Diagnostic Value of Circulating Extracellular miR-134, miR-185, and miR-22 Levels in Lung Adenocarcinoma-Associated Malignant Pleural Effusion.
OBJECTIVE
The accurate and timely diagnosis of malignant pleural effusion (MPE) in lung cancer patients is important because MPE has a poor prognosis and is classified as stage IV disease. Molecular biomarkers for pleural effusion, such as circulating extracellular microRNAs (miRNAs) isolated from pleural fluid, may help in the diagnosis of MPE. The present study examined whether miRNAs that are deregulated in lung cancer (miR-134, miR-185, and miR-22) can serve as diagnostic markers for lung adenocarcinoma-associated MPE (LA-MPE).


METHODS
Real-time reverse transcription quantitative polymerase chain reaction was used to measure the expression of the three miRNAs in samples from 87 patients with pleural effusion comprising 45 LA-MPEs and 42 benign pleural effusions (BPEs). The area under the receiver operating characteristic curve (AUC) was then used to evaluate the diagnostic performance of each of the three miRNAs and compare it with that of the common tumor marker, carcinoembryonic antigen (CEA).


RESULTS
The expression of all three miRNAs was significantly lower in LA-MPE than in BPE (p <0.001). The AUCs for miR-134, miR-185, miR-22, and CEA were 0.721, 0.882, 0.832, and 0.898, respectively. Combining CEA with the three miRNAs increased the diagnostic performance, yielding an AUC of 0.942 (95% confidence interval, 0.864 to 0.982), with a sensitivity of 91.9% and a specificity of 92.5%.


CONCLUSIONS
The present study suggests that the expression levels of circulating extracellular miR-134, miR-185, and miR-22 in patients with pleural effusion may have diagnostic value when differentiating between LA-MPE and BPE.
Department of Internal Medicine, Cheongju St. Mary Hospital, Cheongju, Korea.
Yoon Mi
YM
Shin
Bioevaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon, Korea.
Jieun
J
Yun
Department of Pathology, Chungbuk National University College of Medicine, Cheongju, Korea.
Ok-Jun
OJ
Lee
Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
Hye-Suk
HS
Han
Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
Sung-Nam
SN
Lim
Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
Jin Young
JY
An
Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
Ki Hyeong
KH
Lee
Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
Ki Man
KM
Lee
Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
Kang Hyeon
KH
Choe
Adenocarcinoma; Lung; Pleural effusion; miR-134; miR-185; miR-22