Role of CA125 in predicting ovarian cancer survival - a review of the epidemiological literature

Plasma miR-200b in ovarian carcinoma patients: distinct pattern of pre/post-treatment variation compared to CA-125 and potential for prediction of progression-free survival

Ovarian carcinomas (OvCa) are highly heterogeneous malignancies. We investigated four circulating plasma microRNAs (miR-21, miR-34a, miR-200b and miR-205) as candidate biomarkers. Using qPCR, we assessed the plasma concentration of these markers in 101 women, including 51 previously untreated OvCa patients, 25 healthy women and 25 patients bearing benign pelvic lesions. For a subset of 33 OvCa patients, the assay was repeated at the end of the primary treatment. The pattern of variations (post- minus pre-treatment) of concentration was compared to that of CA-125. A Cox regression model was used to study the association between variations and the progression-free survival (PFS). Plasma miR-200b proved to have a greater average concentration in OvCa samples (median 2-ΔΔCt = 15.18) than in samples linked to non-malignant lesions (median 2-ΔΔCt = 1.26, p-value = 0.0004). Its concentration was highly heterogeneous among OvCa patients, without any correlations with the FIGO stage and the pre-treatment CA-125 level. The decrease in CA-125 concentration was constant and often dramatic, while the variations of miR-200b concentration were much more diverse. The variation of miR-200b was marginally associated with the PFS (hazard ratio=2.95 95%CI=[0.94; 9.28], p=0.06) while miR-200b as a continuous time-dependent variable was significantly associated (HR=1.06 [1.02; 1.10], p=0.003). This study is the first direct empirical evidence that miR-200b can provide additional information, independent of CA-125 in OvCa patients.

Plasma miR-200b in ovarian carcinoma patients: distinct pattern of pre/post-treatment variation compared to CA-125 and potential for prediction of progression-free survival

Ovarian carcinomas (OvCa) are highly heterogeneous malignancies. We investigated four circulating plasma microRNAs (miR-21, miR-34a, miR-200b and miR-205) as candidate biomarkers. Using qPCR, we assessed the plasma concentration of these markers in 101 women, including 51 previously untreated OvCa patients, 25 healthy women and 25 patients bearing benign pelvic lesions. For a subset of 33 OvCa patients, the assay was repeated at the end of the primary treatment. The pattern of variations (post- minus pre-treatment) of concentration was compared to that of CA-125. A Cox regression model was used to study the association between variations and the progression-free survival (PFS). Plasma miR-200b proved to have a greater average concentration in OvCa samples (median 2-ΔΔCt = 15.18) than in samples linked to non-malignant lesions (median 2-ΔΔCt = 1.26, p-value = 0.0004). Its concentration was highly heterogeneous among OvCa patients, without any correlations with the FIGO stage and the pre-treatment CA-125 level. The decrease in CA-125 concentration was constant and often dramatic, while the variations of miR-200b concentration were much more diverse. The variation of miR-200b was marginally associated with the PFS (hazard ratio=2.95 95%CI=[0.94; 9.28], p=0.06) while miR-200b as a continuous time-dependent variable was significantly associated (HR=1.06 [1.02; 1.10], p=0.003). This study is the first direct empirical evidence that miR-200b can provide additional information, independent of CA-125 in OvCa patients.

In vitro selection of RNA aptamers against CA125 tumor marker in ovarian cancer and its study by optical biosensing

Early identification of neoplastic diseases is essential to achieve timely therapeutic interventions and significantly reduce the mortality of patients. A well-known biomarker is the Cancer Antigen 125 (CA125) or 16 mucin (MUC 16), a glycoprotein of the human family of mucins, already used for the diagnostic and prognostic evaluation of ovarian cancer. Therefore, the detection of CA125 to now remains a promising tool in the early diagnosis of this tumor. In this paper, we describe the development of RNA aptamers that bind with high affinity the tumor antigen CA125. We performed eight cycles of selection against CA125 purified protein. The selected aptamers were cloned and sequenced and the binding properties of the most promising sequences were studied by Real Time PCR and Surface Plasmon Resonance (SPR) to evaluate their ability in targeting CA125 protein with perspective applications in aptamer-based bioassays.

The added value of circulating tumor cells examination in ovarian cancer staging

Delayed diagnosis of ovarian cancer (OC) is usually a cause of its high mortality. OC counts for one of the most aggressive gynecological malignancies. Noninvasive biomarkers may be used to help with diagnostic and treatment decisions in OC management. The incidence and clinical significance of occult OC cells (circulating tumor cells-CTCs) in the peripheral blood of patients with newly diagnosed or nondiagnosed OC at the time of surgical intervention were examined in our study. The objective of the study was to isolate and cultivate CTCs in OC patients (mainly stage IIIB-C) by a recently introduced size-based separation method (MetaCell(®)). CTCs were successfully isolated in patients with OC capturing cells with proliferation potential. The cells were enriched in good fitness, which enabled the short term in vitro culture of the CTCs. The CTCs may be used for further downstream applications (e.g. gene expression analysis) even if in the majority of the in vitro CTC cultures no confluence was reached. The CTCs were detected in 77 out of 118 patients (65.2%). CTC positivity was given to the relationship with different disease stage parameters with special focus on CA125 marker levels. The results show that the information on CTC presence may provide new and independent prognosis staging information to the patient description. Several interesting relationships of CA125, age and ascites presence are reported. As shown in our patient sample, patients with ascites tend to have higher CA125 levels, even if the CTCs were not found in the peripheral blood. It suggests that hematogenous dissemination is fully represented by the CTCs while lymphogenic dissemination is represented by elevated CA125. In this context, easy access to CTCs provided by the method applied in our study, both at the time of diagnosis and relapse, may become an increasingly valuable tool in future. This methodology may provide an opportunity for more personalized medicine where treatment for OC may be guided by information from an individual's CTC molecular profile.

Risk of Ovarian Cancer Relapse score: a prognostic algorithm to predict relapse following treatment for advanced ovarian cancer

OBJECTIVE

The aim of this study was to construct a prognostic index that predicts risk of relapse in women who have completed first-line treatment for ovarian cancer (OC).

METHODS

A database of OC cases from 2000 to 2010 was interrogated for International Federation of Gynecology and Obstetrics stage, grade and histological subtype of cancer, preoperative and posttreatment CA-125 level, presence or absence of residual disease after cytoreductive surgery and on postchemotherapy computed tomography scan, and time to progression and death. The strongest predictors of relapse were included into an algorithm, the Risk of Ovarian Cancer Relapse (ROVAR) score.

RESULTS

Three hundred fifty-four cases of OC were analyzed to generate the ROVAR score. Factors selected were preoperative serum CA-125, International Federation of Gynecology and Obstetrics stage and grade of cancer, and presence of residual disease at posttreatment computed tomography scan. In the validation data set, the ROVAR score had a sensitivity and specificity of 94% and 61%, respectively. The concordance index for the validation data set was 0.91 (95% confidence interval, 0.85-0.96). The score allows patient stratification into low (<0.33), intermediate (0.34-0.67), and high (>0.67) probability of relapse.

CONCLUSIONS

The ROVAR score stratifies patients according to their risk of relapse following first-line treatment for OC. This can broadly facilitate the appropriate tailoring of posttreatment care and support.

Prognosis and conditional disease-free survival among patients with ovarian cancer

PURPOSE

Traditional disease-free survival (DFS) does not reflect changes in prognosis over time. Conditional DFS accounts for elapsed time since achieving remission and may provide more relevant prognostic information for patients and clinicians. This study aimed to estimate conditional DFS among patients with ovarian cancer and to evaluate the impact of patient characteristics.

PATIENTS AND METHODS

Patients were recruited as part of the Hormones and Ovarian Cancer Prediction case-control study and were included in the current study if they had achieved remission after a diagnosis of cancer of the ovary, fallopian tube, or peritoneum (N = 404). Demographic and lifestyle information was collected at enrollment; disease, treatment, and outcome information was abstracted from medical records. DFS was calculated using the Kaplan-Meier method. Conditional DFS estimates were computed using cumulative DFS estimates.

RESULTS

Median DFS was 2.54 years (range, 0.03-9.96 years) and 3-year DFS was 48.2%. The probability of surviving an additional 3 years without recurrence, conditioned on having already survived 1, 2, 3, 4, and 5 years after remission, was 63.8%, 80.5%, 90.4%, 97.0%, and 97.7%, respectively. Initial differences in 3-year DFS at time of remission between age, stage, histology, and grade groups decreased over time.

CONCLUSION

DFS estimates for patients with ovarian cancer improved dramatically over time, in particular among those with poorer initial prognoses. Conditional DFS is a more relevant measure of prognosis for patients with ovarian cancer who have already achieved a period of remission, and time elapsed since remission should be taken into account when making follow-up care decisions.

Evaluation of Preoperative Serum Levels of CA 125 and Expression of p53 in Ovarian Neoplasms: A Prospective Clinicopathological Study in a Tertiary Care Hospital

OBJECTIVES

To assess the preoperative serum levels of CA 125 with its diagnostic role and to evaluate the p53 expression in patients of primary ovarian neoplasms. We also wished to judge their relationship with other parameters like clinical staging and histopathologic tumor type.

MATERIALS AND METHODS

The present study was conducted on 86 patients during the study period of 2.5 years. Preoperative CA 125 levels were evaluated by an automated immunoassay analyzer. p53 expression was judged immunohistochemically with pre-diluted monoclonal antibody. An objective scoring was done depending on distinct nuclear immunopositivity.

RESULTS

Median value of preoperative CA 125 levels was 32 U/mL in benign surface epithelial-stromal tumors (BSEST), 53 U/mL in borderline surface epithelial-stromal tumors (BOT), 346 U/mL in malignant surface epithelial-stromal tumors (MSEST) and 560 U/mL in serous adenocarcinomas (SAC). Most of ovarian tumors were in the FIGO stage I (64 cases, 74.4%), but higher stages (II, III, IV) were observed mostly in MSESTs. SACs displayed the maximum p53 expression. Considering the cut-off value of more than 35 U/mL in CA 125 levels, the sensitivity to diagnose MSESTs was 94.7%. Preoperative CA 125 levels strongly and positively correlated with FIGO staging and p53 expression. Similarly p53 expression strongly and positively correlated with FIGO staging and histopathological categories.

CONCLUSION

Higher values of preoperative CA 125 levels and higher expression p53 are associated with MSESTs and BOTs especially of serous type. They strongly correlate with each other and with tumor stage. But there is no serum CA 125 concentration that can clearly differentiate benign and malignant ovarian masses.

Immunological response induced by abagovomab as a maintenance therapy in patients with epithelial ovarian cancer: relationship with survival-a substudy of the MIMOSA trial

PURPOSE

To determine whether abagovomab induces protective immune responses in ovarian cancer patients in first clinical remission. The present analysis is a substudy of monoclonal antibody immunotherapy for malignancies of the ovary by subcutaneous abagovomab trial (NCT00418574).

METHODS

The study included 129 patients, 91 in the abagovomab arm and 38 in the placebo arm. Circulating CA125-specific cytotoxic T lymphocytes (CTL) were measured by a flow cytometry-based interferon-γ producing assay. Human antimouse antibody and anti-anti-idiotypic (Ab3) were assessed by ELISA. Patients were evaluated before starting the treatment and at different time points during induction and maintenance phases.

RESULTS

A similar percentage of patients in both the placebo and abagovomab arms had CA125-specific CTL (26.3 and 31.8 %, respectively; p = 0.673 by Fisher's exact test). Patients with CA125-specific CTL in both arms tended to have an increased relapse-free survival (RFS, log-rank test p = 0.095) compared to patients without. Patients (n = 27) in the abagovomab arm without CA125-specific CTL but that developed Ab3 above the cutoff (defined as median Ab3 level at week 22) had a prolonged RFS compared to patients (n = 24) that did not develop Ab3 above the cutoff (log-rank test p = 0.019).

CONCLUSION

Abagovomab does not induce CA125-specific CTL. However, patients with CA125-specific CTL perform better than patients without, irrespective of abagovomab treatment. Abagovomab-induced Ab3 associate with prolonged RFS in patients without CA125-specific CTL. Further studies are needed to confirm these data and to assess the potential utility of these immunological findings as a tool for patient selection in clinical trial.

CA125 level association with chemotherapy toxicity and functional status in older women with ovarian cancer

OBJECTIVE

Older women with ovarian cancer have increased cancer-related mortality and chemotherapy toxicity. CA125 is a sensitive biomarker for tumor burden. The study evaluates the association between CA125, geriatric assessment (GA), and treatment toxicity.

METHODS

This is a secondary subset analysis of patients 65 years or older with ovarian cancer accrued to a multicenter prospective study that developed a predictive toxicity score for older adults with cancer. Clinical and geriatric covariates included sociodemographics, GA (comorbidity, social support, functional, nutritional, psychological, cognitive status), treatment, and laboratory studies. Using bivariate analyses, we determined the association of abnormal CA125 (≥35 U/mL) with baseline GA, grades 3 to 5 toxicity (Common Terminology Criteria for Adverse Events version 3), dose adjustments, and hospitalization. Logistic regression analysis was used to check for potential confounder for association between CA125 and chemotherapy toxicity.

RESULTS

Fifty-one (10%) of 500 patients accrued to the primary study had a diagnosis of ovarian (92%), peritoneal (4%), or fallopian tube (4%) cancer. Median age was 72 years (range, 65-86 years). Forty-six patients (90%) had stage III-IV disease. Twenty-three patients (45%) received first-line chemotherapy, and 34 (67%) received platinum-doublet therapy. Thirty-six (71%) had an abnormal CA125. Grades 3 to 5 toxicity occurred in 19 patients (37%). Abnormal CA125 was associated with assistance with instrumental activities of daily living (P < 0.05), lower performance status (P = 0.05), grades 3 to 5 toxicity (P = 0.03), nonheme toxicity (P = 0.04), and dose reductions (P = 0.01). No association between CA125 level and total toxicity score was observed.

CONCLUSIONS

Among older women with ovarian cancer, abnormal CA125 was associated with poor pretreatment functional status and an increased probability of chemotherapy toxicity and dose reduction.

A longitudinal analysis with CA-125 to predict overall survival in patients with ovarian cancer

Objective

The objective of this study was to explore the association of longitudinal CA-125 measurements with overall survival (OS) time by developing a flexible model for patient-specific CA-125 profiles, and to provide a simple and reliable prediction of OS.

Methods

A retrospective study was performed on 275 patients with ovarian cancer who underwent at least one cycle of primary chemotherapy in our institute. Serial measurements of patients' CA-125 levels were performed at different frequencies according to their clinical plans. A statistical model coupling the Cox proportional hazards and the mixed-effects models was applied to determine the association of OS with patient-specific longitudinal CA-125 values. Stage and residual tumor size were additional variables included in the analysis.

Results

A total of 1,601 values of CA-125 were included. Longitudinal CA-125 levels, stage, and the residual tumor size were all significantly associated with OS. A patient-specific survival probability could be calculated. Validation showed that, in average, 85.4% patients were correctly predicted to have a high or low risk of death at a given time point. Comparison with a traditional model using CA-125 half-life and time to reach CA-125 nadir showed that the longitudinal CA-125 model had an improved predicative value.

Conclusion

Longitudinal CA-125 values, measured from the diagnosis of ovarian cancer to the completion of primary chemotherapy, could be used to reliably predict OS after adjusting for the stage and residual tumor disease. This model could be potentially useful in clinical counseling of patients with ovarian cancer.

Dual detection of cancer biomarker CA125 using absorbance and electrochemical methods

An enzyme-linked immunoassay based on dual signal transduction mechanisms has been developed for detection of ovarian cancer biomarker CA125. The immunoassay uses a nanoelectrode array (NEA) chip and absorbance methods for the dual detection. The NEA is used to confirm the optical detection of CA125 that is carried out in a high-binding 96-well plate. An alkaline phosphatase (AP) enzyme was used to label the detection antibody to allow for both the optical and electrochemical detection of CA125. Two kinds of substrates were catalyzed by the AP enzyme. para-Nitrophenylphosphate (PNPP) produces chromogenic para-nitrophenol (PNP), which can be optically detected at 405 nm. para-Aminophenylphosphate (PAPP) produces electroactive para-aminophenol (PAP), which can be detected amperometrically between -0.1 and 0.3 V. The linear ranges have been determined to be 5-1000 U mL(-1) and 5-1000 U mL(-1) for the optical and electrochemical immunoassays, respectively. The limit of detection of the optical immunoassay is 1.3 U mL(-1) and 40 U mL(-1) for the optical and electrochemical methods, respectively.

Plasma endothelial protein C receptor influences innate immune response in ovarian cancer by decreasing the population of natural killer and TH17 helper cells

In spite of the growing importance of endothelial protein C receptor/active protein C (EPCR/aPC) in tumor biology, their impact on immunological homeostasis remains largely unexplored. The objective of this study was to assess whether soluble plasma endothelial protein C receptor (sEPCR), which is a regulator of circulating aPC, is involved in innate immune response in cancer patients. In the Ovcar-3 ovarian cancer line, the role of aPC in secretion of cytokines was analyzed. In parallel, in 33 patients, with a diagnosis of ovarian epithelial cancer, sEPCR was quantified, blood immune cell phenotypes were determined by flow cytometry and plasma cytokines were evaluated using a protein array. Spearman’s rank correlation coefficients (r) and coefficient significance was determined by a statistical hypothesis test (α=0.05). Our results show that i) aPC induced the secretion of several cytokines in Ovcar-3 cells; ii) 61% of patients exhibited a concentration of plasma sEPCR well above the baseline (normal plasma level, 100±28 ng/ml); iii) comparing immune cell phenotypes in patients having a normal level of sEPCR with those having a high level of sEPCR, it was found that sEPCR levels were correlated with high intensity of cells expressing CD45ra, CD3, CD8, CD25 and low intensity of cells expressing CD56 (NK cells), CD294 (TH2 cells), IL-2, IL-10, IL-17a (TH17 cells), IL-21 (TH21 cells) and CD29 markers (r ≥0.60); and iv) high levels of sEPCR correlate with high levels of plasma bioactive proteins such as insulin-like growth factor-2 (IGFII), IL-13rα, macrophage inflammatory protein (MIP1α) and matrix metalloproteinase-7 (MMP-7) that have already been proposed as biomarkers for ovarian cancer and particularly those with poor prognosis. In conclusion, sEPCR produced by ovarian cancer cells, by modulating circulating aPC, influences the secretory behavior of tumor cells (cytokines and interleukins). Consequently, sEPCR in turn acts on the innate immune response by decreasing effector cells such as natural killer and T helper cells (TH2, TH17 and TH21).

Identification of O-glycosylated proteins that are aberrantly excreted in the urine of patients with early stage ovarian cancer

Cancer is known to induce or alter the O-glycosylation of selective proteins that may eventually be excreted in the patients' urine. The present study was performed to identify O-glycosylated proteins that are aberrantly excreted in the urine of patients with early stage ovarian cancer (OCa). These urinary glycoproteins are potential biomarkers for early detection of OCa. In this study, urinary proteins of patients with early stage OCa and age-matched OCa negative women were subjected to two-dimensional gel electrophoresis and detection using a lectin that binds to the O-glycosylated proteins. Our analysis demonstrated significant enhanced expression of clusterin and leucine-rich alpha-2-glycoprotein, but lower levels of kininogen in the urine of the OCa patients compared to the controls. The different altered levels of these urinary glycoproteins were further confirmed using competitive ELISA. Our data are suggestive of the potential use of the aberrantly excreted urinary O-glycosylated proteins as biomarkers for the early detection of OCa, although this requires further validation in a large clinically representative population.

Identification of candidate biomarkers using the Experion™ automated electrophoresis system in serum samples from ovarian cancer patients

Ovarian cancer is the most common cause of disease-related death in women globally. Detection of ovarian cancer using new biomarkers is necessary for early diagnosis. To date, there have been no obvious biomarkers for ovarian cancer detection in the incipient stage. In this study, we discovered potential diagnostic serological biomarkers for ovarian cancer using the Experion™ automated electrophoresis system. Sera from 14 healthy women and 84 ovarian cancer patients at stages I- IV were applied to the Experion to compare the protein expression levels. To examine the protein expression pattern of Experion data, proteins in the samples were resolved using 10 and 15% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and visualized by silver staining. The candidate biomarkers elevated in ovarian cancer were purified and determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. α-2-macroglobulin (173.7 kDa), ceruloplasmin (147 kDa), inter-α-trypsin inhibitor family heavy chain-related protein (126 kDa), C-1 inhibitor (115.2 kDa) and hemoglobin α/β (14.4 kDa were overexpressed in the ovarian cancer sera. This study documents a novel way to measure ovarian cancer or cancer-related proteins for biomarkers using the Experion assay system, which should be easily adaptable for high-throughput diagnosis to establish databases of ovarian cancer for clinical applications.

High serum levels of follistatin in patients with ovarian cancer

OBJECTIVE

This study investigated the potential use of serum follistatin (FST) as a marker for ovarian cancer alongside serum cancer antigen-125 (CA-125).

METHODS

Serum samples were collected from patients with ovarian cancer (n = 45), benign ovarian cysts (n = 40) or other cancers (n = 100) and from healthy subjects (n = 60) for the determination of FST and CA-125 levels using enzyme-linked immunosorbent assays. Expression of FST in ovarian tissue was investigated using immunohistochemical staining.

RESULTS

Compared with healthy subjects and patients with benign ovarian cysts, serum FST and CA-125 levels were significantly increased in patients with ovarian cancer. Using the 95% confidence interval for the healthy subjects group as the cut-off value, tumour marker sensitivity and specificity in ovarian cancer were 53.3% and 97% for FST and 77.8% and 84% for CA-125, respectively. Tissue expression of FST protein was more pronounced in ovarian cancer than in normal ovary.

CONCLUSIONS

The serum FST level was elevated in the peripheral blood of patients with ovarian cancer and has potential as a tumour marker for ovarian cancer diagnosis. It may be particularly useful when combined with CA-125 detection to reduce the number of false-positive results.

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.

HE4 protein and SMRP: Potential novel biomarkers in ovarian cancer detection

Epithelial ovarian cancer has the highest mortality of all gynecological cancers, and its progression is often without symptoms. Clinical outcome and survival may be improved if the disease is identified in the early stages. The objective of the study was to evaluate the utility of the serum biomarkers human epididymis protein 4 (HE4), soluble mesothelin-related protein (SMRP) and CA125 in the detection of ovarian cancer. In this retrospective study, the serum concentrations of CA125, HE4 protein and SMRP were measured in a cohort of 70 patients with epithelial ovarian cancer (EOC) compared with 78 healthy controls. Median serum levels of CA125 for ovarian cancer cases were 503.55±560.7 U/ml vs. 9.28±14.47 U/ml in the control group (p<0.001); for SMRP 5.13±7.64 nM vs. 1.02±0.89 nM (p<0.01); and for HE4 597.95±934.59 pM vs. 56.75±43.79 pM (p<0.001), respectively. Positive correlations between the clinical stage of EOC and CA125, HE4 and SMRP serum concentrations were found [(R=0.83; p<0.001); (R=0.64; p<0.001); (R=0.45; p<0.001), respectively]. Data analysis for the whole study group also revealed a significant correlation between plasma concentrations of CA125 and HE4 (R=0.45; p<0.001), between CA125 and SMRP (R=0.38; p<0.001) as well as HE4 and SMRP (R=0.51; p<0.001). Similar significant correlations between serum biomarker concentrations were also found in the ovarian cancer group [CA125 and HE4 (R=0.31; p<0.01); CA125 and SMRP (R=0.25; p<0.05); HE4 and SMRP (R=0.44, p<0.001), respectively]. A significant correlation was observed between the serous histological type of EOC and serum concentration of HE4 in the study group compared with other non-serous types of ovarian cancer (p<0.01). In conclusion, measuring CA125 in combination with new biomarkers such as SMRP and HE4 may improve the accuracy of ovarian cancer diagnosis, particularly in early detection of the disease.

Ovarian metastases resection from extragenital primary sites: outcome and prognostic factor analysis of 147 patients

BACKGROUND

To explore the outcomes and prognostic factors of ovarian metastasectomy intervention on overall survival from extragenital primary cancer.

METHODS

Patients with ovarian metastases from extragenital primary cancer confirmed by laparotomy surgery and ovarian metastases resection were retrospectively collected in a single institution during an 8-year period. A total of 147 cases were identified and primary tumor sites were colorectal region (49.0%), gastric (40.8%), breast (8.2%), biliary duct (1.4%) and liver (0.7%). The pathological and clinical features were evaluated. Patients' outcome with different primary tumor sites and predictive factors for overall survival were also investigated by univariate and multivariate analysis.

RESULTS

Metachronous ovarian metastasis occurred in 92 (62.6%) and synchronous in 55 (37.4%) patients. Combined metastases occurred in 40 (27.2%). Bilateral metastasis was found in 97 (66%) patients. The median ovarian metastasis tumor size was 9 cm. There were 39 (26.5%) patients with massive ascites ≥ 1000 mL on intraoperative evaluation. With a median follow-up of 48 months, the median OS after ovarian metastasectomy for all patients was 8.2 months (95% CI 7.2-9.3 months). In univariate analyses, there is significant (8.0 months vs. 41.0 months, P = 0.000) difference in OS between patients with gastrointestinal cancer origin from breast origin, and between patients with gastric origin from colorectal origin (7.4 months vs. 8.8 months, P = 0.036). In univariate analyses, synchronous metastases, locally invasion, massive intraoperative ascites (≥ 1000 mL), and combined metastasis, were identified as significant poor prognostic factors. In multivariate analyses combined metastasis (RR, 1.72; 95% CI, 1.09-2.69, P = 0.018), locally invasion (RR, 1.62; 95% CI, 1.03-2.54, P = 0.038) and massive intraoperative ascites (RR, 1.58; 95% CI, 1.02-2.49, P = 0.04) were independent factors for predicting unfavorable overall survival.

CONCLUSION

Ovarian metastases are more commonly originated from primary gastrointestinal tract. The prognosis of ovarian metastasis is dismal and the benefit of ovarian metastatectomy is limited. Combined metastasis outside ovaries, locally invasion and massive intraoperative ascites were independent factors for predicting unfavorable overall survival. The identification of the primary tumor is required to plan for adequate treatment for this group of patients.

Multiplexed bead-based immunoassay of four serum biomarkers for diagnosis of ovarian cancer

The purpose of the present study was to evaluate multiplex liquid assay-based measurement of multiple ovarian cancer-associated biomarkers such as hemoglobin, haptoglobin and apolipoprotein E, together with CA125, which has been widely used in the diagnosis of ovarian cancer, in order to provide a higher diagnostic power. We measured the serum levels of CA125, hemoglobin, haptoglobin and apolipoprotein E from the serum of 76 healthy individuals and 69 ovarian cancer patients using a multiplex liquid assay system, Luminex 100. The results were analyzed according to normal versus ovarian cancer, tumor stages and tumor histology. In addition, to validate the use of these biomarkers for the diagnosis of ovarian cancer, the sensitivity and specificity of each biomarker was analyzed by its receiver operating characteristics (ROC) curve. The serum levels of all four biomarkers in ovarian cancer patients were significantly higher than those of healthy individuals. When CA125 was combined with the biomarkers, the overall sensitivity and specificity were significantly improved in the ROC curve, which showed 95 and 75% sensitivity and specificity, respectively. At 95% specificity for all stages the sensitivity increased to 75% compared to 41% for CA125 alone. For stage I+II increased the sensitivity to 68% from 36% for CA125 alone. For stage III+IV the corresponding values were 100 and 95%, respectively. Taken together, the new combination of hemoglobin, haptoglobin and apolipoprotein E with CA125 significantly 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.

Prognostic impact of prechemotherapy serum levels of HER2, CA125, and HE4 in ovarian cancer patients

OBJECTIVE

Human epididymis protein 4 (HE4) has attracted a lot of interest as a relatively novel biomarker for ovarian carcinoma. Research focus has been directed at HE4 as a diagnostic tool with potential for better triage of women with adnexal masses but the prognostic aspect of HE4 in ovarian cancer patients remains to be elucidated. The aim of the present study was to investigate the prognostic value of prechemotherapy serum HER2, cancer antigen 125 (CA125), and HE4 levels in ovarian cancer patients receiving standard combination chemotherapy.

METHODS

Serum from 139 patients with newly diagnosed ovarian cancer was analyzed for HER2, CA125, and HE4 using enzyme-linked immunosorbent assay assays. Samples were collected just before first-line chemotherapy, and all patients were treated with carboplatin-paclitaxel combination chemotherapy.

RESULTS

Increasing levels of serum HE4 (grouped into quartiles) was significantly associated with worse progression-free survival (PFS) (P < 10) and overall survival (P < 10). After adjustment in the Cox model, HE4 serum levels remained an independent prognostic parameter for PFS, with a hazard ratio of 1.77 (95% confidence interval, 1.03-3.04; P = 0.040) for patients with HE4 levels above the median compared with patients with HE4 levels below the median. The shorter PFS for patients with high levels of HE4 also translated into an independent significant difference in overall survival (hazard ratio, 3.17 [95% confidence interval, 1.41-7.10]; P = 0.005).Serum HER2 and CA125 levels did not demonstrate an independent prognostic value.

CONCLUSIONS

High levels of serum HE4 is a strong and independent indicator of worse prognosis in epithelial ovarian cancer patients.

Epitope presentation is an important determinant of the utility of antigens identified from protein arrays in the development of autoantibody diagnostic assays

Autoantibodies represent an attractive biomarker for diagnostic assays principally due to the stability of immunoglobulin in patient serum facilitating measurement with conventional assays. Immune responses to tumorigenesis may facilitate detection of ovarian cancer in the early stages of the disease with identification of a panel of tumour specific autoantibodies. Despite the reporting of many tumour associated autoantibodies using arrays of tumour antigens, this has not led to the advance in diagnostic capability as rapidly as was initially expected. Here we examine the potential diagnostic utility of candidate autoantibody biomarkers identified via screening of serum samples on a high content human protein array from a unique cohort of early stage and late stage ovarian cancer patients. We analyse the performance of autoantibodies to the tumour suppressor protein p53 and the novel autoantigens alpha adducin and endosulfine alpha identified in our array screen. Each antigen has different performance characteristics using conventional ELISA format and Western blot immunoassay. The high attrition rate of promising autoantigens identified by array screening can in part be explained by the presentation of the epitope of the antigen in the subsequent method of validation and this study provides directions on maximising the potential of candidate biomarkers. This article is part of a Special Issue entitled: Translational Proteomics.

Preoperative platelet lymphocyte ratio as an independent prognostic marker in ovarian cancer

INTRODUCTION

Ovarian cancer is associated with high mortality due to presentation at advanced stage and high recurrence following treatment with chemotherapy. Most of the prognostic variables in ovarian cancer, including stage and residual disease, are amenable for assessment only after surgery. Currently there are no established preoperative markers including, CA-125, that can predict overall survival in patients with ovarian cancer. The aim of our study was to evaluate the prognostic significance of the preoperative haematological markers platelet lymphocyte ratio (PLR) and neutrophil lymphocyte ratio (NLR) in patients with ovarian cancer.

METHOD

Preoperative PLR and NLR were evaluated in 235 patients undergoing surgery for ovarian cancer. The prognostic significance of both markers was then determined by both uni- and multivariate analytical methods.

RESULTS

High preoperative PLR (p < 0.001) and NLR (p = 0.001) were significantly associated with poor survival using univariate Cox survival analysis. The median overall survival in patients with a PLR of < 300 was 37.4 months (95% CI 26.1-48.7) and 14.5 months (95% CI 11.7-17.2) in those with a PLR of > 300. PLR (p = 0.03) but not NLR (p = 0.575) retained its significance as a prognostic marker on multivariate Cox's regression analysis, along with stage (p < 0.001) and residual disease (p = 0.015).

CONCLUSION

We have shown for the first time that PLR is a novel independent prognostic marker in patients with ovarian cancer.

Humanized mouse model of ovarian cancer recapitulates patient solid tumor progression, ascites formation, and metastasis

Ovarian cancer is the most common cause of death from gynecological cancer. Understanding the biology of this disease, particularly how tumor-associated lymphocytes and fibroblasts contribute to the progression and metastasis of the tumor, has been impeded by the lack of a suitable tumor xenograft model. We report a simple and reproducible system in which the tumor and tumor stroma are successfully engrafted into NOD-scid IL2Rγ^null (NSG) mice. This is achieved by injecting tumor cell aggregates derived from fresh ovarian tumor biopsy tissues (including tumor cells, and tumor-associated lymphocytes and fibroblasts) i.p. into NSG mice. Tumor progression in these mice closely parallels many of the events that are observed in ovarian cancer patients. Tumors establish in the omentum, ovaries, liver, spleen, uterus, and pancreas. Tumor growth is initially very slow and progressive within the peritoneal cavity with an ultimate development of tumor ascites, spontaneous metastasis to the lung, increasing serum and ascites levels of CA125, and the retention of tumor-associated human fibroblasts and lymphocytes that remain functional and responsive to cytokines for prolonged periods. With this model one will be able to determine how fibroblasts and lymphocytes within the tumor microenvironment may contribute to tumor growth and metastasis, and will make it possible to evaluate the efficacy of therapies that are designed to target these cells in the tumor stroma.

Combination of CA125 and RECAF biomarkers for early detection of ovarian cancer

Ovarian cancer can be cured in up to 90% of cases if diagnosed early. CA125, the most studied ovarian cancer biomarker, exhibits poor sensitivity for detecting early disease stages and low specificity to malignancy. RECAF, the alpha-fetoprotein receptor, is a wide-spectrum oncofetal antigen with clinical potential for cancer diagnosis, screening, and monitoring. This study evaluated the performance of RECAF as a diagnostic tool and the sensitivity of a combination of RECAF and CA125 to detect early stages of ovarian cancer at a cutoff resulting in 100% specificity among healthy women. This retrospective case–control study was designed to measure the serum levels of RECAF and CA125 in normal individuals (n = 106) and cancer patients stages I/II (RECAF, n = 32; CA125, n = 35) and III/IV (RECAF, n = 49; CA125, n = 51). A competitive chemiluminescence assay was developed to measure the circulating RECAF. To eliminate any false positives, we classified as positive any patient with a RECAF or a CA125 value higher than their respective 100% specificity cutoff. We have shown that RECAF discriminated cancer and healthy donors better than CA125, particularly in the early stages (AUC_RECAF = 0.96 and AUC_CA125 = 0.805). CA125 sensitivity was lower in the early stages than in the advance stages; RECAF sensitivity was high at all stages. A combination of CA125 and RECAF detected three out of four early-stage patients, with no false positives. In conclusion, the combination of RECAF and CA125 serum values provides the specificity and the sensitivity necessary to screen for ovarian cancer and in particular, to detect early stages of the disease.

Human xeno-autoantibodies against a non-human sialic acid serve as novel serum biomarkers and immunotherapeutics in cancer

Human carcinomas can metabolically incorporate and present the dietary non-human sialic acid Neu5Gc, which differs from the human sialic acid N-acetylneuraminic acid (Neu5Ac) by 1 oxygen atom. Tumor-associated Neu5Gc can interact with low levels of circulating anti-Neu5Gc antibodies, thereby facilitating tumor progression via chronic inflammation in a human-like Neu5Gc-deficient mouse model. Here we show that human anti-Neu5Gc antibodies can be affinity-purified in substantial amounts from clinically approved intravenous IgG (IVIG) and used at higher concentrations to suppress growth of the same Neu5Gc-expressing tumors. Hypothesizing that this polyclonal spectrum of human anti-Neu5Gc antibodies also includes potential cancer biomarkers, we then characterize them in cancer and noncancer patients' sera, using a novel sialoglycan microarray presenting multiple Neu5Gc-glycans and control Neu5Ac-glycans. Antibodies against Neu5Gcα2-6GalNAcα1-O-Ser/Thr (GcSTn) were found to be more prominent in patients with carcinomas than with other diseases. This unusual epitope arises from dietary Neu5Gc incorporation into the carcinoma marker Sialyl-Tn, and is the first example of such a novel mechanism for biomarker generation. Finally, human serum or purified antibodies rich in anti-GcSTn-reactivity kill GcSTn-expressing human tumors via complement-dependent cytotoxicity or antibody-dependent cellular cytotoxicity. Such xeno-autoantibodies and xeno-autoantigens have potential for novel diagnostics, prognostics, and therapeutics in human carcinomas.

Potential markers for detection and monitoring of ovarian cancer

This paper reviews current screening techniques as well as novel biomarkers and their potential role in early detection of ovarian cancer. Ovarian cancer is one of the most common reproductive cancers and has the highest mortality rate amongst gynecologic cancers. Because most ovarian cancer diagnoses occur in the late stages of the disease, five-year survival rates fall below 20%. To improve survival rates and to lower mortality rates for ovarian cancer, improved detection at early stages of the disease is needed. Current screening approaches include tumor markers, ultrasound, or a combination. Efforts are underway to discover new biomarkers of ovarian cancer in order to surmount the obstacles in early-stage diagnosis. Among serum protein markers, HE4 and mesothelin can augment CA125 detection providing higher sensitivity and specificity due to the presence of these proteins in early-stage ovarian cancer. Detection testing that includes methylation of the MCJ gene and increased expression of vascular endothelial growth factor is correlated to poor prognosis and may predict patient survival outcome. Detection testing of biomarkers with long-term stability and combination panels of markers, will likely lead to effective screening strategies with high specificity and sensitivity for early detection of ovarian cancer.

Breast cancer 1 (BRCA1) protein expression as a prognostic marker in sporadic epithelial ovarian carcinoma: an NCIC CTG OV.16 correlative study

BACKGROUND

Breast cancer 1 (BRCA1) protein inactivation in sporadic ovarian carcinoma (OC) is common and low BRCA1 expression is linked with platinum sensitivity. The clinical validation of BRCA1 as a prognostic marker in OC remains unresolved.

PATIENTS AND METHODS

In 251 patient samples from the NCIC CTG clinical trial, OV.16, BRCA1 protein expression was determined by immunohistochemistry.

RESULTS

For all patients, when BRCA1 score was analyzed as a continuous variable, there was no significant correlation between BRCA1 protein expression and progression-free survival (PFS) [adjusted hazard ratio (HR) = 1.15 (0.96-1.37), P = 0.12] or response rate [HR = 0.89 (0.70-1.12), P = 0.32]. In the 116 patients with minimal residual disease (RD), higher BRCA1 expression correlated significantly with worse PFS [HR = 1.40 (1.04-1.89), P = 0.03]. Subgroup analysis divided patients with minimal RD into low (BRCA1 ≤2.5) and high (BRCA1 >2.5) expression groups. Patients with low BRCA1 expression had a more favorable outcome [median PFS was 24.7 and 16.6 months in patients with low and high BRCA1, respectively; HR = 0.56 (0.35-0.89), P = 0.01].

CONCLUSIONS

This study suggests that BRCA1 protein is a prognostic marker in sporadic OC patients with minimal RD. Further research is needed to evaluate BRCA1 as a predictive biomarker and to target BRCA1 expression to enhance chemotherapeutic sensitivity.

Synthesis and structural characterization of the peptide epitope of the ovarian cancer biomarker CA125 (MUC16)

A highly conserved region of 21 amino acids flanked by cysteine residues, contained within a larger repeated domain, has been proposed to be the antibody-binding site in the ovarian cancer biomarker CA125 (MUC16). In this study solid-phase peptide synthesis with Fmoc protection chemistry was used to assemble a 21-mer peptide corresponding to the most frequently occurring antibody binding sequence in CA125. Potentially significant sequence variants were also synthesized. Peptide secondary structure was investigated using Fourier transform infrared spectroscopy, revealing the consensus sequence peptide to be largely unstructured at physiological pH whether the cysteine residues were reduced or were oxidized to form an intramolecular disulfide bond. Substitution of serine for proline at position 8 (P8S) results in β-sheet formation in peptides involved in intramolecular disulfide bonds. This β-sheet structure does not persist in peptides incapable of intramolecular disulfide bonding because of sequence nor in peptides treated with the reducing agent dithiothreitol. In CA125, P8S is predicted to occur in ∼25% of repeat domains, suggesting that this structural motif is a non-negligible contributor to overall structure and function. These findings suggest that future structural characterization efforts of CA125 should be especially mindful of the amino acid sequence and oxidation state of the protein.