High Level of Serum Soluble Interleukin-2 Receptor Is Associated With Poor Survival in Patients With First Relapsed or Refractory Peripheral T-Cell Lymphoma, Not Otherwise Specified: A Retrospective Study

Abstract

BackgroundPatients with relapsed or refractory peripheral T-cell lymphoma, not otherwise specified (R/R-PTCL-NOS) usually have short survival with conventional salvage chemotherapies. Prediction of poor survival in patients who undergo conventional salvage chemotherapies might help identify candidates for novel therapies that have been recently available for R/R-PTCL-NOS. However, no prognostic marker other than the second-line International Prognostic Index (sIPI) has been reported. We aimed to investigate the prognostic value of serum soluble interleukin-2 receptor (sIL-2R) level in patients with R/R-PTCL-NOS. Patients and MethodsWe retrospectively analyzed 37 patients with R/R-PTCL-NOS who underwent salvage chemotherapy. Serum sIL-2R level was measured within a week before salvage chemotherapy initiation. We determined the cutoff level of serum sIL-2R as 4.03 times the upper limit of normal by using receiver operating characteristic curve analysis. ResultsThe 3-year overall survival (3yOS) was 5.2% and 37.5% in high sIL-2R and low sIL-2R groups, respectively (P = .005). In multivariate analysis, high sIL-2R level was independently associated with lower 3yOS (hazard ratio, 2.30; 95% confidence interval, 1.04-5.11; P = .040). In subgroup analysis, high sIL-2R level did not affect 3yOS in patients with high-risk sIPI (NA [not available] vs. 7.1%; P = .354), but was significantly associated with poor 3yOS in patients with low-risk sIPI (NA vs. 60.0%; P = .037). ConclusionSerum sIL-2R is a useful prognostic marker for patients with R/R-PTCL-NOS. In particular, high sIL-2R level can identify groups of patients with low-risk sIPI who have poor prognosis. Our results suggest that novel therapeutic approaches might be necessary for patients with high-risk sIPI and/or high sIL-2R level.