Association between BMP4 expression and pathology, CT characteristics and prognosis of non-small cell lung cancer

To investigate the association between bone morphogenetic protein 4 (BMP4) expression and clinical pathology, computed tomography (CT) characteristics and prognosis of patients with non-small cell lung cancer (NSCLC).

A total of 76 NSCLC patients treated in our hospital from July 2012 to March 2015 were enrolled. The paired NSCLC and para-carcinoma tissues, as well as their CT image data were collected. The messenger ribonucleic acid (mRNA) and protein levels of BMP4 in NSCLC were detected via quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC). The association between BMP4 level and clinicopathological indexes of NSCLC patients was analyzed. Moreover, Kaplan-Meier method was introduced for analyzing the progression-free survival (PFS) and overall survival (OS) in NSCLC patients with high-level or low-level BMP4. The correlation between CT manifestations and BMP4 level in NSCLC patients was analyzed using the Chi-square test.

The mRNA level of BMP4 in NSCLC tissues was 2.15 times higher than that in para-carcinoma tissues (p<0.05). IHC results revealed 59.21% (45/76) of BMP4-positive NSCLC tissues and 40.79% (31/76) in para-carcinoma tissues. BMP4 level was higher in NSCLC patients with lymph node metastasis and those in clinical stage III and IV than those without lymph node metastasis and in clinical stage I and II (p<0.05). Besides, BMP4 level was not correlated to the gender, age and differentiation degree of NSCLC patients (p>0.05). According to the Kaplan-Meier survival curve, both PFS and OS were significantly shortened in NSCLC patients with high level of BMP4 compared with patients with low level of BMP4 (PFS: 13.28 months vs. 19.34 months, Log-rank test, p=0.016; OS: 15.14 months vs. 22.08 months, Log-rank test, p=0.027). BMP4 level was associated with lobulation sign, spinous process sign, tumor diameter and mediastinal lymph node metastasis in CT findings (p<0.05), rather than spiculation sign, ground glass sign, calcification lesion and CT enhancement value of lung cancer (p>0.05).

BMP4 overexpression is closely associated with the occurrence and development of NSCLC and CT signs. Detection of BMP4 is helpful for evaluating the malignant degree and prognosis of NSCLC.