Clinical features and outcomes of newly diagnosed follicular lymphoma concurrent with diffuse large B-cell lymphoma component

Abstract

Objective: To explore the clinical features and survival of newly diagnosed follicular lymphoma (FL) patients with diffuse large B-cell lymphoma (DLBCL) component. Methods: 1845 newly diagnosed FL patients aged ≥ 18 years with grades 1-3a in 11 medical centers in China from 2000 to 2020 were included, and patients with DLBCL component were screened. The clinical data and survival data of the patients were retrospectively analyzed, and the prognostic factors were screened by univariate and multivariate analysis. Results: 146 patients (7.9% ) with newly diagnosed FL had DLBCL component. The median age was 56 (25-83) years, 79 males (54.1% ) . The pathology of 127 patients showed the proportion of DLBCL component. Patients were divided into two groups according to whether the proportion of DLBCL component was ≥ 50% . The study found that patients with DLBCL component ≥ 50% had higher grade 3 ratio (94.3% vs 91.9% , P=0.010) , Ki-67 index ≥ 70% ratio (58.5% vs 32.9% , P=0.013) and PET-CT SUVmax ≥ 13 ratio (72.4% vs 46.3% , P=0.030) than patients with DLBCL component<50% . All patients received CHOP or CHOP like ± rituximab chemotherapy. The overall response rate (ORR) was 88.2% , and the complete response (CR) rate was 76.4% . In the groups with different proportions of DLBCL component, there was no significant difference in the remission rate after induction treatment and the incidence of disease progression within 2 years after initiation of treatment (POD24) (P<0.05) . The overall estimated 5-year progression free survival (PFS) rate was 58.9% , and the 5-year overall survival (OS) rate was 90.4% . The 5-year OS rate of POD24 patients was lower than that of non POD24 patients (70.3% vs 98.5% , P<0.001) . Compared with non maintenance treatment of rituximab, maintenance treatment of rituximab could not benefit the 5-year PFS rate (57.7% vs 58.8% , P=0.543) , and the 5-year OS rate had a benefit trend, but the difference was not statistically significant (100% vs 87.8% , P=0.082) . Multivariate analysis showed that failure to reach CR after induction treatment was an independent risk factor for PFS (P=0.006) , while LDH higher than normal was an independent risk factor for OS (P=0.031) . Conclusion: FL patients with DLBCL component ≥50% have more invasive clinical and pathological features. CHOP/CHOP like ± rituximab regimen can improve the clinical efficacy of patients. Rituximab maintenance therapy can not benefit the PFS and OS of patients. Failure to reach CR after induction therapy was the independent unfavorable factor for PFS.