Use of Truquant BR radioimmunoassay for early detection of breast cancer recurrence in patients with stage II and stage III disease

Proteomic-based electrochemical non-invasive biosensor for early breast cancer diagnosis

Breast cancer is the second highest cause of cancer-related mortality in women worldwide and in the United States, accounting for around 571,000 deaths per year. Early detection of breast cancer increases treatment results and the possibility of a cure. While existing diagnostic modalities such as mammography, ultrasound, and biopsy exist, some are prohibitively expensive, uncomfortable, time-consuming, and have limited sensitivity, necessitating the development of a cost-effective, rapid, and highly sensitive approach such as an electrochemical biosensor. Our research focuses on detecting breast cancer patients using the ECM1 biomarker, which has higher expression in synthetic urine. Our study has two primary objectives: (i) Diverse ECM1 protein concentrations are measured using electrochemical impedance spectroscopy and ELISA. Establishing a standard curve for the electrochemical biosensor by calibrating ECM-1 protein levels using electrochemical impedance spectroscopy. (ii) Validation of the effectiveness of the electrochemical biosensor. This aim entails testing the unknown concentration of ECM1 in the synthetic urine to ensure the efficiency of the biosensor to detect the biomarker in the early stages. The results show that the synthetic urine solution's ECM-1 detection range ranges from 1 pg/ml to 500 ng/ml. This shows that by detecting changes in ECM-1 protein levels in patient urine, the electrochemical biosensor can consistently diagnose breast cancer in its early stages or during increasing recurrence. Our findings highlight the electrochemical biosensor's efficacy in detecting early-stage breast cancer biomarkers (ECM-1) in patient urine. Further studies will be conducted with patient samples and develop handheld hardware for patient usage.

Carcinoembryonic Antigen, Carbohydrate Antigen 19-9, Cancer Antigen 125, Prostate-Specific Antigen and Other Cancer Markers: A Primer on Commonly Used Cancer Markers

Cancer markers are molecules produced by cancer cells which may serve to identify the presence of cancer. Cancer markers can be differentiated as serum-based, radiology-based and tissue-based, and are one of the most important tools in diagnosing, staging and monitoring of treatment of many cancers. The most used cancer markers are serum cancer markers due to its relative ease and lower cost of testing. However, serum cancer markers have poor mass screening utilization due to poor positive predictive value. Several markers such as prostate-specific antigen (PSA), beta-human chorionic gonadotropin (B-hCG), alpha-fetoprotein (AFP), and lactate dehydrogenase (LDH) are used to aid in diagnosis of cancer in cases of high suspicion. Serum markers such as carcinoembryonic antigen (CEA), AFP, carbohydrate antigen 19-9 (CA 19-9), and 5-hydroxyindoleacetic acid (5-HIAA) play a significant role in assessing disease prognosis as well as response to treatment. This work reviews the role of some of the biomarkers in the diagnosis and treatment of 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.

Design of a Lab-On-Chip for Cancer Cell Detection through Impedance and Photoelectrochemical Response Analysis

In this study, a biochip was fabricated using a light-absorbing layer of a silicon solar element combined with serrated, interdigitated electrodes and used to identify four different types of cancer cells: CE81T esophageal cancer, OE21 esophageal cancer, A549 lung adenocarcinoma, and TSGH-8301 bladder cancer cells. A string of pearls was formed from dielectrophoretic aggregated cancer cells because of the serrated interdigitated electrodes. Thus, cancer cells were identified in different parts, and electron-hole pairs were separated by photo-excited carriers through the light-absorbing layer of the solar element. The concentration catalysis mechanism of GSH and GSSG was used to conduct photocurrent response and identification, which provides the fast, label-free measurement of cancer cells. The total time taken for this analysis was 13 min. Changes in the impedance value and photocurrent response of each cancer cell were linearly related to the number of cells, and the slope of the admittance value was used to distinguish the location of the cancerous lesion, the slope of the photocurrent response, and the severity of the cancerous lesion. The results show that the number of cancerous cells was directly proportional to the admittance value and the photocurrent response for all four different types of cancer cells. Additionally, different types of cancer cells could easily be differentiated using the slope value of the photocurrent response and the admittance value.

Appropriateness and Economic Analysis of Conventional Circulating Biomarkers Assessment in Early Breast Cancer: A Real-World Experience from the E.Pic.A Study

The risk of relapse for early breast cancer (BC) patients persists even after decades and to date, no specific and sensitive effective circulating biomarker for recurrence prediction has been identified yet. The international guidelines do not recommend the assessment of the serum tumor markers CEA and CA15-3 in the follow-up of asymptomatic early BC patients. In our institute, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, as part of the E.Pic.A study, which was designed to assess the economic appropriateness of integrated care pathways in early BC, the use of CEA and CA15-3 as circulating tumor biomarkers in early BC patients was evaluated in 1502 patients one year after surgery, from 2015 to 2018, with an overall expense of EUR 51,764. A total of EUR 47,780 (92%) was used for execution of circulating tumor markers in early BC patients with stage 0, I and II tumors, neglecting the current guidelines and considered inappropriate by our professional board. We found that no patients with stage I BC experienced relapse in the 365 days after surgery, and in any case examination of the circulating markers CEA and CA15-3 was considered crucial for diagnosis of relapse. Our findings suggest that this inadequacy is a low-value area, supporting the reallocation of economic resources for interventions of a higher value for patients.

Prognostic prospect of soluble programmed cell death ligand-1 in cancer management

Aggressive tissue biopsy is commonly unavoidable in the management of most suspected tumor cases to conclusively verify the presence of cancerous cells through histological assessment. The extracted tissue is also immunostained for detection of antigens (tissue tumor markers) of potential prognostic or therapeutic importance to assist in treatment decision. Although liquid biopsies can be a powerful tool for monitoring treatment response, they are still excluded from standard cancer diagnostics, and their utility is still being debated in the scientific community. With a myriad of soluble tissue tumor markers now being discovered, liquid biopsies could completely change the current paradigms of cancer management. Recently, soluble programmed cell death ligand-1 (sPD-L1), which is found in the peripheral blood, i.e. serum and plasma, has shown potential as a pre-therapeutic predictive marker as well as a prognostic biomarker to monitor treatment efficacy. Thus, this review focuses on the emergence of sPD-L1 and promising technologies for its detection in order to support liquid biopsies for future cancer management.

Current immunoassay methods and their applications to clinically used biomarkers of breast cancer

Breast cancer is the leading cause of cancer-related mortality worldwide, with a higher incidence in developed countries. The biomarkers for breast cancer such as estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, CA (cancer antigen) 15-3, CA 27.29, and carcinoembryonic antigen have been recommended for use in the laboratory based on the guidelines of American and European societies. Immunoassays have been frequently and consistently used to detect these clinically established biomarkers of breast cancer. Despite the higher accessibility of serum biomarkers, including CA 15-3, CA 27.29, and CEA, compared to tissue markers, variations in immunoassays affect their standardization and clinical utility. When reviewing the immunoassays used to detect these serum markers, we found that the most frequently used immunoassay was enzyme-linked immunosorbent assay, followed by electrochemiluminescent immunoassay, and then chemiluminescence immunoassay for CA 15-3 and CEA. Meanwhile, the chemiluminescence immunoassay was the most common technique for CA27.29. The electrochemiluminescent immunoassay and monoclonal fluorometric assay have become the preferred methods in 2010-2019 compared to 2000-2009. Analytical and clinical performance factors such as sensitivity, specificity, detection limit, hazard risk to laboratory personnel, speed, and economic feasibility influenced these changes in user preference. When using the immunoassays, there should be a comprehensive understanding of the principles, advantages, vulnerability, and precautions for interpretation. In the future, a combination of immunological biomarkers and genetic platforms will benefit patients with breast cancer by facilitating prognosis prediction and guiding therapeutic intervention.

Association of Circulating Tumor Cells With Late Recurrence of Estrogen Receptor-Positive Breast Cancer: A Secondary Analysis of a Randomized Clinical Trial

Importance

Late recurrence 5 or more years after diagnosis accounts for at least one-half of all cases of recurrent hormone receptor-positive breast cancer.

Objective

To determine whether the presence of circulating tumor cells (CTCs) in a peripheral blood sample obtained approximately 5 years after diagnosis was associated with late clinical recurrence of operable human epidermal growth factor receptor 2-negative breast cancer.

Design, Setting, and Participants

This per-protocol secondary analysis of the Double-Blind Phase III Trial of Doxorubicin and Cyclophosphamide Followed by Paclitaxel With Bevacizumab or Placebo in Patients With Lymph Node Positive and High Risk Lymph Node Negative Breast Cancer enrolled patients from 2007 to 2011 who were without clinical evidence of recurrence between 4.5 and 7.5 years after primary surgical treatment of human epidermal growth factor receptor 2-negative stage II-III breast cancer followed by adjuvant systemic therapy. Patients were enrolled in a subprotocol for secondary analysis from February 25, 2013, to July 29, 2016, after signing consent for the subprotocol. The analysis was performed in April 2018.

Interventions

A blood sample was obtained for identification and enumeration of CTCs.

Main Outcome and Measures

The association between a positive CTC assay result (at least 1 CTC per 7.5 mL of blood) and clinical recurrence.

Results

Among 547 women included in this analysis, the results of the CTC assay were positive for 18 of 353 with hormone receptor-positive disease (5.1% [95% CI, 3.0%-7.9%]); 23 of 353 patients (6.5% [95% CI, 4.2%-9.6%]) had a clinical recurrence. The recurrence rates per person-year of follow-up in the CTC-positive and CTC-negative groups were 21.4% (7 recurrences per 32.7 person-years) and 2.0% (16 recurrences per 796.3 person-years), respectively. In multivariate models including clinical covariates, a positive CTC assay result was associated with a 13.1-fold higher risk of recurrence (hazard ratio point estimate, 13.1; 95% CI, 4.7-36.3). Seven of 23 patients (30.4% [95% CI, 13.2%-52.9%]) with recurrence had a positive CTC assay result at a median of 2.8 years (range, 0.1-2.8 years) before clinical recurrence. The CTC assay result was also positive for 8 of 193 patients (4.1% [95% CI, 1.8%-8.0%]) with hormone receptor-negative disease, although only 1 patient (0.5% [95% CI, 0%-2.9%]) experienced disease recurrence (this patient was CTC negative).

Conclusions and Relevance

A single positive CTC assay result 5 years after diagnosis of hormone receptor-positive breast cancer provided independent prognostic information for late clinical recurrence, which provides proof of concept that liquid-based biomarkers may be used to risk stratify for late recurrence and guide therapy.

Trial Registration

ClinicalTrials.gov identifier: NCT00433511.

Microwave Sensors for Breast Cancer Detection

Breast cancer is the leading cause of death among females, early diagnostic methods with suitable treatments improve the 5-year survival rates significantly. Microwave breast imaging has been reported as the most potential to become the alternative or additional tool to the current gold standard X-ray mammography for detecting breast cancer. The microwave breast image quality is affected by the microwave sensor, sensor array, the number of sensors in the array and the size of the sensor. In fact, microwave sensor array and sensor play an important role in the microwave breast imaging system. Numerous microwave biosensors have been developed for biomedical applications, with particular focus on breast tumor detection. Compared to the conventional medical imaging and biosensor techniques, these microwave sensors not only enable better cancer detection and improve the image resolution, but also provide attractive features such as label-free detection. This paper aims to provide an overview of recent important achievements in microwave sensors for biomedical imaging applications, with particular focus on breast cancer detection. The electric properties of biological tissues at microwave spectrum, microwave imaging approaches, microwave biosensors, current challenges and future works are also discussed in the manuscript.

Glycosylation Changes in Brain Cancer

Protein glycosylation is a posttranslational modification that affects more than half of all known proteins. Glycans covalently bound to biomolecules modulate their functions by both direct interactions, such as the recognition of glycan structures by binding partners, and indirect mechanisms that contribute to the control of protein conformation, stability, and turnover. The focus of this Review is the discussion of aberrant glycosylation related to brain cancer. Altered sialylation and fucosylation of N- and O-glycans play a role in the development and progression of brain cancer. Additionally, aberrant O-glycan expression has been implicated in brain cancer. This Review also addresses the clinical potential and applications of aberrant glycosylation for the detection and treatment of brain cancer. The viable roles glycans may play in the development of brain cancer therapeutics are addressed as well as cancer-glycoproteomics and personalized medicine. Glycoprotein alterations are considered as a hallmark of cancer while high expression in body fluids represents an opportunity for cancer assessment.

Potential plasma lipid biomarkers in early-stage breast cancer

OBJECTIVE

To find new biomarkers for early diagnosis of breast cancer.

RESULTS

847 lipid species were identified from 78 plasma samples (37 breast cancer samples and 41 healthy controls) by ultra HPLC coupled with quadrupole time-of-flight tandem mass spectrometry. These include 321 glycerophospholipids (GPs), 265 glycerolipids (GLs), 91 sphingolipids (SPs), 77 fatty acyls (FAs), 68 sterol lipids (STs), 18 prenol lipids (PRs), 6 polyketides (PKs), and 1 saccharolipid (SL). Separation was observed from an orthogonal signal correction Partial Least Square Discrimination Analysis model. Based on this analysis, six differentiating lipids were identified: PC (20:2/20:5), PC (22:0/24:1), TG (12:0/14:1), and DG (18:1/18:2) had high levels, whereas PE (15:0/19:1) and N-palmitoyl proline had low levels in the breast cancer samples compared with the healthy controls. Furthermore, significant differences in metabolites were found among some clinical characteristics.

CONCLUSIONS

Our results reveal that six specific lipids could serve as potential biomarkers for early diagnosis of breast cancer.

Detection of Lipid and Amphiphilic Biomarkers for Disease Diagnostics

Rapid diagnosis is crucial to effectively treating any disease. Biological markers, or biomarkers, have been widely used to diagnose a variety of infectious and non-infectious diseases. The detection of biomarkers in patient samples can also provide valuable information regarding progression and prognosis. Interestingly, many such biomarkers are composed of lipids, and are amphiphilic in biochemistry, which leads them to be often sequestered by host carriers. Such sequestration enhances the difficulty of developing sensitive and accurate sensors for these targets. Many of the physiologically relevant molecules involved in pathogenesis and disease are indeed amphiphilic. This chemical property is likely essential for their biological function, but also makes them challenging to detect and quantify in vitro. In order to understand pathogenesis and disease progression while developing effective diagnostics, it is important to account for the biochemistry of lipid and amphiphilic biomarkers when creating novel techniques for the quantitative measurement of these targets. Here, we review techniques and methods used to detect lipid and amphiphilic biomarkers associated with disease, as well as their feasibility for use as diagnostic targets, highlighting the significance of their biochemical properties in the design and execution of laboratory and diagnostic strategies. The biochemistry of biological molecules is clearly relevant to their physiological function, and calling out the need for consideration of this feature in their study, and use as vaccine, diagnostic and therapeutic targets is the overarching motivation for this review.

Curing Metastatic Breast Cancer

Metastatic breast cancer is generally considered incurable, and this colors doctor-patient interactions for patients with metastatic disease. Although true for most patients, there appear to be important exceptions, instances where long-term disease-free survival occurs. Although these instances are few in number, they suggest the possibility of cure. How will we move toward cure for a much larger population of patients with metastatic disease? This article outlines a potential research agenda that might move us toward that distant goal.

Assessment of average of normals (AON) procedure for outlier-free datasets including qualitative values below limit of detection (LoD): an application within tumor markers such as CA 15-3, CA 125, and CA 19-9

Average of normals (AON) is a quality control procedure that is sensitive only to systematic errors that can occur in an analytical process in which patient test results are used. The aim of this study was to develop an alternative model in order to apply the AON quality control procedure to datasets that include qualitative values below limit of detection (LoD). The reported patient test results for tumor markers, such as CA 15-3, CA 125, and CA 19-9, analyzed by two instruments, were retrieved from the information system over a period of 5 months, using the calibrator and control materials with the same lot numbers. The median as a measure of central tendency and the median absolute deviation (MAD) as a measure of dispersion were used for the complementary model of AON quality control procedure. The u_bias values, which were determined for the bias component of the measurement uncertainty, were partially linked to the percentages of the daily median values of the test results that fall within the control limits. The results for these tumor markers, in which lower limits of reference intervals are not medically important for clinical diagnosis and management, showed that the AON quality control procedure, using the MAD around the median, can be applied for datasets including qualitative values below LoD.

Noninvasive strategies for breast cancer early detection

Breast cancer screening and presurgical diagnosis are currently based on mammography, ultrasound and more sensitive imaging technologies; however, noninvasive biomarkers represent both a challenge and an opportunity for early detection of cancer. An extensive number of potential breast cancer biomarkers have been discovered by microarray hybridization or sequencing of circulating DNA, noncoding RNA and blood cell RNA; multiplex analysis of immune-related molecules and mass spectrometry-based approaches for high-throughput detection of protein, endogenous peptides, circulating and volatile metabolites. However, their medical relevance and their translation to clinics remain to be exploited. Once they will be fully validated, cancer biomarkers, used in combination with the current and emerging imaging technologies, represent an avenue to a personalized breast cancer diagnosis.

Tumor marker usage and medical care costs among older early-stage breast cancer survivors

PURPOSE

Although American Society of Clinical Oncology guidelines discourage the use of tumor marker assessment for routine surveillance in nonmetastatic breast cancer, their use in practice is uncertain. Our objective was to determine use of tumor marker tests such as carcinoembryonic antigen and CA 15-3/CA 27.29 and associated Medicare costs in early-stage breast cancer survivors.

METHODS

By using Surveillance, Epidemiology, and End Results-Medicare records for patients diagnosed with early-stage breast cancer between 2001 and 2007, tumor marker usage within 2 years after diagnosis was identified by billing codes. Logistic regression models were used to identify clinical and demographic factors associated with use of tumor markers. To determine impact on costs of care, we used multivariable regression, controlling for other factors known to influence total medical costs.

RESULTS

We identified 39,650 eligible patients. Of these, 16,653 (42%) received at least one tumor marker assessment, averaging 5.7 tests over 2 years, with rates of use per person increasing over time. Factors significantly associated with use included age at diagnosis, diagnosis year, stage at diagnosis, race/ethnicity, geographic region, and urban/rural status. Rates of advanced imaging, but not biopsies, were significantly higher in the assessment group. Medical costs for patients who received at least one test were approximately 29% greater than costs for those who did not, adjusting for other factors.

CONCLUSION

Breast cancer tumor markers are frequently used among women with early-stage disease and are associated with an increase in both diagnostic procedures and total cost of care. A better understanding of factors driving the use of and the potential benefits and harms of surveillance-based tumor marker testing is needed.

Novel methylated biomarkers and a robust assay to detect circulating tumor DNA in metastatic breast cancer

The ability to consistently detect cell-free tumor-specific DNA in peripheral blood of patients with metastatic breast cancer provides the opportunity to detect changes in tumor burden and to monitor response to treatment. We developed cMethDNA, a quantitative multiplexed methylation-specific PCR assay for a panel of ten genes, consisting of novel and known breast cancer hypermethylated markers identified by mining our previously reported study of DNA methylation patterns in breast tissue (103 cancer, 21 normal on the Illumina HumanMethylation27 Beadchip) and then validating the 10-gene panel in The Cancer Genome Atlas project breast cancer methylome database. For cMethDNA, a fixed physiologic level (50 copies) of artificially constructed, standard nonhuman reference DNA specific for each gene is introduced in a constant volume of serum (300 μL) before purification of the DNA, facilitating a sensitive, specific, robust, and quantitative assay of tumor DNA, with broad dynamic range. Cancer-specific methylated DNA was detected in training (28 normal, 24 cancer) and test (27 normal, 33 cancer) sets of recurrent stage IV patient sera with a sensitivity of 91% and a specificity of 96% in the test set. In a pilot study, cMethDNA assay faithfully reflected patient response to chemotherapy (N = 29). A core methylation signature present in the primary breast cancer was retained in serum and metastatic tissues collected at autopsy two to 11 years after diagnosis of the disease. Together, our data suggest that the cMethDNA assay can detect advanced breast cancer, and monitor tumor burden and treatment response in women with metastatic breast cancer.

Follow-up tests to detect recurrent disease: patient's reassurance or medical need?

It is widely believed by both doctors and patients that regular follow-up with imaging is important for patients who have been treated for early breast cancer. In reality, current evidence does not support this. Randomised trials have shown no benefit for intensive versus routine follow-up and studies have also shown that follow-up by a general practitioner or nurse specialist is likely to be as effective as by a breast cancer specialist. Specifically there is no evidence that specialised imaging including PET/CT is of any benefit. Newer approaches including the assessment of circulating tumour cells and/or circulating tumour DNA may eventually prove advantageous, but currently must be considered experimental. In summary, current evidence suggests that there is no basis for intensive follow-up beyond standard regular clinical assessment and annual mammography following treatment of early breast cancer. There may be better models for follow-up than the traditional resource-intensive hospital outpatient visit, including nurse-led open access follow-up. Monitoring for long-term sequelae of treatment is becoming as important as the detection of recurrence in an era where long-term survival is increasingly common.

Promoting quality and evidence-based care in early-stage breast cancer follow-up

Evidence-based guidelines for long-term follow-up of early-stage breast cancer patients developed by oncology societies in the United States and Europe recommend that breast cancer survivors undergo regular evaluation with history and physical examination, as well as annual mammography. Routine blood tests, circulating tumor markers, and/or surveillance imaging studies beyond mammography are not recommended in the absence of concerning symptoms or physical examination findings because of lack of supportive clinical evidence. Despite these guidelines, studies have shown that 20% to 40% of oncologists assess serum tumor markers as part of routine monitoring of early-stage breast cancer patients. As part of efforts to both address the financial challenges confronting the health-care system and optimize patient outcomes, the American Society of Clinical Oncology's Cost of Care Task Force identified adherence to breast cancer surveillance guidelines as an opportunity to improve care and reduce cost. However, these recommendations are based on trials done in an era of outdated technology and limited therapeutic options. It is possible that recent improvements in diagnostics and treatments could make earlier detection of recurrent disease important for improving both survival and quality of life outcomes. Research is necessary to further inform optimal breast cancer follow-up strategies, which could impact these recommendations. At this time, outside of well-conducted clinical trials, there is no role for ordering routine serial blood or imaging tests in monitoring for recurrence in early-stage breast cancer patients.

Serum tumor markers in patients with breast cancer

Several serum tumor markers have been investigated in patients with breast cancer for assessing outcome, predicting recurrence and monitoring the therapeutic response. There is a general consensus concerning their limited application in diagnosing malignancy; however, serum tumor markers can be considered for the early detection of recurrence. The most effective markers for this indication are cancer antigens (CA)15-3 and 27.29, and c-erbB-2, although their efficacy in establishing disease progression has not been determined to date. In terms of evaluating prognosis and predicting response to therapy, only the expression of c-erbB-2 has clinical evidence. To conclude, at present, no serum tumor marker is cost effective, and none can be used with confidence in the decision making regarding breast cancer patients.

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.

Is a comparative clinical trial for breast cancer tumor markers to monitor disease recurrence warranted? A value of information analysis

BACKGROUND

Breast cancer tumor markers are used by some clinicians to screen for disease recurrence risk. Since there is limited evidence of benefit, additional research may be warranted.

AIM

To assess the potential value of a randomized clinical trial of breast tumor marker testing in routine follow-up of high-risk, stage II-III breast cancer survivors.

MATERIALS & METHODS

We developed a decision-analytic model of tumor marker testing plus standard surveillance every 3-6 months for 5 years. The expected value of sample information was calculated using probabilistic simulations and was a function of: the probability of selecting the optimal monitoring strategy with current versus future information; the impact of choosing the nonoptimal strategy; and the size of the population affected.

RESULTS

The value of information for a randomized clinical trial involving 9000 women was US$214 million compared with a cost of US$30-60 million to conduct such a trial. The probability of making an alternate, nonoptimal decision and choosing testing versus no testing was 32% with current versus future information from the trial. The impact of a nonoptimal decision was US$2150 and size of population impacted over 10 years was 308,000. The value of improved information on overall survival was US$105 million, quality of life US$37 million and test performance US$71 million.

CONCLUSION

Conducting a randomized clinical trial of breast cancer tumor markers appears to offer a good societal return on investment. Retrospective analyses to assess test performance and evaluation of patient quality of life using tumor markers may also offer valuable areas of research. However, alternative investments may offer even better returns in investments and, as such, the trial concept deserves further study as part of an overall research-portfolio evaluation.

International guidelines for management of metastatic breast cancer (MBC) from the European School of Oncology (ESO)-MBC Task Force: Surveillance, staging, and evaluation of patients with early-stage and metastatic breast cancer

In clinical practice, the surveillance and follow-up of patients with breast cancer (BC) is quite variable. At the 7th European Breast Cancer Conference, the ESO-MBC Task Force convened a series of lectures, followed by open debate, on the use of physical examination, imaging, and laboratory tests in patients with early-stage BC, and for restaging evaluations and follow-up among patients with MBC. Based on the available data, the Task Force recommends against intensive, routine radiologic or blood-based surveillance (with the exception of mammography) in patients with early-stage BC. As systemic therapies for MBC continue to improve, this question might be re-visited in the context of a carefully controlled clinical trial in specific BC subtypes. For patients with MBC, response to therapy should generally be assessed 2-3 months after initiation of treatment, and thereafter every 2-4 months for endocrine therapy or every 2-4 cycles for chemotherapy, depending on the dynamics of the disease, the location and extent of metastatic involvement, and type of treatment. Additional testing should be performed irrespective of the planned intervals if progression of disease is suspected (e.g. in the case of specific symptoms). Use of tumor markers is not recommended for surveillance of early-stage patients, but may be helpful in monitoring response to therapy in patients with metastatic disease. However, change in tumor markers alone should not be used for decision-making. Moving forward, enhanced efforts to document quality of life over time should be made in order to more fully evaluate the risk/benefit ratio of available options.

Mass spectrometry-based quantitative metabolomics revealed a distinct lipid profile in breast cancer patients

Breast cancer accounts for the largest number of newly diagnosed cases in female cancer patients. Although mammography is a powerful screening tool, about 20% of breast cancer cases cannot be detected by this method. New diagnostic biomarkers for breast cancer are necessary. Here, we used a mass spectrometry-based quantitative metabolomics method to analyze plasma samples from 55 breast cancer patients and 25 healthy controls. A number of 30 patients and 20 age-matched healthy controls were used as a training dataset to establish a diagnostic model and to identify potential biomarkers. The remaining samples were used as a validation dataset to evaluate the predictive accuracy for the established model. Distinct separation was obtained from an orthogonal partial least squares-discriminant analysis (OPLS-DA) model with good prediction accuracy. Based on this analysis, 39 differentiating metabolites were identified, including significantly lower levels of lysophosphatidylcholines and higher levels of sphingomyelins in the plasma samples obtained from breast cancer patients compared with healthy controls. Using logical regression, a diagnostic equation based on three metabolites (lysoPC a C16:0, PC ae C42:5 and PC aa C34:2) successfully differentiated breast cancer patients from healthy controls, with a sensitivity of 98.1% and a specificity of 96.0%.

Biomarkers in the diagnosis of primary and recurrent breast cancer

Despite the widespread use of mammography for breast cancer screening, breast cancer remains the most common cause of cancer-related mortality among women worldwide. The identification of biomarkers that identify cancers when they are small, localized and most treatable is an important aim of current breast cancer research. Biomarkers need to be sensitive, specific, reproducible and easily collected from patients from readily accessible tissue or body fluids. While conventional biomarker research has focused on soluble proteins, cell markers, proteomics and DNA methylation, much progress has also been made in the field of immunobiomarkers and multiparameter gene arrays. Currently, no one biomarker has demonstrated sufficient sensitivity and reproducibility for independent clinical and commercial use. This review summarizes the current state of breast cancer biomarker research and anticipated future directions.

Prioritization in comparative effectiveness research: the CANCERGEN Experience

BACKGROUND

Systematic approaches to stakeholder-informed research prioritization are a central focus of comparative effectiveness research. Genomic testing in cancer is an ideal area to refine such approaches given rapid innovation and potentially significant impacts on patient outcomes.

OBJECTIVE

To develop and pilot test a stakeholder-informed approach to prioritizing genomic tests for future study in collaboration with the cancer clinical trials consortium SWOG.

METHODS

We conducted a landscape analysis to identify genomic tests in oncology using a systematic search of published and unpublished studies, and expert consultation. Clinically valid tests suitable for evaluation in a comparative study were presented to an external stakeholder group. Domains to guide the prioritization process were identified with stakeholder input, and stakeholders ranked tests using multiple voting rounds.

RESULTS

A stakeholder group was created including representatives from patient-advocacy groups, payers, test developers, regulators, policy makers, and community-based oncologists. We identified 9 domains for research prioritization with stakeholder feedback: population impact; current standard of care, strength of association; potential clinical benefits, potential clinical harms, economic impacts, evidence of need, trial feasibility, and market factors. The landscape analysis identified 635 studies; of 9 tests deemed to have sufficient clinical validity, 6 were presented to stakeholders. Two tests in lung cancer (ERCC1 and EGFR) and 1 test in breast cancer (CEA/CA15-3/CA27.29) were identified as top research priorities.

CONCLUSIONS

Use of a diverse stakeholder group to inform research prioritization is feasible in a pragmatic and timely manner. Additional research is needed to optimize search strategies, stakeholder group composition, and integration with existing prioritization mechanisms.

Clinical utility of serum tumor markers and circulating tumor cell assays in the treatment of breast cancer

OPINION STATEMENT

Though serum tumor markers and circulating tumor cells (CTCs) have been available to the oncologist for many years, their place in the management of breast cancer remains unclear. Due to issues with sensitivity and specificity, tumor markers are unreliable for the detection of metastases in early stage breast cancer. For patients with metastatic breast cancer without measurable disease (e.g., bone-only disease, pleural effusions, or ascites), it is reasonable to obtain baseline values of serum tumor markers and attempt to correlate them with the first set of scans. In patients with elevated markers at baseline whose tumor marker levels decrease in correlation with an improvement in clinical symptoms, it may be reasonable to use them in conjunction with imaging to help determine whether there is progression of disease. CTCs have been found to hold strong prognostic value for breast cancer in both the early stage and metastatic settings. No large prospective studies to date, however, have shown any predictive value for CTCs and their clinical utility is therefore limited. Whether changing treatment in response to an increase in CTCs without radiologic progression results in improvements in quality of life or survival remains to be seen. CTCs hold great promise in the management of breast cancer and future studies will help delineate their role more appropriately.

Aberrant glycosylation associated with enzymes as cancer biomarkers

BACKGROUND

One of the new roles for enzymes in personalized medicine builds on a rational approach to cancer biomarker discovery using enzyme-associated aberrant glycosylation. A hallmark of cancer, aberrant glycosylation is associated with differential expressions of enzymes such as glycosyltransferase and glycosidases. The aberrant expressions of the enzymes in turn cause cancer cells to produce glycoproteins with specific cancer-associated aberrations in glycan structures.

CONTENT

In this review we provide examples of cancer biomarker discovery using aberrant glycosylation in three areas. First, changes in glycosylation machinery such as glycosyltransferases/glycosidases could be used as cancer biomarkers. Second, most of the clinically useful cancer biomarkers are glycoproteins. Discovery of specific cancer-associated aberrations in glycan structures of these existing biomarkers could improve their cancer specificity, such as the discovery of AFP-L3, fucosylated glycoforms of AFP. Third, cancer-associated aberrations in glycan structures provide a compelling rationale for discovering new biomarkers using glycomic and glycoproteomic technologies.

SUMMARY

As a hallmark of cancer, aberrant glycosylation allows for the rational design of biomarker discovery efforts. But more important, we need to translate these biomarkers from discovery to clinical diagnostics using good strategies, such as the lessons learned from translating the biomarkers discovered using proteomic technologies to OVA 1, the first FDA-cleared In Vitro Diagnostic Multivariate Index Assay (IVDMIA). These lessons, providing important guidance in current efforts in biomarker discovery and translation, are applicable to the discovery of aberrant glycosylation associated with enzymes as cancer biomarkers as well.

Early detection of recurrent breast cancer using metabolite profiling

We report on the development of a monitoring test for recurrent breast cancer, using metabolite-profiling methods. Using a combination of nuclear magnetic resonance (NMR) and two-dimensional gas chromatography-mass spectrometry (GC×GC-MS) methods, we analyzed the metabolite profiles of 257 retrospective serial serum samples from 56 previously diagnosed and surgically treated breast cancer patients. One hundred sixteen of the serial samples were from 20 patients with recurrent breast cancer, and 141 samples were from 36 patients with no clinical evidence of the disease during ∼6 years of sample collection. NMR and GC×GC-MS data were analyzed by multivariate statistical methods to compare identified metabolite signals between the recurrence samples and those with no evidence of disease. Eleven metabolite markers (seven from NMR and four from GC×GC-MS) were shortlisted from an analysis of all patient samples by using logistic regression and 5-fold cross-validation. A partial least squares discriminant analysis model built using these markers with leave-one-out cross-validation provided a sensitivity of 86% and a specificity of 84% (area under the receiver operating characteristic curve = 0.88). Strikingly, 55% of the patients could be correctly predicted to have recurrence 13 months (on average) before the recurrence was clinically diagnosed, representing a large improvement over the current breast cancer-monitoring assay CA 27.29. To the best of our knowledge, this is the first study to develop and prevalidate a prediction model for early detection of recurrent breast cancer based on metabolic profiles. In particular, the combination of two advanced analytical methods, NMR and MS, provides a powerful approach for the early detection of recurrent breast cancer.

CA 15-3: uses and limitation as a biomarker for breast cancer

CA 15-3 which detects soluble forms of MUC-1 protein is the most widely used serum marker in patients with breast cancer. Its main use is for monitoring therapy in patients with metastatic disease. In monitoring therapy in this setting, CA 15-3 should not be used alone but measured in conjunction with diagnostic imaging, clinical history and physical examination. CA 15-3 is particularly valuable for treatment monitoring in patients that have disease that cannot be evaluated using existing radiological procedures. CA 15-3 may also be used in the postoperative surveillance of asymptomatic women who have undergone surgery for invasive breast cancer. In this setting, serial determination can provide median lead-times of 5-6 months in the early detection of recurrent/metastatic breast cancer. It is unclear however, whether administering systemic therapy based on this lead-time improves patient outcome. Consequently, expert panels disagree on the utility of regularly measuring CA 15-3 in the postoperative surveillance of asymptomatic women following a diagnosis of breast cancer. The main limitation of CA 15-3 as a marker for breast cancer is that serum levels are rarely increased in patients with early or localized disease.

The multiplex bead array approach to identifying serum biomarkers associated with breast cancer

Introduction

Breast cancer is the most common type of cancer seen in women in western countries. Thus, diagnostic modalities sensitive to early-stage breast cancer are needed. Antibody-based array platforms of a data-driven type, which are expected to facilitate more rapid and sensitive detection of novel biomarkers, have emerged as a direct, rapid means for profiling cancer-specific signatures using small samples. In line with this concept, our group constructed an antibody bead array panel for 35 analytes that were selected during the discovery step. This study was aimed at testing the performance of this 35-plex array panel in profiling signatures specific for primary non-metastatic breast cancer and validating its diagnostic utility in this independent population.

Methods

Thirty-five analytes were selected from more than 50 markers through screening steps using a serum bank consisting of 4,500 samples from various types of cancer. An antibody-bead array of 35 markers was constructed using the Luminex™ bead array platform. A study population consisting of 98 breast cancer patients and 96 normal subjects was analysed using this panel. Multivariate classification algorithms were used to find discriminating biomarkers and validated with another independent population of 90 breast cancer and 79 healthy controls.

Results

Serum concentrations of epidermal growth factor, soluble CD40-ligand and proapolipoprotein A1 were increased in breast cancer patients. High-molecular-weight-kininogen, apolipoprotein A1, soluble vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, vitamin-D binding protein and vitronectin were decreased in the cancer group. Multivariate classification algorithms distinguished breast cancer patients from the normal population with high accuracy (91.8% with random forest, 91.5% with support vector machine, 87.6% with linear discriminant analysis). Combinatorial markers also detected breast cancer at an early stage with greater sensitivity.

Conclusions

The current study demonstrated the usefulness of the antibody-bead array approach in finding signatures specific for primary non-metastatic breast cancer and illustrated the potential for early, high sensitivity detection of breast cancer. Further validation is required before array-based technology is used routinely for early detection of breast cancer.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for Use of Tumor Markers in Testicular, Prostate, Colorectal, Breast, and Ovarian Cancers

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

Methods: Published reports relevant to use of tumor markers for 5 cancer sites—testicular, prostate, colorectal, breast, and ovarian—were critically reviewed.

Results: For testicular cancer, α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. α-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is <10 μg/L. In colorectal cancer, carcinoembryonic antigen is recommended (with some caveats) for prognosis determination, postoperative surveillance, and therapy monitoring in advanced disease. Fecal occult blood testing may be used for screening asymptomatic adults 50 years or older. For breast cancer, estrogen and progesterone receptors are mandatory for predicting response to hormone therapy, human epidermal growth factor receptor-2 measurement is mandatory for predicting response to trastuzumab, and urokinase plasminogen activator/plasminogen activator inhibitor 1 may be used for determining prognosis in lymph node–negative patients. CA15-3/BR27–29 or carcinoembryonic antigen may be used for therapy monitoring in advanced disease. CA125 is recommended (with transvaginal ultrasound) for early detection of ovarian cancer in women at high risk for this disease. CA125 is also recommended for differential diagnosis of suspicious pelvic masses in postmenopausal women, as well as for detection of recurrence, monitoring of therapy, and determination of prognosis in women with ovarian cancer.

Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

Do serum angiogenic growth factors provide additional information to that of conventional markers in monitoring the course of metastatic breast cancer?

OBJECTIVE

Our work evaluated the potential role of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) serum levels with respect to that of conventional serum tumour markers, CEA and CA 15-3, in monitoring the course of metastatic breast cancer in 56 female patients treated with cytotoxic chemotherapy.

METHODS

VEGF and bFGF concentrations were determined using a quantitative sandwich enzyme immunoassay technique. The positive predictive value (PPV) of each marker and of marker combinations for different types of clinical response was calculated.

RESULTS

The highest PPV for overall disease control was shown by bFGF (70%), which also showed the highest PPV for both partial response (36.4%) and stable disease (63.2%). CEA showed the highest predictive value for progression (69.2%). A combined increase in CEA and bFGF or VEGF was associated with disease progression in all patients.

CONCLUSIONS

Information provided by angiogenic factor levels seems to be independent of and is possibly complementary to that provided by conventional serum markers. bFGF showed the maximum predictive value for disease control and provided additional information to that obtained from CEA or CA 15-3 evaluation. It could therefore be a promising candidate for monitoring response to chemotherapy in advanced breast cancer.

MUC1 gene-derived glycoprotein assays for monitoring breast cancer (CA 15-3, CA 27.29, BR): are they measuring the same antigen?

CONTEXT

There are 2 general types of assays measuring MUC1 gene-derived glycoprotein: assays for cancer antigen (CA) 15-3, which are sandwich assays, and assays for CA 27.29, which are competitive assays. These 2 types of assays measure slightly different parts of this tandem-repeat molecule. Across-method assay differences hinder the exchange of patient test values among integrated health care networks and among countries.

OBJECTIVE

This report evaluates the method differences among these assays to determine if the differences between these assays are mainly related to variations in calibration or differences in analyte specificity.

DESIGN

Data from 22 College of American Pathologists survey challenges were analyzed to compare 10 commercial assay methods for these 2 related analytes. In addition, data from 58 patient samples were analyzed to compare 3 of these assays.

RESULTS

The linear correlation coefficients comparing the within-method medians of these proficiency test distributions were very high (>0.99) for all of the methods; however, the regression slopes varied from 0.836 to 1.095. The regression slopes for the patient specimens varied similarly, but the correlation coefficients were lower.

CONCLUSIONS

This study indicates that many of the test value differences for these measurements are due to differences in assay calibration rather than differences in the specificity of the assay measurement systems. Survey test data potentially could be used to help harmonize these assay differences.

Tumor Markers in Breast Cancer – European Group on Tumor Markers Recommendations

Recommendations are presented for the routine clinical use of serum and tissue-based markers in the diagnosis and management of patients with breast cancer. Their low sensitivity and specificity preclude the use of serum markers such as the MUC-1 mucin glycoproteins (CA 15.3, BR 27.29) and carcinoembryonic antigen in the diagnosis of early breast cancer. However, serial measurement of these markers can result in the early detection of recurrent disease as well as indicate the efficacy of therapy. Of the tissue-based markers, measurement of estrogen and progesterone receptors is mandatory in the selection of patients for treatment with hormone therapy, while HER-2 is essential in selecting patients with advanced breast cancer for treatment with Herceptin (trastuzumab). Urokinase plasminogen activator and plasminogen activator inhibitor 1 are recently validated prognostic markers for lymph node-negative breast cancer patients and thus may be of value in selecting node-negative patients that do not require adjuvant chemotherapy.

FDG PET and tumour markers in the diagnosis of recurrent and metastatic breast cancer

Breast cancer continues to be one of the most common cancers in North America and Western Europe. Positron emission tomography with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG PET) represents a non-invasive functional imaging modality that is based on metabolic characteristics of malignant tumours. In breast cancer, FDG PET is more accurate than conventional methods for staging of distant metastases or local recurrences and enables early assessment of treatment response in patients undergoing primary chemotherapy. Recent data indicate a rationale for the use of FDG PET in cases of asymptomatically elevated tumour marker levels in the presence of uncertain results of conventional imaging. Despite the fact that PET cannot rule out microscopic disease, it does have particular value in providing, in a single examination, a reliable assessment of the true extent of the disease. This technique is complementary to morphological imaging for primary diagnosis, staging and re-staging. It may become the method of choice for the assessment of asymptomatic patients with elevated tumour marker levels. This method, however, cannot replace invasive procedures if microscopic disease is of clinical relevance.