Diagnostic yield of endoscopic retrograde cholangiopancreatography-based cytology for distinguishing malignant and benign intraductal papillary mucinous neoplasm: systematic review and meta-analysis

BACKGROUND AND AIM

Published studies have revealed the diagnostic yield of cytology obtained from endoscopic retrograde cholangiopancreatography (ERCP) in distinguishing malignant and benign intraductal papillary mucinous neoplasm (IPMN). However as a result of small sample sizes, the overall magnitude of benefit is unknown. Additionally, the optimal endoscopic procedure for cytology acquisition is also unclear. The aim of the present study was to evaluate the diagnostic yield of ERCP-based cytology in patients with IPMN and clarify the optimal sampling technique.

METHODS

Relevant studies with a reference standard of definitive surgical histology were identified via MEDLINE and SCOPUS. Malignant IPMN included invasive adenocarcinoma, carcinoma in situ, and high-grade dysplasia. For ERCP, studies using aspiration, brush, and lavage cytology were included. The main objective was the diagnostic yield (pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio) of cytology obtained from ERCP to distinguish malignant and benign IPMN.

RESULTS

Meta-analysis of 13 international studies with 483 IPMN patients was conducted. Pooled sensitivity was 35.1%, specificity 97.2%, and accuracy 92.9%. Among the three ERCP techniques, lavage cytology showed the best diagnostic ability (sensitivity 45.8%, specificity 97.9%). Malignant IPMN were observed in 45.1% (218/483) of patients in ERCP studies.

CONCLUSIONS

Cytology from ERCP has good specificity but poor sensitivity in distinguishing benign from malignant IPMN. Newer techniques or markers are needed to improve diagnostic yield.

Pancreatic duct lavage cytology with the cell block method for discriminating benign and malignant branch-duct type intraductal papillary mucinous neoplasms

BACKGROUND

Differentiation between benign and malignant branch-duct type intraductal papillary mucinous neoplasms (IPMNs) remains challenging.

OBJECTIVE

To examine the usefulness of pancreatic duct lavage cytology with cell block method for discriminating benign and malignant branch-duct type IPMNs.

PATIENTS AND METHODS

Between December 2007 and April 2011, patients with branch-duct type IPMNs having mural nodules on EUS were examined by pancreatic duct lavage cytology by using the cell block method. Cell block sections underwent hematoxylin and eosin staining and mucin immunostainings (MUCs 1, 2, 5AC, and 6).

DESIGN

Single-center, prospective study.

SETTING

Academic medical center.

MAIN OUTCOME MEASUREMENTS

The sensitivity and specificity of cytology were assessed. The agreement between cytological and histological results for MUC was also examined.

RESULTS

Cytology with this method was investigated in 44 patients. Cell block diagnosis was cancer positive (class V or IV) in 11 patients and negative (classes I, II, III, and noninformative) in 33. The sensitivity, specificity, and positive and negative predictive values of this method were 92%, 100%, 100%, and 97%, respectively. The cytological and histological results of MUCs 1, 2, 5AC, and 6 agreed in 88% (15/17), 94% (16/17), 88% (15/17), and 100% (17/17), respectively.

LIMITATIONS

Single center and small number of patients.

CONCLUSIONS

Pancreatic duct lavage cytology with the cell block method may be useful to differentiate between benign and malignant IPMNs preoperatively and as well as to determine their mucin type.

Intraductal papillary mucinous neoplasms of the pancreas: diagnosis and management

Intraductal papillary mucinous neoplasms (IPMNs), characterized by intraductal papillary growth and thick mucin secretion, have increasingly been recognized. Despite modern preoperative evaluation, major difficulties still remain in distinguishing malignant invasive types from benign IPMNs. Following a PubMed database search, all relevant abstracts and articles on IPMN published in English and Chinese were reviewed. Main-duct and the mixed type IPMNs carry a higher risk of malignancy as compared with branch-duct type IPMNs. Treatment of branch-duct type IPMNs remains controversial. Once operation is indicated, intraoperative frozen section of margins plays an important role in the decision concerning the extent and type of surgery. Pancreatectomy, partly preserving both endocrine and exocrine pancreatic function, is advocated for most patients with IPMN, though total pancreatectomy may be necessary in some. Both for patients subjected to surgery and those only observed, IPMN patients need regular close follow-up to identify recurrence or progressive disease.

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.

Pancreatic-duct-lavage cytology in candidates for surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas: should the International Consensus Guidelines be revised?

BACKGROUND

The International Consensus Guidelines are helpful for the management of branch-duct intraductal papillary mucinous neoplasms (IPMNs), because they allow us to exclude malignancy. However, it is not possible to predict malignancy with certainty, and further preoperative differentiation between benign and malignant IPMNs is required to avoid the false-positive results.

OBJECTIVE

To examine the usefulness of pancreatic-duct-lavage cytology by using an originally designed double-lumen catheter for discriminating benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines.

PATIENTS

Pancreatic-duct-lavage cytology was investigated in 24 patients with branch-duct IPMNs who underwent surgical resection based on the International Consensus Guidelines, namely, they either had intramural nodules or the ectatic branch duct was >30 mm in diameter.

DESIGN

Single-center retrospective study.

SETTING

Academic medical center.

MAIN OUTCOME MEASUREMENTS

The sensitivity and specificity of pancreatic-duct-lavage cytology for discriminating benign from malignant IPMNs.

RESULTS

More than 30 mL of pancreatic-duct-lavage fluid was obtained from each patient, and there were no patients with noninformative results. The sensitivity, specificity, positive predictive value, and negative predictive value of the cytologic diagnosis were 78%, 93%, 88%, and 88%, respectively.

LIMITATIONS

Single-center and small number of patients.

CONCLUSIONS

Pancreatic-duct-lavage cytology can improve differentiation between benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines.

Review of the cytologic features of noninvasive ductal carcinomas of the pancreas: differences from invasive ductal carcinoma

Invasive ductal adenocarcinoma (IDA) of the pancreas (IDAP) originating from the ductal gland has a poor prognosis. Noninvasive carcinomas are principally intraductal papillary mucinous carcinomas (IPMCs) and pancreatic intraepithelial neoplasms 3 (PanIN-3). Small papillary-cohesive clusters, individually well-enveloped nuclei in well-preserved cytoplasm, centrally located nuclei, small nuclei (about 10 mum), euchromatin, clearly defined cell borders, small cytoplasm without prominent anisocytosis and no cytoplasm more than 21 mum in shortest diameter, a mixture of goblet cells, and a pleomorphic aspect are common in IPMC and intraductal papillary mucinous neoplasm (IPMN), whereas malignancy in nuclei are observed only in IPMC. PanIN-3 cells have small papillary-cohesive and compact clusters, a monomorphic aspect, and small dense cytoplasm and are highly suggestive of malignancy. IDA cells have loose sheet and solid clusters, poorly preserved cytoplasm, nuclei that tend to adhere to each other, large nuclei, a combination of large nuclei (short diameter <15 mum) with hyperchromatin, a monomorphic aspect, and abundant cytoplasm more than 21 mum in the shortest diameter. To preoperatively differentiate noninvasive IPMC and PanIN-3 from IDAP, these features would be clinically very useful.

Predictive factors of malignant or invasive intraductal papillary-mucinous neoplasms of the pancreas

The aim of this study was to identify useful preoperative diagnostic findings indicative of malignant or invasive intraductal papillary-mucinous neoplasms (IPMN) of the pancreas to determine an optimal operative procedure for IPMN. Sixty-two IPMNs, which consisted of 29 adenomas, 10 borderline tumors, 11 adenocarcinomas in situ, and invasive adenocarcinomas were reviewed from 1990 to 2003. Preoperative predictive factors of malignant or invasive IPMN were analyzed among 10 factors by univariate and multivariate analysis. Diameter of the main pancreatic duct (> or =6 mm) and cytological examination of the pancreatic juice (the presence of malignant cells) were identified as independent predictive factors of malignant IPMN, and only cytological examination of the pancreatic juice (the presence of malignant cells) was identified as an independent predictor of invasive IPMN by multivariate analysis (P < 0.05). There was no recurrent disease in patients with adenoma and adenocarcinoma in situ, whereas recurrences occurred in 6 of 12 patients with invasive IPMN. Patient survival in noninvasive IPMN was significantly (P = 0.018) better than that in invasive IPMN (The overall 5-year survival rates were 87.2% and 49.2%, respectively). These results might be useful for selecting an optimal surgical procedure for IPMN.

Management of intraductal papillary-mucinous neoplasm of the pancreas: treatment strategy based on morphologic classification

GOALS

The aim of this study was to examine and clarify the preoperative markers that are useful for differentiating between benign and malignant lesions of intraductal papillary-mucinous neoplasms (IPMN) of the pancreas, grouped according to morphologic classification.

BACKGROUND

There are various stages of pathology in IPMN, ranging from benign to malignant lesions. Although the determination of appropriate treatment guidelines to deal with IPMN is a critical issue, no such guidelines have been established.

PATIENTS AND METHODS

One hundred twenty cases of IPMN were classified morphologically into either main or branch duct types. We compared the morphologic classification with histopathologic diagnosis using indicators of malignancy detected by imaging such as main duct diameter, the number and diameter of cysts, and the presence or absence of mural nodules. We also examined the usefulness of pancreatic juice cytology and measurement of telomerase activity as indicators of malignancy. Finally, we performed a survival analysis on the basis of morphologic classification to determine prognosis of IPMN.

RESULTS

Whereas a high incidence (64%) of malignant lesions was seen in main duct type IPMN, benign lesions were dominant (80.5%) in branch duct type IPMN. Survival analysis showed that the prognosis was significantly worse in main duct type than in branch duct type IPMN. The lesions were aggravated in all patients with main duct type who did not undergo resection, resulting in death due to progression of the pancreatic lesion. The incidence of mural nodules was a useful indicator in main duct type, whereas main duct diameter and incidence of mural nodules were useful indicators in branch duct type. Although pancreatic juice cytology showed a high accuracy rate with low sensitivity for determining malignancy, measurement of telomerase activity in this juice was very effective for differentiating between benign and malignant lesions.

CONCLUSIONS

The incidence of malignant lesions was extremely high in main duct type IPMN, indicating that surgery is required in all these patients. However, to determine whether surgery is indicated in branch duct type IPMN it is necessary to obtain an appropriate image diagnosis focusing on main duct diameter and mural nodules and also to carry out cytology and measurement of telomerase activity in samples of pancreatic juice.

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.

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.

Aberrant methylation of CpG islands in intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND & AIMS

The functional abrogation of several tumor suppressor genes, including p16, DPC4, and p53, is a major mechanism underlying pancreatic ductal carcinogenesis. However, mutational inactivation of these genes is relatively uncommon in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. We hypothesized that an alternative mechanism for gene inactivation (notably, transcriptional silencing by promoter methylation) could be important in the pathogenesis of IPMNs.

METHODS

Using methylation-specific polymerase chain reaction, we analyzed the methylation status of 7 CpG islands previously identified as aberrantly methylated in pancreatic adenocarcinoma (including preproenkephalin [ppENK], p16, and thrombospondin 1) in 51 IPMNs of different histologic grades. The relationship between methylation status and expression was evaluated using reverse-transcription polymerase chain reaction for ppENK and immunohistochemistry for p16.

RESULTS

We found that more than 80% of the IPMNs exhibited hypermethylation of at least one of these CpG islands. Hypermethylation of ppENK and p16 was detected at a significant higher frequency in high-grade (in situ carcinoma) IPMNs than in low-grade (adenoma/borderline) IPMNs (ppENK, 82% vs. 28%, P = 0.0002; p16, 21% vs. 0%, P = 0.04). Furthermore, the average number of methylated loci was significantly higher in high-grade IPMNs than in low-grade IPMNs (2.4 vs. 0.9; P = 0.0008). Aberrant methylation of ppENK and p16 was associated with loss of expression.

CONCLUSIONS

These results suggest that de novo methylation of multiple CpG islands is one of the critical pathways that contributes to the malignant progression of IPMNs.

Preoperative diagnosis of intraductal papillary-mucinous tumors of the pancreas with attention to telomerase activity

BACKGROUND

It has been reported that, in patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas, it is difficult to distinguish adenoma from carcinoma preoperatively. Recently, it has also been reported that telomerase activity was detected in many patients with carcinoma. In this report, the authors used the method of telomerase repeat amplification protocol (TRAP) assay on pancreatic juice retrieved by endoscopic retrograde pancreatic juice aspiration (ERP aspiration).

METHODS

Pancreatic juice was collected from 28 patients (13 with intraductal carcinoma and 15 with adenoma) using ERP aspiration at either Hiroshima University Hospital or its affiliated hospitals. Two samples of pancreatic juice were collected from each patient. Each sample was examined by cytology for Papanicolaou staining and TRAP assay.

RESULTS

Four of 13 IPMT patients (31%) with intraductal carcinoma were diagnosed accurately by cytology. Seven of nine patients who were classified with benign tumors by cytologic assessment had tumors that expressed telomerase activity. Overall, 11 of 13 IPMT patients (85%) with intraductal carcinoma were diagnosed correctly by cytology associated with telomerase activity. All of the IPMT patients with adenoma were classified with benign tumors by cytologic assessment, and telomerase activity was not expressed.

CONCLUSIONS

In this study, the authors found that telomerase activity was expressed with a comparatively high probability in intraductal carcinoma. These results suggest that telomerase activity in pancreatic juices may be used as an adjunct to cytologic diagnosis and may aid further in distinguishing between benign IPMT and malignant IPMT of the pancreas preoperatively.

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.