Pretreatment serum soluble interleukin-2 receptor level predicts survival in patients with newly diagnosed follicular lymphoma

This retrospective, multicenter observational study investigated the prognostic value of pretreatment serum soluble interleukin-2 receptor (sIL-2R) level for outcomes of newly diagnosed follicular lymphoma (FL) grade 1-3a who required treatment at diagnosis. A total of 628 patients were recorded, and 502 of these were eligible for analysis. Patients were divided into four quartiles, based on their serum sIL-2R levels as follows: Q1 (sIL-2R < 520 IU/mL), Q2 (520 ≤ sIL-2R < 1030 IU/mL), Q3 (1030 ≤ sIL-2R < 2530 IU/mL) and Q4 (sIL-2R ≥ 2530 IU/mL). Using a multivariable Cox proportional-hazards model, we showed the adjusted probability of overall survival (OS) decreased with increasing serum sIL-2R levels (p for trend = .007). Similar trends were observed for disease-specific survival (DSS) and progression-free survival (PFS). In conclusion, pretreatment serum sIL-2R levels significantly and dose-dependently associate with worse outcomes (OS, DSS and PFS) of patients with newly diagnosed FL.