with 41.4% of patients older than 65 years.
A total of 75 (10.2%) out of 734 patients with documented treatment information received monotherapy. These treatments included chlorambucil (3.1%), ibrutinib (2.9%), and rituximab (2.5%).
Up to 36% of patients received chemoimmunotherapy, whereas 53.8% received other combination treatments. The most frequently used chemoimmunotherapies were rituximab, cyclophosphamide, and dexamethasone or prednisone (10.8%). Additionally, combination regimens included bortezomib-based strategies (18.6%), fludarabine and cyclophosphamide (10.6%), CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone; 9.3%), immunomodulatory drug-based regimens (5.7%), as well as chlorambucil plus prednisone (4.4%).
After a 23-month median follow-up period, 123 patients died. Patients had an estimated five-year overall survival (OS) rate of 74.9%. No difference was observed between treatment strategies in terms of the median OS.
In a multivariate Cox regression model, baseline prognostic factors of shortened OS included age 65 years and older (hazard ratio [HR], 0.622; 95% confidence interval [CI], 0.431-0.898; P=0.011), platelet <100×109/L (HR, 0.570; 95% CI, 0.381-0.853; P=0.006), serum albumin <3.5 g/dL (HR, 0.582; 95% CI, 0.369-0.918; P=0.020), β-2 microglobulin concentration ≥4 mg/L (HR, 0.630; 95% CI, 0.429-0.926; P=0.019), LDH ≥250 IU/L (HR, 0.538; 95% CI, 0.326-0.890; P=0.016), and secondary amyloidosis (HR, 0.277; 95% CI, 0.137-0.562; P<0.001).
The researchers noted that these “findings may provide guidance for management of WM and better prognostic stratification of risk-adapted treatment strategies.”