Rituximab maintenance therapy of follicular lymphoma in clinical practice

Standard of care for patients with symptomatic, advanced‐stage follicular lymphoma (FL) is rituximab‐containing chemoimmunotherapy followed by rituximab maintenance. This prospective, multicenter, noninterventional study analyzed how efficacy and safety data from randomized controlled trials translate into clinical practice in Germany. Both treatment‐naïve and relapsed/refractory patients with FL, who responded to rituximab‐containing induction and were scheduled for rituximab maintenance, were observed for 24 months. Effectiveness was measured by response and Kaplan‐Meier survival analysis. In addition, treatment patterns of induction and maintenance, as well as adverse events, were documented. The evaluable study population consisted of 310 first‐line patients and 173 relapsed/refractory patients, including 116 patients with initial Ann‐Arbor stage I/II and 20 patients with FL grade 3B. Regarding first‐line induction, a shift from R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) to R‐bendamustine was observed over time, as well as a decline in radiotherapy. 2‐year progression‐free survival rates were 88.3% (95% confidence interval [CI] 84.0‐92.6) for first‐line patients and 76.0% (95% CI: 68.8‐83.3) for relapsed/refractory patients. Conversion from partial to complete remission (PR, CR) occurred in 53.4% of analyzed first‐line patients with PR, resulting in 69.4% CRs at study end (relapsed/refractory: conversion in 42.9%, final CRs 57.9%). Safety results were consistent with the known safety profile of rituximab in this setting. Both treatment‐naïve and relapsed/refractory patients with FL show favorable 2‐year PFS rates and improvements in the remission status with postinduction rituximab monotherapy as maintenance and consolidation therapy.

The anaplastic variant of centrocytic lymphoma is marked by frequent rearrangements of the bcl-1 gene and high proliferation indices

Ten cases of classic centrocytic lymphoma as defined in the Kiel classification system were investigated for their immunophenotype, their proliferation activity and by means of molecular diagnostics. The findings were compared to those obtained from a group of nine cases of anaplastic centrocytic lymphoma. Both groups showed virtually identical immunohistochemical characteristics with positivity for CD5 and negativity for CD10 and CD23. In the group of anaplastic centrocytic lymphoma, there were considerably higher proliferation indices as documented by staining for the Ki-67 antigen, up to 80% of the tumour cells being positive. Moreover, the cases of anaplastic centrocytic lymphoma had bcl-1 gene rearrangements in eight out of nine cases compared with three out of 10 cases of classic centrocytic lymphoma. DNA analysis was not able to detect bcl-2 gene rearrangement in any case, pointing to a difference compared with lymphomas of germinal centre origin. The coincidence of anaplastic and sometimes blast-like morphology of the tumour cells, high proliferation index and a rearranged bcl-1 gene in nearly all cases of anaplastic centrocytic lymphoma support their classification as high-grade malignant variants of centrocytic lymphoma and suggest a possible role for the bcl-1 locus not only in the origin but also in the progression of centrocytic lymphomas.