Clinical significance of serum mesothelin in patients with mesothelioma and lung cancer.

PURPOSE: High levels of serum-soluble mesothelin family proteins (SMRP) have been found to be associated with malignant mesothelioma (MM), but not lung cancer (LC). To verify the clinical role of this marker for both these tumors, we tested serum SMRP in the largest population of thoracic cancers ever assembled. EXPERIMENTAL DESIGN: SMRP blood concentrations were measured in 107 patients with MM, 215 patients with LC, 130 patients with benign respiratory diseases (BRD), and 262 controls. Statistical comparison between mean serum SMRP levels in all groups was done and receiver operating characteristic curves were constructed to evaluate the performance of this marker. RESULTS: SMRP levels were significantly higher in patients with MM and LC than in patients with benign respiratory diseases and controls (P < 0.001). The area under the receiver operating characteristic curve for serum SMRP discriminating MM and controls was 0.77 (95% confidence interval, 0.71-0.83), with a best cutoff of 1.00 nmol/L (sensitivity, 68.2%; specificity, 80.5%). In both MM and LC, serum SMRP levels did not differ significantly between early and late stages. High SMRP levels proved to be an independent negative prognostic factor in patients with MM. CONCLUSIONS: Our data confirm that serum SMRP is a promising marker for the diagnosis, prognosis, and clinical monitoring of MM. We found that serum SMRP dosage may prove helpful in LC diagnosis as well. These data may also have positive repercussions on secondary preventive medical strategies for workers previously exposed to asbestos.     

Humoral immune response to mesothelin in mesothelioma and ovarian cancer patients.

PURPOSE: Mesothelin is a glycosyl-phosphatidylinositol-anchored glycoprotein present on the cell surface. Mesothelin is a differentiation antigen that is highly expressed on mesothelioma, ovarian cancer, and pancreatic cancer. The existence of a spontaneous humoral immune response to mesothelin in humans has not been fully studied. Here we addressed the issue of whether mesothelin elicits a humoral immune response in patients with mesothelioma and ovarian cancer. EXPERIMENTAL DESIGN: Using an ELISA, we analyzed immunoglobulin G antibodies specific for mesothelin in sera from patients with mesothelioma and epithelial ovarian cancer. Tumor specimens were examined by immunohistochemistry for mesothelin protein expression. RESULTS: Elevated levels of mesothelin-specific antibodies were detected in the sera of 39.1% of patients with mesothelioma (27 of 69 patients) and 41.7% with epithelial ovarian cancer (10 of 24 patients) when compared with a normal control population (44 blood donors; P < 0.01 for both mesothelioma and ovarian cancer). We also found that 53% to 56% of patients with mesothelin immunostaining-positive mesothelioma and ovarian cancer had antibodies specific for mesothelin, whereas only 0% to 8% of patients with negative mesothelin immunostaining had detectable mesothelin-specific antibodies (chi(2) test: P < 0.01 for mesothelioma and P = 0.025 for ovarian cancer). CONCLUSIONS: Our findings indicate that mesothelin is a new tumor antigen in patients with mesothelioma and ovarian cancer and the immunogenicity of mesothelin is associated with its high expression on the tumor cells. Mesothelin represents an excellent target for immune-based therapies.     

Sensitive and specific new enzyme-linked immunosorbent assay for N-ERC/mesothelin increases its potential as a useful serum tumor marker for mesothelioma.

BACKGROUND: Because mesothelioma initially progresses on the surface of the pleura and peritoneum without forming masses, it has been difficult to diagnose at an early stage. It would be very useful to identify a tumor marker that could be used for screening to enable more diagnoses to be made at an early, treatable stage. MATERIALS AND METHODS: We had previously identified N-ERC/mesothelin as a potential biomarker for mesothelioma. In the current work, we used a newly developed ELISA system to gain data on N-ERC/mesothelin levels in various clinical settings. A total of 102 healthy volunteers were recruited. In addition, 39 patients were diagnosed with mesothelioma, 53 patients were diagnosed with diseases that should be distinguished from mesothelioma, and 201 subjects were diagnosed with asbestos-related nonmalignant diseases (including simple exposure to asbestosis) who were treated at any of the cooperating hospitals were enrolled. RESULTS: Serum N-ERC/mesothelin levels measured by a new ELISA system showed that the median values from patients with mesothelioma were extremely high compared with levels obtained from other patients. Analysis in terms of histologic type showed that serum levels of N-ERC/mesothelin were elevated in epithelioid type mesothelioma, especially. In four important models of clinical settings, the sensitivity and specificity of N-ERC/mesothelin were about 71% to 90% and 88% to 93%, respectively. CONCLUSION: N-ERC/mesothelin is a very promising tumor marker for mesothelioma, especially epithelioid mesothelioma.     

Detection of aberrant methylation as a tumor marker in serum of patients with gastric cancer

BACKGROUND: This study aimed to detect hypermethylation in serum DNA from patients with gastric cancer at various stages and to assess the assay for early detection of primary and recurrent disease. MATERIALS AND METHODS: Preoperative serum samples were obtained from 109 patients with gastric cancer. Blood samples were subjected to methylation-specific polymerase chain reaction analysis to determine the methylation status of the promoter region of the p16 and E-cadherin genes. RESULTS: Forty patients (37%) showed hypermethylation of the promoter region in one or both genes (p16, 20 patients; E-cadherin, 26 patients). Of 36 patients with early-stage gastric cancers, 10 (28%) showed aberrant methylated signals. No aberrant methylation was detected in the serum DNA from 10 healthy volunteers. CONCLUSION: Aberrant promoter hypermethylation may prove useful as a new serum marker for gastric cancer.     

血清间皮素在卵巢上皮性癌诊断中的价值

 肿瘤标志物是肿瘤早期诊断的重要辅助手段,其对于肿瘤的早期发现、病情监测以及治疗方案的疗效判断都有着重要意义。临床上对于卵巢癌早期诊断方法主要为血清糖类抗原125（CA125）的检测,但该早期诊断方法精确度、特异度不高。研究发现在进展期的卵巢癌患者中发现可溶性间皮素相关多肽（SMRP）和CA125两者具有共表达的现象。现就血清间皮素在上皮性卵巢癌诊断中的价值进行综述,旨在为临床中上皮性卵巢癌患者的早期诊断、早期治疗提供参考。     

Potential role of serum mesothelin in predicting survival of patients with malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor survival rates. Therefore, it is essential to have effective biological markers predicting the course of the disease and prognosis. The aim of the present study was to highlight the prognostic significance of serum soluble mesothelin-related protein (Se-SMRP) in patients with MPM at diagnosis. Se-SMRP was determined in 60 patients using an ELISA commercial kit. Se-SMRP levels were subdivided into three tertile-based categories and in each category overall survival (OS) indexes were determined using the Kaplan-Meier and Cox regression analyses. The association between Se-SMRP levels and OS was also assessed by restricted cubic spline (RCS) analysis. No notable differences in the Kaplan-Meier probabilities were identified across the Se-SMRP categories (<0.66 nM, 0.66–1.46 nM, >1.46 nM) although an upward trend in death rate ratios (RR) was pointed out by comparing the higher (RR=1.95) and intermediate (RR=1.86) categories with the lower category (RR=1.00). In addition, such an increasing tendency, particularly when the biomarker exceeded 1.0 nM, was confirmed by an RCS function of Se-SMPR levels fitted to survival data using the Cox regression equation. The present study provided evidence in favor of a prognostic value of Se-SMRP in patients with MPM.     

叶酸受体1、间皮素蛋白在卵巢癌中的表达及临床意义

目的 观察叶酸受体1(FOLR1)、间皮素(MSLN)蛋白在卵巢癌中的表达,并分析其临床意义.方法 采用免疫组织化学法检测80例卵巢癌组织及癌旁正常卵巢组织中FOLR1、MSLN蛋白表达情况,比较不同临床特征卵巢癌患者卵巢癌组织中FOLR1、MSLN蛋白的差异.结果 卵巢癌组织中的FOLR1、MSLN阳性表达率均明显高于癌旁正常卵巢组织,差异均有统计学意义(P﹤0.01).低分化、国际妇产科联盟(FIGO)分期为Ⅲ～Ⅳ期、有淋巴结转移的卵巢癌患者的卵巢癌组织中FOLR1、MSLN阳性表达率分别高于高中分化、FIGO分期为Ⅰ～Ⅱ期、无淋巴结转移患者,差异均有统计学意义(P﹤0.05).多因素分析结果显示,FIGO分期是影响卵巢癌患者FOLR1、MSLN表达的因素(P﹤0.05).结论 卵巢癌组织中FOLR1、MSLN蛋白阳性表达率均较高,且受FIGO分期的影响.     

Inhibin as a marker for ovarian cancer.

Inhibin is a polypeptide hormone produced by the granulosa cells of the ovary, and is present in body fluids as dimers of various sizes each comprising an alpha- and beta-subunit. Free forms of the alpha-subunit also circulate, and the presently available radioimmunoassay (Monash assay) cannot distinguish these from biologically active dimeric inhibin. Recently we described a new two-site enzyme immunoassay able for the first time to measure the levels of dimeric inhibin throughout the human menstrual cycle. The sensitivity limit of this assay is 2 pg ml-1 in human serum with cross-reactivity against activin of 0.05%. The normal range of inhibin in post-menopausal women is < 5 pg ml-1, in pre-menopausal women 2-80 pg ml-1 (2-10 pg ml-1 in the follicular phase, 40-80 pg ml-1 in the luteal phase). This assay was used to determine inhibin levels in sera from 15 (five pre-menopausal and ten post-menopausal) patients with granulosa cell tumours of the ovary. It was raised in a pre-menopausal patient preoperatively (261 pg ml-1), in six post-menopausal patients (32, 43, 54, 66, 24 and 58 pg ml-1) and one pre-menopausal patient with recurrent tumour, (237 pg ml-1), all confirmed clinically. Inhibin was normal in six patients in remission. Oestradiol levels were normal in all patients. Serial levels of inhibin predicted recurrence before overt clinical relapse in two patients. In 29 patients with malignant epithelial ovarian tumours inhibin levels were modestly elevated in nine and normal in the rest. Three patients with endometrioid histology, two with undifferentiated tumours, three with mucinous adenocarcinoma and one with clear cell carcinoma had elevated inhibin levels. Functional inhibin is secreted by all granulosa cell tumours of the ovary studied and can be used as a tumour marker to determine response to therapy and predict recurrence and is superior to oestradiol. A more detailed analysis of the levels of inhibin, and its subunits in epithelial ovarian cancer is needed to identify the molecular forms of the immunoreactive material before optimised assays can be applied to this more common tumour.     

Evaluation of serum KL-6, a mucin-like glycoprotein, as a tumor marker for breast cancer.

The utility of serum KL-6 as a tumor marker for breast cancer was evaluated in this study. The sera from 146 patients with breast cancer, 13 with benign breast disease, and 108 healthy individuals were measured for KL-6 titer using a sandwich enzyme immunoassay method. Carcinoembryonic antigen (CEA) and carbohydrate antigen 15-3 (CA15-3) titers were also tested in the same sera from the patients. The mean KL-6 titer of patients with primary breast cancer was 673 units/ml, which was significantly higher than that of benign and healthy individuals (P = 0.037 and P < 0.0001, respectively). The titer of patients with relapsed breast cancer was 1964 units/ml, which was also higher than that of primary cancer (P = 0.013). KL-6 titer was related to tumor stage, distant metastasis, and relapse site (P = 0.0053, P < 0.0001, and P = 0.0251, respectively). Using the cutoff value of 467 units/ml, the sensitivity of KL-6 was 31% for primary breast cancer (16% for stage I and 29% for stage II) and 73% for relapsed breast cancer (50% for local relapse and 89% for distant relapse). The specificity was 92%. The sensitivity of KL-6 was higher than that of CA15-3 and CEA. Combination of the three markers, followed by KL-6 and CEA, raised the sensitivity for primary breast cancer. Single use of KL-6 demonstrated a higher sensitivity than in each combination for relapsed breast cancer. In conclusion, serum KL-6 may be helpful for clinical use as a tumor marker for breast cancer, and it may play an important role, especially in the surveillance of disease relapse.     

Elevated serum insulin-like growth factor binding protein-2 as a prognostic marker in patients with ovarian cancer.

PURPOSE: The purpose of this research was to examine the diagnostic and prognostic significance of elevated serum insulin-like growth factor binding protein (IGFBP)-2 levels in women with ovarian cancer from diagnosis through treatment to relapse or remission. EXPERIMENTAL DESIGN: Serum collected pre- and postoperatively in women newly diagnosed with ovarian cancer, during adjuvant chemotherapy cycles, at 6 months follow-up and at relapse was analyzed for IGFBP-2. Control serum was from women undergoing pelvic or abdominal surgery for benign ovarian disease or nonovarian pathology. RESULTS: IGFBP-2 at diagnosis was significantly elevated (P < 0.0001) in women with ovarian cancer (887 +/- 62 ng/ml) compared with benign controls (337 +/- 25 ng/ml), and women undergoing nonovarian surgery (439 +/- 49 ng/ml) and correlated positively with tumor stage and cellular differentiation but not with CA125. Unexpectedly, IGFBP-2 levels increased additionally 1-week postoperatively in ovarian cancer patients (1581 +/- 90 ng/ml; P = 0.0027) as well as controls (977 +/- 95 ng/ml; P < 0.0001) and was higher in women who had suboptimal debulking compared with optimal debulking of their tumor. IGFBP-2 levels returned to normal in women without evidence of progressive disease, but remained significantly elevated in women who later relapsed. Patients with IGFBP-2 levels in the highest tertile at diagnosis had a significantly shorter progression-free interval and overall survival. CONCLUSION: In ovarian cancer IGFBP-2 is elevated at diagnosis, and corresponds to stage and histology with patients in the highest tertile of IGFBP-2 more likely to relapse and have a poorer outlook. Identification of these patients at diagnosis may allow more individualized, aggressive adjuvant treatment and follow-up, and IGFBP-2 may therefore be an important additional prognostic marker in this disease.     

Detection of tumor DNA in serum of colorectal cancer patients.

We previously found p16 promoter methylation in DNA in the sera of 13 colorectal cancer patients out of 44 (30%) whose tumor DNA exhibited the methylation, using methylation-specific PCR (MSP). To examine whether the cancer detection rate could be improved by using a different tumor marker, we examined the K-ras status in 90 colorectal cancer patients using a mismatch ligation assay. Among the 31 patients showing K-ras gene mutations in their tumors, the same mutations were observed in serum DNA of 11 patients (35%). Among the 90 patients, 63 showed tumors positive for K-ras mutation or p16 promoter methylation, or both, and 22 had serum DNA positive for one or both. K-ras mutation was found even in serum DNA of patients with Dukes A cancer, suggesting that colorectal cancer might be detected even in patients without symptoms by using this ligation assay.     

Detection of serum autoantibodies to tumor suppressor gene p53 with a new enzyme-linked immunosorbent assay in patients with ovarian cancer

Sera from 99 ovarian cancer patients were assayed for serum autoantibodies to p53 using a newly developed enzyme-linked immunosorbent assay (ELISA). Results were compared to the investigation using the former ELISA. The incidence of autoantibodies (25%) was lower using the newly developed ELISA as compared to the previous results (41%). The results were consistent in 79% of patients (P < .001). The incidence of autoantibodies was lower in patients with complete remission (19%) as compared to that of patients with recurrence (30%) and before primary surgery (26%). No statistically significant correlation was found among p53 serum autoantibody status and tumor stage, degree of malignancy, histologic subtype, and residual tumor after primary surgery. Use of the newly developed ELISA resulted in a higher consensus between immunohistochemically negative and autoantibody negative cases. Owing to further purifying of the prepared human recombinant p53. the newly developed ELISA seems to be of higher specificity as compared to the former ELISA.     

Prostasin, a potential serum marker for ovarian cancer: identification through microarray technology

BACKGROUND: Screening biomarkers for ovarian cancer are needed because of its late stage at diagnosis and poor survival. We used microarray technology to identify overexpressed genes for secretory proteins as potential serum biomarkers and selected prostasin, a serine protease normally secreted by the prostate gland, for further study. METHODS: RNA was isolated and pooled from three ovarian cancer cell lines and from three normal human ovarian surface epithelial (HOSE) cell lines. Complementary DNA generated from these pools was hybridized to a microarray slide, and genes overexpressed in the cancer cells were identified. Real-time quantitative polymerase chain reaction was used to examine prostasin gene expression in ovarian cancer and HOSE cell lines. Anti-prostasin antibodies were used to examine prostasin expression and to measure serum prostasin by an enzyme-linked immunosorbent assay in 64 case patients with ovarian cancer and in 137 control subjects. Previously determined levels of CA 125, an ovarian cancer marker, were available from about 70% of all subjects. All statistical tests were two-sided. RESULTS: Prostasin was detected by immunostaining more strongly in cancerous ovarian epithelial cells and stroma than in normal ovarian tissue. The mean level of serum prostasin was 13.7 microg/mL (95% confidence interval [CI] = 10.5 to 16.9 microg/mL) in 64 case patients with ovarian cancer and 7.5 microg/mL (95% CI = 6.6 to 8.3 microg/mL) in 137 control subjects (P<.001, after adjustment for the subject's age, year of collection, and specimen quality). In 14 of 16 case patients with both preoperative and postoperative serum samples, postoperative prostasin levels were statistically significantly lower than preoperative levels (P =.004). In 37 case patients with nonmucinous ovarian cancer and in 100 control subjects for whom levels of CA 125 and prostasin were available, the combination of markers gave a sensitivity of 92% (95% CI = 78.1% to 98.3%) and a specificity of 94% (95% CI = 87.4% to 97.7%) for detecting ovarian cancer. CONCLUSIONS: Prostasin is overexpressed in epithelial ovarian cancer and should be investigated further as a screening or tumor marker, alone and in combination with CA 125.     

Utility of osteopontin and serum mesothelin in malignant pleural mesothelioma diagnosis and prognosis assessment.

PURPOSE: Malignant mesothelioma is a highly aggressive tumor and is often diagnosed too late for a curative treatment. We compared diagnostic and prognostic values of mesothelin and osteopontin in 172 patients suspected of malignant pleural mesothelioma (MPM) and in a control group of 112 asymptomatic asbestos-exposed subjects. EXPERIMENTAL DESIGN: Osteopontin and mesothelin were assayed with commercial ELISA kits in a series of 43 patients with pleural metastases of various carcinomas, 33 patients with benign pleural lesions associated with asbestos exposure, 96 patients with MPMs, and 112 asbestos-exposed healthy subjects. Results were correlated with patient's diagnosis and survival. RESULTS: Serum osteopontin level was higher in MPM patients compared with healthy asbestos-exposed subjects and had a good capability to distinguish between these two populations. However, osteopontin was unable to distinguish between MPM and pleural metastatic carcinoma or benign pleural lesions associated with asbestos exposure. Neither plasma nor pleural fluid osteopontin were more powerful in this respect. Serum mesothelin had a good ability for diagnosing MPM but was unable to identify patients with nonepithelioid mesothelioma subtypes. Survival analysis identified tumor histologic subtype along with serum osteopontin and serum mesothelin as independent prognostic factors in mesothelioma patients. CONCLUSIONS: Osteopontin has a lower diagnostic accuracy than mesothelin in patients suspected of MPM. Insufficient specificity limits osteopontin utility as diagnostic marker. Both molecules have a potential value as prognostic markers.     

Identification of nicotinamide N-methyltransferase as a novel serum tumor marker for colorectal cancer.

PURPOSE: The goal of this study was to identify and validate novel serum markers of human colorectal cancer as potential candidates for noninvasive detection of early colorectal neoplasm. EXPERIMENTAL DESIGN: Employing two-dimensional gel electrophoresis and mass spectrometry, we analyzed 16 matched colorectal cancer and adjacent normal tissue samples. Proteins found to be elevated in cancer tissue were further validated by generating antibodies which were used for immunoblotting of tissue samples and for the development of highly sensitive immunoassays for assessment of serum samples. RESULTS: In total, 735 different proteins were identified in colon tissue. Strong elevation in colorectal cancer for five proteins was confirmed by immunoblot analysis: transforming growth factor-beta induced protein ig-h3 (betaIG-H3), nicotinamide N-methyltransferase (NNMT), nucleoside diphosphate kinase A (nm23-H1), purine nucleoside phosphorylase (PNPH), and mannose-6-phosphate receptor binding protein 1 (M6P1). Elevated levels of NNMT, which is not predicted to be secreted but is known as a cytoplasmic protein, were found in serum from patients with colorectal cancer. Employing a receiver-operating characteristic curve based on the measurement of 109 patients with colorectal cancer and 317 healthy controls, we obtained an area under the curve of 0.84 for NNMT, which was superior to the established tumor marker carcinoembryogenic antigen with an area under the curve of 0.78. CONCLUSIONS: It is proposed that NNMT serum levels may have significance in the early detection and in the management of patients with colorectal cancer.     

Increased serum midkine concentration as a possible tumor marker in patients with superficial esophageal cancer

Midkine, a heparin-binding growth factor, is expressed in numerous cancer tissues and is reportedly elevated in patients with various neoplasms. The aim of this study was to evaluate the clinicopathological significance of serum midkine concentration (S-MK) in patients with superficial esophageal squamous cell carcinoma (SCC). Pretreatment S-MK was measured by enzyme-linked immunosorbent assay in 135 healthy controls, 16 patients with benign esophageal disease, and 60 patients with primary superficial esophageal squamous cell cancer (SESCC). All patients with SESCC underwent curative resection. The disease was staged according to TNM/UICC guidelines. Serum concentrations of carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC-Ag), and cytokeratin 19 fragment (CYFRA21-1) were also evaluated in the same populations. S-MK in patients with SESCC (388+/-411 pg/ml) was significantly higher than in benign esophageal disease or healthy controls (183+/-73 and 154+/-76 pg/ml, respectively). Using the mean + 2 standard deviations of healthy control S-MK (300 pg/ml) as the cut-off level, 50% of patients with esophageal SESCC were deemed positive. This S-MK positivity rate for detecting SESCC was significantly higher than for other tumor markers. Thus, S-MK may be useful as a tumor marker to detect SESCC.     

Evaluation of the ovarian cancer antigen, Ca-125, as a tumor marker

The presence of the Ca-125 antigen was tested in the serum of 46 patients with ovarian cancer in order to determine the prognostic value of preoperative levels and its usefulness for monitoring the clinical response in longitudinal studies; survival (S) and progression-free survival (PFS) were also evaluated. In our series, the specificity of the assay in normal subjects and in patients with benign gynecological diseases is 99.3 and 73.2% respectively, and the sensitivity is 91.9%. Preoperative Ca-125 levels are not correlated with S and PFS, whereas an advantage in S and PFS is clearly shown for patients in whom the marker level decreases after treatment. Serial determinations of Ca-125 serum levels provide a reliable test to assess response to therapy and to predict disease progression.