Pretreatment levels of serum soluble interleukin-2 receptor are useful in selecting the treatment regimen for newly diagnosed advanced-stage follicular lymphoma with low tumor burden

High pre-treatment serum soluble interleukin-2 receptor (sIL-2R) levels are associated with poor overall survival (OS) of patients with newly diagnosed follicular lymphoma (FL). We evaluated the usefulness of pre-treatment sIL-2R levels in selecting a treatment regimen for advanced-stage FL with low tumor burden (FL-LTB). This retrospective, multicenter observational study enrolled consecutive patients who received a rituximab-containing regimen for newly diagnosed advanced stage FL-LTB (grade 1–3a) between 2008 and 2018. We applied a previously reported cut-off value of 1800 IU/mL for sIL-2R. A total of 211 patients were eligible for the analysis. Among patients with high sIL-2R (47 patients, 22.3%), the OS rates for patients treated by rituximab monotherapy (R-mono) (11 patients) were significantly lower than those treated by rituximab-combination chemotherapy (R-chemo) (36 patients): 5-year OS rates were 66.7% and 94.4%, respectively (P = 0.007). Among patients with low sIL-2R (164 patients, 77.7%), OS rates were comparably good between the R-mono group (34 patients) and the R-chemo group (130 patients): 5-year OS rates were 100% and 98.3%, respectively (P = 0.38). Our results suggest that R-chemo may yield better OS than R-mono for patients with newly diagnosed advanced-stage FL-LTB and high pre-treatment serum sIL-2R levels.