Alderuccio JP, et al. - In patients with marginal zone lymphoma (MZL), researchers investigated risk factors for higher-grade transformation (HGT) and its impact on overall survival (OS). The factors that were identified to be the main predictors of increased risk of HGT included failure to achieve complete remission (CR) following initial treatment, elevated lactate dehydrogenase, and more than four nodal sites at the time of MZL diagnosis. Shorter OS was seen in patients with HGT.

Methods

• A total of 453 patients with biopsy-proven MZL from the researchers' institution between 1995 and 2016 were analyzed.
• Analyses of time-to-event outcomes were performed by using Kaplan-Meier, Cox proportional hazards regression, and competing risk methods.

Results

• Biopsy-proven HGT to diffuse large B-cell lymphoma was seen in 34 patients (7.5%), including seven (21%) diagnosed at the time of initial MZL diagnosis.
• The observed median time to HGT was 29 months (range, 1.3 to 135 months) among 27 incident patients.
• Those with nodal/splenic MZL had a higher risk of HGT (subdistribution hazard ratio [SHR], 2.60; P=.023).
• Risk factors for a significantly higher risk for HGT (P < .02) included elevated lactate dehydrogenase (SHR, 2.71), more than four nodal sites (SHR, 2.97), and failure to achieve complete remission (CR) after initial treatment (SHR, 3.76), as identified in multivariable competing risk analysis.
• The only significant predictors of HGT univariably included International Prognostic Index (IPI), Follicular Lymphoma IPI, and Mucosa-Associated Lymphoid Tissue Lymphoma IPI.
• Shorter OS (5-year rate, 65% v 86%; P < .001) was observed in patients with HGT.
• Findings showed shorter OS among patients who presented with HGT within 12 months of MZL diagnosis vs those with HGT at MZL diagnosis combined with those with HGT more than 12 months later (4-year rate, 43% v 81%, P < .001).
• Primary significant predictors for shorter progression-free survival and OS were non-CR and higher scores of IPI, Follicular Lymphoma IPI, and Mucosa-Associated Lymphoid Tissue Lymphoma IPI.