Soluble interleukin 2 receptor (sIL2R) in monitoring advanced lung cancer during chemotherapy

To evaluate the usefulness of measuring sIL2R for diagnostic and prognostic purposes and for monitoring disease during a 6-month period of chemotherapy, and to investigate the clinical significance of sIL2R serum concentrations.

The serum concentration of sIL2R, TPA and lymphocyte subsets CD4, CD8, CD25, CD16 were measured at diagnosis and then 1 and 6 months after the start of chemotherapy.

There were 39 patients (three females, 36 males; mean age 61.6 years) with lung cancer (LC), treated with chemotherapy and 22 control subjects (six females, 16 males; mean age 50.1 years) with non-neoplastic lung diseases.

No significant differences in sIL2R serum concentrations were observed at diagnosis between the control and LC group or when comparing the different histotypes, disease stages (IIIa-b vs IV) and survival (survival < or = 12 vs > 12 months). On comparing the sequential variations of the examined parameters a significant increase in sIL2R (P < 0.007) after 1 and 6 months versus basal value was observed only in patients surviving less than 12 months and in those who did not respond to chemotherapy. Moreover a negative correlation was observed between sIL2R serum concentrations and CD25+ and CD16+ lymphocyte subsets. Evaluation of survival curves of patients with basal sIL2R > or < or = 700 U/ml showed a slightly lower survival rate in the former group.

The present results, confirming the poor utility of sIL2R in the diagnostic phase of the disease, show its usefulness in prognostic evaluation and in the clinical surveillance of patients with advanced lung cancer submitted to polychemotherapy. In this case any variations in sIL2R serum levels are likely to relate to the spread of the neoplasia rather than to the host immune response.