The value of macrophage inhibitory cytokine-1 level in differentiating benign from malignant solitary pulmonary nodules.

INTRODUCTION: Macrophage inhibitory cytokine-1 (MIC-1), a transforming growth factor-ß superfamily cytokine, is involved in tumor pathogenesis, and its measurement can be used as a clinical tool for the diagnosis of a wide range of cancers. OBJECTIVES: The aim of this study was to explore the diagnostic value of serum MIC-1 in patients with solitary pulmonary nodules (SPNs). METHODS: Serum specimens from 158 malignant SPN patients, 110 benign SPN patients, along with 120 healthy volunteers. The levels of serum MIC-1 were measured by sandwich enzyme-linked immunosorbent assay. RESULTS: Serum levels of MIC-1 in malignant SPN patients were significantly higher than those in benign SPN patients (P < .01), or those in healthy volunteers (P < .01). With a cutoff of 685.8 pg/ml, the sensitivity and specificity of MIC-1 in differentiating between malignant SPN patients and benign SPN patients, and between malignant SPN patients and healthy volunteers was, 56.3% and 92.7%, and 65.8% and 96.7%, respectively. An area under the curve (AUC) for malignant SPN resulting from MIC-1, which was significantly better than any other tumor markers tested including carbohydrate antigens 12-5 (CA125), and carcinoembryonic antigen (CEA). CONCLUSIONS: In conclusion, measurement of serum MIC-1 levels could be considered as a diagnostic biomarker for malignant SPN patients.

Mutation analysis of the EGFR gene and its downstream signaling pathway in thymic carcinoma patients from a Chinese Han population.

INTRODUCTION: For thymic carcinoma (TC), which is a rare epithelial neoplasm of the thymus gland, median survival with current treatments is only 2 years. OBJECTIVES: Mutations in the epidermal growth factor receptor (EGFR) gene or its downstream effectors may cause constitutive activation that leads to cell proliferation and metastases. Thus, molecular profiling is essential for selecting TC patients who may respond to anti-EGFR therapies. METHODS: Genomic DNA was extracted from 61 histological samples of TCs. Real-time polymerase chain reaction (PCR) and direct sequencing were used to assess the mutations in the EGFR downstream pathway. RESULTS: Gene mutations were identified in seven patients (11.5%). In particular, the identified mutations included four mutations in the KRAS gene, one mutation in the BRAF gene, one mutation in the PIK3CA gene, and only one mutation in the EGFR gene itself. Gene mutations in the EGFR downstream pathway were associated with shorter survival time and were observed to be an independent prognostic factor for TC patients. CONCLUSION: Mutations in the EGFR downstream pathway are not rare in TCs. These data offer interesting possibilities for the future management of TCs, particularly in the era of new targeted therapies.

Increased lysyl oxidase-like 2 associates with a poor prognosis in non-small cell lung cancer.

BACKGROUND: Lysyl oxidase-like 2 (LOXL2) is a member of the lysyl oxidase family and is associated with invasiveness and metastasis in breast cancer. However, its relevance in non-small cell lung cancer (NSCLC) remained largely unknown. METHODS: LOXL2 protein levels in a cohort of NSCLC and adjacent normal lung tissues were evaluated and analyzed their clinicopathologic and prognostic significance. RESULTS: It was found that cytoplasmic and nuclear LOXL2 levels were higher in lung adenocarcinoma (AD) and squamous cell carcinoma (SCC) tissues than in paired adjacent normal tissues. High LOXL2 levels were associated with p-TNM stage, and cytoplasmic, but not nuclear, LOXL2 levels were an independent prognostic factor in lung AD and SCC patients. CONCLUSION: These results demonstrate that elevated LOXL2 levels are positively associated with poor prognosis in NSCLC patients. LOXL2 might, therefore, serve as a novel prognostic biomarker and potential therapeutic target in NSCLC patients.

Endobronchial ultrasound transbronchial biopsy with guide-sheath for the diagnosis of solitary pulmonary nodules.

The aim of this study was to assess the usefulness of endobronchial ultrasound transbronchial biopsy with guide-sheath (EBUS-GS-TBB) for the diagnosis of solitary pulmonary nodules (SPNs). One hundred and eighty patients, who were diagnosed with SPNs and underwent an endobronchial ultrasound procedure. The diagnostic yield, safety and the associated factors were analyzed. Mean EBUS-GS procedure time was 14±8 min. The average number of biopsy specimens obtained in each SPNs was 5±1.2. One hundred and thirty-four SPNs were diagnosed by EBUS-GS-TBB and the diagnostic rate was 74.4 %. The diagnosis rate of malignancy was 83.3 %, while that of benign disease was 56.7 %. The most important factors that helped enhance EBUS-GS diagnostic accuracy included lesion diameter greater than 20mm, EBUS probe within the lesions and central lesions. No pneumothorax, hemoptysis or other serious complications occurred with the diagnostic procedures. EBUS-GS-TBB is a safe and effective method for diagnosing SPNs.

Diagnostic and prognostic value of serum periostin in patients with non-small cell lung cancer.

The periostin protein is expressed in a variety of human malignancies. The aim of this study was to explore the diagnostic and prognostic value of serum periostin levels in patients with non-small cell lung cancer (NSCLC). We measured serum periostin levels by ELISA in 296 NSCLC patients, 120 benign lung diseases (BLD) patients and 160 healthy controls. The levels of serum periostin in NSCLC patients were significantly elevated compared with those in healthy controls (P < 0.001) and BLD patients (P < 0.001). Using a cutoff value of 30.87 ng/ml, the sensitivity and specificity of periostin in differentiating between NSCLC patients and BLD patients, and between NSCLC patients and healthy controls was, 48.6 and 91.7%, and 51.4 and 97.5%, respectively. Kaplan-Meier log rank analysis revealed that the higher serum periostin levels group had a poorer progression-free survival (PFS) and overall survival (OS) compared with lower periostin group (P = 0.024, P = 0.015, respectively). Further univariate and multivariate Cox regression analysis showed that serum periostin was an independent risk factor of prognosis of NSCLC patients. In conclusion, our study suggests that serum periostin could be considered as a diagnostic and prognostic marker for NSCLC patients.

Serum Cripto-1 is a novel biomarker for non-small cell lung cancer diagnosis and prognosis.

INTRODUCTION: Cripto-1 (CR-1) is highly expressed in several different types of human tumors. However, the clinical significance of CR-1 expression in serum specimens from non-small cell lung cancer (NSCLC) patients has not yet been determined. OBJECTIVES: The aim of this study was to explore the diagnostic and prognostic value of serum CR-1 levels in patients with NSCLC. METHODS: Serum specimens from 592 NSCLC patients, 180 benign lung disease patients and 240 healthy controls were collected. The concentrations of CR-1 were measured by sandwich enzyme-linked immunosorbent assay. RESULTS: Patients with NSCLC had higher serum CR-1 levels than the controls (P < 0.01) and patients with benign lung diseases (P < 0.01). When a cutoff point of 1.8 ng/mL was selected (diagnostic specificity 95%), the diagnostic sensitivity for NSCLC is 56.8%. About 37.5% of carcinoembryonic antigen (CEA)-negative lung cancer patients were CR-1 positive at 95% specificity. In patients with stage I/II lung cancer, use of these two markers in combination results in almost 21% increase in sensitivity, at 95% specificity, compared with CEA alone. Uni-variate analysis revealed that NSCLC patients with positive CR-1 had a shorter overall survival (OS) and progression-free survival (PFS) than those with negative CR-1 [hazard ratio (HR) of 2.93, P = 0.005; HR of 2.12, P = 0.005]. Cox multi-variate analysis indicated that CR-1 was an independent prognostic indicator of PFS and OS (HR of 1.91, P = 0.006; HR of 1.82, P = 0.007). Kaplan-Meier survival curves further confirmed that patients with negative CR-1 had longer PFS and OS (P = 0.026 and P = 0.011, respectively). CONCLUSIONS: In conclusion, measurement of serum CR-1 is a useful diagnostic and prognostic marker for NSCLC patients.

Value of radial probe endobronchial ultrasound-guided localization of solitary pulmonary nodules with the combination of ultrathin bronchoscopy and methylene blue prior to video-assisted thoracoscopic surgery.

The aim of this study was to assess the clinical value of radial probe endobronchial ultrasound (RP-EBUS)-guided localization of solitary pulmonary nodules (SPNs) with the combination of ultrathin bronchoscopy and methylene blue prior to video-assisted thoracoscopic surgery (VATS). An ultrathin bronchoscope was used to localize the lesions under RP-EBUS guidance in 48 patients (18 men and 30 women; age range, 41-72 years; mean age, 54 years), who subsequently underwent VATS resection. The lesion size, distance from the parietal pleura, localization time and complications were evaluated. The RP-EBUS-guided localization success rate was 72.9%. The lesion size ± standard deviation was 12.8±4.2 mm and the mean distance from the parietal pleura was 11.2±9.7 mm. The mean localization time was 15.7±8.3 min. The major complication of RP-EBUS-guided localization was asymptomatic hemorrhage in 4 patients (8.3%). The VATS resection success rate was 95.8%. In terms of pathological type, the 48 lesions included atypical adenomatous hyperplasia (n=4), adenocarcinoma in situ (n=5), minimally invasive adenocarcinoma (n=7), adenocarcinoma (n=18), squamous cell carcinoma (n=1), inflammation (n=6), hamartoma (n=4) and tuberculosis (n=3). Therefore, RP-EBUS-guided localization with the combination of an ultrathin bronchoscope and methylene blue prior to VATS resection is a promising technique for SPNs, it plays an important role in the accurate localization of SPNs and it is an effective and safe technique to assist VATS resection of such nodules.

Serum cripto-1 as a clinical marker for lung cancer.

BACKGROUND: Cripto-1 (CR-1) plays an important role in angiogenesis related to tumor growth, in concert with vascular endothelial growth factor (VEGF), and enhanced expression of CR-1 has been reported in lung cancer tissue. METHODS: Patients with lung cancer (n = 156) and healthy volunteers (n = 60) were enrolled in the study. Serum CR-1 and VEGF concentrations were measured using enzyme-linked immunosorbent assay. RESULTS: Patients with lung cancer had higher serum CR-1 (4.03 ± 1.49 ng/mL vs. 1.13 ± 0.43 ng/mL, p<0.05) and VEGF (503.62 ± 112.74 pg/mL vs. 398.62 ± 117.84 pg/mL, p<0.05) levels than the control group. With stage progression in non-small cell lung cancer (NSCLC), serum CR-1 levels increased, and patients with distant metastasis had higher levels than those without metastasis (p<0.05). In NSCLC, the low CR-1 group (<1.54 ng/mL) had a better overall survival rate compared with the high CR-1 group (>1.54 ng/mL, p<0.05). CONCLUSIONS: Our study suggests that serum CR-1 is a useful diagnostic and prognostic marker for NSCLC patients.

Response to nab-paclitaxel and nedaplatin in a heavily-metastatic thymic carcinoma: A case report.

Metastatic thymic carcinoma is an aggressive cancer that usually responds poorly to multimodal therapies. Although surgical resection is the preferred treatment for patients with advanced or metastatic disease, the clinical prognosis is typically poor. The present study describes a 63-year-old patient with thymic carcinoma who underwent a range of antitumor treatments, including surgical resection, post-operative radiotherapy and post-operative chemotherapy with several drugs, but ultimately responded to treatment with nab-paclitaxel (nab-P) and nedaplatin. Subsequent to six cycles of nab-P and nedaplatin, the lung and peritoneal metastases decreased in size and the pleural effusion was reduced. To the best of our knowledge, this is the first study to describe the response of an advanced thymic carcinoma to nab-P chemotherapy.

Prognostic value of soluble H7-B4 in pleural effusion associated with lung cancer.

B7-H4, a member of the inhibitory B7 family, can restrain T cell proliferation, activation, and cytokine secretion and may be involved in immune evasion in cancer patients. This study aimed to evaluate the diagnostic and prognostic value of pleural effusion levels of soluble B7-H4 (sB7-H4) in lung cancer patients with malignant pleural effusion (MPE). Pleural effusion samples were collected from 98 lung cancer patients with malignant effusion and from 60 patients with nonmalignant pleural effusion. Pleural effusion concentrations of sB7-H4 were measured using sandwich enzyme-linked immunosorbent assay. Malignant effusion exhibited higher sB7-H4 levels than those in nonmalignant effusion (P < 0.01). Lung cancer patients with pleural effusion sB7-H4 levels below 35.8 ng/ml had a longer overall survival than those with higher levels (P < 0.05). By multivariate analysis, pleural effusion sB7-H4 was an independent prognostic factor in patients with MPE. In conclusion, measurement of sB7-H4 might be a useful diagnostic and prognostic value for MPE patients.

Diagnostic value of soluble receptor-binding cancer antigen expressed on SiSo cells and carcinoembryonic antigen in malignant pleural effusion in patients with lung cancer.

AIM: The aim of this study was to evaluate the diagnostic value of soluble receptor-binding cancer antigen expressed on SiSo cells (sRCAS1) and carcinoembryonic antigen (CEA) in lung cancer patients with malignant pleural effusion (MPE) and benign pleural effusion (BPE). METHODS: Pleural effusion samples from 118 patients were classified on the basis of diagnosis as MPE (n=60) and BPE (n=58). The concentration of sRCAS1 was determined by enzyme-linked immunosorbent assay. The CEA levels were also determined in all patients. RESULTS: Of 60 MPE patients, 50 had sRCAS1>9.7 U/mL and 54 had CEA>5.5 ng/mL. The concentration of both sRCAS1 and CEA in MPE was significantly higher compared with that in BPE (P<0.01 in both cases). With a cutoff point of 9.7 U/mL, sRCAS1 had a sensitivity of 83.3% and a specificity of 91.4% for differential diagnosis. The combined detection of sRCAS1 and CEA had a sensitivity of 98.3% and a specificity of 96.6% to distinguish MPE from BPE. CONCLUSION: The combined detection of sRCAS1 and CEA may be more valuable in the differential diagnosis between MPE and BPE.

WITHDRAWN: Clinical significance and prognostic value of serum RCAS1 in patients with non-small cell lung cancer.

Ahead of Print article withdrawn by publisher. Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is a human tumor-associated antigen that induces cell-cycle arrest and apoptosis in cells. The aim of this study was to explore the clinical significance and prognostic value of serum RCAS1 levels in patients with non-small cell lung cancer (NSCLC). Serum specimens from 97 patients with NSCLC, 30 healthy volunteers (HVs) and 60 patients with benign lung diseases (BLD) were collected. The concentrations of RCAS1 were measured by enzyme-linked immunosorbent assay (ELISA). Serum RCAS1 levels were higher in the NSCLC group in comparison with the HV and BLD groups (p<0.001). With a cutoff point of 19.8 U/mL, RCAS1 showed a good diagnostic performance for NSCLC. Univariate analysis revealed that NSCLC patients with elevated RCAS1 levels had significantly shorter overall survival times (p=0.013). By multivariate analysis, serum RCAS1 was identified as an independent prognostic factor (p=0.003). Measurement of RCAS1 might be a useful diagnostic and prognostic marker in NSCLC.

Serum receptor-binding cancer antigen expressed on SiSo cells (RCAS1) as a diagnostic and prognostic marker for non-small cell lung cancer.

BACKGROUND: Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is a human tumor-associated antigen that induces cell-cycle arrest and apoptosis in cells bearing the RCAS1 receptor. The aim of the study was to elucidate the diagnostic and prognostic value of RCAS1 levels in patients with non-small cell lung cancer. METHODS: Sera collected from 30 healthy volunteers, 40 patients with benign lung diseases and 97 non-small cell lung cancer cases were subjected to RCAS1 ELISA, and relationships between serum RCAS1 and clinical characteristics were evaluated. RESULTS: Serum RCAS1 levels were higher in the non-small cell lung cancer group than in the healthy volunteers and benign lung disease groups (P <0.001). With a cutoff level 19.8 U/ml, RCAS1 had a sensitivity of 87.6%, a specificity of 82.5% and an accuracy of 86.1% for non-small cell lung cancer. Univariate analysis revealed that non-small cell lung cancer patients with elevated RCAS1 levels had significantly shorter overall survival (P = 0.042) than the other two groups. By multivariate analysis, serum RCAS1 was identified as an independent prognostic factor (P = 0.003). CONCLUSIONS: Assessment of serum RCAS1 levels could be considered as a diagnostic and prognostic marker in non-small cell lung cancer.

Prognostic values of VEGF and endostatin with malignant pleural effusions in patients with lung cancer.

AIMS: Angiogenesis is important in malignant pleural effusion (MPE) formation and it is regulated by a number of pro- and anti-angiogenic cytokines. The purpose of this study was to evaluate the prognostic value of angiogenic factor vascular endothelial growth factor (VEGF) and angiogenesis inhibitor endostatin in lung cancer patients with MPE, and investigate the relationship between these two kinds of agent. METHODS: Using enzyme-linked immunoadsorbent assay, the concentrations of VEGF and endostatin were measured in pleural effusions (PE) and serum from a total of 70 lung cancer patients with MPE and 20 patients with tuberculosis. RESULTS: Compared to patients with tuberculosis, the levels of VEGF and endostatin in both PE and serum were significantly higher in patients with lung cancer. There were statistically significant correlations between VEGF levels in PE and serum (r=0.696, <0.001), endostatin levels in PE and serum (r=0.310, p=0.022), and VEGF and endostatin levels in PE (r=0.287, p=0.019). Cox multivariate analysis revealed that elevated pleural VEGF and endostatin levels and serum endostatin level were independent predictors of shorter overall survival. CONCLUSION: Both pro- and anti-angiogenic factors are likely contributors to PE formation. Our results suggest that the levels of VEGF and endostatin in PE, together with endostatin in serum, may be potential prognostic parameters for lung cancer patients with MPE.

Serum YKL-40 level is associated with the chemotherapy response and prognosis of patients with small cell lung cancer.

This study was to explore the association between the serum YKL-40 level and the clinical characteristics, the response to chemotherapy and prognosis in small cell lung cancer (SCLC). Serum YKL-40 levels were detected and compared in 120 patients with SCLC pre- and post-chemotherapy, and in 40 healthy controls. Receiver operating characteristics (ROC) curves were adopted for diagnosis and calculation of area under ROC curve in SCLC. The Kaplan-Meier method, univariate and multivariate Cox regression analysis were used to analyze the correlation between pre-chemotherapy serum YKL-40 levels and progression-free survival (PFS) and overall survival (OS). The pre-chemotherapy serum YKL-40 levels were significantly higher than those of the controls (p<0.001). The post-chemotherapy serum YKL-40 levels in the SCLC cases were lower than pre-chemotherapy serum YKL-40 levels in these cases (p = 0.026). The patients with high serum YKL-40 showed a poorer response to chemotherapy than those patients with low serumYKL-40 (p = 0.031). Univariate analysis revealed that SCLC patients with high serum YKL-40 had a shorter PFS and OS than those with low serum YKL-40 (HR of 1.74, p = 0.033; HR of 1.33, p = 0.001). Cox multivariate analysis indicated that YKL-40 was an independent prognostic indicator of PFS and OS (HR of 1.12, p = 0.029; HR of 1.84, p = 0.025). Kaplan-Meier survival curves further confirmed that patients with low serum YKL-40 have longer PFS and OS (p = 0.016 and p = 0.041, respectively). These results suggest that YKL-40 is a potential prognostic marker of chemotherapy response in SCLC.

Elevated expression of Cripto-1 correlates with poor prognosis in non-small cell lung cancer.

Human Cripto-1 (CR-1) plays an important oncogenic role during tumorigenesis and is overexpressed in a wide range of carcinomas, yet little is known about CR-1 in non-small cell lung cancer (NSCLC). The aims of this study were to detect CR-1 expression in NSCLC and to analyze its association with prognosis of NSCLC patients. The expression of CR-1 messenger RNA (mRNA) and protein in 35 cases of NSCLC and corresponding noncancerous tissue samples was examined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. Immunohistochemistry was performed to detect the expression of CR-1 in 128 NSCLC tissues. The expression levels of CR-1 mRNA and protein in NSCLC tissues were significantly higher than those in corresponding noncancerous tissues (P < 0.001). A high level of CR-1 expression was correlated with poor tumor differentiation (P = 0.002), tumor-node-metastasis (TNM) stage (P = 0.004), and lymph node metastasis (P = 0.001). The results of the Kaplan-Meier analysis indicated that a high expression level of CR-1 resulted in a significantly poor prognosis of NSCLC patients. Multivariate Cox regression analysis revealed that CR-1 expression level was an independent prognostic parameter for the overall survival rate of NSCLC patients. Our data suggest that the high expression of CR-1 may play an important role in the progression of NSCLC, and CR-1 expression may offer a valuable marker for predicting the outcome of patients with NSCLC.

GSTP1 Ile105Val polymorphism is associated with lung cancer risk among Asian population and smokers: an updated meta-analysis.

Many studies have examined the association between the GSTP1 Ile105Val (rs 1695) gene polymorphism and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. The PubMed and CNKI database was searched for case-control studies published up to July 2012. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 42 studies, comprising 12,304 lung cancer cases and 15,729 controls were included. Overall, for G allele carriers (GA + GG) versus homozygote AA, the pooled OR was 1.05 (95% CI 0.99-1.10 P = 0.092 for heterogeneity), for GG versus AA the pooled OR was 1.04 (95% CI 0.96-1.12 P = 0.084 for heterogeneity). In the stratified analysis by ethnicity, gender, histological types of lung cancer and smoking status, a significant association was found in Asians and smokers, not in Caucasian or mixed population, Male, Female population, lung AC, SCC, SCLC or non-smokers. Publication bias was found by using the funnel plot and Egger's test. Overall, there is no evidence showing a significant correlation between GSTP1 Ile105Val gene polymorphism and lung cancer risk in overall population, however stratified analysis by ethnicity, histology, gender and smoking status, it correlate with increased lung cancer susceptibility among Asians and smokers.

The diagnostic and prognostic value of serum human kallikrein-related peptidases 11 in non-small cell lung cancer.

The aim of this study was to explore the diagnostic and prognostic value of serum human kallikrein-related peptidases 11 (KLK11) level in non-small cell lung cancer (NSCLC). Serum specimens from 138 patients with NSCLC and 40 healthy controls were collected. The concentration of KLK11 was measured by enzyme-linked immunosorbent assay (ELISA). The concentration of KLK11 in NSCLC was significantly higher compared to that in the controls (P<0.01). The serum KLK11 levels decreased with stage, presence of lymph node, and distant metastases, regardless of histology, age, and sex. With a cutoff point of 1.05 ng/ml, KLK11 showed a good diagnostic performance for NSCLC. Univariate analysis revealed that NSCLC patients with serum high KLK11 had a longer overall survival (OS) and progression-free survival (PFS) than those with low KLK11 (HR of 0.36, P=0.002; HR of 0.46, P=0.009). Cox multivariate analysis indicated that KLK11 was an independent prognostic indicator of PFS and OS (HR of 0.53, P=0.042; HR of 0.48, P=0.037). Kaplan-Meier survival curves further confirmed that patients with high KLK11 have longer PFS and OS (P=0.003 and P=0.018, respectively). In conclusion, the measurement of KLK11 might be a useful diagnostic and prognostic test for NSCLC patients.

Serum-soluble receptor-binding cancer antigen expressed on SiSo cells as a clinical marker in lung cancer.

The aim of this study was to explore the diagnostic value of levels of the serum-soluble receptor-binding cancer antigen expressed on SiSo cells (sRCAS1) expressed in lung cancer patients. Enzyme-linked immunosorbent assay was performed to detect serum sRCAS1 levels in 138 patients with lung cancers of various types and in 40 healthy controls. Our results showed that the patients with lung cancer had higher serum sRCAS1 levels than the controls. As disease stages progressed in lung cancer, serum sRCAS1 levels increased; patients with lymph node and distant metastases had higher levels than those without metastases, regardless of histology, age, and gender. At a cutoff value of 19.2 U/ml, sRCAS1 was 91.3% sensitive and 72.5% specific for lung cancer. In conclusion, these results suggest that sRCAS1 levels could have a clinical value for the diagnosis and management of lung cancer and could be used as a new tumor marker of lung cancer.

Diagnostic value of pleural interleukin 17 and carcinoembryonic antigen in lung cancer patients with malignant pleural effusions.

Interleukin 17 (IL-17) has been found to be increased in some human cancers; however, the possible implication of IL-17 in regulating antitumor responses in lung cancer patients with malignant pleural effusions (MPE) remains to be elucidated. This study aimed to investigate the diagnostic value of pleural IL-17 and carcinoembryonic antigen (CEA) in MPE and benign pleural effusions (BPE). Pleural effusion samples from 108 patients were classified on the basis of diagnosis as MPE (n = 56) and BPE (n = 52). The concentration of IL-17 was determined by enzyme-linked immunosorbent assay (ELISA). The CEA levels were also determined in all patients. A significant difference was observed in the levels of CEA (P < 0.01) between MPE and BPE. The concentration of IL-17 in MPE was significantly higher compared to that in BPE (P < 0.01). With a cutoff point of 15.7 pg/ml, IL-17 had a sensitivity of 76.8 % and a specificity of 80.8 % for differential diagnosis. The combined detection of IL-17 and CEA had a sensitivity of 96.4 % and a specificity of 92.3 % to distinguish MPE from BPE. The combined detection of IL-17 and CEA may be more valuable in the differential diagnosis between MPE and BPE.