CA 125: the past and the future

Over the last 15 years, substantial progress has been made in understanding the potential and the limitations of the CA 125 assay. More than 2000 papers have been published concerning laboratory and clinical studies of CA 125. The original CA 125 assay utilized the OC 125 antibody that recognizes the CA 125 epitope on a high molecular weight glycoprotein. Despite repeated attempts, the gene encoding the peptide component has not yet been cloned. Monoclonal antibodies have been raised against other epitopes expressed by this molecule, leading to the development of the CA 125-II assay that exhibits less day-to-day variation. Using either assay, elevated levels of CA 125 are detected in a number of benign conditions, including endometriosis. CA 125 is most consistently elevated in epithelial ovarian cancer, but can be expressed in a number of gynecologic (endometrial, fallopian tube) and non-gynecologic (pancreatic, breast, colon and lung) cancers. The best established application of the CA 125 assay is in monitoring ovarian cancer. The rate of decline in CA 125 during primary chemotherapy has been an important independent prognostic factor in several multivariate analyses. Persistent elevation of CA 125 at the time of a second look surgical surveillance procedure predicts residual disease with > 95% specificity. Rising CA 125 values have preceded clinical detection of recurrent disease by at least 3 months in most, but not all studies. Given the modest activity of salvage chemotherapy, this information has not yet impacted on survival. Rising CA 125 during subsequent chemotherapy has been associated with progressive disease in more than 90% of cases. CA 125 may serve as an effective surrogate marker for clinical response in phase II trials of new drugs. CA 125 levels can aid in distinguishing malignant from benign pelvic masses, permitting effective triage of patients for primary surgery. Early detection of ovarian cancer remains the most promising application of CA 125. An algorithm has been developed that estimates the risk of ovarian cancer (ROC) based upon the level and trend of CA 125 values. A major trial has been initiated that uses the ROC algorithm to trigger transvaginal sonography and/or subsequent laparotomy. Such a trial could demonstrate improvement in survival through early detection. This strategy should provide adequate specificity, but sensitivity for early stage disease may not be optimal. In the future, improved sensitivity may be attained using multiple markers and neural network analysis. Most serum tumor markers have been proteins or carbohydrates, but lipid markers such as lysophosphatidic acid deserve evaluation. Genomic and proteonomic technologies should identify additional novel markers.     

Progress and challenges in screening for early detection of ovarian cancer

Ovarian cancer is characterize by few early symptoms, presentation at an advanced stage, and poor survival. As a result, it is the most frequent cause of death from gynecological cancer. During the last decade, a research effort has been directed toward improving outcomes for ovarian cancer by screening for preclinical, early stage disease using both imaging techniques and serum markers. Numerous biomarkers have shown potential in samples from clinically diagnosed ovarian cancer patients, but few have been thoroughly assessed in preclinical disease and screening. The most thoroughly investigated biomarker in ovarian cancer screening is CA125. Prospective studies have demonstrated that both CA125 and transvaginal ultrasound can detect a significant proportion of preclinical ovarian cancers, and refinements in interpretation of results have improved sensitivity and reduced the false-positive rate of screening. There is preliminary evidence that screening can improve survival, but the impact of screening on mortality from ovarian cancer is still unclear. Prospective studies of screening are in progress in both the general population and high-risk population, including the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), a randomized trial involving 200,000 postmenopausal women designed to document the impact of screening on mortality. Recent advances in technology for the study of the serum proteome offer exciting opportunities for the identification of novel biomarkers or patterns of markers that will have greater sensitivity and lead time for preclinical disease than CA125. Considerable interest and controversy has been generated by initial results utilizing surface-enhanced laser desorption/ionization (SELDI) in ovarian cancer. There are challenging issues related to the design of studies to evaluate SELDI and other proteomic technology, as well as the reproducibility, sensitivity, and specificity of this new technology. Large serum banks such as that assembled in UKCTOCS, which contain preclinical samples from patients who later developed ovarian cancer and other disorders, provide a unique resource for carefully designed studies of proteomic technology. There is a sound basis for optimism that further developments in serum proteomic analysis will provide powerful methods for screening in ovarian cancer and many other diseases.     

A multiplex platform for the identification of ovarian cancer biomarkers

Background

Currently, there are no FDA approved screening tools for detecting early stage ovarian cancer in the general population. Development of a biomarker-based assay for early detection would significantly improve the survival of ovarian cancer patients.

Methods

We used a multiplex approach to identify protein biomarkers for detecting early stage ovarian cancer. This new technology (Proseek^® Multiplex Oncology Plates) can simultaneously measure the expression of 92 proteins in serum based on a proximity extension assay. We analyzed serum samples from 81 women representing healthy, benign pathology, early, and advanced stage serous ovarian cancer patients.

Results

Principle component analysis and unsupervised hierarchical clustering separated patients into cancer versus non-cancer subgroups. Data from the Proseek^® plate for CA125 levels exhibited a strong correlation with current clinical assays for CA125 (correlation coefficient of 0.89, 95% CI 0.83, 0.93). CA125 and HE4 were present at very low levels in healthy controls and benign cases, while higher levels were found in early stage cases, with highest levels found in the advanced stage cases. Overall, significant trends were observed for 38 of the 92 proteins (p < 0.001), many of which are novel candidate serum biomarkers for ovarian cancer. The area under the ROC curve (AUC) for CA125 was 0.98 and the AUC for HE4 was 0.85 when comparing early stage ovarian cancer versus healthy controls. In total, 23 proteins had an estimated AUC of 0.7 or greater. Using a naïve Bayes classifier that combined 12 proteins, we improved the sensitivity corresponding to 95% specificity from 93 to 95% when compared to CA125 alone. Although small, a 2% increase would have a significant effect on the number of women correctly identified when screening a large population.

Conclusions

These data demonstrate that the Proseek^® technology can replicate the results established by conventional clinical assays for known biomarkers, identify new candidate biomarkers, and improve the sensitivity and specificity of CA125 alone. Additional studies using a larger cohort of patients will allow for validation of these biomarkers and lead to the development of a screening tool for detecting early stage ovarian cancer in the general population.

     

Pre-treatment neutrophil to lymphocyte ratio is elevated in epithelial ovarian cancer and predicts survival after treatment

Purpose  Inflammatory cells can both suppress and stimulate tumor growth, and the influence of inflammatory cells on clinical outcome has been the focus of many studies. The purpose of this study was to evaluate the effectiveness of the neutrophil to lymphocyte ratio (NLR), a measure of the systemic inflammatory response, as an additional discriminative biomarker in epithelial ovarian cancer and to determine whether it predicts survival and recurrence. Methods  We studied 192 patients with epithelial ovarian cancer, 173 with benign ovarian tumors, 229 with benign gynecologic disease, and 405 healthy controls. Serum CA125 levels and leukocyte counts according to subtypes were recorded prior to treatment in all study subjects. In epithelial ovarian cancer, the diagnostic usefulness of NLR, in combination with CA125, was evaluated. The correlation between NLR and overall and disease-free survival was analyzed using both univariate and multivariate analyses adjusting for the known prognostic factors (age, stage, cell type, and grade). Results  Preoperative NLR in ovarian cancer subjects (mean 6.02) was significantly higher than that in benign ovarian tumor subjects (mean 2.57), benign gynecologic disease subjects (mean 2.55), and healthy controls (mean 1.98) (P < 0.001). The sensitivity and specificity of NLR in detecting ovarian cancer was 66.1% (95% CI, 59.52–72.68%) and 82.7% (95% CI, 79.02–86.38%), respectively (cutoff value: 2.60). In early stage ovarian cancer, CA125 was not elevated in 19 out of 49 patients. Seven (36.8%) of these 19 patients were NLR positive. On Cox multivariate analysis, NLR positive, stage III/IV, and older age were independent poor prognostic factors, and being NLR positive was the most powerful predictive variable (Hazard Ratio = 8.42 [95% CI: 1.09–64.84], P = 0.041). Conclusions  Our findings provide evidence for the association between NLR and epithelial ovarian cancer. Preoperative NLR, in combination with CA125, may represent a simple and cost-effective method of identifying ovarian cancers, and an elevated NLR may predict an adverse outcome in ovarian cancer.     

Development of multiplexed bead-based immunoassays for the detection of early stage ovarian cancer using a combination of serum biomarkers

CA125 as a biomarker of ovarian cancer is ineffective for the general population. The aim of this study was to evaluate multiplexed bead-based immunoassay of multiple ovarian cancer-associated biomarkers such as transthyretin and apolipoprotein A1, together with CA125, to improve the identification and evaluation of prognosis of ovarian cancer. We measured the serum levels of CA125, transthyretin, and apolipoprotein A1 from the serum of 61 healthy individuals, 84 patients with benign ovarian disease, and 118 patients with ovarian cancer using a multiplex liquid assay system, Luminex 100. The results were then analyzed according to healthy and/or benign versus ovarian cancer subjects. When CA125 was combined with the other biomarkers, the overall sensitivity and specificity were significantly improved in the ROC curve, which showed 95% and 97% sensitivity and specificity, respectively. At 95% specificity for all stages the sensitivity increased to 95.5% compared to 67% for CA125 alone. For stage I+II, the sensitivity increased from 30% for CA125 alone to 93.9%. For stage III+IV, the corresponding values were 96.5% and 91.6%, respectively. Also, the three biomarkers were sufficient for maximum separation between noncancer (healthy plus benign group) and stage I+II or all stages (I-IV) of disease. The new combination of transthyretin, and apolipoprotein A1 with CA125 improved both the sensitivity and the specificity of ovarian cancer diagnosis compared with those of individual biomarkers. These findings suggest the benefit of the combination of these markers for the diagnosis of ovarian cancer.     

Early detection of ovarian cancer: background, rationale, and structure of the Yale Early Detection Program.

Ovarian cancer has received national attention as a highly virulent disease. Its lack of early warning symptoms and the failure to develop highly sensitive screening tests have led some physicians to recommend prophylactic oophorectomies to women with relatives who have had ovarian cancer. Others have recommended routine screening of otherwise normal women for CA 125, a circulating tumor marker, and ultrasound examinations. Each of these techniques is associated with substantial false-positive rates that could lead to unnecessary surgery. A review of epidemiologic data suggests that familial ovarian cancer kindreds are rare, but women with first-degree relatives who have had ovarian cancer have a significant risk themselves for developing ovarian cancer. In addition, women with a great number of ovulatory cycles are at an increased risk for the disease. Circulating tumor markers are frequently elevated in women with advanced ovarian cancer, but their value in early detection of ovarian cancer has yet to be established. Advances in endovaginal ultrasound and color Doppler flow technology have significantly improved our ability to assess pelvic organs. This article presents the background, rationale, and structure of the Yale Early Detection Program for ovarian cancer, whose goals are to identify the best techniques for diagnosing ovarian cancer in an early stage, to determine the frequency with which such tests should be employed, to assess false-positive results, and to identify women who might benefit from prophylactic oophorectomies.     

Peritoneal fluid cytokines and the differential diagnosis of benign and malignant ovarian tumors and residual/recurrent disease examination

This study aimed to assess the potential value of peritoneal fluid cytokine examination for the differential diagnosis of ovarian tumors and for evaluating residual or recurrent disease after treatment. The cytokines that are commonly elevated in ovarian cancer, VEGF, IL-6, bFGF, IL-8 and M-CSF, and a reference ovarian tumor marker, CA 125, were measured in peritoneal fluids of 53 previously untreated patients with epithelial ovarian cancer, 18 ovarian cancer patients after surgical treatment and chemotherapy, and 17 patients with benign epithelial ovarian tumors. Non-parametric statistical analysis of data was performed. Ovarian cancer peritoneal fluids, as compared to peritoneal fluids of patients with benign ovarian tumors, contained significantly higher concentrations of IL-6, VEGF and CA 125, and significantly lower concentrations of bFGF and M-CSF, but only the levels of IL-6 and VEGF were significantly higher in peritoneal fluids of stage I and II ovarian cancer patients than of patients with benign ovarian conditions. IL-6 at the cutoff level of 400 pg/mL discriminated benign and malignant ovarian tumors with 92% sensitivity and 60% specificity, while VEGF at the cutoff of 400 pg/mL had 90% sensitivity and 80% specificity. At the cutoff level of 1200 pg/mL, IL-6 had 84% sensitivity and 87% specificity. A radical decrease in local cytokine and CA 125 levels in patients after treatment was independent of therapy outcome. IL-6 and VEGF measurements in peritoneal fluids might be useful for the differential diagnosis of malignant and benign ovarian conditions, but not for residual or recurrent disease examination.     

Prevalence screening for ovarian cancer in postmenopausal women by CA 125 measurement and ultrasonography.

OBJECTIVE--To assess the performance of the sequential combination of serum CA 125 measurement and ultrasonography in screening for ovarian cancer. DESIGN--The serum CA 125 concentration of each subject was determined and those with a concentration > or = 30 U/ml were recalled for abdominal ultrasonography. If ultrasonography gave abnormal results surgical investigation was arranged. Volunteers were followed up by annual postal questionnaire. SETTING--General practice, occupational health departments, ovarian cancer screening clinic. SUBJECTS--22,000 women volunteers who were postmenopausal and aged over 45 years. MAIN OUTCOME MEASURES--Apparent sensitivity, specificity, positive predictive value, years of cancer detected. RESULTS--41 women had a positive screening result and were investigated surgically. 11 had ovarian cancer (true positive result) and 30 had other disorders or no abnormality (false positive result). Of the 21,959 volunteers with a negative screening result, eight subsequently presented clinically with ovarian cancer (false negative result) and 21,951 had not developed ovarian cancer during follow up (apparent true negative result). The screening protocol achieved a specificity of 99.9%, a positive predictive value of 26.8%, and an apparent sensitivity of 78.6% and 57.9% at one year and two year follow up respectively. The estimated number of years of cancer detected by the prevalence screen was 1.4 years. CONCLUSIONS--This screening protocol is highly specific for ovarian cancer and can detect a substantial proportion of cases at a preclinical stage. Further investigation is required to determine the effect of the screening protocol on the ratio of early to late stage disease detected and on mortality from ovarian cancer.     

The prognostic value of the tumor marker CA 15-3 at initial diagnosis of patients with breast cancer

CA 15-3 has been most widely used as a serum tumor marker in follow-up and detection of breast cancer recurrence. In this study we have specifically focused upon the prognostic implications and utility of preoperative CA 15-3 levels. We have identified on our database 414 patients with breast cancer in whom serial levels of the serum tumor marker CA 15-3 had been determined at diagnosis and follow-up. We have analyzed the follow-up and clinical outcomes in these patients and from this data we have assessed the potential of CA 15-3 as a predictor of five-year overall and disease-free survival. Our results show that an initially elevated CA 15-3 level is associated with a very poor prognosis in both early and late stage disease. Elevated pre-biopsy CA 15-3 levels are associated with 14% five-year disease-free survival rates and 17% overall survival rates at five years. In contrast, normal CA 15-3 levels are associated with 47% five-year disease-free survival rates and 54% overall survival rates at five years (p<0.01). Comparison of five-year survival rates between patients with elevated and normal CA 15-3 levels in early breast cancer (stage I and II) also showed significant differences, with survival being 41% and 75%, respectively (p<0.01).     

Tumor antigen NB/70K and CA 125 levels in the blood of preoperative ovarian cancer patients and controls: a preliminary report of the use of the NB12123 and CA 125 radioimmunoassays alone and in combination

The NB12123 and CA125 radioimmunoassays, murine monoclonal antibody assays for measuring circulating levels of human ovarian tumor associated antigens NB/70K and CA 125, respectively, have been previously described. In the present study, preoperative serum samples were obtained from patients undergoing laparotomy for benign neoplastic ovarian tumors (N = 16), cancer of the cervix (N = 22), cancer of the uterus (N = 20), and cancer of the ovary (N = 47). Controls (N = 50) were obtained from healthy blood bank donors. No correlation was observed between the levels of NB/70K and CA 125 in these samples (r2 = .079, linear regression analysis). In general, increasing levels of both antigens were present with increasing tumor burden and higher histological grade. In addition, both markers were most elevated in the serum of ovarian cancer patients with serous and unclassified adenocarcinomas. Using 40 AU and 35 unit cut-offs for the NB/70K and CA 125 assay, respectively, overall specificity for healthy controls and patients with benign diseases approaches 100%. The combined sensitivity of the assays for ovarian cancer patient sera in this study indicates that the assays may be helpful in establishing a pre operative diagnosis of ovarian cancer. Complementarity of the NB/70K and CA 125 assays has been demonstrated, indicating that one or both assays may be used to monitor as many as 85% of ovarian cancer patients.     

Investigation of ovarian cancer associated sialylation changes in N-linked glycopeptides by quantitative proteomics

ABSTRACT: BACKGROUND: In approximately 80% of patients, ovarian cancer is diagnosed when the patient is already in the advanced stages of the disease. CA125 is currently used as the marker for ovarian cancer; however, it lacks specificity and sensitivity for detecting early stage disease. There is a critical unmet need for sensitive and specific routine screening tests for early diagnosis that can reduce ovarian cancer lethality by reliably detecting the disease at its earliest and treatable stages. Results: In this study, we investigated the N-linked sialylated glycopeptides in serum samples from healthy and ovarian cancer patients using Lectin-directed Tandem Labeling (LTL) and iTRAQ quantitative proteomics methods. We identified 45 N-linked sialylated glycopeptides containing 46 glycosylation sites. Among those, ten sialylated glycopeptides were significantly up-regulated in ovarian cancer patients' serum samples. LC-MS/MS analysis of the non-glycosylated peptides from the same samples, western blot data using lectin enriched glycoproteins of various ovarian cancer type samples, and PNGase F (+/-) treatment confirmed the sialylation changes in the ovarian cancer samples. Conclusion: Herein, we demonstrated that several proteins are aberrantly sialylated in N-linked glycopeptides in ovarian cancer and detection of glycopeptides with abnormal sialylation changes may have the potential to serve as biomarkers for ovarian cancer.     

Tissue quantification of CA 125 in epithelial ovarian cancer.

The objectives of this study were the determination of CA 125 in the cytosol of healthy and carcinomatous ovarian tissue by immunoanalysis, analysis of its correlation with the biological characteristics of ovarian carcinoma, determination of serum CA 125 levels, and study of the prognostic value of the marker in cytosol. The levels of the marker depend not only on the tumor's production rate, so its determination in tissue can indicate more accurately if the tumor is a producer of the marker and establish its value for the prognosis of the disease. Determination of CA 125 in tissue was performed by immunoanalysis in 50 ovarian epithelial cancer samples, 13 benign pathology samples and 32 healthy ovary samples. The presurgical serum level of the marker was also obtained. The correlation between the CA 125 level in the cytosol and the different biological characteristics of the ovarian carcinoma, the serum levels of the marker and survival were analyzed. The CA 125 level proved to be higher in malignant tissue (p < 0.0001). There was a significant association between the tissue marker and histological type (high CA 125 was associated with serous and endometrioid tumors) and between the marker and survival. No relation with stage was found. There was a correlation between the CA 125 level in the cytosol and serum both variables being dependent, with a correlation coefficient of 0.44. This good correlation speaks in favor of the usefulness of CA 125 determination in serum in the follow-up of ovarian cancer. Tumors having high tissue expression of CA 125 were found to have a double relative risk of death, independently of tumor stage.     

血清HE4、FS、SMRP及CA125在卵巢癌患者中的表达及临床意义

目的:探讨血清人附睾蛋白4(HE4)、卵泡抑素(FS)、可溶性间皮素相关蛋白(SMRP)、糖类抗原125(CA125)在卵巢癌患者中的表达水平及临床意义。方法:选取2014年6月-2017年9月我院收治的卵巢癌患者60例作为卵巢癌组,另选取同期收治的卵巢良性肿瘤患者32例作为良性组,选取同期健康体检妇女40例作为对照组,检测三组受试者血清HE4、FS、SMRP、CA125水平,对比三组HE4、FS、SMRP、CA125阳性表达率,并分析血清HE4、FS、SMRP、CA125对卵巢癌的诊断价值。结果:三组受试者的HE4、FS、SMRP、CA125水平整体对比有统计学意义(P0.05),其中卵巢癌组与良性组HE4、FS、SMRP、CA125水平高于对照组,且卵巢癌组高于良性组,差异有统计学意义(P0.05)。三组受试者的HE4、FS、SMRP、CA125阳性表达率整体对比有统计学意义(P0.05),卵巢癌组与良性组HE4、FS、SMRP、CA125阳性表达率高于对照组,且卵巢癌组高于良性组,差异有统计学意义(P0.05)。联合检测的灵敏度高于FS、SMRP单项检测,差异有统计学意义(P0.05),联合检测的特异度高于HE4、FS、SMRP、CA125单项检测,但差异无统计学意义(P0.05)。结论:卵巢癌患者血清HE4、FS、SMRP、CA125水平及阳性表达率均较高,四项指标联合检测可提高诊断卵巢癌的灵敏度及特异度。     

人附睾蛋白4在卵巢癌中的应用进展

卵巢癌是妇科常见的恶性肿瘤,其死亡率居妇科恶性肿瘤之首,早期发现有助于提高患者的五年生存率。人附睾蛋白(HE4)属于蛋白酶抑制剂家族,是一种新的卵巢癌肿瘤标志物。HE4在卵巢癌组织中及患者血清中处于高表达状态。研究表明在早期诊断方面HE4比糖类抗原125(CA125)有更高的灵敏度和特异度,在疾病的治疗过程中可以预测肿瘤细胞减灭术的满意度及患者对铂类的反应,在卵巢癌的复发及预后的监测中HE4也有很大的临床应用价值。     

Characterization of serum biomarkers for detection of early stage ovarian cancer

We have previously reported the identification of three ovarian cancer biomarker panels comprised of SELDI-TOF-MS peaks representing 14 differentially expressed serum proteins for the diagnosis of ovarian cancer. Using micro-LC-MS/MS, we identified five m/z peaks as transthyretin (TTR 13.9 kDa, TTR fragment 12.9 kDa), beta-hemoglobin (Hb, 15.9 kDa), apolipoprotein AI (ApoAI, 28 kDa) and transferrin (TF, 79 kDa). Western and/or ELISA methods confirmed the differential expression of TTR, Hb, and TF, and multivariate analyses resulted in improving the detection of early stage ovarian tumors (low malignant potential and malignant; receiver operating characteristic, ROC 0.933) as compared to cancer antigen CA125 alone (ROC 0.833). Interestingly, when CA125 was included with our markers in the multivariate analysis, the ROC increased to 0.959. Furthermore, multivariate analysis with only the mucinous subtype of early stage ovarian tumors, showed our markers to greatly improve the detection of disease (ROC 0.959) as compared to CA125 alone (ROC 0.613). Interestingly, the combination of CA125 with our markers did not seem to further improve the detection of mucinous tumors (ROC 0.955). We conclude that TTR, Hb, ApoAI and TF, when combined with CA125 should significantly improve the detection of early stage ovarian cancer.     

CA 125 in biological fluids

CA 125 is not a specific tumor marker, and is synthesized by normal and malignant cells of different origin (mainly in tissues derived from the müllerian epithelia) in a similar proportion. Abnormal CA 125 levels may be found in fluids of different origin (ascites, pleura, pericardium, amniotic fluid, cyst fluid, bronchoalveolar fluid, etc.) and in serum from patients with these fluids. Differences in serum CA 125 found in malignant or benign diseases may be related to the number of cells that synthesize the marker, and are highly dependent on the access to serum, where the marker is normally determined. Moreover, CA 125 is a very good tumor marker in ovarian and lung cancer. The sensitivity of CA 125 in ovarian cancer is related to stage (40-95%), histological type (lower levels in mucinous adenocarcinoma), and the marker is useful in the early detection of recurrence (sensitivity 80%) and in therapy monitoring. It's sensitivity in lung cancer is lower than in ovarian cancer, 39% in locoregional malignancies and 69% in metastatic disease, but clearly related to stage and histology (mainly in adenocarcinomas and large cell lung cancer) and it is useful in prognosis and disease monitoring.     

Measurement of Phospholipids May Improve Diagnostic Accuracy in Ovarian Cancer

Background

More than two-thirds of women who undergo surgery for suspected ovarian neoplasm do not have cancer. Our previous results suggest phospholipids as potential biomarkers of ovarian cancer. In this study, we measured the serum levels of multiple phospholipids among women undergoing surgery for suspected ovarian cancer to identify biomarkers that better predict whether an ovarian mass is malignant.

Methodology/Principal Findings

We obtained serum samples preoperatively from women with suspected ovarian cancer enrolled through a prospective, population-based rapid ascertainment system. Samples were analyzed from all women in whom a diagnosis of epithelial ovarian cancer (EOC) was confirmed and from benign disease cases randomly selected from the remaining (non-EOC) samples. We measured biologically relevant phospholipids using liquid chromatography/electrospray ionization mass spectrometry. We applied a powerful statistical and machine learning approach, Hybrid huberized support vector machine (HH-SVM) to prioritize phospholipids to enter the biomarker models, and used cross-validation to obtain conservative estimates of classification error rates.

Results

The HH-SVM model using the measurements of specific combinations of phospholipids supplements clinical CA125 measurement and improves diagnostic accuracy. Specifically, the measurement of phospholipids improved sensitivity (identification of cases with preoperative CA125 levels below 35) among two types of cases in which CA125 performance is historically poor - early stage cases and those of mucinous histology. Measurement of phospholipids improved the identification of early stage cases from 65% (based on CA125) to 82%, and mucinous cases from 44% to 88%.

Conclusions/Significance

Levels of specific serum phospholipids differ between women with ovarian cancer and those with benign conditions. If validated by independent studies in the future, these biomarkers may serve as an adjunct at the time of clinical presentation, to distinguish between women with ovarian cancer and those with benign conditions with shared symptoms and features.     

Clinical evaluation of a new two-site assay for CA125 antigen

As appropriate surgery and chemotherapy can improve both quality of life and survival of patients with ovarian adenocarcinoma, there has been a pressing need for "serodiagnostic" assays to enable close patient monitoring. CA 125 antigen has previously been described as a useful tumor marker of ovarian cancer. This is the first clinical evaluation of a radioimmunoassay using two new monoclonal antibodies, B27.1 and B43.13, that react with separate sites on the glycoprotein marker CA 125. Using the new assay, the majority of patients with clinically or radiologically detectable disease had serum CA 125 antigen levels well above the upper limit seen with random apparently healthy donors, while only three patients who were believed free of disease had elevated levels. Disease progression was associated with increasing values of serum CA 125 antigen, while response to therapy was associated with a steady decline in serum CA 125 antigen levels. Seven patients had steadily rising serum CA 125 antigen levels after initially having normal levels. The mean lead time between rise above normal and clinical or radiological evidence of relapse was 5 months (range 2 to 12 months). The merits of further surgical intervention are illustrated by the serial values of two patients followed after chemotherapy. The assay appears to have value in monitoring response to therapy and in detecting disease relapse at a time when appropriate therapeutic intervention is still possible or likely to be beneficial. Furthermore, monitoring CA 125 antigen was shown to be of benefit in assessing response to chemotherapy in a few patients with metastatic adenocarcinoma of unknown primary, and may be useful in this group of patients in determining those likely to benefit from aggressive chemotherapy.     

Free CA125 promotes ovarian cancer cell migration and tumor metastasis by binding Mesothelin to reduce DKK1 expression and activate the SGK3/FOXO3 pathway

Objective: CA125/MUC16 is an O-glycosylated protein that is expressed on the surfaces of ovarian epithelial cells. This molecule is a widely used tumor-associated marker for diagnosis of ovarian cancer. Recently, CA125 was shown to be involved in ovarian cancer metastasis. The purpose of this study was to investigate the mechanism of CA125 during ovarian cancer metastasis.Methods: We analyzed the Oncomine and CSIOVDB databases to determine the expression levels of DKK1 in ovarian cancer. DKK1 expression levels were upregulated or downregulated and applied with CA125 to Transwell and Western blot assays to ascertain the underlying mechanism by which CA125 stimulates cell migration via the SGK3/FOXO3 pathway. Anti-mesothelin antibodies (anti-MSLN) were used to block CA125 stimulation. Then the expression levels of DKK1were tested by enzyme-linked immunosorbent assay (ELISA) to eliminate the blocking effect of anti-MSLN to CA125 stimulation. Xenograft mouse models were used to detect the effects of CA125 and anti-MSLN on ovarian cancer metastasis in vivo.Results: DKK1 levels were downregulated in ovarian tumor tissues according to the analyses of two databases and significantly correlated with FIGO stage, grade and disease-free survival in ovarian cancer patients. DKK1 levels were downregulated by CA125 stimulation in vitro. Overexpression of DKK1 reversed the ability of exogenous CA125 to mediate cell migration by activating the SGK3/FOXO3 signaling pathway. Anti-MSLN abrogated the DKK1 reduction and increased the apoptosis of ovarian cancer cells. The use of anti-MSLN in xenograft mouse models significantly reduced tumor growth and metastasis accelerated by CA125.Conclusions: These experiments revealed that the SGK3/FOXO3 pathway was activated, wherein decreased expression of DKK1 was caused by CA125, which fuels ovarian cancer cell migration. Mesothelin is a potential therapeutic target for the treatment of ovarian cancer metastasis.     

血清OPN、HE4和CA125检测对卵巢癌的临床意义

目的：探讨联合检测血清OPN、HE4和CA125对卵巢癌的临床意义。方法：选择2010年6月-2012年7月西安市中心医院妇科及陕西省肿瘤医院妇瘤科收治的35例卵巢癌患者、73例卵巢良性肿瘤患者及40例同期体检的健康妇女为研究对象,应用ELISA法检测患者手术前后血清OPN、HE4水平,电化学发光法检测患者手术前后血清CA125水平,计算3种肿瘤标志物单项以及联合检测在卵巢癌诊断中的敏感性及特异性。结果：（1）卵巢癌患者术前血清OPN、HE4和CA125水平分别为94.6±61.06ng/mL、412.3±278.62 pmol/mL和398.64±220.91 U/mL,与卵巢良性肿瘤组及正常对照组比较差异有统计学意义（P〈0.05）;（2）卵巢癌患者手术前与术后1月血清OPN、HE4和CA125水平比较,差异均有统计学意义（P〈0.05）;（3）血清OPN、HE4和CA125水平联合检测诊断卵巢癌的敏感性（94.3%）显著高于血清OPN、HE4和CA125单项指标检测（分别为37.1%、71.4%和77.1%）,联合检测与单项指标检测比较差异均有统计学意义（P〈0.05）,而血清OPN、HE4和CA125联合检测诊断卵巢癌的特异性（78.8%）稍低于血清OPN、HE4和CA125单项指标检测（分别为87.6%、100%和80.5%）,联合检测与单项指标检测的特异性比较差异无统计学意义（P〉0.05）。血清HE4单项指标检测的特异性高达100%。结论：联合检测卵巢癌患者血清OPN、HE4和CA125水平可作为诊断和评估卵巢癌预后的参考指标。