Abstract: Objective To investigate the expression and clinical significance of IGFBP4 and PAPPA in patients with non-small cell lung cancer（NSCLC）. Methods Total RNA was extracted from 55 pairs of NSCLC tissues and adjacent noncancerous tissues.IGFBP4 and PAPPA expression was detected using real-time quantitative RT-PCR. Results IGFBP4 expression was significantly lower in NSCLC tissue than in adjacent lung tissue，but significantly higher than in normal lung tissue（P<0.05）.IGFBP4 expression was significantly higher in squamous carcinoma tissues than in adenocarcinoma.Furthermore，survival was longer in patients with high IGFBP4 expression than in those with low expression（P<0.05）.However，IGFBP4 expression did not correlate with age，gender，histological dif-ferentiation grade or lymph node metastasis.PAPPA expression was significantly higher in NSCLC tissue than in adjacent or normal lung tissue（P<0.05）.PAPPA expression was higher in cases of adenocarcinoma or lymph node metastasis than in cases of squamous carcinoma or cases without lymph node metastasis（P<0.05）.Survival was shorter in patients expressing high levels of PAPPA than in those expressing low levels（P<0.05）.However，PAPPA expression was not related with age，sex or clinical stage.There was a signifi-cant positive correlation between IGFBP4 and PAPPA expression in NSCLC tissues（r=0.512，P=0.000）. Conclusions IGFBP4 and PAPPA may correlate with tumor growth in NSCLC，and may be useful as molecular prognostic indicators of NSCLC.

Key words:  Lung neoplasms, Non-small cell lung cancer, IGFBP4, PAPPA, Real-time quantitative RT-PCR