Tumour marker CA 50 levels compared to signs and symptoms in the diagnosis of pancreatic cancer

Biochemical diagnostics of pancreatic cancer - Present and future

Pancreatic cancer is one of the deadliest cancers having an exceptionally high mortality rate. Despite a relatively low incidence (10th among cancers), it is the fourth leading cause of cancer-related deaths in most developed countries. Improving early diagnosis of pancreatic cancer and strengthening the standardised comprehensive treatment remain the main focus of pancreatic cancer research. Tumor markers are usually tumor-associated proteins of clinical relevance in these patients. Although tumor markers carbohydrate antigen (CA 19-9) and carcino-embryonic antigen (CEA) are commonly used, neither demonstrate high diagnostic accuracy. Recently, hematopoietic growth factors (HGFs) and various enzymes have been reported as potential biomarkers for pancreatic cancer. These include macrophage-colony stimulating factor (M-CSF) and granulocyte-colony stimulating factor (G-CSF), interleukin-3 (IL-3), macrophage inhibitory cytokine (MIC-1) and various enzymes (alcohol dehydrogenase, aldehyde dehydrogenase, lysosomal exoglycosidases). With the development of molecular technology, detecting K-ras mutation in serum via polymerase chain reaction (PCR) is becoming more common and efficient. Because K-ras mutation rates are high in many cancers, some regard it as a potential tumor marker. Others have shown the value of serum miRNAs in detection of pancreatic cancer. Unfortunately, there are currently no effective methods of sufficient diagnostic accuracy to detect early-stage surgically resectable pancreatic cancer. In this article we highlight these biomarkers and summarise recent developments in the diagnosis and treatment of pancreatic cancer.

Evaluation of the analytical and clinical performances of time-resolved fluoroimmunoassay for detecting carcinoma antigen 50

We developed a TR-FIA kit for quantitative detection of CA50. This study aims to evaluate the analytical and clinical performances of this kit. Precision, accuracy, specificity, sensitivity, stability, and endogenous interference of this kit are evaluated. Reference range is established. Coincidence rate and correlation between TR-FIA and RIA are evaluated. ROC is adopted to evaluate the diagnostic performance. This kit shows excellent precision with a coefficients of variation (CVs) ranged from 2.2-9.3%, accuracy (average recovery, 98.5%), sensitivity (minimum detectable concentration is 0.2 U/mL), specificity (all cross-reactivity is less than 0.1% except CA199, which is 0.175%), and storage stability (recoveries, 90.8-100.4%). Bilirubin, hemoglobin, and triglyceride dose not interfere with CA50 detection (recovery, 97.13-109.1%). The range from 0-25 U/mL is chosen as the reference range. There are good correlation (r = 0.804) and coincidence (p = 0.608, kappa = 0.924) between TR-FIA and RIA. Diagnostic performance of this kits, which based on RIA results, is perfect (AUC = 0.996), and the diagnostic accuracy for malignancy diagnosis is in moderate degree (AUC, 0.802-0.861). The TR-FIA (CA50) kit performs well in analytical and clinical performances, and can be employed in the clinical diagnosis of malignancy.

Molecular markers in pancreatic cancer diagnosis

Pancreatic ductal adenocarcinoma (PDAC) represents a fatal neoplasia with a high mortality rate. Effective early detection methods are needed since this is the best way to cure this disease. During the last several years, many investigations focused on determining relevant biomarkers that may be present during early stages of pancreatic tumor development. Although several biomarkers have been proposed for pancreatic cancer detection, the clinical applicability has been confusing. Currently, although CA19-9 is one test used, the sensitivity and specificity for the disease are less than optimal. Here, we review several new potential serum, plasma and stool markers that are currently under evaluation. Although these have not been sufficiently validated for routine clinical use, these markers could prove valuable with further investigations. We keep the hope that a combination of some of these novel biomarkers can be a useful tool for early PDAC diagnosis before image techniques and/or patient's symptoms reveal disease in an incurable state.

Carbohydrate markers of pancreatic cancer

Pancreatic cancer is the fourth most common cause of death from cancer in the world and the sixth in Europe. Pancreatic cancer is more frequent in males than females. Worldwide, following diagnosis of pancreatic cancer, <2% of patients survive for 5 years, 8% survive for 2 years and <50% survive for only approx. 3 months. The biggest risk factor in pancreatic cancer is age, with a peak of morbidity at 65 years. Difficulty in the diagnosis of pancreatic cancer causes a delay in its detection. It is one of the most difficult cancers to diagnose and therefore to treat successfully. Additional detection of carbohydrate markers may offer a better diagnosis of pancreatic cancer. Carbohydrate markers of cancer may be produced by the cancer itself or by the body in response to cancer, whose presence in body fluids suggests the presence and growth of the cancer. The most widely used, and best-recognized, carbohydrate marker of pancreatic cancer is CA 19-9 [CA (carbohydrate antigen) 19-9]. However, the relatively non-specific nature of CA 19-9 limits its routine use in the early diagnosis of pancreatic cancer, but it may be useful in monitoring treatment of pancreatic cancer (e.g. the effectiveness of chemotherapy), as a complement to other diagnostic methods. Some other carbohydrate markers of pancreatic cancer may be considered, such as CEA (carcinoembryonic antigen), CA 50 and CA 242, and the mucins MUC1, MUC2 and MUC5AC, but enzymes involved in the processing of glycoconjugates could also be involved. Our preliminary research shows that the activity of lysosomal exoglycosidases, including HEX (N-acetyl-β-D-hexosaminidase), GAL (β-D-galactosidase), FUC (α-L-fucosidase) and MAN (α-D-mannosidase), in serum and urine may be used in the diagnosis of pancreatic cancer.

Limitations in improving detection of pancreatic adenocarcinoma

OBJECTIVE

To review the current trends in pancreatic cancer research and propose alternatives for an earlier diagnosis.

METHOD

A search was conducted using the PubMed and Scielo electronic databases to find statistics related to the incidence of pancreatic cancer.

RESULTS

Pancreatic cancer is the fourth most common cause of cancer mortality in the USA; in Colombia the incidence of this neoplasia is 4.5 per 100,000 individuals; and in Peru, amongst digestive diseases, it is the fifth most common cause. In Brazil and Chile this cancer has increased in incidence, while in Mexico, it has decreased in terms of the relative percentage of gastrointestinal cancers from 1976 to 2003. Chronic pancreatitis, cigarette smoking, diabetes, obesity and dietary mutagen exposure are the most consistent risk factors implicated in the development of pancreatic cancer; however, the genetic and molecular changes underlying the epidemiological association between these factors and pancreatic cancer remain largely unknown, and only 5-10% are hereditary in nature.

CONCLUSION

The prognosis for pancreatic cancer has not changed substantially for at least the last 20 years. The most useful tumor marker for pancreatic adenocarcinoma is still the carbohydrate antigen 19-9 (CA19-9). Currently, a multimodal-screening approach of endoscopic ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography are the most effective methods to detect pancreatic cancer in high-risk patients. Future options for early detection of this malignancy are focused on new molecular markers, telomerase enzyme, receptor-targeted imaging using multifunctional nanoparticles, detection of glycan changes and epigenetics.

Evaluation of carbohydrate antigen 50 in human serum using magnetic particle-based chemiluminescence enzyme immunoassay

A magnetic particles (MPs)-based chemiluminescence enzyme immunoassay (CLEIA) with high sensitivity, specificity, rapidity, and reproducibility was proposed for the evaluation of tumor marker, carbohydrate antigen 50 (CA50) in human serum. The immunomagnetic particles coated with anti-fluorescein isothiocyanate (FITC) antibody was used as dispersed solid phase for the immunoassay, which was based on a sandwich immunoreaction of FITC-labeled anti-CA50 antibody, CA50 antigen, and alkaline phosphatase (ALP)-labeled anti-CA50 antibody, and was based on a subsequent chemiluminescence reaction of ALP with 4-methoxy-4-(3-phosphate-phenyl)-spiro-(1,2-dioxetane-3,2'-adamantane) (AMPPD) solution. The CL emission intensity was directly proportional to the amount of analyte present in a sample solution. The effects of several physicochemical parameters, including the concentration of FITC-labeled anti-CA50 antibody, the dilution ratio of ALP-labeled anti-CA50 antibody, the volume of MPs and substrate, the immunoreaction time and other relevant variables upon the immunoassay were studied and optimized. The proposed method exhibited advantages in a lower minimum detectable concentration of 1.0 U mL(-1) with comparison to the commercially available immunoradiometric assay (IRMA), and showed a larger linear range of 0 to 300 U mL(-1), as well as less total assay time of only 50 min with comparison to both IRMA and microplate CLEIA. The coefficient of variation was less than 7 and 11% for intra- and inter-assay precision, respectively. This method has been successfully applied to the evaluation of CA50 in human serum with recoveries from 82 to 112%, and showed a good correlation with the commercially available CA50 IRMA.

Serum markers in patients with resectable pancreatic adenocarcinoma: macrophage inhibitory cytokine 1 versus CA19-9

PURPOSE

More accurate serum markers of pancreatic cancer could improve the early detection and prognosis of this deadly disease. We compared the diagnostic utility of a panel of candidate serum markers of pancreatic cancer.

EXPERIMENTAL DESIGN

We collected preoperative serum from 50 patients with resectable pancreatic adenocarcinoma, as well as sera from 50 patients with chronic pancreatitis and 50 age/sex-matched healthy controls from our institution. Sera were analyzed for the following candidate markers of pancreatic cancer: CA19-9, macrophage inhibitory cytokine 1 (MIC-1), osteopontin, tissue inhibitor of metalloproteinase 1, and hepatocarcinoma-intestine-pancreas protein levels.

RESULTS

By logistic regression analysis, MIC-1 and CA19-9 were significant independent predictors of diagnosis. Receiver operating characteristic curve analysis showed that MIC-1 was significantly better than CA19-9 in differentiating patients with pancreatic cancer from healthy controls (area under the curve is 0.99 and 0.78, respectively; P = 0.003), but not in distinguishing pancreatic cancer from chronic pancreatitis (area under the curve of 0.81 and 0.74, respectively; P = 0.63). Hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein, osteopontin, and tissue inhibitor of metalloproteinase 1 serum levels did not provide additional diagnostic power.

CONCLUSION

In the differentiation of patients with resectable pancreatic cancer from controls, serum MIC-1 outperforms other markers including CA19-9.

An evidence-based approach to the diagnosis and staging of pancreatic cancer

Technology has revolutionized the diagnosis and staging of pancreatic malignancy. Previously, staging of disease was accomplished by exploratory laparotomy. Now, however, tumor size, lymph node and vascular involvement and the presence of metastases can be reliably assessed prior to operation using a widely available series of diagnostic tests, facilitating a preoperative assessment of tumor resectability. Appropriate use of these tests often spares patients with unresectable disease the need for operative intervention. As part of our staging algorithm we routinely employ a combination of clinical suspicion, a high-resolution helical CT scan and a serum CA 19-9 level. Endoscopic ultrasonography is useful in the patient in whom CT findings are equivocal, or in whom a tissue diagnosis is desired. Laparoscopy is reserved for patients with suspected advanced disease despite imaging findings to the contrary. Using this strategy, pancreatic malignancy may be diagnosed as expeditiously and as cost-effectively as is possible given current technology.

Elevated levels of opioid growth factor in the plasma of patients with pancreatic cancer

Opioid growth factor (OGF, [Met5]-enkephalin) is an endogenous peptide that regulates the growth of human pancreatic cancer. To evaluate whether human subjects with pancreatic cancer have alterations in plasma levels of OGF, fasting blood samples were obtained from 15 patients with histologically confirmed pancreatic adenocarcinoma. Forty-five subjects with other malignancies, 20 patients with acute pancreatitis, and 30 aged-matched patients without cancer served as control populations. Individuals with pancreatic cancer had OGF values, as determined by radioimmunoassay, that were up to 7.3-fold greater than control subjects. No differences were found between OGF values obtained from patients with other malignancies, acute pancreatitis, or subjects without cancer. The sensitivity and specificity of OGF for pancreatic cancer were greater than either CA 19-9 or CEA. These data indicate that pancreatic cancer is associated with a marked increase in plasma OGF levels and suggest that this peptide may serve as a useful diagnostic tool in the screening for this disease.

Screening for early pancreatic ductal adenocarcinoma in hereditary pancreatitis

Patients with hereditary pancreatitis have a 40% lifetime risk of developing pancreatic ductal adenocarcinoma. Existing methods of diagnosing pancreatic cancer such as tumor markers, endoscopy, and radiological imaging lack the sensitivity and specificity for early diagnosis, particularly in a background of chronic pancreatitis. Molecular based strategies offer new avenues of screening for pancreatic ductal adenocarcinoma in these high-risk patients, which may allow the development of highly sensitive and specific diagnostic tests for the early detection of cancer.