Analytical and clinical evaluation of a new tumor marker in breast cancer: CA 27.29

Study of serum tumor markers CEA, CA 15.3 and CA 27.29 as diagnostic parameters in patients with breast carcinoma

Serum levels of CEA, CA 15.3 and CA 27.29 were measured during the follow-up of 499 breast cancer patients. Studies included three different groups of women: 82 blood donors free of disease, 42 patients with non-malignant breast diseases and 499 breast cancer patients. After the determinaion of cut-off values, serum levels of tumor markers did not show significant elevations in benign breast diseases. On the basis of our results CA 15.3 (sensitivity = 57%; accuracy = 87%) was the most effective marker, CA 27.29 (sensitivity = 62%; accuracy = 83%) was the most sensitive and CEA (sensitivity = 45%; accuracy = 81%) was the least sensitive and effective marker.

The combined use of markers was evaluated by step-wise logistic regression analysis. The regression coefficients showed that CA 15.3 (coeff. = 2.97) and CA 27.29 (coeff. = 1.46) were suitable for the detection of possible metastases during follow-up. Finally, we studied the relationship between pT, pN, pM and circulating levels of CA 15.3 and CA 27.29.

Current status of mucins in the diagnosis and therapy of cancer

Mucins are the most abundant high molecular weight glycoproteins in mucus. Their nature and glycosylation content dictates the biochemical and biophysical properties of viscoelastic secretions, pointing out an important role in diverse biological functions, such as differentiation, cell adhesions, immune responses, and cell signaling. Mucins are expressed in tubular organs by specialized epithelial cells in the body. Their aberrant expression is well documented in a variety of inflammatory or malignant diseases. From a prognosis point of view, their expression and alterations in glycosylation are associated with the development and progression of malignant diseases. Therefore, mucins can be used as valuable markers to distinguish between normal and disease conditions. Indeed, this alteration in glycosylation patterns generates several epitopes in the oligosaccharide side chains that can be used as diagnostic and/or prognostic markers. Furthermore, these characteristic tumor-associated epitopes are extensively used as appropriate immunotargets of malignant epithelial cells. Therefore, in an effort to detect and treat cancer at the earliest stage possible, mucins are analyzed as potential markers of disease for diagnosis, progression, and for therapeutic purposes. In this review, we focused on the current status of the distribution of mucins in normal and pathologic conditions and their clinical use both in cancer diagnosis and therapeutics treatments.

Analysis of mucins: role in laboratory diagnosis

Mucins are high molecular weight glycoproteins with complex oligosaccharide side chains attached to the apomucin protein backbone byO-glycosidic linkage; they are found in crude mucus gels that protect epithelial surfaces in the major tracts of the body and as transmembrane proteins expressed on the apical cell surface of glandular and ductal epithelia of various organs. Changes in the sequence of glycosylation of mucins in different settings generate a variety of epitopes in the oligosaccharide side chains of mucins, including newly expressed blood-group antigens, distinguishing between normal and diseased states. Tumour-associated epitopes on mucins and their antigenicity make them suitable as immunotargets on malignant epithelial cells and their secretions, creating a surge of interest in mucins as diagnostic and prognostic markers for various diseases, and even influencing the design of mucin-based vaccines. This review discusses the emerging roles of mucins such as MUC1 and MUC4 in cancer and some other diseases, and stresses how underglycosylated and truncated mucins are exploited as markers of disease and to monitor widespread metastasis, making them useful in patient management. Furthermore the type, pattern and amount of mucin secreted in some tissues have been considered in the classification and terminology of neoplasia and in specific organs such as the pancreas. These factors have been instrumental in pathological classification, diagnosis and prognostication of neoplasia.

A reliable biomarker derived from plasmalogens to evaluate malignancy and metastatic capacity of human cancers

Antigen tumor markers employed in monitoring therapeutical approaches are limited by their specificity (Sp) and sensitivity (Se). The aim of this study was to investigate the suitability of a lipid tumor marker derived from ether-linked phospholipids and to compare it with others usually assayed in clinical practice. Complex lipids from normal and pathological breast, lung, and prostate tissue were isolated and analyzed by TLC and c-GLC methods. Results were compared as pooled samples, or by means of the averaged percent changes with respect to the composition observed in the normal tissue of the same patient. Sp, Se, negative-predictive (NPV) and positive- predictive values (PPV) were established for conventional markers and for the proposed lipid-derived marker. Results demonstrated that the content of monoenoic fatty acyl chains was significantly increased in total lipids, phosphatidylethanolamine, and especially in ethanolamine-containing ether lipids of neoplastic tissues with respect to their corresponding normal ones. Major changes were observed in the plasmalogen sub-fraction where the ratio monoenoic/saturated fatty acids can distinguish with high Se normal tissues from either benign or neoplastic tissues from breast, lung, or prostate lesions. Analyses of fatty acyl chains from ethanolamine-containing plasmalogens provided a reliable tumor marker that correlated with high Se and linearity with metastases spreading. This fact may be useful in prognosis of the most frequently observed human cancers.

CA27.29: a valuable marker for breast cancer management. A confirmatory multicentric study on 603 cases

Recently, a fully automated method has become commercially available to measure the MUC-1-associated antigen CA27.29. The present investigation was performed in order to compare CA27.29 and CA15.3 in a wide series of patients affected with breast cancer. Overall, 603 cases with breast cancer and 194 healthy controls were investigated. Patients were enrolled in 4 institutions, while assays were performed in one laboratory. CA27.29 was measured by the ACS:180 BR assay (Bayer Diagnostics) and CA15.3 by the AxSYM (Abbott Laboratories). An excellent correlation was found between the results obtained by the two methods. The two markers showed comparable results in healthy controls, with higher levels in post-menopausal than in pre-menopausal subjects. The markers were significantly higher in primary breast cancer than in controls. The areas under the receiver operating characteristics (ROC) curves of the two tests were comparable, but CA27.29 showed better sensitivity in cases with low antigen concentrations (below the cut-off point). Accordingly, when comparing each test in different stage categories, significance levels of the differences were higher for CA27.29 than for CA15.3 for all T categories versus healthy controls, for pT1 versus pT2, for all N categories versus healthy controls and for node-negative versus N1-3 patients. From the results of the present study, that has been performed on samples taken at diagnosis and prior to any treatment from the widest series of patients with primary breast cancer reported so far, we can draw the following conclusions: CA27.29 provides comparable results to CA15.3; CA27.29 seems more sensitive than CA15.3 to limited variations of tumour extension; however, it cannot help clinicians in distinguishing stage I patients from stage II patients. However, from the point of view of clinical decision making, CA27.29 provides comparable results to CA15.3. CA27.29 is therefore suitable for routine use in the management of patients with breast cancer.