CA 494--a new tumor marker for the diagnosis of pancreatic cancer

Biosensors for early diagnosis of pancreatic cancer: a review

Pancreatic cancer is characterized by extremely high mortality and poor prognosis and is projected to be the leading cause of cancer deaths by 2030. Due to the lack of early symptoms and appropriate methods to detect pancreatic carcinoma at an early stage as well as its aggressive progression, the disease is often quite advanced by the time a definite diagnosis is established. The 5-year relative survival rate for all stages is approximately 8%. Therefore, detection of pancreatic cancer at an early surgically resectable stage is the key to decrease mortality and to improve survival. The traditional methods for diagnosing pancreatic cancer involve an imaging test, such as ultrasound or magnetic resonance imaging, paired with a biopsy of the mass in question. These methods are often expensive, time consuming, and require trained professionals to use the instruments and analyze the imaging. To overcome these issues, biosensors have been proposed as a promising tool for the early diagnosis of pancreatic cancer. The present review critically discusses the latest developments in biosensors for the early diagnosis of pancreatic cancer. Protein and microRNA biomarkers of pancreatic cancer and corresponding biosensors for pancreatic cancer diagnosis have been reviewed, and all these cases demonstrate that the emerging biosensors are becoming an increasingly relevant alternative to traditional techniques. In addition, we discuss the existing problems in biosensors and future challenges.

The sensitivity and specificity of serum glycan-based biomarkers for cancer detection

Most of clinically used serum biomarkers for cancer detection were established in early 1980s when the Nobel Prize in physiology or medicine was awarded for the "discovery of the principle for the production of monoclonal antibodies." Using this "Nobel" technology, various monoclonal antibodies were obtained when different types of cancer cells were injected into mice and the ligands on the cancer cell surface were characterized. Both aberrant glycan structures and aberrant glycan-associated glycoproteins were revealed as a common feature of cancer cell surfaces through the specific interactions with the monoclonal antibodies. These results indicate that the biosynthesis of the environment-sensitive glycan structures goes awry in cancer cells, which is beyond genetic mutations. Later on, the glycan-related biomarkers were detected in the sera of cancer patients and then developed into serum biomarkers, such as CA125, CA153, CA195, CA199, CA242, CA27.29, CA50, and CA724, which are still in clinical use as of today. During the past 30 years, even with the advancement of different OMICS technologies not limited to genomics, epigenomics, proteomics, glycomics, lipidomics, and metabolomics, very few serum biomarkers have been introduced into clinical practice. The reason is that most of the newly discovered cancer biomarkers are inferior in terms of sensitivity and specificity to these biomarkers. We will summarize the reported sensitivity and specificity of currently used cancer biomarkers, especially the glycan-related biomarkers, in the forms of tables and radar plots and discuss the pros and cons of currently used cancer biomarkers.

Carbohydrate antigen 19-9 for differential diagnosis of pancreatic carcinoma and chronic pancreatitis

AIM: To evaluate the utility of carbohydrate antigen 19-9 (CA19-9) for differential diagnosis of pancreatic carcinoma and chronic pancreatitis.

METHODS: We searched the literature for studies reporting the sensitivity, specificity, and other accuracy measures of serum CA19-9 levels for differentiating pancreatic carcinoma and chronic pancreatitis. Pooled analysis was performed using random-effects models, and receiver operating characteristic (ROC) curves were generated. Study quality was assessed using Standards for Reporting Diagnostic Accuracy and Quality Assessment for Studies of Diagnostic Accuracy tools.

RESULTS: A total of 34 studies involving 3125 patients with pancreatic carcinoma and 2061 patients with chronic pancreatitis were included. Pooled analysis of the ability of CA19-9 level to differentiate pancreatic carcinoma and chronic pancreatitis showed the following effect estimates: sensitivity, 0.81 (95%CI: 0.80-0.83); specificity, 0.81 (95%CI: 0.79-0.82); positive likelihood ratio, 4.08 (95%CI: 3.39-4.91); negative likelihood ratio, 0.24 (95%CI: 0.21-0.28); and diagnostic odds ratio, 19.31 (95%CI: 14.40-25.90). The area under the ROC curve was 0.88. No significant publication bias was detected.

CONCLUSION: Elevated CA19-9 by itself is insufficient for differentiating pancreatic carcinoma and chronic pancreatitis, however, it increases suspicion of pancreatic carcinoma and may complement other clinical findings to improve diagnostic accuracy.

Pancreatic cancer screening

Accumulating data indicate that clinically available abdominal imaging tests such as EUS and MRI/MRCP can detect asymptomatic precursor benign (IPMN, PanIN) and invasive malignant pancreatic neoplasms, such as ductal adenocarcinoma, in individuals with an inherited predisposition. These asymptomatic FPCs detected have been more likely to be resectable, compared to symptomatic tumors. The most challenging part of screening high-risk individuals is the selection of individuals with high-grade precursor neoplasms for preventive treatment (ie, surgical resection before development of invasive cancer). Ongoing and future research should focus on formulating and validating a model for FPC risk and neoplastic progression using patient characteristics, imaging, and biomarkers. The comparative cost and effectiveness of various approaches for screening and surveillance of high-risk individuals also deserves study. For now, screening is best performed in high-risk individuals within the research protocols in academic centers with multidisciplinary teams with expertise in genetics, gastroenterology, radiology, surgery, and pathology.

Advances in diagnosis, treatment and palliation of pancreatic carcinoma: 1990-2010

Several advances in genetics, diagnosis and palliation of pancreatic cancer (PC) have occurred in the last decades. A multidisciplinary approach to this disease is therefore recommended. PC is relatively common as it is the fourth leading cause of cancer related mortality. Most patients present with obstructive jaundice, epigastric or back pain, weight loss and anorexia. Despite improvements in diagnostic modalities, the majority of cases are still detected in advanced stages. The only curative treatment for PC remains surgical resection. No more than 20% of patients are candidates for surgery at the time of diagnosis and survival remains quite poor as adjuvant therapies are not very effective. A small percentage of patients with borderline non-resectable PC might benefit from neo-adjuvant chemoradiation therapy enabling them to undergo resection; however, randomized controlled studies are needed to prove the benefits of this strategy. Patients with unresectable PC benefit from palliative interventions such as biliary decompression and celiac plexus block. Further clinical trials to evaluate new chemo and radiation protocols as well as identification of genetic markers for PC are needed to improve the overall survival of patients affected by PC, as the current overall 5-year survival rate of patients affected by PC is still less than 5%. The aim of this article is to review the most recent high quality literature on this topic.

Serum tumor markers in pancreatic cancer-recent discoveries

The low prevalence of pancreatic cancer remains an obstacle to the development of effective screening tools in an asymptomatic population. However, development of effective serologic markers still offers the potential for improvement of diagnostic capabilities, especially for subpopulations of patients with high risk for pancreatic cancer. The accurate identification of patients with pancreatic cancer and the exclusion of disease in those with benign disorders remain important goals. While clinical experience largely dismissed many candidate markers as useful markers of pancreatic cancer, CA19-9 continues to show promise. The present review highlights the development and the properties of different tumor markers in pancreatic cancer and their impact on the diagnostic and treatment of this aggressive disease.

Biliary tract obstruction in chronic pancreatitis

Bile duct strictures are a common complication in patients with advanced chronic pancreatitis and have a variable clinical presentation ranging from an incidental finding to overt jaundice and cholangitis. The diagnosis is mostly made during investigations for abdominal pain but jaundice may be the initial clinical presentation. The jaundice is typically transient but may be recurrent with a small risk of secondary biliary cirrhosis in longstanding cases. The management of a bile duct stricture is conservative in patients in whom it is an incidental finding as the risk of secondary biliary cirrhosis is negligible. Initial conservative treatment is advised in patients who present with jaundice as most will resolve once the acute on chronic attack has subsided. A surgical biliary drainage is indicated when there is persistent jaundice for more than one month or if complicated by secondary gallstones or cholangitis. The biliary drainage procedure of choice is a choledocho-jejunostomy which may be combined with a pancreaticojejunostomy in patients who have associated pain. Since many patients with chronic pancreatitis have an inflammatory mass in the head of the pancreas, a Frey procedure is indicated but a resection should be performed when there is concern about a malignancy. Temporary endoscopic stenting is reserved for cholangitis while an expandable metal stent may be indicated in patients with severe co-morbid disease.

Review article: current practice and future perspectives in detection and diagnosis of pancreatic cancer

Pancreatic cancer is the tenth most prevalent malignancy and the fifth most common cause of cancer death in the developed world. Less than 10% of patients survive for more than 1 year following diagnosis and the 5-year survival rate (0.4%) is the lowest of any cancer. The poor prognosis associated with this diagnosis led in the past to therapeutic nihilism on the part of clinicians who were all too aware of the limitations of their available therapeutic strategies. Breaking this therapeutic impasse requires a significant expansion in the knowledge of clinicians concerning the pathogenesis and behaviour of pancreatic cancer. Recent advances in the scientific understanding of the aetiology of pancreatic cancer has facilitated progress towards the development of promising and innovative approaches to the early detection and diagnosis of pancreatic cancer. While acknowledging that pancreatic cancer will continue to present significant challenges to both scientists and clinicians in the foreseeable future, it is becoming increasingly clear that recent advances in our scientific knowledge base holds the potential to significantly improve prognosis for patients. The challenge facing both scientists and clinicians is how best to translate such promising scientific advances into survival and quality of life benefits to patients.

Excess cancer mortality in six Dutch pedigrees with the familial atypical multiple mole-melanoma syndrome from 1830 to 1994

An increased incidence of systemic cancers has been described in some reports of familial atypical multiple mole-melanoma kindreds. If the gene defect underlying the familial atypical multiple mole-melanoma syndrome is not only important for the development of melanoma of the skin, the impact of the defect on life expectancy may be much higher than previously thought. We investigated all-cause mortality from 1830 to the present and causes of death from 1941 to 1994 in proven, obligate, and potential CDKN2 mutation carriers to obtain an estimate of the impact of a hereditary defect of the CDKN2 gene on mortality. From 1830 to 1994 there were 65 deaths, although only 42 deaths were expected [standardized mortality ratio (SMR) 1.6, 95% confidence interval (CI) 1.2-2.0] and the SMR doubled with calendar time. Excess mortality was shown in most of the families, but was confined to ages 35-70 y (SMR 2.1, 95%CI 1.5-2.9). Excess mortality could be fully attributed to cancer mortality, especially to pancreatic carcinoma and melanoma of the skin. There appeared to be some heterogeneity among the families, especially due to the specific cancer pattern within a family. The impact of the defect of the CDKN2 gene is rising over calendar time, mainly because the mortality in the general population has been falling. Excess mortality was not only due to melanoma, but also to pancreatic carcinoma. Therefore, follow-up programs of affected family members should not be confined to a regular check of the atypical nevi.

CAM 17.1--a new diagnostic marker in pancreatic cancer

CAM 17.1-Ab is a recently described monoclonal antibody that detects a mucus glycoprotein with high specificity for intestinal mucus, particularly in the colon, small intestine, biliary tract and pancreas. We investigated the expression and release of CAM 17.1 in pancreatic carcinoma cell lines and tissue specimens of normal pancreas, chronic pancreatitis and pancreatic cancer. CAM 17.1 was weakly expressed on normal ductal cells and chronic pancreatitis, whereas it was overexpressed in pancreatic cancer. Serum analysis using a new enzyme-linked antibody sandwich assay (CAM 17.1/WGA) of patients with chronic pancreatitis, pancreatic cancer or other gastrointestinal cancer and of healthy blood donors revealed a high sensitivity (67%) and excellent specificity (90%) of CAM 17.1/WGA assay in pancreatic cancer. In comparison with the tumour marker CA19-9, the sensitivity of the CAM 17.1/WGA assay was similar to the sensitivity of CA 19-9 (67% and 76%, P = 0.22), whereas the specificity of CAM 17.1/WGA assay was higher than in CA 19-9 (90% compared with 78% in chronic pancreatitis, P > 0.05).

Pancreatic adenocarcinoma

Pancreatic carcinoma is one of the most enigmatic and aggressive malignant disease facing oncologists. A precocious propensity to spread along peripancreatic neurons and lymphatic channels conspires with the limited activity of standard chemotherapeutic agents and the inability to deliver large doses of radiotherapy to the upper abdomen, leaving radical surgical resection as the primary treatment capable of influencing long-term survival. Theoretically, when the tumor is small and confined to the pancreas, adequate locoregional control is possible by radical resection of the tumor, lymph nodes, peripancreatic neurons, and surrounding soft tissue. Realistically, at the time of initial diagnosis, 50% of patients have distant metastases to the liver or peritoneal surface, and more than 80% of the remaining patients have locally advanced tumors. Fewer than 10% of all patients with a small pancreatic adenocarcinoma confined to the pancreas are candidates for cure by use of radical resection as the sole treatment modality. Given these sobering statistics on the late presentation of this tumor, it is not surprising that, even after radical resection, the overall median survival time is only 18 to 20 months and the overall 5-year survival is approximately 10%. These dismal results led to a call in the early 1970s for abandonment of radical therapy in this disease and for treatment of all patients with palliative care only. These statistics are discouraging, but over the last 10 years a therapeutic renaissance has erupted. This resurgence has been driven by surgeons performing pancreaticoduodenectomy with low perioperative mortality rates and excellent functional results. It has been fueled by the use of adjuvant and neoadjuvant chemoradiotherapy protocols. Improved radiographic imaging techniques such as endoscopic retrograde cholangiopancreatography, helical computed tomography scan, and endoscopic ultrasonography are beginning to show promise in facilitating an earlier diagnosis and in providing highly accurate tumor staging without operation. It is hoped that recent observations on the molecular genetics of pancreatic adenocarcinoma will lead to a better understanding of tumor biology, which in turn should result in a more rational application of new diagnostic and therapeutic strategies. Effective percutaneous, endoscopic, and laparoscopic techniques have been developed concomitant with the recent advances in radiographic and endoscopic imaging. These minimally invasive options can now provide meaningful, long-lasting palliation and improved quality of life for the large number of patients with unresectable or metastatic disease who have no other treatment options. The therapeutic nihilism so pervasive in previous decades has no place in the contemporary treatment of patients with pancreatic adenocarcinoma. True long-term survival seems possible for a growing proportion of patients, and minimally invasive, effective palliation is achievable in the vast majority of patients. It is only through aggressive recruitment of patients for treatment, application of novel diagnostic and therapeutic protocols, and further laboratory investigation into the biology of pancreatic cancer that the momentum of the last decade toward improved outcome and quality of life can be sustained.

Expression of cathepsin E in pancreas: a possible tumor marker for pancreas, a preliminary report

Ductal cancers of the pancreas frequently express markers of gastrointestinal epithelial cells. Cathepsin E (CTSE) is a non-secretory, intracellular, but non-lysosomal proteinase found in the highest concentration in the superficial epithelial cells of the stomach. The aims of our study were to examine the expression of CTSE in the pancreas, to establish an assay system of CTSE and to evaluate the diagnostic usefulness of CTSE in the pancreatic juice. Eleven patients with pancreatic ductal adenocarcinoma, 10 with mucin-producing adenoma, 3 with intraductal papillary hyperplasia and 43 with chronic pancreatitis were examined. Surgically resected pancreatic tissues were subjected to immunohistochemistry for CTSE. Pancreatic juice was collected from the patients and subjected to sandwich ELISA and Western analysis for detecting CTSE. Positive staining for CTSE was observed in pancreatic ductal adenocarcinoma by immunohistochemistry. CTSE was also expressed in mucin-producing adenoma, intraductal papillary hyperplasia and mucinous hyperplasia. CTSE in the pancreatic juice was present in 8 of 11 patients with pancreatic ductal adenocarcinoma, 5 of 10 patients with mucin-producing tumor, 1 of 3 patients with intraductal papillary hyperplasia and 4 of 43 patients with chronic pancreatitis. The detection frequency of CTSE in the pancreatic juice was significantly higher in the patients with pancreatic ductal adenocarcinoma than in the patients with chronic pancreatitis. Our findings suggest that the expression of CTSE is associated with the pathogenesis of pancreatic ductal adenocarcinoma, that CTSE in the pancreatic juice seems to be a useful marker for a definitive diagnosis and that CTSE may be expressed at a relatively early stage of multistep carcinogenesis in pancreatic lesions.

Molecular oncology in pancreatic cancer

Cancer of the pancreas still has a very poor prognosis despite improved diagnostic methods and therapeutic regimens. The reasons for the aggressiveness of this cancer are not known, and the molecular mechanisms that govern the growth of pancreatic cancer cells are still not clearly defined. During the past two decades the development of new molecular biological techniques has offered new perspectives for a better understanding of pancreatic cancer. Tumor markers such as CA19-9 and CEA are used for diagnosis and for following the postoperative course of cancer patients. Characterization of pancreatic cancer cells using several molecular biological techniques has revealed overexpression or altered expression of growth factors and adhesion molecules, implying altered cell-cell and growth-regulatory interactions. In pancreatic cancer mutations in oncogenes and tumor suppressor genes are frequently detected in p53 and K-ras. This article reviews the possible molecular approaches for diagnosis, prognosis, or even therapy of pancreatic cancer.

Clinical relevance of serological markers in the detection and follow-up of pancreatic adenocarcinoma

Pancreatic adenocarcinoma is a relatively common malignancy and its incidence is increasing. Prognosis in these patients is poor, and surgery, the only effective treatment, saves only a minority of patients. The number in this small group of patients might be increased by early detection of pancreatic tumours. This review examines the current status of pancreatic tumour associated proteins in the detection of pancreatic cancer. As well as existing markers, the review also reports on newer markers that may offer advantages over existing ones in the detection of pancreatic adenocarcinoma. This is particularly important because recent studies have identified high-risk groups susceptible to pancreatic cancer. Future research in pancreatic cancer should be directed at earlier detection, and tumour markers may play an important role in this process.

Tumor markers. An update

Cancer remains the second leading cause of death in developed countries, and the incidence of certain tumors is increasing despite emphasis on prevention and screening. Tumor markers are biologic or biochemical substances that are produced by tumor cells and then secreted into the circulation in detectable amounts. This article covers some of the more common tumor markers currently being utilized for diagnostic and prognostic purposes.

Diagnosis and staging of pancreatic neoplasms

The relative value of current approaches to the diagnosis and staging of pancreatic cancer is discussed. A rational sequence of testing is recommended based on the clinical presentation of the patient and the local institutional expertise and facilities that are available.

Flow cytometric identification of cell surface markers on cultured human colonic cell lines using monoclonal antibodies

BACKGROUND

The expression of tumor-associated cell surface antigens is a reflection of the state of cell differentiation of tumor cells in culture.

METHOD

Monoclonal antibodies (MoAbs) against the tumor-associated antigens carcinoembryonic antigen (CEA) and CA19-9 and the extracellular matrix protein CD44 were used to label the cell surface of human colonic cells in culture. The binding of each antibody to its respective antigen was measured by fluorescence-activated flow cytometry and expressed as a percentage of positive cells.

RESULTS

The human colon adenocarcinoma cell (HCAC) line, LS-180, showed strong binding with CEA (81%), CA 19-9 (87%), and CD44 (83%). LS-174t cells, a trypsinized variant of LS-180 cells, showed less binding with CEA (66%) and CA 19-9 (49%), but no binding with CD44. With cells from HCAC line HT-29, antigen expression was highly variable for CEA (13% +/- 18) and CD44 (31% +/- 35) but was consistently positive for CA19-9 (33% +/- 13). The expression of CEA in the Caco-2 cell line was weak (24%), whereas there was no expression of CA19-9 and CD44. Normal human colon fibroblast cells (CCD-18Co) did not recognize the monoclonal antibodies to CEA or CA 19-9, but were strongly positive with the CD44 antibody (97%).

CONCLUSIONS

These results support the concept that the expression of the tumor associated markers CEA and CA19-9 and the cell surface marker CD44 on human colonic cell lines varies with the degree of cellular differentiation. Carcinoembryonic antigen and/or CA19-9 were expressed in all four human colon adenocarcinoma cell lines, but not in the normal colon fibroblast cells (CCD-18Co). Using these two MoAbs appeared to be a more reliable measure of the state of differentiation of human colon adenocarcinoma cells.