Original Article


Elevated Circulating Levels of Osteopontin Are Associated with Metastasis in Advanced Non-Small Cell Lung Cancer

Yong Liang, Hui Li, Bin Hu, Xing Chen, Jin-bai Miao, Tong Li, Bin You, Qi-rui Chen, Yi-li Fu, Yang Wang, Sheng-cai Hou

Abstract

Objective: To investigate the relationship between postoperative metastasis and circulating levels of osteopontin in non-small cell lung cancer (NSCLC).
Methods:The expression of osteopontin mRNA were detected with RT-PCR technique. The circulating levels of osteopontin were measured through ELASA in 46 NSCLC cases that had not been received any anti-cancer treatment at the time of sampling. The tissues from fifteen patients with benign pulmonary diseases were studied as control group.
Results: The overall median mRNA expression level of osteopontin was approximately 70-fold higher in tumor tissues than in matched normal lung tissues (P<0.001). Over-expression of osteopontin mRNA was significantly associated with clinical stage (P=0.009). Advanced disease states had higher circulating level of osteopontin (stage I+II versus stage III+VI). In multivariate analysis, stage was the only independent factor influencing circulating levels of osteopontin. All patients were followed up for 12 months, 2 of the 46 patients with both osteopontin mRNA expression and elevated plasma osteopontin levels had local recurrence and 10 had distant metastasis. There was a significant difference in the osteopontin levels between metastasis group and non-metastasis group.
Conclusion: Preoperative plasma levels of osteopontin are significantly associated with post-operative metastasis in advanced NSCLC.