Comparison of three tumor markers--CA-125, lipid-associated sialic acid (LSA), and NB/70K--in monitoring ovarian cancer

Determination of sialic acid in saliva by means of surface-enhanced Raman spectroscopy as a marker in adnexal mass patients: ovarian cancer vs benign cases

Background

To demonstrate the use of surface-enhanced Raman spectroscopy (SERS) to determine sialic acid (SA) levels in saliva using silver nanoparticles as substrates, in adnexal mass patients scheduled for surgical intervention to remove invasive masses, with the aim to compare SA levels in benign tumor vs ovarian cancer patients.

Methods

Quantification of SA levels was accomplished by measuring their SERS and calibrating with analytical reagent SA. The mean SA concentration in saliva from 37 benign adnexal mass resulted smaller (5.1 mg/dL) than the mean concentration in 15 Ovarium cancer patients (23 mg/dL). The cancer condition was determined by biopsy of the removed adnexal mass. The CA-125 biomarker was also measured. The predictive potential of both biomarkers is discussed, together with the malignity risk index (MRI).

Results

Our results showed a sensitivity/specificity of 80%/100% with a cutoff to distinguish between benign/cancer cases of SA 15.5 mg/dL, as established from a ROC analysis. Our results suggest that SA may be a more useful biomarker than CA-125 to detect ovarian cancer.

Conclusions

Our results suggest that the SA levels measured from saliva may be as good predictors as the MRI index for the presence of ovarian cancer in sensitivity/negative predictive value and outperforms it in specificity/positive predictive value.

Electronic supplementary material

The online version of this article (10.1186/s13048-018-0433-9) contains supplementary material, which is available to authorized users.

Sialic acids: biomarkers in endocrinal cancers

Sialylations are post translational modification of proteins and lipids that play important role in recognition, signaling, immunological response and cell-cell interaction. Improper sialylations due to altered sialyl transferases, sialidases, gene structure and expression, sialic acid metabolism however lead to diseases and thus sialic acids form an important biomarker in disease. In the endocrinal biology such improper sialylations including altered expression of sialylated moieties have been shown to be associated with disorders. Cancer still remains to be the major cause of global death and the cancer of the endocrine organs suffer from the dearth of appropriate markers for disease prediction at the early stage and monitoring. This review is aimed at evaluating the role of sialic acids as markers in endocrinal disorders with special reference to cancer of the endocrine organs. The current study is summarized under the following headings of altered sialylations in endocrinal cancer of the (i) ovary (ii) pancreas (iii) thyroid (iv) adrenal and (v) pituitary gland. Studies in expression of sialic acid in testis cancer are limited. The future scope of this review remains in the targeting of endocrinal cancer by targeting altered sialylation which is a common expression associated with endocrinal cancer.

Fine needle aspiration cytology of ovarian tumors with histological correlation

BACKGROUND

Till today, there has been some hesitation to accept the role of fine needle aspiration cytology (FNAC) in pelvic mass. We have tried to study the role of ultrasonography (USG) and computed tomography (CT) guided FNAC as diagnostic and supportive investigation for ovarian tumors.

AIM

To evaluate the current status of image-directed percutaneous aspiration of ovarian neoplasm for the purpose of early detection of malignancy.

MATERIALS AND METHODS

Seventy-four fine needle aspirations of ovarian neoplasms were performed between January 2007 and December 2008 by transabdominal approach under USG and CT guidance and correlated with histopathological findings and tumor markers.

RESULTS

A total of 47 (63.5%) cases were assessed as malignant and 21 (28.3%) as benign and 6 (8.1%) as inconclusive. The neoplastic lesions were categorized as per World Health Organization (WHO) classification.

CONCLUSION

With the availability of modern techniques, USG and CT guided FNAC can be an optimum modality for the diagnosis of primary and metastatic ovarian neoplasms and evaluation of recurrent malignant tumors, which has great impact on patient management consequently.

Ovarian cancer detection from metabolomic liquid chromatography/mass spectrometry data by support vector machines

Background

The majority of ovarian cancer biomarker discovery efforts focus on the identification of proteins that can improve the predictive power of presently available diagnostic tests. We here show that metabolomics, the study of metabolic changes in biological systems, can also provide characteristic small molecule fingerprints related to this disease.

Results

In this work, new approaches to automatic classification of metabolomic data produced from sera of ovarian cancer patients and benign controls are investigated. The performance of support vector machines (SVM) for the classification of liquid chromatography/time-of-flight mass spectrometry (LC/TOF MS) metabolomic data focusing on recognizing combinations or "panels" of potential metabolic diagnostic biomarkers was evaluated. Utilizing LC/TOF MS, sera from 37 ovarian cancer patients and 35 benign controls were studied. Optimum panels of spectral features observed in positive or/and negative ion mode electrospray (ESI) MS with the ability to distinguish between control and ovarian cancer samples were selected using state-of-the-art feature selection methods such as recursive feature elimination and L1-norm SVM.

Conclusion

Three evaluation processes (leave-one-out-cross-validation, 12-fold-cross-validation, 52-20-split-validation) were used to examine the SVM models based on the selected panels in terms of their ability for differentiating control vs. disease serum samples. The statistical significance for these feature selection results were comprehensively investigated. Classification of the serum sample test set was over 90% accurate indicating promise that the above approach may lead to the development of an accurate and reliable metabolomic-based approach for detecting ovarian cancer.

Lipid-associated sialoprotein in the cerebrospinal fluid: association with brain malignancies

BACKGROUND

Changes in the glycosylation process by tumor cells result in larger amounts of sialoproteins on their surface compared with normal cells. Sialoproteins then are released into the surrounding environment primarily by shedding or cell lysis. In the current study, the authors attempted to evaluate whether lipid-associated sialoprotein (LSP) in the cerebrospinal fluid (CSF) can distinguish patients with primary and metastatic brain tumors from those without brain tumors as well as determine response to treatment.

METHODS

CSF samples were obtained from a tissue bank. The concentration of LSP was determined after chloroform:methanol extraction followed by protein precipitation. One-way analysis of variance and Scheffe pairwise comparisons were used for statistical analysis.

RESULTS

The CSF of neurologically normal controls, patients with a normal leukocyte count (< or = 5/microl), and patients with various neurologic disorders or systemic tumors without central nervous system (CNS) malignancies contained similar levels of LSP. The CSF from patients with a normal leukocyte count and newly diagnosed primary or metastatic brain tumors contained on average 3.7-fold higher levels of LSP compared with CSF from patients without CNS tumors (P = 0.0001). The CSF from patients with brain tumors with progressive disease not responding to treatment contained high levels of LSP comparable to the levels found in newly diagnosed patients. The CSF from treatment-responsive patients contained decreased levels of LSP similar to that found in control patients.

CONCLUSIONS

The LSP in CSF may be a useful marker with which to determine the presence of intracranial malignancies and assess response to treatment.

Sialic acid concentration in different stages of malignant lymphoma and leukemia in children

Sialic acid concentration in the blood serum of 104 children suffering from leukemia and malignant lymphomas was determined. A significant higher concentration of sialic acid was found at the onset of the disease, compared to the controls. In the group of children suffering from acute lymphoblastic leukemia a dependence was noted between the stage of the disease and the concentration of sialic acid in the serum. The high concentration of sialic acid at the onset of the disease, although decreasing during treatment, rose again during relapses of the disease. It seems that determination of sialic acid concentration may be useful in monitoring treatment.

Clinical evaluation of new cancer-associated antigen CA125 II in epithelial ovarian cancers: comparison with CA125

With use of monoclonal antibodies (moABs) M 11 and OC125, a sensitive sandwich immunoradiometric assay (IRMA) for CA125 II was developed. CA125 antigen was adsorbed by moAB OC125 and M 11, but horseradish peroxidase-labelled OC125 did not compete with M 11, indicating that although these two moABs recognized CA125 antigen, they reacted with separate antigenic determinants. We also demonstrate that the dual capture technique with OC125 and M 11 antibodies has a larger dynamic range than OC125 alone. This could potentially increase the sensitivity in terms of low CA125 levels. Forty-six patients with ovarian cancer before therapy and a further 20 cases during follow-up were evaluated for the presence of two serum tumor markers: CA125 II and CA125. The overall positive rate for CA125 II was 97.8%, compared with 91.3% with CA125. Serum CA125 II levels were closely correlated with serum CA125 levels (r = 0.918). The mean CA125 II levels before treatment, at response, and at recurrence were 194.3, 19.6, and 103.5 U/mL, respectively. Normalization of serum CA125 II levels at response does not imply absence of microscopic residual disease. CA125 II changes during follow-up suggest recurrence and can be used to monitor individual patients.

What do CA 125 and other antigens tell us about ovarian cancer biology?

CA 125 is an antigenic determinant on a high molecular weight glycoprotein. A monoclonal antibody has been produced which recognizes this, and allows us to measure the expression of CA 125 in serum. Tissue distribution of the CA 125 determinant is most commonly seen in serous tumors of the ovary, with highest levels in borderline and frankly malignant serous cystadenocarcinomas. Occasionally cancers of the breast, gastrointestinal tract, and kidney will show elevated levels of CA 125. Normal tissues which show varying levels of CA 125 include decidual tissue and structures derived from celomic epithelium. CA 125 is clearly tumor associated, but not tumor specific. Quantitative correlation of CA 125 levels with tumor volume has not been demonstrated. This observation limits the clinical usefulness of CA 125 as a screening tool, particularly in premenopausal patients who do not have a diagnosis of ovarian cancer. An undetectable level of CA 125 antigen does not rule out the presence of an early ovarian cancer. When CA 125 is used to monitor disease state in patients with known ovarian cancers (whose tumors do express CA 125), changes in levels of CA 125 do correlate with gross changes in tumor volume. Good prognostic significance is attributed to a rapid decline in CA 125 levels following induction chemotherapy in patients with advanced ovarian cancer. However, an undetectable serum level of CA 125 does not predict clinical cure for a patient with ovarian cancer. Further clinical studies continue in the use of CA 125 as a screening tool and as a means to monitor treatment responses of known ovarian cancer.

Coordinate elevation of serum markers in ovarian cancer but not in benign disease

Effective screening for occult ovarian cancer will require a strategy that is both sensitive and specific. Preliminary data suggest that CA 125 is elevated at diagnosis in a majority of patients with ovarian cancer. Although CA 125 is sufficiently specific to prompt its evaluation as one component of a strategy to detect ovarian cancer in postmenopausal women, a further improvement in specificity would facilitate cost-effective screening. In an attempt to develop a more specific screening strategy, multiple markers were assayed in a panel of sera from 47 patients with ovarian cancer and in a separate panel of sera from 50 individuals with benign disease whose serum CA 125 levels exceeded 35 U/ml. Among the patients with ovarian cancer, elevations of CA 125 (greater than 35 U/ml) were observed in 91%, CA 15-3 (greater than 30 U/ml) in 57%, TAG 72 (greater than 10 U/ml) in 49%, placental alkaline phosphatase (PLAP) in 25%, human milk fat globule protein (HMFG) 1 in 77%, HMFG2 in 62%, and NB/70K in 57%. Among the 50 sera selected from patients with benign disease, CA 125 was more than 35 U/ml in 100% and more than 65 U/ml in 42%. Among those patients with benign disease and elevated CA 125, NB/70K was elevated in 62%, HMFG1 in 26%, and HMFG2 in 12%, whereas TAG 72 and CA 15-3 were elevated in only 6% and 2%, respectively. In addition PLAP appeared promising; elevated enzyme levels were not found in the benign disease group. Among patients with ovarian cancer with CA 125 levels more than 35 U/ml, either TAG 72 or CA 15-3 was elevated in 77%. In the false-positive group, only 6% had elevations of one or the other marker. The CA 125 levels in cancer patients were, however, substantially greater than in patients with benign disease. If sera from patients with ovarian cancer were diluted to a range comparable to that found in benign disease, at least one of the two confirmatory tests was elevated in 63% of the samples from the malignant cases. Consequently, use of CA 15-3 and TAG 72 in combination with CA 125 can increase the apparent specificity of the CA 125 assay for distinguishing malignant from benign disease. Prospective studies will be required to test critically whether the use of additional serum markers in combination with the CA 125 assay would contribute to the specificity of a cost-effective screening strategy for ovarian cancer.