Serum levels of IGF-I and IGFBP-3 in patients with lung cancer during chemotherapy.

The aim of this study was to assess serum levels of insulin-like growth factors (IGF-I and IGFBP-3) in patients with lung cancer during chemotherapy. The study included 38 patients (33 males and 5 females; mean age 59.8) diagnosed histologically with lung cancer. Twenty-five patients (65%) had non-small cell lung cancer (NSCLC) and 13 patients (35%) had small cell lung cancer (SCLC). Squamous cell carcinoma was established in 30% (11 patients) of all patients with NSCLC, adenocarcinoma in 13% (5 patients), and non-small cell cancer in 36% (9 patients). The control group consisted of 10 healthy volunteers. Peripheral blood samples were taken before and after four cycles of chemotherapy. IGF-I and IGFBP-3 levels were assessed by ELISA method. Serum levels of IGF-I measured before chemotherapy were significantly higher in both NSCLC and SCLC groups in comparison with controls. No significant differences were observed in serum IGF-I levels before and after four cycles of chemotherapy. The levels were still high after chemotherapy in patients with NSCLC and SCLC. Serum levels of IGFBP-3 were markedly lower in patients with NSCLC both before and after treatment compared to controls. No significant differences were found in patients with NSCLC before and after cytoreduction treatment. Prior to treatment, serum IGFBP-3 levels were significantly lower in patients with SCLC in comparison with controls. After cytoreduction treatment, the levels were decreased when compared to controls but without statistical significance. In conclusion, both before and after chemotherapy serum levels of IGF-I were significantly higher, whereas IGFBP-3 levels were lower in patients with NSCLC and SCLC compared to controls. Chemotherapy had no influence on the serum levels of IGF-I and IGFBP-3. Neither a histological type of NSCLC nor clinical staging had any effect on the serum levels of IGF-I and IGFBP-3.