ORLANDO, Fla.Patients with follicular lymphoma, grade 3 (FL-3), are generally excluded from trials of diffuse large B-cell lymphoma (DLBCL) and often from studies evaluating treatment of FL as well. For that reason, little is known about the outcome of patients with FL-3.

Now, a retrospective study has found that patients with FL-3 treated with aggressive chemotherapy regimens have improved outcomes when rituximab is added to the therapy. In fact, in the “rituximab era,” the outcome of patients with FL-3 is comparable to DLBCL, a population that also benefits from treatment with rituximab and chemotherapy, reported Philip J. Bierman, MD, University of Nebraska Medical Center, Omaha, Neb., and colleagues.

The investigators analyzed the Nebraska Lymphoma Study Group database and identified patients with FL-3 treated with aggressive combination chemotherapy regimens with and without rituximab. Progression-free survival (PFS) and overall survival (OS) of these patients were compared with PFS and OS of patients with DLBCL who were treated with similar aggressive chemotherapy regimens combined with rituximab. Patients who were not treated with anthracycline-containing or mitoxantrone-containing regimens were excluded from analysis, Dr. Bierman told those attending the 52nd American Society of Hematology Annual Meeting and Exposition.

Between February 1999 and January 2009, 60 patients with FL-3 treated with aggressive chemotherapy regimens combined with rituximab were identified. Median age was 56 years (range, 37-87); 45% were male. Performance status was 0-1 in 80%; LDH was elevated in 15%; 68% had stage 3-4 disease; and 13% had at least 2 sites of extranodal disease. Fifteen patients (25%) had bulky disease (≥5 cm) at diagnosis. Results of treatment for these patients were compared with those of 144 patients with FL-3 treated with aggressive chemotherapy regimens without rituximab between June 1983 and January 1999, and to results for 341 patients with DLBCL who were treated with aggressive chemotherapy regimens combined with rituximab between September 1996 and January 2009. Treatment outcomes for these 3 groups of patients are summarized in Table 1. Please click here for more study data.

A multivariate analysis (accounting for older patients, and more patients with elevated LDH, extranodal disease, and bulky disease in the DLBCL group) revealed that patients with FL-3 who were not treated with rituximab had a significantly higher risk of disease progression or death (RR 1.75; P=0.02). There were no significant differences in PFS when comparing patients with FL-3 and those with DLBCL who were treated with aggressive chemotherapy regimens and rituximab.

Patients with FL-3 treated without rituximab had inferior OS when compared with those treated with rituximab (RR 1.58), although this difference was not significant (P=0.16). The multivariate analysis also revealed no significant differences in OS when patients with FL-3 who received rituximab were compared with similarly treated patients with DLBCL (P=0.50).