CA 242 is a new tumor marker for pancreatic cancer

Capitalizing glycomic changes for improved biomarker-based cancer diagnostics

Cancer serum biomarkers are valuable or even indispensable for cancer diagnostics and/or monitoring and, currently, many cancer serum markers are routinely used in the clinic. Most of those markers are glycoproteins, carrying cancer-specific glycan structures that can provide extra-information for cancer monitoring. Nonetheless, in the majority of cases, this differential feature is not exploited and the corresponding analytical assays detect only the protein amount, disregarding the analysis of the aberrant glycoform. Two exceptions to this trend are the biomarkers α-fetoprotein (AFP) and cancer antigen 19-9 (CA19-9), which are clinically monitored for their cancer-related glycan changes, and only the AFP assay includes quantification of both the protein amount and the altered glycoform. This narrative review demonstrates, through several examples, the advantages of the combined quantification of protein cancer biomarkers and the respective glycoform analysis, which enable to yield the maximum information and overcome the weaknesses of each individual analysis. This strategy allows to achieve higher sensitivity and specificity in the detection of cancer, enhancing the diagnostic power of biomarker-based cancer detection tests.

Serum CA199 levels are significantly increased in patients suffering from liver, lung, and other diseases

CA199 is a sialic acid containing glycan antigen found in both glycoproteins and glycolipids, which is recognized by monoclonal antibodies generated by hybridoma technology. The increased serum CA199 levels measured by using the monoclonal antibodies have been used as diagnostic or prognostic biomarker for pancreatic cancer. Even though increased serum CA199 levels are also observed in other cancers and noncancer diseases, it is largely unknown if CA199 levels could serve as biomarkers for other diseases as well. Therefore, in our current study, serum CA199 levels from 45,645 patients with 47 clinically defined diseases and 14,783 healthy controls who attended their annual physical examination were collected and measured by the clinical laboratory in the Affiliated Hospital of Qingdao University over the past 5 years. Based on the median, mean, and -Log₁₀p values, we found that patients with pancreatic cancer, lung fibrosis, cirrhosis, liver cancer, hepatitis, and pancreatitis had the highest media and mean serum CA199 levels with statistical significance based on the -Log₁₀p values. Unexpectedly, patients suffering from gout and anemia had significantly low CA199 levels compared to that of the healthy controls. These results showed that serum CA199 levels are not only increased in pancreatic and other cancer patients but also either increased or decreased in noncancer diseases. The overall data indicated that the abnormal serum CA199 level might be an indicator of system malfunction rather than a cancer biomarker in general.

CA242 as a biomarker for pancreatic cancer and other diseases

CA242 is a sialic acid-containing carbohydrate antigen attached to core proteins/lipids detected on the cell surface or in serum. Increased serum levels of CA242 have been used clinically as diagnostic biomarkers for pancreatic, colorectal, and other cancers. Since CA242 is overexpressed in malignant tumor tissues compared to that in normal tissues, it is believed that serum CA242 is a product of cancer cells. Thus far, the serum CA242 levels in patients suffering from different types of cancer and noncancerous diseases have not been systematically compared. In our current study, we acquired data of serum CA242 levels from 34,680 patients with 27 clinically defined diseases and from healthy controls (1317) in the clinical laboratory of our hospital over the past 5 years. The mean, median, and -log₁₀p values were calculated. Our data showed that patients with pancreatic cancer, cervical cancer, and lymphoma had the highest median values of serum CA242, which were followed by esophagus cancer, colon cancer, ovarian cancer, type 2 diabetes mellitus, rectal cancer, coronary heart disease, breast cancer, diabetic nephropathy, acute myocardial infarction, and 15 other types of diseases compared to that of healthy controls. In contrast, patients suffering from sequela of brain damage and anemia had statistically lower median values than healthy controls. Based on the -log₁₀p values, the increased serum CA242 levels could be used not only for diagnosis of pancreatic and other cancers, but also for diagnosis of type 2 diabetes mellitus and coronary heart disease, suggesting CA242 might be a systemic malfunction biomarker associated with cancers and other chronic diseases.

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.

CA 19.9, CA 242 and CEA in the Diagnosis and Follow-up of Pancreatic Cancer

The diagnosis of pancreatic cancer is usually made in the advanced stages of the disease when the prognosis is poor. We compared the behavior of CA19.9, CEA and the newly proposed mucin CA242 in a consecutive series of 42 pancreatic carcinomas. A control group was recruited of 21 patients with benign pancreatic diseases. With the recommended cutoffs (37 U/ml for CA19.9, 20 U/ml for CA242 and 8 ng/ml for CEA) we obtained a specificity of 90% for CA19.9 and of 85% for CA242 and CEA. The sensitivity was 85.7% for CA19.9, 73.8% for CA242 and 26.2% for CEA. CA19.9 and CA242 showed identical behavior in various TNM stages of cancer and in stages HI and TV of the Hermreck classification. Moreover, CA19.9 and CA242 showed identical behavior in 10 patients monitored during the survival period who developed recurrence of disease. ROC curve evaluation demonstrated that CA242 and CA19.9 were very similar. The results of CA242 were better than those of CA19.9 in the false positive range under 10%, whereas CA19.9 had a better performance in the true positive range over 70%. CA242 could be used instead of CA19.9 for diagnosing pancreatic carcinoma.

Tumor Markers in the Diagnosis, Monitoring and Therapy of Pancreatic Cancer: State of the Art

The present review focuses on the utility of serum tumor markers in screening, diagnosis, prognosis and monitoring of pancreatic cancer. Serum determination of all tumor markers studied offers no help in screening or early diagnosis of pancreatic cancer. For diagnosis, blood group-related antigens, in particular CA 19-9, are considered the best indicators of this neoplasm. However, as occurs with other glycoproteic tumor markers, the circulating levels of CA 19-9 are significantly influenced by jaundice, probably because its liver metabolism is reduced. Therefore, the finding of elevated CA 19-9 levels in jaundiced patients has to be evaluated with caution. Since pancreatic cancer recurrences are not susceptible to treatment, the clinical role of widespread use of tumor marker determination in follow-up programs is limited and calls for a critical evaluation.

Pancreatic cancer: diagnosis and treatments

Pancreatic cancer is one of the deadliest cancers, with exceptionally high mortality. Despite the relatively low incidence rate (10th), it is the fourth leading cause of cancer-related deaths in most developed countries. To improve the early diagnosis of pancreatic cancer and strengthen the standardized comprehensive treatment are still the main focus of pancreatic cancer research. Here, we summarized the rapid developments in the diagnosis and treatments of pancreatic cancer. Regarding diagnosis, we reviewed advances in medical imaging technology, tumor markers, molecular biology (e.g., gene mutation), and proteomics. Moreover, great progress has also been made in the treatments of this disease, including surgical resection, chemotherapy, targeted radiotherapy, targeted minimally invasive treatment, and molecular targeted therapy. Therefore, we also recapitulated the development, advantages, and disadvantages of each of the treatment methods in this review.

Diagnostic value of serum carbohydrate antigen 19-9 in pancreatic cancer: a meta-analysis

Pancreatic cancer is a highly malignant cancer with increasing incidence and mortality worldwide. Carbohydrate antigen 19-9 (CA19-9) has been widely reported to play a role in the diagnosis of pancreatic cancer patients. However, published data on this subject are inconclusive. There was no meta-analysis that has been previously performed to evaluate critically the diagnostic accuracy of CA19-9 for pancreatic cancer. Therefore, we performed a meta-analysis to evaluate the sensitivity and specificity of CA19-9 in the diagnosis of pancreatic cancer. We conducted a comprehensive search to identify studies in which the pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating curves (SROC) could be determined. A total of 11 studies that included 2,316 individuals who fulfilled all of the inclusion criteria were considered for analysis. The summary estimates for serum CA19-9 in the diagnosis of pancreatic cancer in these studies were pooled sensitivity 0.80 (95 % confidence interval [CI] 0.77-0.82), specificity 0.80 (95 % CI 0.77-0.82), and DOR 14.79 (95 % CI 8.55-25.59), and the area under the curve was 0.87. Our meta-analysis showed that serum CA19-9 plays important role in the diagnosis of pancreatic cancer.

CA19-9 and CA242 as tumor markers for the diagnosis of pancreatic cancer: a meta-analysis

Pancreatic cancer has the worst prognosis of any gastrointestinal cancer, with the mortality approaching the incidence. Early detection is crucial for improving patient prognosis. We therefore performed a meta-analysis to evaluate and compare the sensitivity and specificity of CA19-9 and CA242 in pancreatic cancer. We searched PubMed, EMBASE, and the Cochrane Library for studies that evaluated the diagnostic validity of CA19-9 and CA242 between January 1966 and March 2011. Meta-analysis methods were used to pool sensitivity and specificity and to construct a summary receiver-operating characteristic (SROC) curve. A total of 11 studies that included 2,316 patients who fulfilled all of the inclusion criteria were considered for analysis. The pooled sensitivities for CA242 and CA19-9 were 0.719 (95 % confidence interval [CI] 0.690-0.746) and 0.803 (95 % CI 0.777-0.826), respectively. The pooled specificities of CA242 and CA19-9 were 0.868 (95 % CI 0.849-0.885) and 0.802 (95 % CI 0.780-0.823), respectively. The diagnostic odds ratio (DOR) estimate was significantly higher for CA242 (16.261) than for CA19-9 (15.637). Our meta-analysis showed that CA242 and CA19-9 could play different roles in the diagnosis of pancreatic cancer. Although the sensitivity of CA242 is lower than that of CA19-9, its specificity is greater.

Evaluation of CA 242 as a tumor marker in gallbladder cancer

PURPOSE

Gallbladder and pancreas share common embryological origin, and malignancies of these organs may share common tumor antigens. CA 242 is a tumor marker for pancreatic cancer, but has not been studied in gallbladder cancer (GBC). We measured serum CA 242 levels in patients with GBC and compared it with those in patients with gallstones (GS) and healthy volunteers.

METHODS

We enrolled consecutive patients with GBC (cases), GS (disease controls), and healthy volunteers (healthy controls). Serum CA 242, CEA, and CA 19-9 levels were measured using ELISA. Receiver operator curve was plotted for all the three markers.

RESULTS

We studied 117 patients with GBC, 58 with GS, and 10 healthy volunteers. Among patients with GBC, 81 (69%) also had GB calculi. Patients with GBC more often had elevated CA 242 levels (64%) compared to those with GS (17%; p < 0.001) and healthy controls (0%; p < 0.001). The median levels of CA 242 was higher in the GBC group (59 [199] U/ml) compared to the GS group (10 [13] U/ml; p < 0.001) and the control group (3 [14.5] U/ml; p < 0.001). The sensitivity, specificity, positive predictive value (PPV), and negative predictive values of CA 242 for diagnosis of GBC were 64%, 83%, 88%, and 53%, respectively. At a cutoff of 45 U/ml, the specificity and PPV increased to 100%. CA 242 had higher AOC (0.759) compared to CEA (0.528) and CA 19-9 (0.430).

CONCLUSIONS

CA 242 is a promising tumor marker for GBC and performs better than CEA and CA 19-9.

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.

Diagnostic and prognostic value of plasma tumor M2 pyruvate kinase in periampullary cancer: evidence for a novel biological marker of adverse prognosis

OBJECTIVE

This prospective study examines the diagnostic and prognostic use of tumor-M2-pyruvate kinase (Tu-M2-PK) used in conjunction with carbohydrate antigen (CA) 19-9 in patients with subsequently histologically confirmed periampullary malignancy.

METHODS

Plasma Tu-M2-PK and serum CA 19-9 levels were measured at admission in a cohort of patients with suspected pancreatic cancer. Values for Tu-M2-PK and serum CA 19-9 were compared with a control group comprising jaundiced patients in whom malignancy was excluded by endoscopic retrograde cholangiopancreatography and nonjaundiced individuals undergoing laparoscopic cholecystectomy.

RESULTS

The mean (SD) plasma Tu-M2-PK level for patients with histologically proven malignancy was 40.5 (26.4) U/mL and for noncancer patients, 29.9 (20.9) U/mL (Mann-Whitney U = 1163, P = 0.006). Tumor-M2-pyruvate kinase had an area under the curve of 0.623 on receiver operating characteristic curve analysis, and at optimal cutoff of 27 U/mL, sensitivity is 66%, and specificity is 58%.However, on multivariate Cox regression modeling, elevated Tu-M2-PK (>27 U/mL) was strongly correlated with the subsequent finding of poorly differentiated cancer and/or metastatic disease and strongly predicted survival on Kaplan-Meier analysis.

CONCLUSION

An elevated Tu-M2-PK more than 27 U/mL measured on admission in suspected periampullary cancer is a predictor of adverse prognosis in periampullary cancer.

CEA, CA 19-9, and CA 125 in the differential diagnosis of benign and malignant pancreatic diseases with or without jaundice

BACKGROUND AND OBJECTIVES

In this study, the value of the serum tumor markers carcinoembryonic antigen (CEA), CA 19-9, and CA 125 was assessed in the differential diagnosis of benign and malignant pancreatic diseases with and without obstructive jaundice.

METHODS

Serum levels of CEA, CA 19-9, and CA 125 were measured by immunoradiometric assay before the treatment in 123 patients with pancreatic carcinoma and 58 patients with a benign pancreatic disease.

RESULTS

The sensitivity of CEA, CA 19-9, and CA 125 in the diagnosis of pancreatic carcinoma was 39.0%, 81.3%, and 56.9%; and specificity was 91.4%, 75.9%, and 77.6%, respectively. Although there was no significant difference between the CA 19-9 positivity ratios of the jaundiced (84.3%) and nonjaundiced (73.5%) patient subgroups of the pancreatic carcinoma, this ratio was significantly higher in the jaundiced subgroup (64.7%) than the nonjaundiced subgroup (7.3%) of the benign pancreatic diseases (P < 0.001). The CEA and CA 125 positivity ratios of jaundiced and nonjaundiced subgroups of patients with benign and malignant pancreatic diseases were not significantly different.

CONCLUSIONS

In the differential diagnosis of pancreatic carcinoma from benign pancreatic diseases, CA 19-9 can be useful in the nonjaundiced patients, whereas CA 125 provides a limited contribution in jaundiced patients.

Evaluation of the diagnostic value of serum tumor markers, and fecal k-ras and p53 gene mutations for pancreatic cancer

OBJECTIVE

To evaluate the diagnostic value for pancreatic cancer of four serum tumor markers, carbohydrate antigen (CA) 199, CA242, CA50 and carcino-embryonic antigen (CEA), and fecal k-ras and p53 gene mutations.

METHODS

From February 2002 to March 2004, 136 patients were consecutively diagnosed with pancreatic cancer in the three participating medical centers. The diagnosis was confirmed by pathology in 53 patients, of whom five were excluded because they did not have measurement of serum tumor marker. The remaining 48 patients comprised the case group in the study. Ninety-six patients with benign digestive diseases diagnosed during the same period were recruited as control subjects. They were matched by sex and age. In both groups, serum CA199, CA242, CA50 and CEA were measured by ELISA, and fecal k-ras and p53 gene mutations were measured by PCR-restriction fragment length polymorphism and PCR-single strand conformational polymorphism, respectively. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to compare their diagnostic value, as well as the sensitivity, specificity and likelihood ratio. Moreover, independent and sensitive tests from these non-invasive approaches were selected to form a parallel test that may have further improved sensitivity for diagnosis of pancreatic cancer.

RESULTS

The AUC of serum CA199 and CA242 were 0.821 (95%CI 0.725-0.917) and 0.821 (95%CI 0.723-0.919), respectively. The optimal diagnostic value of serum CA199 for pancreatic cancer was 93 U/mL, with a sensitivity of 73.7% and specificity of 91.4%. The positive likelihood ratio of CA199 was 8.57, and the negative likelihood ratio was 0.29. The optimal diagnostic value of serum CA242 was 25 U/mL, with a sensitivity of 71.1% and specificity of 93.5%. The positive likelihood ratio of CA242 was 10.94, and the negative likelihood ratio was 0.31. The sensitivity of fecal k-ras gene mutation for diagnosis of pancreatic cancer was 77.4%, and the specificity was 81.2%. The positive and negative likelihood ratios of fecal k-ras gene mutation were 4.12 and 0.28, respectively. The sensitivity and specificity of fecal p53 gene mutation were 25.8% and 95.3%, respectively, and its positive and negative likelihood ratios were 5.49 and 0.78. The rate of fecal k-ras mutation was higher in patients with benign pancreatic diseases (57.14%) than that of controls with non-pancreatic disorders. The values of serum tumor markers and fecal k-ras and p53 gene mutation rates were not significantly different in subgroups according to site or stage of pancreatic cancer. The sensitivity and specificity of the parallel test of serum CA199 and fecal k-ras gene mutation were 94.06% and 74.22%, respectively, while the sensitivity and specificity of the parallel test of serum CA242 and fecal k-ras were 93.47% and 75.92%, respectively.

CONCLUSIONS

Serum CA199 and CA242 are valuable diagnostic tools for pancreatic cancer. The diagnostic value is further improved when they are combined with fecal k-ras gene mutation measurement.

Systematic review of carbohydrate antigen (CA 19-9) as a biochemical marker in the diagnosis of pancreatic cancer

BACKGROUND

Although many biochemical markers have been examined in pancreatic cancer none are definitive for pre-operative diagnosis. This systematic review examines studies using biochemical markers for the diagnosis of pancreatic cancer in order to appraise their role in contemporary management algorithms.

METHODS

A search of the MEDLINE database was undertaken using the key words pancreatic neoplasm and serum tumour marker. Only studies providing original data on sensitivity and specificity are included and data are presented on diagnostic accuracy, effect of cholestasis and the relation of tumour stage to blood levels of markers.

RESULTS

CA 19-9 is the most extensively evaluated with pooled data from 2283 patients. The median sensitivity of CA 19-9 for diagnosis is 79 (70-90%) and median specificity 82 (68-91%). CA 19-9 elevation in non-malignant jaundice results in a fall in specificity. Combination with other markers improves accuracy.

CONCLUSION

As the most extensively evaluated marker, CA 19-9 should be used in contemporary algorithms for the diagnosis of pancreatic cancer. Elevated values should be repeated after relief of jaundice.

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.

Clinical aspects of altered glycosylation of glycoproteins in cancer

Alteration of the expression of carbohydrate structures is frequently observed in tumor cells. This review summarizes the different changes of O- and N-linked glycoproteins observed in cancer cells, the impact of the tumor-related carbohydrate phenotypes on the clinical outcome of the cancer disease, and the various ways in which carbohydrate structures can interact with different carbohydrate-detecting adhesion molecules, selectins, and sialoadhesins. Various ways of inhibiting the formation of cell adhesion-engaged carbohydrates on the cell surface, or inhibiting the binding are discussed. Carbohydrate structures which are in clinical use as circulating tumor markers and the effect of genotypes on tumor marker concentrations are reviewed.

Clinical aspects of altered glycosylation of glycoproteins in cancer

Alteration of the expression of carbohydrate structures is frequently observed in tumor cells. This review summarizes the different changes of O- and N-linked glycoproteins observed in cancer cells, the impact of the tumor-related carbohydrate phenotypes on the clinical outcome of the cancer disease, and the various ways in which carbohydrate structures can interact with different carbohydrate-detecting adhesion molecules, selectins, and sialoadhesins. Various ways of inhibiting the formation of cell adhesion-engaged carbohydrates on the cell surface, or inhibiting the binding are discussed. Carbohydrate structures which are in clinical use as circulating tumor markers and the effect of genotypes on tumor marker concentrations are reviewed.

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.

Serum CA 242: the search for a valid marker of pancreatic cancer

Many efforts have been made to find valuable serum tumour markers which help the diagnosis of pancreatic cancer. In the present study we investigated the diagnostic value of CA 242 in comparison with two other routinely used tumour markers (CA 19-9 and CA 50). Two-hundred and seventy six subjects were enrolled in this study: 46 patients with pancreatic cancer preoperatively, 53 with chronic pancreatitis, 28 with acute pancreatitis, 49 with other malignancies, 50 with miscellaneous non-neoplastic digestive diseases, and 50 healthy subjects. CA 242 was determined in serum by means of a two-step fluoroimmunometric assay. Sensitivities of CA 242, CA 19-9 and CA 50 for pancreatic cancer when all patients were considered were 41.3%, 54.3% and 47.8%, respectively (95% specificity level). No significant improvement was achieved by combination of CA 242 with CA 19-9 and/or CA 50. Cholestasis affected serum levels of CA 242 in patients without pancreatic cancer, but not in those with this tumour. The metastatic stage of pancreatic cancer appeared to influence the levels of CA 242. In conclusion, CA 242 serum assay does not seem to improve diagnostic accuracy for pancreatic cancer compared to CA 19-9 and CA 50.

Brachytherapy and pancreatic cancer

Advances in diagnostic and therapeutic technology have not appreciably changed the outlook of patients with pancreatic cancer. While those patients presenting with localized resectable disease have the best prognosis, local control and intra-abdominal metastases remain significant obstacles to survival. Localized chemoradiation has modestly improved median survival in localized and locally advanced disease. Patients presenting with locally advanced disease at diagnosis benefit from surgical palliation which includes biliary and gastric bypass. Intraoperative interstitial brachytherapy has been effective when utilized at laparotomy to improve local control in locally advanced disease. Advances in laparoscopic techniques have provided the ability to more accurately stage patients prior to laparotomy and perform palliative procedures without the need for laparotomy. The utilization of high-dose-rate brachytherapy has proven effective in palliating obstructive symptoms with minimal morbidity on an outpatient basis. Recent efforts have focused on preoperative chemoradiation to improve resectability in selected patients and prophylactic hepatic irradiation to reduce metastases for patients with locally advanced disease.

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.

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.

Comparative study of CA242 and CA19-9 in chronic pancreatitis

CA242 has been proved to be useful in the diagnosis of pancreatic cancer. The aim of the present study was to clarify the mechanisms contributing to the high specificity of CA242 as compared with CA19-9 resulting from scarce serum elevation of this antigen in patients with chronic pancreatitis by correlating serum levels and endoscopic retrograde choledocho-pancreatography (ERCP) findings and by immunohistochemical analysis. Serum CA19-9 levels were significantly elevated in patients with calcification and with main pancreatic duct (MPD) stenosis or obstruction. On the other hand, serum CA242 levels showed no significant elevation in patients with such factors. Even though such pathological conditions were considered to lead to the stagnation of pancreatic juice, serum CA242 levels seemed to be less affected than serum CA19-9 levels. Immunohistochemical studies of chronic pancreatitis tissues revealed that CA242 was expressed less frequently and less intensely than CA19-9, and the difference in expression was more prominent in the centroacinar cells and terminal ductules. From the results of the present study, it is conceivable that CA242 is less influenced by the stagnation of the pancreatic juice than CA19-9 because of the low levels of expression in ductal systems, which results in the release of this antigen into the circulation in lower amounts than that of CA19-9.

Circulating blood group related carbohydrate antigens as tumour markers

The various blood group related carbohydrate structures which are in clinical use as circulating tumour makers are reviewed. Their location on carbohydrate chains and their structural characteristics are shown, and their clinical performance in various malignant diseases is reviewed. The available data on their sensitivity, specificity and predictive value are shown; and carcinomas of the pancreas, ventricle, colon-rectum and ovary are identified as diseases in which these markers can be of good benefit for follow-up. Future research should be devoted to studies of the function of these structures, and to studies of their gene-transcription.

Preoperative serum levels of CEA and CA 242 in colorectal cancer

Preoperative serum levels of CEA and CA 242 were determined in 260 patients with colorectal cancer and in 92 patients with benign colorectal diseases. The overall sensitivity of the CEA test was 43% and of the CA 242 test 39%. The corresponding specificities were 90% and 87% respectively, using 5 ng ml-1 as cut-off level for CEA and 20 U ml-1 for CA 242. The sensitivity of CEA was 26%, 32%, 38% and 77% for Dukes A, B, C and D colorectal cancer, and the sensitivity of CA 242 was 26%, 26%, 40% and 67%, respectively. The correlation between CEA and CA 242 was low. Concomitant elevation of both markers was seen in 5%, 12%, 18% and 59% of patients with Dukes A, B, C and D colorectal cancer, respectively. Of all the patients, 23% showed elevation of both the CEA and the CA 242 level, whereas CEA alone was elevated in 20% and CA 242 alone in 15% of the patients with colorectal cancer. Combined use of both markers raised the overall sensitivity from 43% to 58%, but reduced the specificity from 90% to 80%. The increase in sensitivity by combining the two markers was most marked in Dukes A, B and C colorectal cancer. Either or both of the markers were elevated in 46%, 46% and 60% of the patients respectively. The clinical value of combining CEA and CA 242 seems very promising and should be further investigated in prospective studies.

Comparative study of CA242 and CA19-9 for the diagnosis of pancreatic cancer

A comparative study of a new tumour marker, CA242, and CA19-9 was conducted with special reference to their diagnostic usefulness in pancreatic cancer. CA242 showed sensitivity similar to that of CA19-9 for overall cases and early cases (stage I tumour) of pancreatic cancer. For other malignancies, the positive rates of CA242 were lower than those of CA19-9 except for colorectal cancer. An important characteristics of CA242 was that it was only slightly and infrequently elevated in the sera of patients with benign diseases such as chronic pancreatitis, chronic hepatitis and liver cirrhosis. This characteristic was more apparent in the patients with benign obstructive jaundice, indicating that the serum level of this marker was scarcely affected by cholestasis. Using cut-off levels corresponding to a 90% specificity, the clinical results obtained with CA242 in the diagnosis of pancreatic cancer were similar to those obtained with CA19-9, except that CA19-9 was falsely negative in some patients with early-stage pancreatic cancer. These findings suggest the usefulness of this marker for screening pancreatic cancer in patients on their first hospital visit. However, CA242 was found to be influenced by the Lewis blood group system. This unfavourable result is attributed to the C241 catcher antibody of this assay system, which has almost the same epitope specificity as the C50 and the NS19-9 monoclonal antibodies. In conclusion, CA242 is superior to CA19-9 in diagnosing pancreatic cancer by virtue of its higher specificity.

CA 242, a new tumour marker for pancreatic cancer: a comparison with CA 19-9, CA 50 and CEA

The serum expression of a novel tumour marker, CA 242, defined by monoclonal antibody C 242, was studied in 179 patients with pancreatic cancer. The results were compared with CA 19-9, CA 50 and CEA. CA 242 is a carbohydrate closely related, but not identical, to CA 19-9 and CA 50. The overall sensitivity of the CA 242 assay was 74%: 55% in stage I, 83% in stage II-III and 78% in stage IV disease. The specificity calculated from 112 patients with benign diseases was 91%. CA 19-9 had a higher sensitivity of 83%, but the specificity was only 81%. When comparing the markers by receiver operating characteristic analysis, the sensitivities were almost identical at all specificity levels. The CA 242 level was elevated in 7%, 15% and 7% of patients with benign pancreatic, biliary and liver disease respectively. The corresponding figures for CA 19-9 were 19%, 28% and 15% respectively. The sensitivity of CA 242 was higher than that of CA 50 and CEA at all specificity levels. In conclusion, tumour marker CA 242 seems to be a useful diagnostic tool for the diagnosis of pancreatic cancer, and is an alternative to CA 19-9. The advantage of CA 242 over CA 19-9 is its higher specificity when using the recommended cut-off levels of the assays.

The patterns of coexpression of tumor-associated antigens CA 19-9, TAG-72, and DU-PAN-2 in human pancreatic cancer

Coexpression of CA 19-9, DU-PAN-2, and TAG-72 was examined by a multilabeling immunohistochemical procedure in 31 surgically resected human pancreatic carcinomas. CA 19-9 was expressed in 74%, DU-PAN-2 in 84%, and TAG-72 in 65% of the cases. CA 19-9 and DU-PAN-2 were coexpressed in 16 cases (52%), CA 19-9 and TAG-72 in 10 cases (32%), DU-PAN-2 and TAG-72 in 8 cases (26%), and all three antigens in 10 tumors (32%). With the combination of the three antibodies, all 31 tumors were labeled. However, heterogeneity in antigen expression existed and the antibodies against CA 19-9, DU-PAN-2, and TAG-72 depicted 55%, 49%, and 35% of the tumor cells, respectively. The average number of cells coexpressing CA 19-9 and DU-PAN-2, CA 19-9 and TAG-72, DU-PAN-2, and TAG-72 was 22%, 11%, and 10%, respectively. Only about 3% of tumor cells coexpressed all three antigens, whereas 8% of tumor cells did not express any of the antigens. There was no correlation between the patterns of antigen expression and age or sex. However, there was a tendency of reduced CA 19-9, DU-PAN-2, and TAG-72 expression in less differentiated tumor areas. The results show that: 1) pancreatic cancer cells coexpress two or three antigens in different proportions; and 2) although the sensitivity for pancreatic cancer reaches 100% by all three antibodies, a remarkable heterogeneity exists and a minor fraction of tumor cells does not seem to produce any of these antigens.