[Interleukin 3 (IL-3) in diagnosis and monitoring of non-small-cell lung cancer].

Several circulating tumour markers for non-small-cell lung cancer (NSCLC) have been identified. Recent studies have focused on a new family of markers--hematopoietic growth factors. Some clinical investigations have shown cell surface receptors for interleukin 3 (IL-3) in lung cancer cells and autologous production of IL-3 in various human cell lines derived from NSCLC. The purpose of this investigation was to compare serum levels of IL-3 in non-small-cell lung cancer with a control group, to assess pre- and post treatment levels of IL-3 in relation to levels of commonly accepted tumour markers such as carcino-embryonic antigen (CEA) and cytokeratin fragment 19 (CYFRA 21-1), and to define the diagnostic sensitivity and specificity of IL-3 in NSCLC. In this study, the serum level of tumour markers was measured in 34 patients with NSCLC and in 20 healthy subjects. Serum samples were drawn before surgery and 10, 30, 90, 180 and 270 days after surgery. IL-3 and CEA were assayed using ELISA system and CYFRA 21-1 was measured by radioimmunoassay (RIA). Preoperative level of IL-3 was significantly increased in cancer patients relative to the control group. Concentrations of tumour markers were decreased after surgery and then increased (IL-3 and CEA) during chemio- or radiotherapy. The diagnostic sensitivity of IL-3 was 44% and the diagnostic specificity--85%. This investigation is one of the first studies assessing serum levels of IL-3 in the cancer patients. These results suggest that IL-3 may be useful in diagnostics of NSCLC, but this subject needs further studies.