Patterns of therapy initiation during the first decade for patients with follicular lymphoma who were observed at diagnosis in the rituximab era.

Immediate treatment for asymptomatic, low-tumor burden follicular lymphoma (FL) has not shown an overall survival benefit over "watch and wait" (W/W) strategy. We estimated incidence of treatment initiation at specific time points and assessed its association with the presence of any criteria such as GELF, BNLI, GITMO at diagnosis. FL patients managed by W/W strategy were identified from the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic Lymphoma SPORE between 2002 and 2015. Cumulative incidence estimates of treatment initiation were calculated using transformation (as the first event) and death as competing risks. 401 FL patients were identified on W/W strategy. At a median follow-up of 8 years, 256 (64%) initiated treatment. For patients on the W/W strategy for 5 years, the likelihood of treatment initiation in the next 5 years was 12% compared to 43% at diagnosis unlike transformation rates which remained steady. Patients with any of popular treatment criteria at diagnosis did not have increased therapy initiation rates (44% vs. 42%) during the first 5 years or lymphoma-related death rates at 10 years (6% vs. 7%). Identifying biological differences in patients with early vs. late or no progression is a critical next step in understanding outcomes in W/W patients.