Asymptomatic pancreatic cysts: a decision analysis approach to observation versus resection

Analyzing Intraductal Papillary Mucinous Neoplasms Using Artificial Neural Network Methodologic Triangulation

Intraductal papillary mucinous neoplasms (IPMN) are a type of mucinous pancreatic cyst. IPMN have been shown to be pre-malignant precursors to pancreatic cancer, which has an extremely high mortality rate with average survival less than 1 year. The purpose of this analysis is to utilize methodological triangulation using artificial neural networks and regression to examine the impact and effectiveness of a collection of variables believed to be predictive of malignant IPMN pathology. Results indicate that the triangulation is effective in both finding a new predictive variable and possibly reducing the number of variables needed for predicting if an IPMN is malignant or benign.

Patient Preferences for Management of Cystic Neoplasms of the Pancreas: A Cross-Sectional Survey Study

OBJECTIVE

The aim of this study was to determine how patient anxiety, knowledge, and cancer worry influence preferences for management of pancreatic cysts.

METHODS

We performed a prospective, cross-sectional study using a disease-specific survey instrument. We included patients older than 18 years who were diagnosed with a pancreatic cyst. A telephone survey instrument was developed to assess baseline anxiety using the Hospital Anxiety and Depression Scale (HADS), knowledge regarding pancreatic cysts, cancer worry, and patient preferences using a standard gamble.

RESULTS

Of the 100 studied participants (median age, 65 years; 72% women), median Hospital Anxiety and Depression Scale score was 4 (normal range). In terms of knowledge, 96% of the patients were not aware of their specific cyst type, and 58% were unaware of the possibility of any cyst-related malignancy. Overall, 8% of respondents had some degree of cancer worry. Respondents were more willing to undergo magnetic resonance imaging surveillance compared with endoscopic ultrasound or surgery. Knowledge of cyst type was a significant predictor of willingness to undergo invasive testing.

CONCLUSIONS

There is a significant gap in patient knowledge with respect to pancreatic cysts. Greater emphasis on patient education can help patients make informed decisions regarding cyst management.

Surgical treatments of cystic neoplasms of the pancreas: an Asian university hospital experience

Background

Premalignant and malignant cystic neoplasms of the pancreas are relatively rare, but absolute indications for surgical resection. Modern imaging modalities have increased recognition of asymptomatic cysts resulting in therapeutic dilemmas of whether surgery or observation is appropriate.

Objectives

To examine our surgical experience with cystic neoplasms of the pancreas.

Methods

A retrospective study of patients who had cystic neoplasms of the pancreas and underwent surgical resections from June 2000 to April 2013. Presenting symptoms, surgical procedures, pathological diagnoses, and postoperative complications were analyzed.

Results

Data from 16 patients were examined. Two patients had asymptomatic cystic neoplasms. Fourteen had symptoms ranging from 2 days to 6 years before diagnosis and surgery. Six patients underwent pylorus preserving pancreaticoduodenectomy, 4 underwent distal pancreatectomy with splenectomy, 2 underwent splenic preserving distal pancreatectomy, and 1 each underwent a classical Whipple operation, total pancreatectomy, distal pancreatectomy with splenectomy with partial resection of the posterior gastric wall, and distal pancreatectomy with splenectomy with left colectomy. The operative time ranged from 150 to 450 minutes. Operative blood transfusion ranged from 0 to 5 units. Four patients had mucinous cystadenoma, 4 had intraductal papillary mucinous neoplasia with varying degree of dysplasia and carcinomatous changes, 6 had other malignancies, and 2 had other benign cysts. Postoperative complications occurred in 3 patients. There was no perioperative mortality.

Conclusion

Any suspicion of malignant changes in asymptomatic cysts should have them considered for surgical resection. Meticulous surgical techniques are important for pancreatic resection to minimize the occurrence of postoperative complications.

Quality of life and functional outcome after resection of pancreatic cystic neoplasm

OBJECTIVES

The objectives of this study were to assess the long-term quality of life (QOL) after the resection of a primary pancreatic cyst and to determine predictors of outcome. Secondary outcomes were pancreatic function and survival.

METHODS

One hundred eight consecutive patients, who underwent resection between 1992 and 2007 and had nearly 60 months follow-up, were reviewed. Questionnaires and function tests were collected during scheduled outpatient clinic visits.

RESULTS

At follow-up, 20 patients had died. Five-year overall survival was 94% for benign and 62% for malignant neoplasia. Of 88 living patients, 65 (74%) returned questionnaires. Generic physical and mental QOL scores were equal or better compared with healthy references. None of the disease-specific symptom scales were above mean 50, implicating none to mild complaints. Independent predictors for good generic QOL were young age (P < 0.05) and resected malignancy (P < 0.05); predictors for good gastrointestinal QOL were male sex (P < 0.1), limited resection (P < 0.05), endocrine insufficiency (P < 0.05), and employment (P < 0.05). Endocrine insufficiency prevalence was 40%, and 59% for exocrine insufficiency.

CONCLUSIONS

After cyst resection, long-term QOL is equal to healthy references, pancreatic insufficiency is prevalent but does not impair QOL, and survival relates positive compared with solid pancreatic adenocarcinoma. The excellent long-term outcome justifies proceeding with surgery once a medical indication for resection has been established.

Prediction of malignancy in cystic neoplasms of the pancreas: a population-based cohort study

OBJECTIVES

Pancreatic cystic neoplasms (PCNs) are being detected with increased frequency. The aims of this study were to determine the incidence of malignancy and develop an imaging-based system for prediction of malignancy in PCN.

METHODS

We conducted a retrospective cohort study of patients ≥18 years of age with confirmed PCN from January 2005 to December 2010 in a community-based integrated care setting in Southern California. Patients with history of acute or chronic pancreatitis were excluded. Malignancy diagnosed within 3 months of cyst diagnosis was considered as pre-existing. Subsequent incidence of malignancy during surveillance was calculated based on person-time at risk. Age- and gender-adjusted standardized incidence ratio (SIR) was calculated with the non-cyst reference population. Recursive partitioning was used to develop a risk prediction model based on cyst imaging features.

RESULTS

We identified 1,815 patients with confirmed PCN. A total of 53 (2.9%) of patients were diagnosed with cyst-related malignancy during the study period. The surveillance cohort consisted of 1,735 patients with median follow-up of 23.4 months. Incidence of malignancy was 0.4% per year during surveillance. The overall age- and gender-adjusted SIR for pancreatic malignancy was 35.0 (95% confidence level 26.6, 46.0). Using recursive partitioning, we stratified patients into low (<1%), intermediate (1-5%), and high (9-14%) risk of harboring malignant PCN based on four cross-sectional imaging features: size, pancreatic duct dilatation, septations with calcification as well as growth. Area under the receiver operator characteristic curve for the prediction model was 0.822 (training) and 0.808 (testing).

CONCLUSIONS

Risk of pancreatic malignancy was lower than previous reports from surgical series but was still significantly higher than the reference population. A risk stratification system based on established imaging criteria may help guide future management decisions for patients with PCN.

A review of pancreatic cyst fluid analysis in the differential diagnosis of pancreatic cyst lesions

Diagnosis and management of pancreatic cyst lesions is challenging as there is currently no investigation that offers both high diagnostic sensitivity and high specificity for the identification of potentially malignant lesions. Accurate classification of these lesions is vital in order to avoid unnecessary treatment of benign lesions and missed opportunities for early treatment of lesions that are malignant/pre-malignant. Pancreatic cyst fluid analysis has an important role in diagnosis, although all currently available investigations based on fluid analysis have significant limitations. Cytological analysis can reveal features that are specific for a certain class of cyst, but offers limited sensitivity in detecting malignant/pre-malignant cysts. Measurement of tumour markers, particularly carcinoembryonic antigen can also be informative. Concentrations of cyst fluid carcinoembryonic antigen tend to be higher in malignant/pre-malignant cysts, although there is a wide overlap between the various classes of cyst. A number of studies have suggested that diagnostic carcinoembryonic antigen cut-offs can be chosen that provide a high degree of specificity but limited sensitivity. Studies of the analytical validity of tumour marker assays in pancreatic cyst fluid analysis have highlighted discrepancies in some fluid specimens, which require further investigation. DNA analysis also has a role. In particular, K-Ras-2 mutational analysis appears to provide high specificity for detection of malignant/pre-malignant lesions. A number of diagnostic algorithms have been published, integrating use of available investigations in order to achieve the optimum discrimination of benign and potentially malignant cysts. Research into new biochemical markers and optimal use of available pancreatic cyst fluid analyses is ongoing.

Imaging of indeterminate pancreatic cystic lesions: a systematic review

BACKGROUND

Pancreatic cystic lesions are an increasing problem and investigation of these cysts can be fraught with difficulty. There is currently no gold standard for diagnosis or surveillance. This review was undertaken to determine the present reliability of the characterisation, assessment of malignant potential and diagnosis of pancreatic cystic lesions using available imaging modalities.

METHODS

A Medline search using the terms 'pancreatic', 'pancreas', 'cyst', 'cystic', 'lesions', 'imaging', 'PET'. 'CT', 'MRI' and 'EUS' was performed. Publications were screened to include studies examining the performance of CT, MRI, MRCP, EUS and 18-FDG PET in the determination of benign or malignant cysts, cyst morphology and specific diagnoses.

RESULTS

Nineteen studies were identified that met the inclusion criteria. 18-FDG PET had a sensitivity and specificity of 57.0-94.0% and 65.0-97.0% and an accuracy of 94% in determining benign versus malignant cysts. CT had a sensitivity and specificity of 36.3-71.4% and 63.9-100% in determining benign disease but had an accuracy of making a specific diagnosis of 39.0-44.7%. MRI had a sensitivity and specificity of 91.4-100.0% and 89.7% in assessing main pancreatic duct communication.

CONCLUSION

CT is a good quality initial investigation to be used in conjunction with clinical data. MRCP can add useful information regarding MPD communication but should be used judiciously. PET may have a role in equivocal cases to determine malignancy. Further examination of CT-PET in this patient group is warranted.

The association of quality-of-life measures with malignancy and survival in patients with pancreatic pathology

OBJECTIVES

This study assessed whether pretreatment quality-of-life (QoL) scores could predict the presence of pancreatic malignancy and survival.

METHODS

Patients with pancreatic lesions completed the SF-36, containing 8 domains: physical functioning, role-physical, role-emotional, bodily pain, vitality, mental health, social functioning, and general health. Data obtained included age, sex, resectability, additional antineoplastic therapy, stage, pathology, and survival. Patients were categorized by pathology (benign vs malignant), stage (local, regional, or distant), resectability (resected vs not), survival (<1 vs >1 year), and their pretreatment QoL scores.

RESULTS

Of the 323 patients assessed, 210 had malignancies. In 6 of the 8 domains, patients with malignancies had lower median QoL scores compared with patients with benign lesions. Of the patients with malignancies, patients surviving at 1 year or less had lower pretreatment scores in all domains. Stage, resection, adjuvant therapy, and vitality score were independent predictors of survival.

CONCLUSIONS

Patients with pancreatic malignancies had lower QoL scores than patients with benign pancreatic disease. Patients with malignancies surviving at 1 year or less had lower scores, even after controlling for stage. This suggests that pretreatment QoL scores are associated with pancreatic malignancy and survival.

High-grade atypical epithelial cells in pancreatic mucinous cysts are a more accurate predictor of malignancy than "positive" cytology

BACKGROUND

The Sendai guidelines for risk assessment of malignancy in patients with mucinous cysts lists "positive" cytology as a high-risk feature. In the current study, the authors hypothesized that a cytological threshold of high-grade atypical epithelial cells (AEC) is a more accurate predictor of malignancy.

METHODS

The clinical, radiological, and cytological data of 112 patients with histologically confirmed mucinous cysts of the pancreas were reviewed. Cytology slides were blindly reviewed and cells were classified as benign, AEC, or malignant. On histology, neoplasms were grouped as benign (low-grade and moderate dysplasia) and malignant (high-grade dysplasia/carcinoma in situ and invasive carcinoma).

RESULTS

There were 92 patients with an intraductal papillary mucinous neoplasm (IPMN) and 20 with a mucinous cystic neoplasm; 39 were malignant and 73 were benign (42 with low-grade dysplasia and 31 with moderate dysplasia). Only 28% (11 of 39) of the malignant cysts were cytologically malignant with a sensitivity of 29%, a specificity of 100%, and an accuracy of 75%. AEC detected 17 additional cancers (44% of all malignant cysts; 16% more than detected on the basis of "positive" cytology). By using AEC as a surgical triage threshold, the sensitivity was 72%, the specificity was 85%, and the accuracy was 80%, with similar values for small (≤ 3 cm) branch duct IPMN. Nine of 73 (12%) benign cysts were identified with AEC, 4 of which had moderate dysplasia. AEC had a positive predictive value of 87% for the detection of a mucinous cyst with moderate dysplasia or worse.

CONCLUSIONS

AEC are a more accurate predictor of malignancy than "positive" cytology in aspirates of pancreatic mucinous cysts, including small branch duct IPMN. AEC warrant a "suspicious" interpretation for appropriate surgical triage.

Asymptomatic pancreatic cystic neoplasm: a cost-effectiveness analysis of different strategies of management

BACKGROUND

Optimal management of asymptomatic pancreatic cystic neoplasm is not known.

OBJECTIVE

In a decision analysis, the cost-effectiveness of different strategies for managing solitary, asymptomatic pancreatic cystic neoplasm were compared.

INTERVENTION

Three strategies were examined in a Markov model with a third-party-payer perspective. In strategy I, the natural history of the lesion was followed without any specific intervention. In strategy II, an aggressive surgical approach was considered in that all patients were considered for resection. In strategy III, an initial EUS-guided FNA with cyst fluid analysis was performed for risk stratification, and patients with mucinous cysts were considered for resection. Transitional probabilities, discounted cost, and utility values to estimate quality-adjusted life years were obtained from published information. An operability risk score based on patient age, comorbidity, and size and location of the cyst was developed to estimate the probability of surgical resection.

RESULTS

In the baseline analysis, strategy III yielded the highest quality-adjusted life years with an acceptable incremental cost-effectiveness ratio. In a Monte Carlo analysis, the relative risk of patients developing unresectable pancreatic cancer was decreased in strategy III compared to the other strategies. Although threshold analyses identified few important parameters influencing the conclusion of the analysis, operability risk score was the critical determinant of the optimal management strategy.

LIMITATIONS

Indirect costs were not considered in this analysis.

CONCLUSION

For asymptomatic patients with incidental solitary pancreatic cystic neoplasm, a blanket policy of surgical resection for all patients cannot be justified. A strategy based on risk stratification of malignant potential by EUS-guided FNA and cyst fluid analysis is the most cost-effective strategy.

Cystic lesions of the pancreas. A diagnostic and management dilemma

BACKGROUND/AIMS

Due to enhanced imaging modalities, pancreatic cysts are being increasingly detected, often as an incidental finding. They comprise a wide range of differing underlying pathologies from completely benign through premalignant to frankly malignant. The exact diagnostic and management pathway of these cysts remains problematic and this review attempts to provide an overview of the pathology underlying pancreatic cystic lesions and suggests appropriate methods of management.

METHODS

A search was undertaken with a Pubmed database to identify all English articles using the keywords 'pancreatic cysts', 'serous cystadenoma', 'intraductal papillary mucinous tumour', 'pseudocysts', 'mucinous cystic neoplasm' and 'solid pseudopapillary tumour'.

RESULTS

The mainstay of assessment of pancreatic cysts is cross-sectional imaging incorporating CT and MRI. Fine-needle aspiration (FNA) (often with endoscopic ultrasound) may provide valuable additional information but can lack sensitivity. Symptomatic cysts, increasing age and multilocular cysts (with a solid component and thick walls) are predictors of malignancy. A raised cyst aspirate CEA, CA 19-9 and mucin content (including abnormal cytology), if present, can accurately distinguish premalignant and malignant cysts from benign ones.

CONCLUSION

In summary, all patients with pancreatic cystic lesions, whether asymptomatic or symptomatic, must be thoroughly investigated to ascertain the underlying nature of the cyst. Small asymptomatic cysts (<3 cm) with no suspicious features on imaging or FNA may be safely followed up. Follow-up should continue for at least 4 years, with a repeat FNA if needed. An algorithm for the management of pancreatic cystic tumours is also suggested. and IAP.