The establishment of a preoperative diagnosis of pancreatic carcinoma using cell specimens from pancreatic duct brushing with special attention to p53 mutations

Telomerase activity in pancreatic juice differentiates pancreatic cancer from chronic pancreatitis: A meta-analysis

BACKGROUND/OBJECTIVE

To evaluate the usefulness of genetic markers in pancreatic juice (PJ), and the combination of these markers with telomerase activity in the differential diagnosis of pancreatic ductal adenocarcinoma (PDAC) from chronic pancreatitis.

METHODS

We conducted a meta-analysis for the diagnostic utility of the four major altered genes in PDAC (KRAS, CDKN2A/p16, TP53, and SMAD4/DPC4), telomerase activity, and a combination assay using PJ samples. A literature search was conducted in MEDLINE, Cochrane Library, and Web of Science. Data were pooled and presented as diagnostic sensitivity and specificity with 95% confidence intervals (CIs).

RESULTS

Thirty-nine studies fulfilled the inclusion criteria. Pooled estimates of KRAS analysis were as follows: sensitivity was 0.67 (95% CI, 0.63-0.71) and specificity, 0.82 (95% CI, 0.79-0.85). For telomerase activity analysis, sensitivity was 0.82 (95% CI, 0.76-0.87) and specificity, 0.96 (95% CI, 0.90-0.99). The other three tumor suppressors demonstrated low sensitivity. The data did not suggest any publication bias. A combined analysis of KRAS and telomerase activity showed a higher diagnostic sensitivity (0.94; 95% CI, 0.83-0.99) than KRAS alone. A combined analysis of telomerase activity and cytology revealed more reliable diagnostic accuracy than telomerase activity alone, with high sensitivity (0.88; 95% CI, 0.74-0.96) and specificity (1.00; 95% CI, 0.91-1.00).

CONCLUSIONS

The most reliable marker in PJ samples for diagnosis of PDAC was telomerase activity. Telomerase activity can play a central role in diagnostic analysis using PJ samples, and can increase diagnostic accuracy when combined with KRAS mutations or cytological examination.

The Significance of p53 and K-ras Immunocytochemical Staining in the Diagnosis of Malignant Biliary Obstruction by Brush Cytology during ERCP

BACKGROUND/AIMS

Brush cytology during ERCP can provide a pathologic diagnosis in malignant biliary obstruction. K-ras and p53 mutations are commonly found in biliary and pancreatic cancers. We evaluated the diagnostic yield of brush cytology and the changes obtained by adding p53 and K-ras staining.

METHODS

One hundred and forty patients with biliary obstruction who underwent ERCP with brush cytology during a 7-year period were included. The sensitivity and specificity of brush cytology only and with the addition of p53 and K-ras staining were obtained.

RESULTS

Malignant biliary obstruction was confirmed in 119 patients. The sensitivity and specificity of brush cytology were 78.2% and 90.5%, respectively. The sensitivity of cytology was 77.3% at the ampulla-distal common bile duct (CBD), 92.6% at the mid common hepatic duct (CHD), and 94.7% at the proximal CBD-CHD (p<0.05); these values did not differ with the degree or the length of the obstruction. In the 97 patients who received additional p53 and K-ras staining, the sensitivity of cytology plus p53 was 88.2%, cytology plus K-ras was 84.0%, and cytology plus p53 and K-ras was 88.2%. The sensitivity of cytology plus p53 was higher than that of brush cytology only (95% confidence interval: 83.69-92.78 vs 72.65-83.65) but not that of cytology plus K-ras.

CONCLUSIONS

Brush cytology for malignant biliary obstruction has a high diagnostic accuracy. Adding p53 staining can further improve the diagnostic yield, whereas K-ras staining does not.

Diagnosis of biliary tract lesions by histological sectioning of brush bristles as alternative to cytological smearing

AIM

To increase the diagnostic potential of endoscopic biliary tract brushing, we devised an approach alternative to cytological smearing, leading to the preoperative histological examination of the collected material.

METHODS

One hundred twelve consecutive biliary brush specimens were included. All patients presented a stricture of the biliary tract, leading to a diagnostic procedure by brushing. Immediately following brushing, the endoscopist immersed the brush into methanol and sent it to the pathology laboratory. The brush was introduced into a cassette for paraffin embedding and sections parallel to the long axis of brush were cut until the metal wire was almost reached, then the block was rotated and new sections were obtained from the opposite side. Samples of the mucosa, inflammatory cell aggregates, small fragments of carcinomas, or isolated cells were observed, and displayed an optimal fixation, allowing a definite diagnosis that proved mandatory for therapy in the vast majority of cases (99.1%).

RESULTS

The results obtained in 112 consecutive cases using such technique compared with final histological diagnosis proved: 91% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 87% negative predictive value (NPV) (P < 0.001). In nonoperated patients, the clinical diagnosis after at least 6 months of follow-up showed: 95.5% sensitivity, 100% specificity, 100% PPV, and 88.2% NPV (P < 0.001).

CONCLUSION

Such novel approach to the preoperative diagnosis of biliary tract lesions proved to be highly sensitive and specific, limiting the inadequate preoperative diagnoses to less than 1%.

Endoscopic retrograde cholangiopancreatography tissue sampling: when and how?

A 69-year-old man presented with obstructive jaundice. Endoscopic retrograde cholangiopancreatography was performed for biliary tree decompression and diagnostic tissue acquisition. Techniques, indications, methodologic considerations, and interpretation of tissue sampling at endoscopic retrograde cholangiopancreatography in patients with biliary/pancreatic strictures are discussed. This case-based educational presentation focuses on the importance of interdisciplinary communication between endoscopists and pathologists for optimal tissue sampling, interpretation, and diagnostic accuracy.

Current treatment strategies for pancreatic cancer in the elderly

Pancreatic cancer, which is responsible for >90% of exocrine pancreatic tumours, is typically a disease of the elderly (> or =70 years of age). However, older patients are less likely to be staged than younger patients despite having a worse overall 5-year survival rate than their younger counterparts. Various radiological, ultrasonographic and endoscopic investigations are used not only as diagnostic tools but also to accurately stage the cancer for possible surgery. Many patients with pancreatic cancer have mutations of the K-ras oncogene, and various tumour suppressor genes are also inactivated. Pancreas resection can be performed in elderly resectable patients without excess mortality, even in those >80 years of age. However, treatment for locally advanced, unresectable and metastatic pancreatic cancer is palliative. Fluorouracil-based chemoradiation for locally advanced or unresectable cancer, and gemcitabine for patients with metastatic disease, can result in clinical benefits. Placement of a stent in the biliary tract has been shown to improve symptoms of obstructive jaundice or ascites, as well as quality of life. As molecular targets are identified, interventions with targeted specific agents may improve tumour control. However, further studies will be needed to demonstrate whether or not various agents targeting signal transduction pathways or nuclear transcription factors are useful for elderly patients with advanced pancreatic cancer.

Pancreatic and bile duct brushing cytology in 1000 cases: review of findings and comparison of preparation methods

BACKGROUND

Duct brushing cytology is an important tool in evaluation of the extrahepatic biliary tract and large pancreatic ducts. The emergence of neoadjuvant therapies underscores the importance of accurate preoperative diagnosis by noninvasive means. Liquid-based preparation methods, such as ThinPrep, have become popular for nongynecologic cytology specimens.

METHODS

Findings from bile and pancreatic duct brushings were reviewed over the 10-year period of 1994-2003. Cytologic material, imaging reports, and clinical data were reviewed and pathologic and clinical follow-up data were obtained. The slides were prepared by direct smear only (18.8%), direct smear plus cytospin (14.4%), or direct smear plus ThinPrep (66.8%).

RESULTS

A total of 1118 specimens were identified (1008 bile duct, 110 pancreatic duct) from 864 patients. The cytologic findings were: 53.5% negative, 16.5% malignant, 18.2% suspicious for malignancy, 11% atypical/inconclusive, 0.8% inadequate. Follow-up in the form of either histology or at least 6 months clinical observation was available for 82.2% of cases (n = 971). Overall operating characteristics were: 52.6% sensitivity, 99.4% specificity, 98.9% positive predictive value, 67.1% negative predictive value, and 75.7% accuracy. Diagnostic agreement between cytology and follow-up was the main variable analyzed. Agreement was significantly affected by characteristics of the sampled lesion, with ductal narrowing having the lowest rate of malignancy. In addition, the ThinPrep method showed superior sensitivity and accuracy compared with other preparation methods (P = .02). Nonsignificant associations were noted for patient age and gender, site of lesion, and the presence of either stones or prior stent.

CONCLUSION

In a large dataset from a single institution, brushing cytology showed modest sensitivity and high specificity. Diagnostic agreement was considerably better for benign cases. The combination of direct smear and the ThinPrep method showed superior sensitivity and accuracy.

Serum tumor markers and molecular biological diagnosis in pancreatic cancer

Recent studies on genetic abnormalities in pancreatic ductal cancer have led to the investigation of tumor markers and genetic markers in both serum and pancreatic juice (PJ). Serum type 1 chain carbohydrate antigens such as CA19-9 are positive in nearly 80% of patients with pancreatic cancer (PCa), of which most are in advanced stage, whereas false-positive rates are relatively high at 20%-30% in benign hepatobiliary and pancreatic diseases. Although the prevalence of type 2 chain carbohydrate antigens, such as SLX, is relatively low, cancer specificity of these antigens is high. However, serum tumor markers have limited diagnostic value for early detection of PCa. In PJ collected endoscopically from patients with PCa, K-ras mutations (KRM) are detectable in > 80%, whereas KRM are observed in 20%-30% of PJ from patients with chronic pancreatitis (CP), reflecting benign mucous cell hyperplasia harboring KRM. Thus, a qualitative analysis of KRM in PJ is unsuitable for diagnosis of PCa. On the other hand, using an hybridization protection assay that can quantitatively determine KRM, KRM were positive in 66% of PCa but only in 40% of CP cases, indicating that qualitative analysis of KRM in PJ may be useful for differentiating PCa from CP. p53 Mutations are found in 4%-50% in PJ from patients with PCa but are not detectable in PJ from CP, suggesting that the specificity of p53 mutations is very high for PCa. Furthermore, p53 mutations were detected in 7 of 15 (47%) patients with PCa in which the PJ cytologic diagnosis was negative. Telomerase (TE) activity or its catalytic subunit, h-TERT, was reportedly positive >80% in PJ from PCa but was detected in <20% of PJ from CP. TE activity in PJ from CP originates from lymphocytes. The development and application of these new genetic and epigenetic markers with high specificity and sensitivity for PCa in serum and PJ will significantly improve our diagnostic accuracy.

Carcinoma of the head of the pancreas versus chronic pancreatitis: diagnostic dilemma with significant consequences

Although carcinoma of the head of the pancreas and chronic pancreatitis are usually easy to distinguish on clinical presentation and subsequent investigation, there can be enough overlap in the presenting features and on imaging studies that differentiation is sometimes extremely difficult. As this confusion may lead to either major pancreatic resection for benign disease, or rejection of surgery for a potentially curable lesion, all attempts to arrive at a correct diagnosis should be pursued. This article provides an update of investigative techniques in pancreatic disease, and offers an algorithm for the clinical approach to the patient who appears to present with this diagnostic and therapeutic dilemma.

Cytologic diagnosis of adenocarcinoma in biliary and pancreatic duct brushings

Biliary and pancreatic duct brush specimens are relatively uncommon specimens seen by pathologists. Not only can the findings of malignancy be subtle, the implications of a malignant diagnosis can be significant. This review focuses on cholangiocarcinoma and pancreatic ductal adenocarcinoma sampled by endoscopic brush cytology, with an emphasis on diagnostic criteria for adenocarcinoma. In addition, assessment of specimen adequacy, utilization of liquid-based preparations, molecular diagnosis, and timing of liver transplantation in patients with primary sclerosing cholangitis are also briefly discussed.

Molecular diagnosis of early pancreatic ductal adenocarcinoma in high-risk patients

The prevalence of pancreatic cancer in the general population is too low--even in high-prevalence areas such as Northern Europe and North America (8-12 per 10(5) population)--relative to the diagnostic accuracy of present detection methods to permit primary screening in the asymptomatic adult population. The recognition that the lifetime risk of developing pancreatic cancer for patients with hereditary pancreatitis (HP) is extremely high (20% by the age of 60 years and 40% by the age of 70 years) poses considerable challenges and opportunities for secondary screening in those patients without any clinical features of pancreatic cancer. Even for secondary screening, the detection of cancer at a biological stage that would be amenable to cure by surgery (total pancreatectomy) still requires diagnostic modalities with a very high sensitivity and specificity. Conventional radiological imaging methods such as endoluminal ultrasound and endoscopic retrograde pancreatography, which have proved to be valuable in the early detection of early neoplastic lesions in patients with familial pancreatic cancer, may well be applicable to patients with HP but only in those without gross morphological features of chronic pancreatitis (other than parenchymal atrophy). Unfortunately, most cases of HP also have associated gross features of chronic pancreatitis that are likely to seriously undermine the diagnostic value of these conventional imaging modalities. Pre-malignant molecular changes can be detected in the pancreatic juice of patients. Thus, the application of molecular screening in patients with HP is potentially the most powerful method of detection of early pancreatic cancer. Although mutant (mt) K-ras can be detected in the pancreatic juice of most patients with pancreatic cancer, it is also present in patients with non-inherited chronic pancreatitis who do not progress to pancreatic cancer (at least in the short to medium term), as well as increasingly in the older population without pancreatic disease. Nevertheless, the presence of mt-K-ras may identify a genuinely higher-risk group, enabling additional diagnostic imaging and molecular resources to be focussed on such a group. What is clear is that prospective multi-centre studies, such as that being pursued by the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer (EUROPAC), are essential for the development of an effective secondary screening programme for these patients.

Pancreatic intraductal sampling during ERCP in patients with chronic pancreatitis and pancreatic cancer: cytologic studies and k-ras-2 codon 12 molecular analysis in 47 cases

BACKGROUND

A preoperative tissue diagnosis of pancreatic cancer is desirable but difficult to obtain.

METHODS

Pancreatic brush cytology, salvage cytology, and collection of pancreatic juice were attempted prospectively during ERCP in 34 patients with pancreatic cancer and 11 with chronic pancreatitis. K-ras-2 codon 12 was analyzed for presence and type of point mutations.

RESULTS

Brush cytology coupled with salvage cytology had a sensitivity of 74%. The addition of cytologic analysis of pancreatic juice did not substantially improve sensitivity (76%). K-ras-2 was mutated in both cancer (87%) and pancreatitis (40%). The specificity for cytology was 100% and for K-ras-2 mutations 60%. Combining cytology with mutation analysis increased sensitivity to 93% but reduced the positive predictive value. The negative predictive value never exceeded 75%. None of the patients with chronic pancreatitis had cancer develop (median follow-up 60 months).

CONCLUSIONS

Pancreatic ductal brushing with salvage cytology is useful in the diagnosis of cancer, whereas cytologic analysis of pancreatic juice can be abandoned. At present, K-ras-2 mutation is not useful for differentiating pancreatic cancer from chronic pancreatitis or the identification of patients with chronic pancreatitis at risk for malignant transformation.

Bcl-2 expression in pancreas development and pancreatic cancer progression

Apoptosis is important for both tissue development and differentiation; its deregulation may contribute to tumourigenesis. In order to clarify the role of Bcl-2, an apoptosis-inhibiting protein, in pancreatic morphogenesis and tumour progression, its immunohistochemical expression was evaluated in 12 samples of fetal pancreas, in 10 samples of adult pancreas with ductal hyperplastic lesions, in 120 cases of primary pancreatic ductal adenocarcinoma, and in 43 synchronous metastatic lymph nodes. To evaluate the role of apoptosis in pancreatic cancer, p53 expression was also studied in tumour samples. Bcl-2 cytoplasmic acinar and ductal immunostaining was found in all fetal and adult tissue samples; ductal hyperplastic lesions were constantly negative. Thirty out of 120 (25%) tumours and 3 out of 43 (7%) lymph nodes expressed Bcl-2, whereas 67 out of 120 (56%) expressed nuclear p53. Well-differentiated tumours (G1) were more frequently Bcl-2-positive (p=0.002); furthermore, there was an inverse correlation between Bcl-2 and p53 expression in primary tumours (p=0.02). Neither Bcl-2 nor p53 influenced patients' prognosis, which was instead affected by N (p=0.02) and M (p<0.0001) status and stage of the disease (p=0.002). It is concluded that Bcl-2 regulates pancreatic morphogenesis and tissue homeostasis from early fetal to adult life and can be considered a phenotypic marker of normal exocrine pancreas. On the other hand, the lack of expression in preneoplastic lesions and the low positivity found in primary tumours and lymph node metastases suggest that Bcl-2 does not play a centralrole in pancreatic tumourigenesis and cancer progression.

Brush cytology in the assessment of pancreatico-biliary strictures: a review of 406 cases

AIMS

To assess the accuracy of brush cytology in patients investigated for pancreatico-biliary strictures.

METHODS

All pancreatico-biliary brush cytology specimens submitted from two major teaching hospitals over a 6.5 year period were reviewed. Four hundred and forty eight satisfactory specimens from 406 patients with adequate clinical and/or pathological follow up data were examined in the study period.

RESULTS

Two hundred and forty six patients (60.6%) were shown to have neoplastic strictures. One hundred and forty seven tumours were identified cytologically, including 87 of 146 pancreatic carcinomas, 29 of 47 cholangiocarcinomas, one of one bile duct adenoma, four of seven carcinomas of the gallbladder, eight of 13 ampullary carcinomas, two of three ampullary adenomas, 10 of 16 malignancies of undetermined origin, none of two islet cell tumours, one of three hepatocellular carcinomas, and five of eight metastatic tumours. The three adenomas identified on brush cytology could not be distinguished from adenocarcinoma morphologically. One hundred and sixty patients (39.4%) had benign strictures, most often as a result of chronic pancreatitis and bile duct stones. There were three false positive cytological diagnoses mainly as a result of the misinterpretation of cases with relatively scant and/or degenerative atypical epithelial cells. Forty one cases were reported as atypical or suspicious of malignancy on brush cytology, of which 29 were ultimately shown to have carcinoma. The overall diagnostic sensitivity and specificity were 59.8% and 98.1%, respectively. The sensitivity increased from 44.3% in the initial third of cases to 70.7% in the final third of cases examined in the series.

CONCLUSIONS

Brush cytology, in conjunction with other clinical and radiological investigations, is a useful technique in the assessment of patients with suspected pancreatico-biliary neoplasia.

Value of p53 immunostaining in pancreatico-biliary brush cytology specimens

Brush cytology is routinely used in the assessment of pancreatico-biliary strictures but the technique has limited diagnostic sensitivity in malignant lesions. It has been suggested that ancillary techniques, such as the identification of p53 immunoreactivity, might improve diagnostic accuracy. p53 protein expression was examined in 143 consecutive brush cytology specimens from patients with pancreatic or bile duct strictures and correlated with conventional cytological assessment and clinicopathologic follow-up data. Sixty-three of 89 (70.8%) malignant strictures were identified cytologically while 45 cases (50.6%) were p53 immunoreactive. One case of bile duct adenoma with high-grade dysplasia was reported as consistent with adenocarcinoma cytologically and was p53 negative. There was one false-positive diagnosis with conventional cytology and, in a separate case, with p53 immunostaining. Nineteen specimens (13.3%) were considered atypical cytologically and p53 expression proved accurate in only 12 cases (four immunopositive carcinomas and eight negative benign strictures). In conclusion, p53 immunostaining proved less sensitive than conventional cytology in this series and its routine diagnostic use could not be supported.

Different amounts of K-ras mutant epithelial cells in pancreatic carcinoma and mass-forming pancreatitis

Clinically, differential diagnosis of pancreatic carcinoma (PC) and so-called "mass-forming pancreatitis (MFP)" is difficult. We analyzed the amount, ductal level, and K-ras mutation of ductal hyperplasia and intraductal carcinoma in surgically resected cases of MFP (n = 18) and PC (n = 16). DNAs extracted from microdissected epithelial foci were analyzed for K-ras codon 12 mutation by nested polymerase chain reaction and restriction fragment length polymorphism. The histology of MFP showed severe destruction of exocrine tissue and pancreatic stones and/or protein plugs (72%, 13 of 18 cases) in mostly peripheral ducts. The average basal membrane lengths of nonpapillary and papillary hyperplasia in cases of carcinoma were about 4 and 15 times more than those of MFP, respectively. The frequency of K-ras mutation in hyperplastic foci increased from nonpapillary [six (27%) of 22] to papillary foci [16 (64%) of 25] in K-ras mutant PCs, but there was no difference between nonpapillary [one (6%) of 18] and papillary foci (none of 19) in K-ras wild-type PCs, and also between nonpapillary (none of 24) and papillary foci [one (7%) of 14] in MFPs.

Ductal lesions in patients with chronic pancreatitis show K-ras mutations in a frequency similar to that in the normal pancreas and lack nuclear immunoreactivity for p53

BACKGROUND

Chronic pancreatitis (CP) is considered to be a risk factor for the development of pancreatic carcinoma. The detection of K-ras mutations in the duodenal or pancreatic juice has been held to be a reliable tool for its early diagnosis. However, K-ras mutations also occur in hyperplastic ductal epithelium, making it difficult to interpret their role in pancreatic carcinogenesis.

METHODS

The study included 30 resection specimens, 15 from patients with alcoholic CP, and 15 from patients with idiopathic CP. The mean duration of disease was 6.8 years. A total of 429 ductal lesions were classified according to the World Health Organization classification (1996) and microdissected. K-ras analysis was performed by means of polymerase chain reaction (45 cycles), constant denaturing gel electrophoresis, and sequencing. Immunostaining was performed with antibodies against p53, Ki-S5, carcinoembryonic antigen, and two types of mucins.

RESULTS

The 30 specimens demonstrated all types of ductal lesions. Severe cellular atypia was not observed. A total of 429 ductal lesions were analyzed. Approximately 4.4% of the lesions (19 of 429) from 27% of the patients (8 of 30) showed K-ras mutations, but they were unrelated to the duration or type of CP. Immunostaining for mutated p53 protein always was negative. Increased proliferative activity was noted only in patients with papillary hyperplasia. No patient developed pancreatic carcinoma within a follow-up period of at least 3 years.

CONCLUSIONS

Ductal lesions in patients with CP exhibit K-ras mutations without additional indications of neoplastic transformation such as severe dysplasia or mutated p53 protein. Therefore, for diagnostic and therapeutic purposes, the detection of K-ras mutations should be supplemented by the demonstration of additional genetic alterations or clinical signs of malignancy.

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.

Diagnostic p53 immunostaining of endobiliary brush cytology: preoperative cytology compared with the surgical specimen

BACKGROUND

Endobiliary brush cytology is important in the distinction of malignant and benign causes of extrahepatic bile duct obstruction. The additional diagnostic value of p53 immunostaining on these cytology specimens was assessed.

METHODS

All patients with extrahepatic bile duct obstruction who underwent endoscopic retrograde cholangiopancreatography (ERCP) with endobiliary brush cytology and subsequent surgery at the Academic Medical Center in Amsterdam during a 3-year period were studied. p53 Immunocytology was compared with the corresponding conventional light microscopic cytology and p53 immunostaining of the subsequent surgical specimen.

RESULTS

Fifty-three patients with the following diagnoses were included: pancreatic carcinoma (23), bile duct carcinoma (15), ampullary carcinoma (5), lymph node metastases (2), carcinoma of unknown origin (4), chronic pancreatitis (3), and primary sclerosing cholangitis (1). Fifty-one percent of the carcinomas showed positive p53 immunostaining; all four surgical specimens without carcinoma were negative. The sensitivities of conventional light microscopic cytology, p53 immunocytology, and both tests combined were 29%, 24%, and 43%, respectively. These sensitivities were higher in cases of bile duct carcinoma (46%, 40%, and 66%) compared with cases of pancreatic carcinoma (13%, 9%, and 22%). Specificities of both tests were 100%.

CONCLUSIONS

p53 Immunostaining on endobiliary brush cytology may be helpful in the diagnosis of malignant extrahepatic bile duct stenosis, especially in patients with bile duct carcinoma. Cancer (Cancer Cytopathol)