Patterns of delivery of chemoimmunotherapy to patients with follicular lymphoma in the United States: Results of the National LymphoCare Study

BACKGROUND Drug choice and delivered dose of treatment potentially influence outcome in patients treated for follicular lymphoma (FL). Historically, observational studies have evaluated drug choice. The National LymphoCare Study (NLCS) is a prospective, observational study of patients with FL who were enrolled at academic and community practice sites in the United States between 2004 and 2007. In the current study, the authors report on measures of delivered dose and its impact on outcomes for the most common first-line regimens. METHODS All evaluable patients with FL who were treated with initial rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP); rituximab plus cyclophosphamide, vincristine, and prednisone (R-CVP); or rituximab plus a fludarabine-containing regimen (R-Flu) were included. Associations between baseline factors, choice of treatment, number of cycles received, completion of therapy, and patient outcomes were assessed. RESULTS A total of 646 patients received R-CHOP, 297 received R-CVP, and 222 received R-Flu. Characteristics were similar between the 3 groups with the following exceptions. Patients receiving R-CHOP were more often found to have grade 3 FL and patients receiving R-CVP were older and had higher Follicular Lymphoma International Prognostic Index scores. The majority of patients (80%) received ≥ 5 cycles of treatment. Toxicity, but not disease progression, was commonly cited as the reason for the early discontinuation of treatment (51% vs 6%). Time to retreatment was shorter for patients receiving ≤ 4 cycles, regardless of the treatment regimen used. The number of cycles was associated with overall survival, progression-free survival, and lymphoma-related mortality for patients receiving R-CVP. CONCLUSIONS The majority of patients with FL receiving chemoimmunotherapy in the NLCS completed ≥ 5 cycles of treatment. Strategies to improve dose delivery appear unlikely to impact outcomes, except possibly in patients receiving R-CVP. Although early treatment discontinuation appears to be associated with survival, this analysis does not implicate causality.