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Open Access Research article

Prognostic value of secreted phosphoprotein-1 in pleural effusion associated with non-small cell lung cancer

He Zhang12, Hong-bing Liu1, Dong-mei Yuan1, Zhao-feng Wang1, Yun-fen Wang1 and Yong Song1*

Author Affiliations

1 Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, 305 East Zhongshan Road, 210002 Nanjing, Jiangsu Province, China

2 Department of Respiratory Medicine, Yijishan Hospital, Wannan Medical College, Wuhu, China

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BMC Cancer 2014, 14:280  doi:10.1186/1471-2407-14-280

Published: 23 April 2014



Malignant pleural effusion (MPE) is a common complication of advanced lung cancer. Research has shown that secreted phosphoprotein-1 (SPP1) is essential in MPE associated with lung cancer. This retrospective study was performed to evaluate the prognostic significance of SPP1 in the MPE of patients with non-small cell lung cancer (NSCLC).


MPE specimens were obtained from 85 NSCLC patients (study group), and pleural effusion specimens were obtained from 24 patients with benign lung disease (control group). Specimens were tested for SPP1 using enzyme-linked immunosorbent assay (ELISA). Based on the cutoff value of receiver operating characteristic (ROC) curve analysis, the study patients were divided into a high-SPP1-expression subgroup and a low-expression subgroup. The primary and secondary endpoints of this study were progression-free survival (PFS) and overall survival (OS).


The SPP1 levels of the study group were significantly higher compared to those of the controls (Mann–Whitney U test, P = 0.017). The number of extrapulmonary metastases was significantly higher in the high-SPP1-expressing patients than in the low-expressing patients (P = 0.03). Kaplan-Meier survival analysis showed that SPP1 levels were negatively associated with OS and PFS in both subgroups of study patients (P = 0.026; P = 0.039, respectively). Cox regression analysis showed that SPP1 was an independent prognostic factor in patients with NSCLC (HR = 1.832, 95% confidence interval: 1.003–3.345; P = 0.049).


SPP1 in pleural effusion can be used for the auxiliary diagnosis of MPE and used to determine the prognosis of patients with NSCLC.

Secreted phosphoprotein-1; Osteopontin; Wmalignant pleural effusion; Non-small cell lung cancer; Prognosis