Comparison of breast cancer mucin (BCM) and CA 15-3 in human breast cancer

Nanotechnology‐based electrochemical biosensors for monitoring breast cancer biomarkers

Breast cancer is categorized as the most widespread cancer type among women globally. On-time diagnosis can decrease the mortality rate by making the right decision in the therapy procedure. These features lead to a reduction in medication time and socioeconomic burden. The current review article provides a comprehensive assessment for breast cancer diagnosis using nanomaterials and related technologies. Growing use of the nano/biotechnology domain in terms of electrochemical nanobiosensor designing was discussed in detail. In this regard, recent advances in nanomaterial applied for amplified biosensing methodologies were assessed for breast cancer diagnosis by focusing on the advantages and disadvantages of these approaches. We also monitored designing methods, advantages, and the necessity of suitable (nano) materials from a statistical standpoint. The main objective of this review is to classify the applicable biosensors based on breast cancer biomarkers. With numerous nano-sized platforms published for breast cancer diagnosis, this review tried to collect the most suitable methodologies for detecting biomarkers and certain breast cancer cell types.

Carbohydrate recognition by boronolectins, small molecules, and lectins

Carbohydrates are known to mediate a large number of biological and pathological events. Small and macromolecules capable of carbohydrate recognition have great potentials as research tools, diagnostics, vectors for targeted delivery of therapeutic and imaging agents, and therapeutic agents. However, this potential is far from being realized. One key issue is the difficulty in the development of "binders" capable of specific recognition of carbohydrates of biological relevance. This review discusses systematically the general approaches that are available in developing carbohydrate sensors and "binders/receptors," and their applications. The focus is on discoveries during the last 5 years.

Intensive post-operative follow-up of breast cancer patients with tumour markers: CEA, TPA or CA15.3 vs MCA and MCA-CA15.3 vs CEA-TPA-CA15.3 panel in the early detection of distant metastases

Background

In breast cancer current guidelines do not recommend the routine use of serum tumour markers. Differently, we observed that CEA-TPA-CA15.3 (carcinoembryonic (CEA) tissue polypeptide (TPA) and cancer associated 115D8/DF3 (CA15.3) antigens) panel permits early detection and treatment for most relapsing patients. As high sensitivity and specificity and different cut-off values have been reported for mucin-like carcinoma associated antigen (MCA), we compared MCA with the above mentioned tumour markers and MCA-CA15.3 with the CEA-TPA-CA15.3 panel.

Methods

In 289 breast cancer patients submitted to an intensive post-operative follow-up with tumour markers, we compared MCA (cut-off values, ≥ 11 and ≥ 15 U/mL) with CEA or CA15.3 or TPA for detection of relapse. In addition, we compared the MCA-CA15.3 and CEA-TPA-CA15.3 tumour marker panels.

Results

Distant metastases occurred 19 times in 18 (6.7%) of the 268 patients who were disease-free at the beginning of the study. MCA sensitivity with both cut-off values was higher than that of CEA or TPA or CA15.3 (68% vs 10%, 26%, 32% and 53% vs 16%, 42%, 32% respectively). With cut-off ≥ 11 U/mL, MCA showed the lowest specificity (42%); with cut-off ≥ 15 U/mL, MCA specificity was similar to TPA (73% vs 72%) and lower than that of CEA and CA15.3 (96% and 97% respectively). With ≥ 15 U/mL MCA cut-off, MCA sensitivity increased from 53% to 58% after its association with CA15.3. Sensitivity of CEA-TPA-CA15.3 panel was 74% (14 of 19 recurrences). Eight of the 14 recurrences early detected with CEA-TPA-CA15.3 presented as a single lesion (oligometastatic disease) (5) or were confined to bony skeleton (3) (26% and 16% respectively of the 19 relapses). With ≥ 11 U/mL MCA cut-off, MCA-CA15.3 association showed higher sensitivity but lower specificity, accuracy and positive predictive value than the CEA-TPA-CA15.3 panel.

Conclusion

At both the evaluated cut-off values serum MCA sensitivity is higher than that of CEA, TPA or CA15.3 but its specificity is similar to or lower than that of TPA. Overall, CEA-TPA-CA15.3 panel is more accurate than MCA-CA15.3 association and can "early" detect a few relapsed patients with limited metastatic disease and more favourable prognosis. These findings further support the need for prospective randomised clinical trial to assess whether an intensive post-operative follow-up with an appropriate use of serum tumour markers can significantly improve clinical outcome of early detected relapsing patients.

Tumour marker measurements in the diagnosis and monitoring of breast cancer

Elevation of established blood tumour markers correlates with the stage of breast cancer. The major role of current blood markers is therefore in the diagnosis and monitoring of metastatic disease. A combination of markers is better than a single marker with the most widely adopted combination being CEA and one MUC1 mucin, commonly detected as either CA15.3 or CA27.29. Tumour marker measurement is now used as a complementary test in the diagnosis of symptomatic metastases. In the monitoring of therapeutic response to both endocrine and cytotoxic therapies in advanced disease, biochemical assessment using blood markers not only correlates with conventional UICC criteria but has a lot of advantages which make it a potentially superior way of assessment. In this regard, CA15.3, CEA and ESR are the best validated combination. Studies are ongoing to evaluate the use of sequential blood tumour marker measurements in the follow-up of patients after treatment for their primary breast cancer, in terms of both early detection and early therapeutic intervention. Further randomized studies are also required to ascertain that marker-directed therapy is superior to the current practice for metastatic disease. In line with clinical studies, intensive laboratory work is being carried out to optimize the use of blood markers in advanced disease as well as to exploit their use in screening and diagnosis of early primary breast cancer.

Purification and characterization of a new 85-kDa glycoprotein antigen from human breast tumor

A new breast-tumor-associated antigen (BTAA) was purified and partially characterized from human breast tumor. By DEAE-cellulose discontinuous NaCl-gradient chromatography of a crude extract of human malignant breast tumor, 3 major protein peaks were obtained. Circulating antibodies against one of the protein peaks, HF1, was observed in breast-cancer patients. The antibodies were absent in patients with carcinoma of the uterine cervix, lung, stomach and liver or with benign breast diseases and in healthy women. Absorption of the sera of breast-cancer patients with normal human breast tissue pellet did not remove the HF1-reactive circulating antibodies. The BTAA was partially purified from HF1 by subjecting the fraction to SDS-PAGE and eluting the band 3 (HF1-3). Western-blot analysis confirmed the presence of the BTAA in HF1-3. Using an affinity column of protein-A-Sepharose-bound IgG, purified from breast-cancer patients' sera, the BTAA was also recovered from HF1. Purification of the BTAA was achieved by subjecting HF1 to size-exclusion high-performance liquid chromatography (SE-HPLC). The antigen was characterized as a glycoprotein with MW of approximately 85 kDa and appeared not to be related either to murine mammary-tumor virus (MuMTV) structural antigens or to human fetal antigens. The BTAA-reactive circulating antibodies in the breast-cancer patients were of IgG, sub-type, and the level of these antibodies significantly decreased in patients following surgical removal of the breast tumors.

[CA 15-3 and breast cancer]

The precise clinical value of CA 15-3 antigen has yet to be determined. With no role in screening for early breast cancer and, even if CA 15-3 seems to be correlated with bulky initial tumor burden, it appears to have no independent prognostic value. The clinical interest of CA 15-3 remains the early detection of the first recurrence. In this regard, more than 75% of first recurrences (all sites included) are associated with a significant rise in CA 15-3 levels, with a particular sensitivity for bone, liver, and lung metastases but which appears lower for locoregional recurrences. More sensitive and specific than CEA, and this whatever the site of recurrence, the rise of CA 15-3 may precede the clinically or radiologically diagnostic of recurrence by a mean lead time from 6 to 9 months. Furthermore CA 15-3 is a reliable marker for clinical course and seems to be of potential interest in monitoring disease follow-up during therapy. In the situation of a clinically isolated elevation of CA 15-3, which investigations, if any, have to be done?, and if negative must do we initiate a treatment for a "biological recurrence"? All these questions remain still opened, and today on consensual attitude can be recommended. In this issue, only results of well-designed prospective trials could help us to determine more rationally, an optimal diagnostic and therapeutic strategy.

Tumour markers in oncology: past, present and future

Historically, tumour markers are substances selectively released by tumour cells in the blood stream so that they can be detected in the serum or other body fluids for clinical monitoring of various malignancies. The term is now extended to cell or tissue characteristics, such as cytogenetic markers, oncogenes or abnormally expressed proteins with various biological functions (enzymes, receptors, etc.), which help characterize the tumour type and constitute specific biological targets for new drugs. Serum markers can be classified in three main categories: (i) oncofetal antigens which are normally expressed only during fetal life, (ii) carbohydrate antigens as part of glycolipids or glycolipoproteins (mucins) and (iii) miscellaneous, including tissue specific enzymes, cytoskeletal proteins, etc. Most carbohydrate antigens which are useful in serum diagnosis of human cancers show tumour type-specific aberrant glycosylation, with O instead of N linkage to protein moieties. Despite a huge progression in analytical performances with immunoassays, and because of still insufficient biological sensitivity and specificity, serum assays of tumour markers are not effective in mass screening, their usefulness being restricted to the follow-up of diagnosed patients. Selective expression of specific antigens allows in vivo detection of occult tumour masses (immunoscintigraphy) and immunotargetting of drugs as therapy. Cell and tissue markers comprise markers of transformation (molecular genetics, oncogenes and anti-oncogenes, etc.), differentiation (hormone receptors, etc.), proliferation (growth factors, Ki67, etc.) and metastatic potential (proteases, etc.). Although masking the functional aspects of many of these markers, as for hormone or growth factor receptors, immunoanalytical methods, specially immunohistochemistry, are rapidly expanding in clinical oncology as tools for diagnosis, prognosis and, promisingly, treatment adjustment.