Baseline correlations and prognostic impact of serum monoclonal proteins in follicular lymphoma.

The presence of a serum monoclonal component has been associated with poor outcomes in some lymphomas. However, data in follicular lymphoma (FL) are scarce. We studied 311 FL patients diagnosed at a single institution, for whom information on serum immunofixation electrophoresis (sIFE) at diagnosis was available. Baseline characteristics and outcomes were compared between patients with a positive (+sIFE) and a negative sIFE (-sIFE). sIFE was positive in 82 patients (26%). Baseline features were comparable between both groups, except for an older age and higher proportion of elevated β2 -microglobulin levels in the +sIFE group. With a median follow-up of 4.6 years, a +sIFE was associated with a higher risk of early relapse (POD24, 27% vs. 15%, P = 0·02), shorter progression-free survival (PFS; 42% vs. 52% at 5 years, P = 0·008), and shorter overall survival (OS; 59% vs. 77% at 10 years, P = 0·046). In patients >60 years, a +sIFE was an independent predictor of OS [hazard ratio (HR) = 2·4, 95% confidence interval (CI): 1·2-5·0; P = 0·02]. Approximately one quarter of patients with FL has a +sIFE at diagnosis, which is a predictor of poor outcome. These findings encourage further investigation of its relationship with B-cell biology and the tumour microenvironment.