Use of a murine monoclonal antibody for detection of circulating plasma DF3 antigen levels in breast cancer patients

Mucin 1 and venous thrombosis in tumor-bearing mice and patients with cancer

INTRODUCTION

Mucins released from epithelial tumors have been proposed to play a role in cancer-associated thrombosis. Mucin1 (MUC1) is a transmembrane mucin that is overexpressed in a variety of human malignancies, including breast and pancreatic cancer. We analyzed the association of MUC1 and venous thrombosis in a mouse tumor model and in patients with cancer.

MATERIALS AND METHODS

We used a human pancreatic cancer cell line HPAF-II that expresses a high level of MUC1. We grew HPAF-II tumors in the pancreas of Crl:NU-Foxn1nu male mice. MUC1 in plasma and extracellular vesicles (EVs) isolated from plasma was measured using an enzyme-linked immunosorbent assay. MUC1 in EVs and venous thrombi from tumor-bearing mice was assessed by western blotting. We measured MUC1 in plasma from healthy controls and patients with stomach, colorectal or pancreatic cancer with or without venous thromboembolism.

RESULTS AND DISCUSSION

MUC1 was detected in the plasma of mice bearing HPAF-II tumors and was associated with EVs. MUC1 was present in venous thrombi from mice bearing HFAP-II tumors. Recombinant MUC1 did not induce platelet aggregation. Levels of MUC1 were higher in patients with pancreatic cancer compared with healthy controls. In contrast to the mouse model, MUC1 was present in EV-free plasma in samples from healthy controls and patients with cancer. There was no significant difference in the levels of MUC1 in cancer patients with or without VTE. Our data did not find any evidence that MUC1 contributed to VTE in patients with cancer.

Dendritic Cell Vaccines: A Shift from Conventional Approach to New Generations

In the emerging era of cancer immunotherapy, immune checkpoint blockades (ICBs) and adoptive cell transfer therapies (ACTs) have gained significant attention. However, their therapeutic efficacies are limited due to the presence of cold type tumors, immunosuppressive tumor microenvironment, and immune-related side effects. On the other hand, dendritic cell (DC)-based vaccines have been suggested as a new cancer immunotherapy regimen that can address the limitations encountered by ICBs and ACTs. Despite the success of the first generation of DC-based vaccines, represented by the first FDA-approved DC-based therapeutic cancer vaccine Provenge, several challenges remain unsolved. Therefore, new DC vaccine strategies have been actively investigated. This review addresses the limitations of the currently most adopted classical DC vaccine and evaluates new generations of DC vaccines in detail, including biomaterial-based, immunogenic cell death-inducing, mRNA-pulsed, DC small extracellular vesicle (sEV)-based, and tumor sEV-based DC vaccines. These innovative DC vaccines are envisioned to provide a significant breakthrough in cancer immunotherapy landscape and are expected to be supported by further preclinical and clinical studies.

Armored modified vaccinia Ankara in cancer immunotherapy

Cancer immunotherapy relies on unleashing the patient´s immune system against tumor cells. Cancer vaccines aim to stimulate both the innate and adaptive arms of immunity to achieve durable clinical responses. Some roadblocks for a successful cancer vaccine in the clinic include the tumor antigen of choice, the adjuvants employed to strengthen antitumor-specific immune responses, and the risks associated with enhancing immune-related adverse effects in patients. Modified vaccinia Ankara (MVA) belongs to the family of poxviruses and is a versatile vaccine platform that combines several attributes crucial for cancer therapy. First, MVA is an excellent inducer of innate immune responses leading to type I interferon secretion and induction of T helper cell type 1 (Th1) immune responses. Second, it elicits robust and durable humoral and cellular immunity against vector-encoded heterologous antigens. Third, MVA has enormous genomic flexibility, which allows for the expression of multiple antigenic and costimulatory entities. And fourth, its replication deficit in human cells ensures a excellent safety profile. In this review, we summarize the current understanding of how MVA induces innate and adaptive immune responses. Furthermore, we will give an overview of the tumor-associated antigens and immunomodulatory molecules that have been used to armor MVA and describe their clinical use. Finally, the route of MVA immunization and its impact on therapeutic efficacy depending on the immunomodulatory molecules expressed will be discussed.

Mucins as Potential Biomarkers for Early Detection of Cancer

Early detection significantly correlates with improved survival in cancer patients. So far, a limited number of biomarkers have been validated to diagnose cancers at an early stage. Considering the leading cancer types that contribute to more than 50% of deaths in the USA, we discuss the ongoing endeavors toward early detection of lung, breast, ovarian, colon, prostate, liver, and pancreatic cancers to highlight the significance of mucin glycoproteins in cancer diagnosis. As mucin deregulation is one of the earliest events in most epithelial malignancies following oncogenic transformation, these high-molecular-weight glycoproteins are considered potential candidates for biomarker development. The diagnostic potential of mucins is mainly attributed to their deregulated expression, altered glycosylation, splicing, and ability to induce autoantibodies. Secretory and shed mucins are commonly detected in patients' sera, body fluids, and tumor biopsies. For instance, CA125, also called MUC16, is one of the biomarkers implemented for the diagnosis of ovarian cancer and is currently being investigated for other malignancies. Similarly, MUC5AC, a secretory mucin, is a potential biomarker for pancreatic cancer. Moreover, anti-mucin autoantibodies and mucin-packaged exosomes have opened new avenues of biomarker development for early cancer diagnosis. In this review, we discuss the diagnostic potential of mucins in epithelial cancers and provide evidence and a rationale for developing a mucin-based biomarker panel for early cancer detection.

RNA-combine: a toolkit for comprehensive analyses on transcriptome data from different sequencing platforms

Background

Understanding the transcriptome has become an essential step towards the full interpretation of the biological function of a cell, a tissue or even an organ. Many tools are available for either processing, analysing transcriptome data, or visualizing analysis results. However, most existing tools are limited to data from a single sequencing platform and only several of them could handle more than one analysis module, which are far from enough to meet the requirements of users, especially those without advanced programming skills. Hence, we still lack an open-source toolkit that enables both bioinformatician and non-bioinformatician users to process and analyze the large transcriptome data from different sequencing platforms and visualize the results.

Results

We present a Linux-based toolkit, RNA-combine, to automatically perform the quality assessment, downstream analysis of the transcriptome data generated from different sequencing platforms, including bulk RNA-seq (Illumina platform), single cell RNA-seq (10x Genomics) and Iso-Seq (PacBio) and visualization of the results. Besides, this toolkit is implemented with at least 10 analysis modules more than other toolkits examined in this study. Source codes of RNA-combine are available on GitHub: https://github.com/dongxuemin666/RNA-combine.

Conclusion

Our results suggest that RNA-combine is a reliable tool for transcriptome data processing and result interpretation for both bioinformaticians and non-bioinformaticians.

Mucin1 and Mucin16: Therapeutic Targets for Cancer Therapy

The mucin (MUC) family is a group of highly glycosylated macromolecules that are abundantly expressed in mammalian epithelial cells. MUC proteins contribute to the formation of the mucus barrier and thus have protective functions against infection. Interestingly, some MUC proteins are aberrantly expressed in cancer cells and are involved in cancer development and progression, including cell growth, proliferation, the inhibition of apoptosis, chemoresistance, metabolic reprogramming, and immune evasion. With their unique biological and structural features, MUC proteins have been considered promising therapeutic targets and also biomarkers for human cancer. In this review, we discuss the biological roles of the transmembrane mucins MUC1 and MUC16 in the context of hallmarks of cancer and current efforts to develop MUC1- and MUC16-targeted therapies.

MUC Glycoproteins: Potential Biomarkers and Molecular Targets for Cancer Therapy

MUC proteins have great significance as prognostic and diagnostic markers as well as a potential target for therapeutic interventions in most cancers of glandular epithelial origin. These are high molecular weight glycosylated proteins located in the epithelial lining of several tissues and ducts. Mucins belong to a heterogeneous group of large O-glycoproteins that can be either secreted or membrane-bound. Glycosylation, a post-translational modification affects the biophysical, functional and biochemical properties and provides structural complexity for these proteins. Aberrant expression and glycosylation of mucins contribute to tumour survival and proliferation in many cancers, which in turn activates numerous signalling pathways such as NF-kB, ERα, HIF, MAPK, p53, c-Src, Wnt and JAK-STAT, etc. This subsequently induces cancer cell growth, proliferation and metastasis. The present review mainly demonstrates the functional aspects of MUC glycoproteins along with its unique signalling mechanism and role of aberrant glycosylation in cancer progression and therapeutics. The importance of MUC proteins and its subtypes in a wide spectrum of cancers including but not limited to breast cancer, colorectal cancer, endometrial and cervical cancer, lung cancer, primary liver cancer, pancreatic cancer, prostate cancer and ovarian cancer has been exemplified with significance in targeting the same. Several patents associated with the MUC proteins in the field of cancer therapy are also emphasized in the current review.

Study of a soluble tumor-associated marker composed of CEA related molecules recognized by three monoclonal antibodies

Three MAbs, MLuC2, MLuC8 and MLuC9, directed against a molecule that is produced and secreted by carcinoma cells were studied with the aim of developing a double-determinant immunoradiometric assay (DDIRMA). We demonstrated by means of immunoblotting, immunodepletion and DDIRMA techniques, that MLuC9 reacted against the CEA molecule, whereas MLuC2 and MLuC8 reacted against a 90 Kd molecule related to CEA. The DDIRMA performed with the anti-CEA as a catcher MAb and the anti-90 Kd as a tracer MAb was found to be positive with the HT29 soluble extract, which suggests the existence of CEA/90 Kd dimeric molecules. The same reactivity was found when sera from patients with lung carcinomas were tested, which excludes that this molecule could be an artefact due to the cell solubilization procedures. The association between CEA and the 90 Kd molecule was further confirmed by immunodepletion experiments in which the immunoprecipitation with one MAb not only removed the recognized molecule, but also partially immunodepleted the material from the other.

A Phase I Dose-Escalation Trial of BN-CV301, a Recombinant Poxviral Vaccine Targeting MUC1 and CEA with Costimulatory Molecules

PURPOSE

BN-CV301 is a poxviral-based vaccine comprised of recombinant (rec.) modified vaccinia Ankara (MVA-BN-CV301; prime) and rec. fowlpox (FPV-CV301; boost). Like its predecessor PANVAC, BN-CV301 contains transgenes encoding tumor-associated antigens MUC1 and CEA as well as costimulatory molecules (B7.1, ICAM-1, and LFA-3). PANVAC was reengineered to make it safer and more antigenic.

PATIENTS AND METHODS

This open-label, 3+3 design, dose-escalation trial evaluated three dose levels (DL) of MVA-BN-CV301: one, two, or four subcutaneous injections of 4 × 10⁸ infectious units (Inf.U)/0.5 mL on weeks 0 and 4. All patients received FPV-CV301 subcutaneously at 1 × 10⁹ Inf.U/0.5 mL every 2 weeks for 4 doses, then every 4 weeks. Clinical and immune responses were evaluated.

RESULTS

There were no dose-limiting toxicities. Twelve patients enrolled on trial [dose level (DL) 1 = 3, DL2 = 3, DL3 = 6). Most side effects were seen with the prime doses and lessened with subsequent boosters. All treatment-related adverse events were temporary, self-limiting, grade 1/2, and included injection-site reactions and flu-like symptoms. Antigen-specific T cells to MUC1 and CEA, as well as to a cascade antigen, brachyury, were generated in most patients. Single-agent BN-CV301 produced a confirmed partial response (PR) in 1 patient and prolonged stable disease (SD) in multiple patients, most notably in KRAS-mutant gastrointestinal tumors. Furthermore, 2 patients with KRAS-mutant colorectal cancer had prolonged SD when treated with an anti-PD-L1 antibody following BN-CV301.

CONCLUSIONS

The BN-CV301 vaccine can be safely administered to patients with advanced cancer. Further studies of the vaccine in combination with other agents are planned.See related commentary by Repáraz et al., p. 4871.

Exploring the potential of mucin 13 (MUC13) as a biomarker for carcinomas and other diseases

BACKGROUND

Mucin 13 (MUC13) is a cell surface glycoprotein aberrantly expressed in a variety of epithelial carcinomas. Thus far, the role of MUC13 in various diseases remains elusive. To the best of our knowledge, this is the first study to examine the potential of MUC13 as a serum biomarker in a variety of carcinomas and other conditions.

METHODS

We developed a recombinant MUC13 protein, mouse monoclonal antibodies and enzyme immunoassay (ELISA) for MUC13. We used this assay to measure MUC13 levels in the supernatants of cancer cell lines and a large cohort of serum samples from healthy and diseased individuals.

RESULTS

MUC13 is secreted from cancer cell lines, with highest levels found in ovarian cancer cell lines. MUC13 levels in human sera were significantly increased in patients with renal failure and 20%-30% of patients with ovarian, liver, lung and other cancers. MUC13 was also elevated in 70% of patients with active cutaneous melanoma, but not uveal melanoma. Furthermore, we identified significant MUC13 elevations in the serum of patients with vasculitis (ANCA-positive) autoantibodies, but not in those with inflammatory bowel disease.

CONCLUSIONS

Serum MUC13 is frequently elevated not only in a variety of malignant cases but also in some benign pathologies, thus appearing to be a non-specific disease biomarker. Nonetheless, serum MUC13 is clearly highly elevated in some carcinoma patients, and its relationship with tumor progression in this context warrant further research. Future studies that examine the correlation between serum MUC13 levels to stage of cancer could elucidate prognostic potential.

Comparison of CA 15-3 and CEA in diagnosis and monitoring of breast cancer

In order to assess the utility of the tumor-associated antigen CA15-3 in the diagnosis of breast cancer, this new tumor marker was measured pre-operatively in 1342 patients. This group comprised 509 patients with malignant disease (134 with breast cancer and 375 with other malignancies not involving the breast) and 833 patients with benign surgical diseases (95 patients with fibroadenoma of the breast, 738 with other benign diseases). The results were compared with those for carcino-embryonic antigen (CEA) in the diagnosis of breast cancer. CA15-3 was above the normal limits of 25 U/ml in 31% of the patients with breast cancer, in 22% of patients with other malignancies, and in 9% of patients with benign diseases. CEA was elevated in 26% of patients with breast cancer (> 3ng/ml). CA15-3 levels were above 50 U/ml in 13% of the breast cancer patients, in 6%) of patients with other malignancies, and in 0.2% of the patients with benign diseases. There was a good correlation between CA 15-3 level and tumor stage in breast cancer. CA 15-3 serum levels were over 50 U/ml in respectively 0%, 2%, 13%, and 73% of the patients with stages I, II, III, and IV. CA 15-3 and CEA were also determined in 671 patients who had received initial curative surgery of breast cancer, and who regularly attended our follow-up clinic.

CA15-3 was found to be more sensitive than CEA in detecting recurrences of breast cancer. In the post-care period, carcinoma recurred in 205 patients. Of these 73% had CA15-3 concentrations above 25 U/ml, whereas only 50% had CEA values above 3 ng/ml (p< 0.0001). Although neither CA15-3 nor CEA are sensitive enough for the screening and diagnosis of early breast cancer, CA 15-3 is superior to CEA in the detection of breast cancer metastases.

The expansion of targetable biomarkers for CAR T cell therapy

Biomarkers are an integral part of cancer management due to their use in risk assessment, screening, differential diagnosis, prognosis, prediction of response to treatment, and monitoring progress of disease. Recently, with the advent of Chimeric Antigen Receptor (CAR) T cell therapy, a new category of targetable biomarkers has emerged. These biomarkers are associated with the surface of malignant cells and serve as targets for directing cytotoxic T cells. The first biomarker target used for CAR T cell therapy was CD19, a B cell marker expressed highly on malignant B cells. With the success of CD19, the last decade has shown an explosion of new targetable biomarkers on a range of human malignancies. These surface targets have made it possible to provide directed, specific therapy that reduces healthy tissue destruction and preserves the patient's immune system during treatment. As of May 2018, there are over 100 clinical trials underway that target over 25 different surface biomarkers in almost every human tissue. This expansion has led to not only promising results in terms of patient outcome, but has also led to an exponential growth in the investigation of new biomarkers that could potentially be utilized in CAR T cell therapy for treating patients. In this review, we discuss the biomarkers currently under investigation and point out several promising biomarkers in the preclinical stage of development that may be useful as targets.

Production of Monoclonal Antibodies against a New Carcinoma-associated Marker in View of Developing a Serological Test

By immunizing a mouse with human metastatic breast tumor cells from patient effusions and infiltrated lymph nodes, a monoclonal antibody (MLuC2), which identifies a new carcinoma-associated marker, was raised. The reactivity of this reagent was studied by immunohistochemistry on live and fixed cells from tumor cell lines and on frozen sections from surgical specimens. Besides reacting with 73% of breast carcinomas, MLuC2 also reacted with 93% of non-small cell lung carcinoma (NSCLC) and with a few normal tissues. The MLuC2-recognized molecule (CaMLuC2), whose MW was 90 KDa according to immunoblotting experiments, was found to be detectable in the serum and could therefore be of particular interest for serological diagnostic applications. Since the CaMLuC2 epitope was not polyexpressed on the bearing molecule, we produced a new generation of MAbs in order to define epitopes coexpressed with CaMLuC2 on the same 90 KDa molecule, and which are therefore suitable to develop a double-determinant immunoradiometric assay (DDIRMA) for the detection of this marker in the sera of lung carcinoma patients. Different analyses by immunohistochemistry, binding inhibition tests and DDIRMA, proved that the two new reagents developed, MLuC8 and MLuC9, recognize the same or closely related epitopes, which are however different from CaMLuC2, but which are all present on the same molecule. Preliminary immunoradiometric tests performed on sera from lung cancer and control patients showed a good specificity but a low sensitivity. In fact, only 42% of the 28 tested sera samples from NSCLC patients scored positive despite the fact that more than 90% of the NSCLC expressed the relevant antigen

Circulating Ca 15.3 Levels in Breast Cancer. Our Present Experience

CA 15.3 is an antigen expressed by human breast carcinoma cells, and defined by two monoclonal antibodies, 115D8 and DF3. We used IRMA to determine the circulating serum levels of CA 15.3 in 1178 subjects with breast cancer, non-breast malignancies, benign diseases and controls. A threshold level of 40 U/ml was established with 140 healthy controls and 650 patients with benign diseases (respectively 0% subjects and 1.5% patients had abnormal antigen levels). Elevated CA 15.3 was found in 12 of 184 patients with malignancies different from breast cancer (6.5%), either epithelial carcinomas with distant metastases, mainly in the liver, or primary liver tumors. Breast cancer patients (n=204) were analysed by prior therapy, UICC stage and WHO response to therapy. Eight of 134 (5.9%) patients with stage II or III breast cancer at presentation and no evidence of disease (NED) had elevated CA 15.3. All of 22 patients with stage IV breast cancer not responding to therapy (SD and PD) had antigen levels > 40 U/ml, as did 10 of 34 (29.4%) stage IV patients in objective response (CR+PR). Three of 14 pretreatment patients had abnormal marker levels, and they later proved to have distant metastases. Serum CA 15.3 values were statistically different (p < 0.01) in NED (20.6 ± 11.2 U/ml), CR+PR (33.5 ± 24.0 U/ml), stable disease (98.8 ± 50.4 U/ml) and progressive disease (> 200 U/ml) breast cancer patients. Our results suggest that circulating CA 15.3 antigen levels agree with the stage of breast cancer and with the response to therapy.

CA 15-3 in Human Breast Cancer.: Comparison with Tissue Polypeptide Antigen (TPA) and Carcinoembryonic Antigen (CEA)

CEA, TPA, CA 15-3 were assayed in 238 patients in follow-up for breast cancer after surgery. CA 15-3 showed the best sensitivity and specificity; the predictive value of a positive CA 15-3 test was three times higher than CEA and TPA. No association was found between marker positivity and the number of organs involved by metastases. CA 15-3 positivity was significantly associated with visceral rather than soft tissue recurrences; no significant similar association was observed for CEA and TPA. CA 15-3 serum levels were early predictors of relapse in four out of nine patients within a 6-12 month follow-up period.

Carcinoembryonic Antigen and Breast Carcinoma Antigen (CA 15.3) in Preoperative Staging and Postoperative Monitoring of Patients with Carcinoma of the Breast

Serum levels of carcinoembryonic antigen (CEA) and breast carcinoma antigen (CA 15.3) were determined in patients with breast carcinoma: in 129 before initial surgical or nonsurgical treatment and in 134 afterwards. Before any initial treatment, CEA was elevated in 15% of patients with Stage IV disease and CA 15.3 was high in 11% with Stage III and 48% with Stage IV. While monitoring management active disease was associated with elevated serum CEA in 66% of the patients, with elevated CA 15.3 in 73% and with at least one of the markers elevated in 86%. Both tests had high specificity (93% and 98%). The rise in serum CEA and, even more so, of serum CA 15.3 roughly paralleled the increase in bulk of the tumor: from locoregional disease through metastases to the lungs, bones, lungs with bones, and liver. Decreases in the levels of serum CEA and CA 15.3 reflected response to therapy, increases in the level of at least one marker - treatment failure, and levels fluctuating above the normal range indicated stationary disease.

During follow-up, the predictive value of a negative test (levels within the normal range), suggesting that the patient might be free of disease, was 61% for CEA alone, 67% for CA 15.3 alone, and 80% for the two tests combined. We conclude that an elevated serum level of only one of the markers was useful for staging, implying advanced disease. Determination of both markers jointly was useful for monitoring the effectiveness of the therapy and for follow-up aimed at detection of relapse.

CA 15.3 and CEA Plasma Level Monitoring in Patients with Breast Cancer

CA 15.3 and CEA were determined in the serum of 217 patients with early and advanced breast carcinoma.

CA 15.3 was high (> 30 U/ml) in 1/6 (17%) patients with stage III primary tumor, in 4/77 (5%) patients without clinical signs of disease after mastectomy, in 67/102 (65%) patients with advanced disease in progression, and in 13/32 (41%) patients with advanced disease not in progression and undergoing therapy. The corresponding incidences of pathological CEA values (> 2.5 ng/ml) were 33, 8, 55 and 14%>. The combination of the two markers brings about a certain improvement in the sensitivity for recognising patients with advanced disease in progression (79/102 = 77%). The presence of high values of CA 15.3 is statistically correlated to the prevalent site of metastases (bone and viscera > soft tissues). Monitoring the two markers during antitumor therapy in 36 patients showed good accordance (56%) between CA 15.3 changes and response to therapy. The decrease of the marker in patients who achieved partial remission was statistically significant.

In conclusion, CA 15.3 is more sensitive than CEA in recognising patients with advanced disease in progression and gives better accordance with the response to therapy. The simultaneous use of the two markers may be useful in the follow-up of operated patients and in monitoring the disease during treatment.

The Role of a New Monoclonal Antibody Assay in the Detection of Recurrent Breast Cancer

The immunoradiometric assay “CA 15-3”, recently developed to measure a breast tumor-associated antigen, gave a mean serum value of 13.8 U/ml (S.D. 6.2) for this antigen in 156 non-cancer controls (36 biopsies for a benign breast lesion and 120 healthy controls).

Setting a cut-off value of 30 U/ml (specificity 99.3%), only 3 out of 58 primary breast cancer cases were positive. In metastatic breast cancer, 11 out of 33 cases with limited recurrence (33.3%) and 36 out of 56 cases with extensive recurrence (64.3%) gave abnormal values in this assay, above the cut-off point, with an overall sensitivity of 52.8%; the difference between the sensitivity values in the two groups of recurrent cases was statistically significant (P < 0.01).

According to the findings of the present study, CA 15-3 has no role in the detection of primary breast cancer, but its usefulness in disease monitoring can be hypothesized, as circulating levels of the antigen seem to be dependent on the tumor mass.

The clinical value of CEA and CA 15-3 in breast cancer management

The value of tumour-associated antigens CEA and CA 15-3 was studied in patients with breast cancer over a 4-year period. A total of 252 patients with primary or recurrent disease had available and corresponding CEA and CA 15-3 values at diagnosis and during follow-up and were studied in detail. Preoperative and three-monthly serial postoperative levels were measured in each patient. Ten of 11 patients presenting with primary and concurrent metastatic disease had elevated CA 15-3 levels (> 25 I.U./ml) as compared to 6 with CEA (> 5 ng/ml). Fourty-seven patients developed locoregional recurrence of which 15 had concurrent metastatic disease. CA 15-3 was elevated in 14 cases while CEA in 11. Of 32 patients with locoregional recurrence alone, 18 later developed metastatic disease at a mean follow-up time of 17.5 months. There was a significant correlation between CA 15-3 value at locoregional recurrence and time to subsequent metastasis (r = 0. -0.57, P = 0.0133). CEA was elevated in 64%, CA 15-3 in 87% and either marker in 94% of 87 patients diagnosed with metastatic disease. Of 53 patients with serial markers and metastatic disease, 72% (38/53) had rising CA 15-3 levels prior to diagnosis with a mean lead time of 9.9 months. Use of CEA in conjunction improved lead time detection to 83%.

This study demonstrates that CA 15-3 is superior to CEA at detecting metastatic disease at initial presentation and during follow-up. Use of CEA in conjunction with CA 15-3 improves the detection of systemic disease.

Analysis of the Temporal Compressibility of Breast Tumour Marker Assays: Development of a “Near Patient” Assay

The aim of this study was to investigate whether immunoassays for circulating MUC1 antigen in breast cancer could be compressed in time so that serum level results would be made available during the time of the patient's visit to clinic.

Two assays were used: - The EMCA (Euro DPC) is a liquid phase immunoassay and the ELSA CA15-3 (CIS) is a double determinant solid phase immunoradiometric assay. The effects of shortened incubation times were investigated by assaying standards and unknown samples and comparing the results with those using the standard kit protocols. The binding kinetics of the monoclonal antibodies employed in the assays were analysed separately.

We conclude that the EMCA assay can be shortened to 35 min and we have attributed this to the fast binding kinetics inherent in a liquid phase assay. This shortened assay may produce the basis for a useful “near patient” assay. By comparison, the solid phase ELSA CA15-3 assay cannot be compressed without loss in assay performance.

CA 15.3 in Nonmalignant Liver Diseases

CA 15.3 is a recent tumor marker for a wide range of cancers that is usually used for monitoring breast carcinoma patients. This study was performed to evaluate CA 15.3 behaviour in 161 patients with benign diffuse hepatic diseases who underwent thorough clinical and biochemical evaluation. Abnormal serum levels of this antigen were found in 8.7% of the 161 patients, 11.6% of the 86 cirrhotics, and 5.3% of the 75 noncirrhotic patients. The correlation between CA 15.3 and certain parameters characteristic of liver diseases was checked. IgA showed the most relevant correlation (r = 0.39, p < 0.00001) and in our series a normal level of IgA was practically determinant of normal CA 15.3 levels. Our results also support the role played by hepatocellular dysfunction in increasing levels of this antigen in spite of the low number of false-positive results. CA 15.3 can be used as a tumor marker in these patients at levels used for healthy subjects.

Mucins: Structural diversity, biosynthesis, its role in pathogenesis and as possible therapeutic targets

Mucins are the main structural components of mucus that create a selective protective barrier for epithelial surface and also execute wide range of other physiological functions. Mucins can be classified into two types, namely secreted mucins and membrane bounded mucins. Alterations in mucin expression or glycosylation and mislocalization have been seen in various types of pathological conditions such as cancers, inflammatory bowel disease and ocular disease, which highlight the importance of mucin in maintaining homeostasis. Hence mucins can be used as attractive target for therapeutic intervention. In this review, we discuss in detail about the structural diversity of mucins; their biosynthesis; its role in pathogenesis; regulation and as possible therapeutic targets.

TG4010: a vaccine with a therapeutic role in cancer

One of the strategies to enhance immune response against tumors has been the use of vaccines against tumor-associated antigens (TAAs). MUC1 is a TAA that is overexpressed in many malignancies being linked to worse prognosis. Moreover, tumor MUC1 is hypoglycosylated revealing new epitopes that are antigenic and potential T-cell targets. TG4010 is a recombinant viral vaccine targeting MUC1, also encoding for IL-2. TG4010 has been tested in Phase I-II trials demonstrating a consistent safety profile with mild local reactions as main side effect. These studies have confirmed immune responses to the vaccine product. Clinical efficacy has been observed mainly in patients with non-small-cell lung cancer in combination with chemotherapy. Peripheral activated NK cells are currently being validated as biomarkers of response.

Update on Mucin-1 immunotherapy in cancer: a clinical perspective

INTRODUCTION

Mucin 1 (MUC1) is particularly well suited as a cancer immunotherapy target due to the elevated protein expression and aberrant forms associated with malignancy. A variety of therapeutic strategies have been explored, including antibodies intended to induce cancer cell destruction, and vaccinations with peptides, tumor extracts, and gene expression systems.

AREAS COVERED

MUC1 immunotherapeutic strategies have included vaccination with peptide sequences, glycan molecules, viruses, and dendritic cells, monoclonal antibodies and monoclonal antibody conjugates. Here we review the relevant clinical trials in each field of immunotherapy with particular focus on large and recently published trials.

EXPERT OPINION

Long clinical experience in the trial setting has reduced concerns of immunotherapy associated toxicities and inappropriate immune responses, with the main limitation (common to many experimental approaches) being a lack of clinical efficacy. However, there have been sufficient treatment-associated responses to justify continued pursuit of MUC1 targeted immunotherapies. The focus now should be on application to the relevant cancers under appropriate circumstances and combination with the emerging non-specific immunotherapy approaches such as the PD-1 pathway inhibitors.

Glycosylation-Based Serum Biomarkers for Cancer Diagnostics and Prognostics

Cancer is the second most common cause of death in developed countries with approximately 14 million newly diagnosed individuals and over 6 million cancer-related deaths in 2012. Many cancers are discovered at a more advanced stage but better survival rates are correlated with earlier detection. Current clinically approved cancer biomarkers are most effective when applied to patients with widespread cancer. Single biomarkers with satisfactory sensitivity and specificity have not been identified for the most common cancers and some biomarkers are ineffective for the detection of early stage cancers. Thus, novel biomarkers with better diagnostic and prognostic performance are required. Aberrant protein glycosylation is well known hallmark of cancer and represents a promising source of potential biomarkers. Glycoproteins enter circulation from tissues or blood cells through active secretion or leakage and patient serum is an attractive option as a source for biomarkers from a clinical and diagnostic perspective. A plethora of technical approaches have been developed to address the challenges of glycosylation structure detection and determination. This review summarises currently utilised glycoprotein biomarkers and novel glycosylation-based biomarkers from the serum glycoproteome under investigation as cancer diagnostics and for monitoring and prognostics and includes details of recent high throughput and other emerging glycoanalytical techniques.

Combination of MUC1 and MUC4 expression predicts clinical outcome in patients with oral squamous cell carcinoma

BACKGROUND

Both MUC1 and MUC4 are high molecular weight glycoproteins and are independent indicators of worse prognosis in many human epithelial cancers including oral squamous cell carcinoma (OSCC). However, there has been no investigation of the clinical importance of the co-expression of MUC1 and MUC4 in OSCC. The aim of this study was to evaluate the co-expression profile of MUC1/MUC4 and analyze the prognostic significance in OSCC.

METHODS

We examined the expression profile of MUC1 and MUC4 in OSCC tissues from 206 patients using immunohistochemistry. The co-expression profile of MUC1/MUC4 and its prognostic significance in OSCC was statistically analyzed.

RESULTS

MUC1 and MUC4 overexpression were strongly correlated with each other (p < 0.0001) and a combination of both MUC1 and MUC4 expression was a powerful indicator for tumor aggressiveness such as tumor size (p = 0.014), lymph node metastasis (0.0001), tumor stage (p = 0.006), diffuse invasion (p = 0.028), and vascular invasion (p = 0.014). The MUC1/MUC4 double-positive patients showed the poorest overall and disease-free survival. Multivariate analysis revealed that MUC1/MUC4 double-positivity was the strong independent prognostic factor for overall and disease-free survival (p = 0.007 and (p = 0.0019), in addition to regional recurrence (p = 0.0025).

CONCLUSIONS

Taken together, these observations indicate that the use of a combination of MUC1/MUC4 can predict outcomes for patients with OSCC. This combination is also a useful marker for predicting regional recurrence. MUC1 and MUC4 may be attractive targets for the selection of treatment methods in OSCC.

Human prominin-1 (CD133) is detected in both neoplastic and non-neoplastic salivary gland diseases and released into saliva in a ubiquitinated form

Prominin-1 (CD133) is physiologically expressed at the apical membranes of secretory (serous and mucous) and duct cells of major salivary glands. We investigated its expression in various human salivary gland lesions using two distinct anti-prominin-1 monoclonal antibodies (80B258 and AC133) applied on paraffin-embedded sections and characterized its occurrence in saliva. The 80B258 epitope was extensively expressed in adenoid cystic carcinoma, in lesser extent in acinic cell carcinoma and pleomorphic adenoma, and rarely in mucoepidermoid carcinoma. The 80B258 immunoreactivity was predominately detected at the apical membrane of tumor cells showing acinar or intercalated duct cell differentiation, which lined duct- or cyst-like structures, and in luminal secretions. It was observed on the whole cell membrane in non-luminal structures present in the vicinity of thin-walled blood vessels and hemorrhagic areas in adenoid cystic carcinoma. Of note, AC133 labeled only a subset of 80B258–positive structures. In peritumoral salivary gland tissues as well as in obstructive sialadenitis, an up-regulation of prominin-1 (both 80B258 and AC133 immunoreactivities) was observed in intercalated duct cells. In most tissues, prominin-1 was partially co-expressed with two cancer markers: carcinoembryonic antigen (CEA) and mucin-1 (MUC1). Differential centrifugation of saliva followed by immunoblotting indicated that all three markers were released in association with small membrane vesicles. Immuno-isolated prominin-1–positive vesicles contained CEA and MUC1, but also exosome-related proteins CD63, flotillin-1, flotillin-2 and the adaptor protein syntenin-1. The latter protein was shown to interact with prominin-1 as demonstrated by its co-immunoisolation. A fraction of saliva-associated prominin-1 appeared to be ubiquitinated. Collectively, our findings bring new insights into the biochemistry and trafficking of prominin-1 as well as its immunohistochemical profile in certain types of salivary gland tumors and inflammatory diseases.

Targeted proteomics pipeline reveals potential biomarkers for the diagnosis of metastatic lung cancer in pleural effusion

The ability to discriminate lung cancer malignant pleural effusion (LC-MPE) from benign pleural effusion has profound implications for the therapy and prognosis of lung cancer. Here, we established a pipeline to verify potential biomarkers for this purpose. In the discovery phase, label-free quantification was performed for the proteome profiling of exudative pleural effusion in order to select 34 candidate biomarkers with significantly elevated levels in LC-MPE. In the verification phase, signature peptides for 34 candidates were first confirmed by accurate inclusion mass screening (AIMS). To quantify the candidates in PEs, multiple reaction monitoring mass spectrometry (MRM-MS) with stable isotope-labeled standards (SIS) peptides was performed for the 34 candidate biomarkers using the QconCAT approach for the generation of the SIS peptides. The results of the MRM assay were used to prioritize candidates based on their discriminatory power in 82 exudative PE samples. The five potential biomarkers (ALCAM, CDH1, MUC1, SPINT1, and THBS4; AUC > 0.7) and one three-marker panel (SPINT1/SVEP1/THBS4; AUC = 0.95) were able to effectively differentiate LC-MPE from benign PE. Collectively, these results demonstrate that our pipeline is a feasible platform for verifying potential biomarkers for human diseases.

Current approaches and challenges in monitoring treatment responses in breast cancer

Monitoring response to treatment is a key element in the management of breast cancer that involves several different viewpoints from surgery, radiology, and medical oncology. In the adjuvant setting, appropriate surgical and pathological evaluation guides adjuvant treatment and follow up care focuses on detecting recurrent disease with the intention of improving long term survival. In the neoadjuvant setting, assessing response to chemotherapy prior to surgery to include evaluation for pathologic response can provide prognostic information to help guide follow up care. In the metastatic setting, for those undergoing treatment, it is crucial to determine responders versus non-responders in order to help guide treatment decisions. In this review, we present the current guidelines for monitoring treatment response in the adjuvant, neoadjuvant, and metastatic setting. In addition, we also discuss challenges that are faced in each setting.

MUC1 has prognostic significance in malignant peritoneal mesothelioma

BACKGROUND

Overexpression of MUC1 predicts poor survival in most cancers. Routine immunohistochemical detection of MUC1 is performed for differential diagnosis in malignant peritoneal mesothelioma (MPM). However, the prognostic significance of MUC1 in MPM has not been determined. 


METHOD

We investigated MUC1 expression and other prognostic factors in relation to survival in 42 patients (20 males and 22 females) for whom archival samples were available, using immunohistochemistry. MUC1 was expressed in 38/42 (90%) patients. Its prognostic significance was statistically analyzed using the Kaplan-Meier method.


RESULTS

High expression of MUC1 (immunohistochemical score of 5-8), was correlated with poor survival in several categories: all subtypes of tumors (p=0.001), male gender (p=0.017), female gender (p=0.001), epitheloid tumors (p=0.001), epitheloid tumors in males (p=0.005), epitheloid tumors in females (p=0.003), and age at diagnosis (AAD) <60 years (p=0.001). Amongst the other clinicopathological variables, univariate analysis also showed that male gender (p=0.007), sarcomatoid histology (p=0.001), peritoneal cancer index (PCI) ≥20 (p=0.013) and AAD ≥60 (p=0.001), correlated with poor survival. Multivariate analysis showed that only AAD ≥60 (p=0.049) was an independent prognostic factor, and that high MUC1 expression significantly correlated with the following categories: all subtypes of tumors (p=0.001), male gender (p=0.002), female gender (p=0.031), epitheloid tumors (p=0.031), and AAD <60y (p=0.012).


CONCLUSION

AAD and high MUC1 expression in the tumor are indicators of poor prognosis. MUC1 evaluation by immunohistochemistry may serve as a useful prognostic tool in MPM, but may need further confirmation in a larger patients' cohort.

The prognostic role of preoperative and (early) postoperatively change in CA15.3 serum levels in a single hospital cohort of primary operable breast cancers

Measuring CA15.3 serum levels in the early breast cancer setting is not recommended by current ASCO guidelines. In this large single center study, we assess the prognostic value of preoperative (n = 3746), postoperative (n = 4049) and change in (n = 3252) CA15.3, also across different breast cancer phenotypes. Preoperative, postoperative and change in CA15.3 were all significant (p = 0.0348, p < 0.0001, p < 0.0001 respectively in multivariate analysis) predictors of distant metastasis free survival. For breast cancer specific survival, only postoperative and change in CA15.3 were significant predictors (p < 0.0001 both). Multivariate prognostic models did not improve by incorporating information on preoperative CA15.3, but did improve when introducing information on postoperative CA15.3 for distant metastasis (p = 0.0365) and on change in CA15.3 for breast cancer specific survival (p = 0.0291). Change in CA15.3 impacts on prognosis (distant metastasis) differently in different breast cancer phenotypes. A decrease in CA15.3 may be informative of improved prognosis in basal like and HER2 like breast cancer.

CA 15-3 cell lines and tissue expression in canine mammary cancer and the correlation between serum levels and tumour histological grade

Background

Mammary tumours are the most common malignancy diagnosed in female dogs and a significant cause of mortality and morbidity in this species. Carbohydrate antigen (CA) 15–3 is a mucinous glycoprotein aberrantly over-expressed in human mammary neoplasms and one of the most widely used serum tumour markers in women with breast cancer. The aim of this study was to investigate the antigenic analogies of human and canine CA 15–3 and to assess its expression in canine mammary cancer tissues and cell lines. Immunohistochemical expression of CA 15–3 was evaluated in 7 canine mammary cancer cell lines and 50 malignant mammary tumours. As a positive control, the human breast carcinoma cell line MCF7 and tissue were used. To assess CA 15–3 staining, a semi-quantitative method was applied. To confirm the specificity and cross-reactivity of an anti-human CA 15–3 antibody to canine tissues, an immunoblot analysis was performed. We also investigated serum CA 15–3 activity to establish whether its expression could be assigned to several tumour characteristics to evaluate its potential use as a serum tumour marker in the canine mammary oncology field.

Results

Immunocytochemical analysis revealed CA 15–3 expression in all examined canine mammary cancer cell lines, whereas its expression was confirmed by immunoblot only in the most invasive cells (CMT-W1, CMT-W1M, CMT-W2 and CMT-W2M). In the tissue, an immunohistochemical staining pattern was observed in 34 (68%) of the malignant tumours. A high statistical correlation (p = 0.0019) between serum CA 15–3 levels and the degree of tumour proliferation and differentiation was shown, which indicates that the values of this serum marker increase as the tumour stage progresses.

Conclusions

The results of this study reveal that CA 15–3 is expressed in both canine mammary tumour cell lines and tissues and that serum levels significantly correlate with the histological grade of the malignancy.

MUC1-C oncoprotein as a target in breast cancer: activation of signaling pathways and therapeutic approaches

Mucin 1 (MUC1) is a heterodimeric protein formed by two subunits that is aberrantly overexpressed in human breast cancer and other cancers. Historically, much of the early work on MUC1 focused on the shed mucin subunit. However, more recent studies have been directed at the transmembrane MUC1-C-terminal subunit (MUC1-C) that functions as an oncoprotein. MUC1-C interacts with EGFR (epidermal growth factor receptor), ErbB2 and other receptor tyrosine kinases at the cell membrane and contributes to activation of the PI3KAKT and mitogen-activated protein kinase kinase (MEK)extracellular signal-regulated kinase (ERK) pathways. MUC1-C also localizes to the nucleus where it activates the Wnt/β-catenin, signal transducer and activator of transcription (STAT) and NF (nuclear factor)-κB RelA pathways. These findings and the demonstration that MUC1-C is a druggable target have provided the experimental basis for designing agents that block MUC1-C function. Notably, inhibitors of the MUC1-C subunit have been developed that directly block its oncogenic function and induce death of breast cancer cells in vitro and in xenograft models. On the basis of these findings, a first-in-class MUC1-C inhibitor has entered phase I evaluation as a potential agent for the treatment of patients with breast cancers who express this oncoprotein.

Transmembrane mucins as novel therapeutic targets

Membrane-tethered mucin glycoproteins are abundantly expressed at the apical surfaces of simple epithelia, where they play important roles in lubricating and protecting tissues from pathogens and enzymatic attack. Notable examples of these mucins are MUC1, MUC4 and MUC16 (also known as cancer antigen 125). In adenocarcinomas, apical mucin restriction is lost and overall expression is often highly increased. High-level mucin expression protects tumors from killing by the host immune system, as well as by chemotherapeutic agents, and affords protection from apoptosis. Mucin expression can increase as the result of gene duplication and/or in response to hormones, cytokines and growth factors prevalent in the tumor milieu. Rises in the normally low levels of mucin fragments in serum have been used as markers of disease, such as tumor burden, for many years. Currently, several approaches are being examined that target mucins for immunization or nanomedicine using mucin-specific antibodies.

Mucins in cancer: function, prognosis and therapy

Epithelia are protected from adverse conditions by a mucous barrier. The secreted and transmembrane mucins that constitute the mucous barrier are largely unrecognized as effectors of carcinogenesis. However, both types of mucins are intimately involved in inflammation and cancer. Moreover, diverse human malignancies overexpress transmembrane mucins to exploit their role in signalling cell growth and survival. Mucins have thus been identified as markers of adverse prognosis and as attractive therapeutic targets. Notably, the findings that certain transmembrane mucins induce transformation and promote tumour progression have provided the experimental basis for demonstrating that inhibitors of their function are effective as anti-tumour agents in preclinical models.

Increased serum tumor markers (CA125 and CA15.3) in primary plasma cell leukemia: a case report and review of the literature

73-year-old woman complaining of bone pain and weight loss was suspected to have a malignant disease, and extensive laboratory investigations were carried out. She was diagnosed with multiple myeloma; however, because of the finding of extremely high serum levels of CA125 and CA15.3 and focal liver lesions, a concomitant solid tumor was suspected, which was then excluded with the appropriate tests, including an ultrasound-guided liver biopsy. While being diagnosed, the patient developed a rapidly evolving plasma cell leukemia with a simultaneous increase in CA125 and CA15.3. After treatment with cyclophosphamide and dexamethasone, the peripheral blood plasma cells disappeared and there was a dramatic decrease in the CA125 and CA15.3 tumor markers. High levels of the latter can be observed in patients with aggressive plasma cell dyscrasias, an observation that is crucial in order to avoid unnecessary tests that can result in treatment delay.

Retargeting of human T cells to tumor-associated MUC1: the evolution of a chimeric antigen receptor

MUC1 is a highly attractive immunotherapeutic target owing to increased expression, altered glycosylation, and loss of polarity in >80% of human cancers. To exploit this, we have constructed a panel of chimeric Ag receptors (CAR) that bind selectively to tumor-associated MUC1. Two parameters proved crucial in optimizing the CAR ectodomain. First, we observed that the binding of CAR-grafted T cells to anchored MUC1 is subject to steric hindrance, independent of glycosylation status. This was overcome by insertion of the flexible and elongated hinge found in immunoglobulins of the IgD isotype. Second, CAR function was highly dependent upon strong binding capacity across a broad range of tumor-associated MUC1 glycoforms. This was realized by using an Ab-derived single-chain variable fragment (scFv) cloned from the HMFG2 hybridoma. To optimize CAR signaling, tripartite endodomains were constructed. Ultimately, this iterative design process yielded a potent receptor termed HOX that contains a fused CD28/OX40/CD3zeta endodomain. HOX-expressing T cells proliferate vigorously upon repeated encounter with soluble or membrane-associated MUC1, mediate production of proinflammatory cytokines (IFN-gamma and IL-17), and elicit brisk killing of MUC1(+) tumor cells. To test function in vivo, a tumor xenograft model was derived using MDA-MB-435 cells engineered to coexpress MUC1 and luciferase. Mice bearing an established tumor were treated i.p. with a single dose of engineered T cells. Compared with control mice, this treatment resulted in a significant delay in tumor growth as measured by serial bioluminescence imaging. Together, these data demonstrate for the first time that the near-ubiquitous MUC1 tumor Ag can be targeted using CAR-grafted T cells.

Preoperative CA 15-3 and CEA serum levels as predictor for breast cancer outcomes

BACKGROUND

To investigate the association between tumor markers [cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA)] and clinicopathological parameters and patient outcomes in breast cancer.

MATERIALS AND METHODS

A total of 740 patients with stages I-III breast cancer had preoperative CA 15-3 and CEA concentrations measured. Univariate and multivariate analyses were used to investigate associations between marker concentration and clinicopathological parameters and patient outcomes.

RESULTS

Among 740 patients, elevated preoperative levels of CA 15-3 and CEA were identified in 92 (12.4%) and 79 (10.7%) patients, respectively. Tumor size (>5 cm), node metastases (> or =4), and advanced stage (> or =III) were associated with higher preoperative levels. Elevated CA 15-3 and CEA levels were associated with poor disease-free survival (DFS, P = 0.0014, P = 0.0001, respectively) and overall survival (OS, P = 0.018, P = 0.015) even in stage-matched analysis. Patients with normal levels of both CA 15-3 and CEA showed better DFS and OS than those with elevated group. In multivariate analysis, age (<35 years), tumor size (>2 cm), node metastases, estrogen receptor expression, and elevated CA 15-3 and CEA preoperative values were independent prognostic factors for DFS.

CONCLUSION

High preoperative CA 15-3 and CEA levels may reflect tumor burden and are associated with advanced disease and poor outcome. Measuring preoperative levels of CA 15-3 and CEA can be helpful for predicting outcomes.

MUC-1 (CA 15–3 Antigen) as a Highly Reliable Predictor of Response to EGFR Inhibitors in Patients with Bronchioloalveolar Carcinoma: An Experience on 26 Patients

Background

Bronchioloalveolar carcinoma (BAC) is a histological subtype of non-small cell lung cancer (NSCLC), particularly of adenocarcinoma. Given its multifocality and the poor activity of chemotherapy, there is no established treatment for BAC, although promising results have been achieved with inhibitors of the epidermal growth factor receptor (EGFR). No tumor marker has been validated in the diagnosis and follow-up of lung cancer, in particular to predict the outcome of treatment with EGFR inhibitors.

Purpose

As CA 15–3 antigen serum levels are reported to be pathologically abnormal in adenocarcinoma of the lung, we chose this tumor marker to monitor treatment with EGFR inhibitors of patients affected by adenocarcinoma with BAC features or pure BAC.

Patients and methods

We collected data from 26 consecutive Caucasian patients with BAC, mostly women and never smokers, who received EGFR inhibitors.

Results

We noticed that all patients with normal CA 15–3 serum levels at baseline (15/26, 57.7%) showed a response to EGFR inhibitors, whereas all patients with abnormal CA 15–3 serum levels (11/26, 42.3%) did not.

Conclusion

Our data suggest that CA 15–3 levels might be a predictive factor for the response to EGFR inhibitors in patients with BAC.

Evaluation of serum tumour markers concentrations in patients with homozygous β-thalassaemia in relation to demographical, clinical and biochemical parameters

Increased life expectancy in patients with homozygous beta-thalassaemia consequently increases the risk for neoplastic diseases. This study was conducted to assess the levels of five common tumour markers in thalassaemic patients and to investigate possible correlations to demographical, clinical and laboratory data. Eighty-five patients (44 female and 41 male) with homozygous beta-thalassaemia (mean age = 27.92 +/- 12.5), on regular blood transfusions and adequate chelation treatment, and 60 sex and age- matched healthy controls were enrolled in the study. Blood samples for the determination of carcinoma antigen (CA) 15.3, CA 125, CA 19.9, carcinoembryonic antigen (CEA) and alpha-fetoprotein (a-FP) were collected from every subject. Results showed that 69% of the thalassaemic patients had abnormal levels of CA 15.3, whereas only sporadic cases had increased levels of CA 125 and CA 19.9. On the contrary, all controls had normal levels of CA 15.3, CA 19.9 and CA 125. CEA and a-FP were within reference ranges both in the thalassaemic and in the control group. Levels of CA 15.3 were significantly lower in patients aged less than 20 years compared to older patients. Male patients had significantly increased levels of CA 15.3 compared to female patients. Relatively recent studies show an increased expression of CA 15.3 on progenitor cells of the erythroid lineage and increased amounts of circulating progenitor cells even in well-transfused thalassaemic patients. However, it seems that there are also other factors contributing to this phenomenon. In conclusion, our results indicate that CA 15.3 seems to be an unreliable marker of occult malignancy in patients with beta-thalassaemia. However, more studies are needed to support these preliminary results.