Inflammatory Phenotype Does Not Appear to Impact Survival, Disease Transformation in Waldenstrom Macroglobulinemia

Patients with Waldenstrom macroglobulinemia (WM) who present with characteristics suggestive of a concomitant inflammatory syndrome do not differ from patients with non-inflammatory WM in terms of response to treatment, progression-free survival (PFS), transformation to diffuse large B-cell lymphoma (DLBCL), or even overall survival (OS). This is according to a study presented at the 62nd American Society of Hematology Annual Meeting & Exposition by lead study author Dikelele Elessa, MD, of the Hôpitaux de Paris in France.

The study was a retrospective analysis that included 242 patients with WM who were followed at a single hospital in France between 2007 and 2018. Dr. Elessa and colleagues identified 67 patients who had an inflammatory phenotype characterized by elevated C-reactive protein (CRP), among other factors. Another nine patients were determined to have an inflammatory syndrome of unknown origin.

At the time of treatment initiation, the median age of the study cohort was 69 years. The median CRP was 40.5mg/L, which correlated with fibrinogen (95% confidence interval [CI], 0.18-0.76; P=0.006) and inversely correlated with albuminemia (P<0.001).

Inflammatory syndrome represented an indication for front-line therapy in 40% (n=20) of patients. A total of 62 patients were treated, with 60% of patients receiving rituximab-based therapy and 39% receiving monotherapy. The overall response rate was 84%. There was a significant association between inflammatory and hematological response (odds ratio, 13.8; 95% CI, 2.07-74.6; P=0.005).

Over a median follow-up of 12.6 years, the median PFS following front-line therapy was 32 months. The estimated PFS in this population was 68% (95% CI, 55-78) at 10 months, 59% (95% CI, 46-70) at 20 months, and 30% (95% CI, 19-42) at five years.

There was no difference between patients with versus without the inflammatory phenotype in terms of the median OS (14.0 vs. 16.4 years, respectively; P=0.71). At five years, the estimated OS in patients with the inflammatory phenotype was 85% (95% CI, 71-93) versus 84% (95% CI, 75-90) in patients without an inflammatory phenotype. Overall, three patients received a secondary diagnosis of DLBCL.

“Studying medullary cytokine environment, WM cells, tumoral microenvironment, and M paraprotein contributions could elucidate the underlying pathophysiological mechanisms involved,” the researchers concluded.