Cyst fluid amylase and CEA levels in the differential diagnosis of pancreatic cysts: a single-center experience with histologically proven cysts

Revisiting the performance of cyst fluid carcinoembryonic antigen as a diagnostic marker for pancreatic mucinous cysts: a comprehensive 20-year institutional review

OBJECTIVE

Elevated pancreatic cyst fluid carcinoembryonic antigen (CEA) has been routinely used to classify mucinous cysts. This study incorporates original data that established the CEA ≥192 ng/mL threshold with over 20 years of additional data and reassesses the diagnostic performance of CEA for differentiating mucinous from non-mucinous cysts.

DESIGN

1169 pancreatic cysts (1999-2021) with CEA results were identified. 394 cases had histological confirmation as the diagnostic standard. Additionally, 237 cysts without histological confirmation demonstrated KRAS, GNAS, or RNF43 mutations by molecular testing and were combined with the histologically confirmed cysts for separate analysis on a total cohort of 631 cysts.

RESULTS

Median CEA was significantly higher in mucinous cysts (323.9 ng/mL, n=314) versus non-mucinous cysts (204.6 ng/mL, n=80) (p<0.001). Receiver operating characteristic curve analysis demonstrated an optimal CEA cut-off of 20 ng/mL (area under the curve: 80%), though the specificity was lower than desired (sensitivity 89%, specificity 64%). At the previously established threshold of 192 ng/mL, sensitivity and specificity were 56% and 78%, respectively. To achieve a specificity of 85% as originally reported, a CEA threshold of 250 ng/mL was needed; the 13 false positive cases at this threshold included 4 benign simple cysts, 2 squamoid cysts, 1 serous cystadenoma, 1 lymphoepithelial cyst and 5 more uncommon entities. All results remained similar within the total cohort after including additional cases with KRAS/GNAS/RNF43 mutations only.

CONCLUSION

Cyst fluid CEA continues to be a useful test in the diagnosis of mucinous pancreatic cysts but does not appear as specific as previously reported. Raising the CEA threshold to 250 ng/mL to maintain specificity for differentiating mucinous from non-mucinous cysts may be considered.

Predictive ability of pancreatic cyst fluid biomarkers: A systematic review and meta-analysis

BACKGROUND

Mucinous pancreatic cysts harbor the potential to progress to highly lethal pancreatic ductal adenocarcinoma (PDAC). Since these precursor cysts require cancer surveillance or surgical resection, they need to be reliably distinguished from harmless pancreatic cysts. Current clinical and radiographic assessment is imperfect and the value of cyst fluid analysis for differential diagnosis is unclear. Therefore, we set out to investigate the value of cyst fluid biomarkers in distinguishing pancreatic cysts.

METHODS

We performed a systematic review of the current literature to identify articles that evaluated the diagnostic performance of clinically relevant and promising candidate cyst fluid biomarkers, with a particular emphasis on DNA-based biomarkers. Meta-analysis was performed for biomarkers targeted at identifying cyst type and presence of high-grade dysplasia or PDAC.

RESULTS

Data from a total of 42 studies was analyzed. Mutations in KRAS and/or GNAS allowed identification of mucinous cysts with a sensitivity of 79% and specificity of 98%. This exceeded the performance of the traditional biomarker carcinoembryonic antigen (CEA; sensitivity 58%, specificity 87%). Mutations in VHL were specific for serous cystadenomas (SCAs; sensitivity 56%, specificity 99%) and help to exclude mucinous cysts. Mutations in CDKN2A, PIK3CA, SMAD4, and TP53 each had high specificities of 97%, 97%, 98%, and 95%, respectively, to identify high-grade dysplasia or PDAC in mucinous cysts.

CONCLUSIONS

Cyst fluid analysis can be a valuable tool in the characterization of pancreatic cysts, with relevant clinical implications. Our results support the use of DNA-based cyst fluid biomarkers in the multidisciplinary diagnostic work-up of pancreatic cysts.

Epidemiology, clinical features and diagnostic work-up of cystic neoplasms of the pancreas: Interim analysis of the prospective PANCY survey

INTRODUCTION

A prospective survey to evaluate the diagnostic workup of cystic pancreatic neoplasms (CPNs) according to the Italian guidelines.

METHODS

An online data sheet was built.

RESULTS

Fifteen of the 1385 patients (1.1%) had non cystic neoplastic lesions. Forty percent (518/1295) had at least one 1st degree relative affected by a solid tumor of the digestive and extra-digestive organs. Symptoms/signs associated with the cystic lesion were present in 24.5% of the patients. The cysts were localized in the head of the pancreas in 38.5% of patients. Of the 2370 examinations (1.7 examinations per patient) which were carried out for the diagnosis, magnetic resonance imaging was performed as a single test in 48.4% of patients and in combination with endoscopic ultrasound in 27% of the cases. Of the 1370 patients having CPNs, 89.9% had an intraductal papillary mucinous neoplasm (IPMN) (70.1% a branch duct IPMN, 6.2% a mixed type IPMN and 4.6% a main duct IPMN), 12.7% had a serous cystadenoma, 2.8% a mucinous cystadenoma, 1.5% a non-functioning cystic neuroendocrine neoplasm, 0.7% a solid-pseudopapillary cystic neoplasm, 0.3% a cystic adenocarcinoma, and 1.2% an undetermined cystic neoplasm. Seventy-eight (5.7%) patients were operated upon after the initial work-up.

CONCLUSIONS

This prospective study offers a reliable real-life picture of the diagnostic work-up CPN.

EUS-Guided Pancreatic Cyst Ablation: a Clinical and Technical Review

PURPOSE OF REVIEW

Pancreatic cystic lesions represent a growing public health dilemma, particularly as our population ages and cross-sectional imaging becomes more sensitive. Mucinous cysts carry a clinically significant risk of developing pancreatic cancer, which carries an extremely poor prognosis. Determining which cysts will develop cancer may be challenging, and surgical resection of the pancreas carries significant morbidity. The goal of this paper is to review the rationale for cyst ablation and discuss prior and current research on cyst ablation techniques and efficacy. Indications, contraindications, and factors related to optimal patient selection are outlined.

RECENT FINDINGS

Endoscopic ultrasound-guided chemoablation of pancreatic cysts has been performed in neoplastic cysts, with varying levels of efficacy. Safety concerns arose due to the risk of pancreatitis in alcohol-based treatments; however, the most recent data using a non-alcohol chemoablation cocktail suggests that ablation is effective without the need for alcohol, resulting in a significantly more favorable adverse event profile. Endoscopic ultrasound-guided chemoablation of neoplastic pancreatic cysts is a promising, minimally invasive approach for treatment of cysts, with recent significant advances in safety and efficacy, suggesting that it should play a role in the treatment algorithm.

Management of Intraductal Papillary Mucinous Neoplasms: Controversies in Guidelines and Future Perspectives

Purpose of review

Management of intraductal papillary mucinous neoplasm (IPMN) is currently based on consensus, in the absence of evidence-based guidelines. In recent years, several consensus guidelines have been published, with distinct management strategies. In this review, we will discuss these discrepancies, in order to guide treating physicians in clinical management.

Recent findings

The detection rate of pancreatic cysts has increased substantially with the expanded use of high-quality imaging techniques to up to 45%. Of these cysts, 24–82% are IPMNs, which harbour a malignant potential. Timely detection of high-risk lesions is therefore of great importance. Surgical management is based on the presence of clinical and morphological high-risk features, yet the majority of resected specimens appear to be low risk.

Summary

International collaboration and incentive large-scale prospective registries of individuals undergoing cyst surveillance are needed to accumulate unbiased data and develop evidence-based guidelines. Additionally, development of non-invasive, accurate diagnostic tools (e.g. biomarkers) is needed to differentiate between neoplastic and non-neoplastic pancreatic cysts and detect malignant transformation at an early stage (i.e. high-grade dysplasia).

The Role of Next-Generation Sequencing in the Cytologic Diagnosis of Pancreatic Lesions

CONTEXT

- Integration of the analysis of genetic markers with endoscopic ultrasound-guided fine-needle aspiration and cytologic evaluation has increased the accuracy of the preoperative diagnosis of pancreatic lesions. The application of high-throughput gene panel analysis using next-generation sequencing platforms is now offering a great opportunity for further improvements.

OBJECTIVE

- To review the application of next-generation sequencing to the preoperative diagnosis of pancreatic lesions.

DATA SOURCES

- For data acquisition, a PubMed search using the terms next-generation sequencing, pancreas, pancreatic lesions, pancreatic tumors, and EUS-FNA was performed covering the years 2000-2017.

CONCLUSIONS

- KRAS remains the gene most widely studied for preoperative single-gene tests. Next-generation sequencing reliably allows analysis of multiple gene markers starting from limited amounts of DNA. The study of multigene panels has become a very attractive option for the management and preoperative risk stratification of patients with pancreatic cancer.

Role of biochemistry and cytological analysis of cyst fluid for the differential diagnosis of pancreatic cysts: A retrospective cohort study

BACKGROUND

Management of pancreatic cysts is based on neoplastic-nonneoplastic discrimination. Endoscopic ultrasound (EUS) enables to differentiate neoplastic-nonneoplastic lesions and also allows fine-needle aspiration (FNA). In this study, we aim to assess feasibility and clinical relevance of cytological and biochemical analysis in differential diagnosis of cystic pancreatic lesions in patients who had undergone endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) due to pancreatic cysts.

METHODS

Participants were 96 patients who had undergone EUS-FNA for differential diagnosis of pancreatic cysts. Pancreatic cysts were classified as benign-mucinous, nonmucinous, and malignant according to patient history, physical examination, EUS appearance, and cystic fluid assessment. Tumor markers (CEA, CA(cancer antigens) 72.4, CA 19-9) , amylase, lipase and cytological assesment were compared between 3 different groups. Receiver-operating characteristics (ROC) curves were constructed to identify appropriate cut-off values.

RESULTS

Fluid CEA and CA 72.4 levels for benign-mucinous and malignant cysts were significantly higher than for nonmucinous cysts (P ≤ 0.04). A cut-off CEA level of 207 ng/mL differentiated mucinous etiology with a sensitivity of 72.7%, specificity of 97.7%, and accuracy of 89.5%. The sensitivity, specificity, and accuracy of the CA 72.4 cut-off level of 3.32 ng/mL were 80%, 69.5%, and 73.6%, respectively.

CONCLUSION

Cyst fluid CEA and CA 72.4 levels have a high accuracy in discriminating mucinous from nonmucinous cysts. When combined with cytology their accuracy rate increases.

Endoscopic ultrasound-guided ablation therapy for pancreatic cysts

Pancreatic cysts are being encountered frequently because of rapid advances in radiologic technology and an increased cross-sectional imaging demand. Management of pancreatic cystic tumors is challenging because most of them are asymptomatic; they are potentially malignant, and surgery has substantial morbidity and mortality. Endoscopic ultrasound (EUS)-guided fine-needle aspiration of pancreatic cystic tumors is accepted as a minimally invasive technique, which also enables injection of ablative agents into cysts under EUS guidance. In this review, the basic procedural steps and technical considerations of cyst ablation and their clinical issues including safety, feasibility, and therapeutic outcome will be summarized.

EUS and EUS-FNA diagnosis of suspected pancreatic cystic neoplasms: Is the sum of the parts greater than the CEA?

BACKGROUND

Carcinoembryonic antigen (CEA) is suggested as the single most useful EUS/EUS-FNA derived test for the diagnosis of mucinous pancreatic cysts.

STUDY AIMS

To investigate the yield and diagnostic performance of EUS/EUS-FNA on an intention to diagnose basis and to determine the utility of the recommended CEA and amylase cut-off values.

PATIENTS AND METHODS

A retrospective study of a prospectively maintained database of 433 procedures performed in a 10 year period. Diagnostic performance of EUS-FNA was determined in 133 procedures with a definite diagnosis.

RESULTS

CEA value was determined in significantly fewer procedures (58.6%) than EUS diagnosis was stated (83.4%; p < 0.0001), cyst fluid appearance recorded (89.4%) or adequate sample for cytology obtained (76.7%; p < 0.005). Median CEA was significantly higher in mucinous cysts than non-mucinous (175 ng/ml vs 3 ng/ml, p < 0.0001) and in malignant cysts compared to benign (8945 ng/ml vs 93 ng/ml, p < 0.001). On an intention-to-diagnose analysis, a CEA cut-off of 110 ng/ml was significantly less accurate (42.8%) than EUS diagnosis (67.7%), cytology (58.6%) or aspirate appearance (66.9%; p < 0.05 for all comparisons). However, the combination of EUS diagnosis, cytology and CEA provided higher sensitivity (91%), specificity (75%) and accuracy (85.7%) than each component test alone (p < 0.05 for all comparisons). Median amylase was significantly higher in benign compared to high-risk mucinous cysts ((11,429IU/L vs. 113IU/L; p < 0.05.

CONCLUSION

The combination of EUS, cytology and CEA performed well. Malignant cysts had a higher CEA value than benign cysts. On an intention to diagnose basis a CEA cut-off of 110 ng/ml performed poorly.

Management of Incidental Pancreatic Cystic Lesions

BACKGROUND

Pancreatic cystic lesions (PCL) are common. They are increasingly detected as an incidental finding of transabdominal ultrasound or cross-sectional imaging. In contrast to other parenchymal organs, dysontogenetic pancreatic cysts are extremely rare. In symptomatic patients the most frequent PCL are acute and chronic pseudocysts. The majority of incidental cystic lesions, however, are neoplasias which have different risks of malignancy.

METHODS

PubMed was searched for studies, reviews, meta-analyses, and guidelines using the following key words: ('pancreatic cystic lesions' OR 'cystic pancreatic lesions' OR 'intraductal papillary mucinous neoplasia' OR 'mucinous cystic neoplasia' OR 'pancreatic cyst' OR 'pancreatic pseudocyst') AND (management OR treatment OR outcome OR prognosis OR diagnosis OR imaging OR 'endoscopic ultrasound' EUS-FNA OR EUS OR 'endoscopic ultrasonography' OR CT OR MRI). Retrieved papers were reviewed with regard to the diagnostic and therapeutic management of incidental PCL.

RESULTS

In addition to clinical criteria, transabdominal ultrasonography including contrast-enhanced ultrasonography, cross-sectional radiological imaging, and endoscopic ultrasound (EUS) are used for diagnostic characterization and risk assessment. EUS plays an outstanding role in differential diagnosis and prognostic characterization of incidental PCL. In a single examination it is possible to perform high-resolution morphological description, perfusion imaging, as well as fine-needle aspiration of cyst content, cyst wall, and solid components. An international consensus guideline has defined worrisome and high-risk criteria for the risk assessment of mucinous pancreatic cysts, which are mainly based on the results of EUS and cross-sectional imaging. Nevertheless, despite diagnostic progress and guideline recommendations, differential diagnosis and management decisions remain difficult. This review will discuss problems in and approaches to the diagnosis of incidental PCL.

CONCLUSION

An evidence-based algorithm for the diagnosis of incidental PCL is proposed.