The serum levels of soluble interleukin-2 receptor α and lactate dehydrogenase but not of B2-microglobulin correlate with selected clinico-pathological prognostic factors and response to therapy in childhood soft tissue sarcomas

The objective of this study is to establish the clinical utility of serum soluble IL-2 receptor (sIL-2R alpha) and B2-Microglobulin (B2-M) as markers for diagnosis, prognosis and treatment monitoring in childhood soft tissue sarcomas (STS). sIL-2R alpha and B2-M were measured prospectively before treatment, in complete remission (CR) during and after therapy and at relapse by ELISA in 35 children with STS and in 50 healthy controls (once). The sIL-2R alpha correlated with age thus it was presented as multiplication of the upper normal range for age. Pre-treatment level of sIL-2R alpha but not of B2-M exceeded significantly that of healthy children. SIL-2R alpha levels were significantly increased in patients with advanced stages, poor-risk histology and non-responders. Patients' age > 10 years, unfavourable tumour localisation and incomplete resection were not accompanied by the increase of any marker. Good response to chemotherapy was paralleled by a decline of sIL-2R alpha pre-treatment level (P < 0.001). None of the markers predicted event-free and overall survival. At relapse, sIL-2R alpha increased; however; it was not statistically different from the level stated in remission. Monitoring of B2-M during therapy did not reflect the disease course. After completion of therapy the levels of sIL-2R alpha and B2-M were significantly lower than during treatment, but still higher than in controls. sIL-2R alpha was proven to be a promising marker for diagnosis and treatment monitoring in children with STS. It correlated also with some clinical variables known to have important prognostic role (STS stage, histological subtype and response to therapy); however, it failed to predict EFS and OS. To the contrary, B2-M proved to have no clinical value in the diagnostics, prognostics and treatment monitoring in paediatric STS.