Presentation and management of pancreatic cystic neoplasms

Surveillance and management for serous cystic neoplasms of the pancreas based on total hazards-a multi-center retrospective study from China

Background

Serous cystic neoplasms (SCN) rarely have malignant potential, so accurate diagnosis of SCN is crucial for proper clinical management, especially to avoid unnecessary surgeries. However, the misdiagnosis of other pancreatic cystic neoplasm instead of SCN may highly increase the risk of malignancy in patients who receive no surgery.

Methods

Data from a total of 678 patients with pathologically confirmed to have SCN at sixteen institutions in China from January 1^st, 2006 to December 31^st, 2016 were retrieved to evaluate the malignancy risk of SCN.

Results

Among the 678 patients confirmed to have SCN with postoperative pathologic analysis, 649 patients (95.7%) had only one lesion and the average maximum diameter was 3.8±2.47 cm. Four patients were pathologically verified as having serous cystadenocarcinoma, so the SCN actual malignancy rate was 0.6%, while the mortality due to pancreatic surgery in these high-volume centers was nearly 0.2-2%. However, among the 99 SCN patients based on preoperative radiology, three were confirmed to have intraductal papillary mucinous neoplasms (IPMN), nine as mucinous cystic neoplasms (MCN), and four as solid pseudopapillary tumors (SPT) after postoperative pathological analysis. Thus, the total theoretical malignancy rate resulting from preoperative misdiagnosis was elevated to approximately 2.9%, higher than the risk of perioperative mortality.

Conclusions

When SCN can't be accurately distinguished from cystic tumors of pancreas, the malignant risk of cystic tumors may be higher than perioperative risk. However, if it can be diagnosed as SCN accurately, surgery can be avoided as well.

AKR1B10 expression by immunohistochemistry in surgical resections and fine needle aspiration cytology material in patients with cystic pancreatic lesions; potential for improved nonoperative diagnosis

Cystic pancreatic tumors account for 10% of cystic lesions in the pancreas. Evaluation focuses on identifying lesions that require surgical resection due to actual or potential malignancy. Cystic tumors with malignant potential include mucinous cystic neoplasms (MCNs), intraductal papillary mucinous neoplasms (IPMNs), and cystic neuroendocrine tumors (NETs). The sensitivity of endoscopic fine needle aspiration (FNA) to diagnose such lesions is low, and a more accurate marker of malignant potential is needed. Aldo-keto reductase 1B10 (AKR1B10) was originally found in human hepatocellular carcinoma. Since then, it has been identified in pancreatic adenocarcinoma and pancreatic intraepithelial neoplasia. Because there is difficulty in determining the malignant potential of cystic pancreatic tumors, we set out to examine the expression of AKR1B10 in these lesions as a potential biomarker of malignancy. AKR1B10 expression was analyzed in cell blocks from FNAs and surgical resection specimens using immunohistochemistry. We examined MCN (n=28), IPMN (n=18), and cystic NET (n=20) as well as nonmucinous cysts including pseudocysts (n=13) and serous cystadenomas (n=16). AKR1B10 expression was seen in 45 of 46 (98%) mucinous lesions evaluated. Strong staining (2+-3+/60%-100% staining) was seen in 16 of 18 (89%) IPMNs and 25 of 28 (90%) MCNs. No staining was seen in the nonmucinous lesions (n=49). In conclusion, AKR1B10 is upregulated in mucinous cystic pancreatic tumors, and this staining can be accomplished in cytology FNA material, making AKR1B10 a promising biomarker of malignant potential. Most importantly, this application could impact the clinical management of these patients by determining the best candidates for surgical resection.

Managing incidental pancreatic cystic neoplasms with integrated molecular pathology is a cost-effective strategy

BACKGROUND AND STUDY AIMS

Current guidelines recommend using endoscopic ultrasound (EUS), carcinoembryonic antigen (CEA) testing and cytology to manage incidental pancreatic cystic neoplasms (PCN); however, studies suggest a strategy including integrated molecular pathology (IMP) of cyst fluid may further aid in predicting risk of malignancy. Here, we evaluate several strategies for diagnosing and managing asymptomatic PCN using healthcare economic modeling.

PATIENTS AND METHODS

A third-party-payer perspective Markov decision model examined four management strategies in a hypothetical cohort of 1000 asymptomatic patients incidentally found to have a 3 cm solitary pancreatic cystic lesion. Strategy I used cross-sectional imaging, recommended surgery only if symptoms or risk factors emerged. Strategy II considered patients for resection without initial EUS. Strategy III (EUS + CEA + Cytology) referred only those with mucinous cysts (CEA > 192 ng/mL) for resection. Strategy IV implemented IMP; a commercially available panel provided a "Benign," "Mucinous," or "Aggressive" classification based on the level of mutational change in cyst fluid. "Benign" and "Mucinous" patients were followed with surveillance; "Aggressive" patients were referred for resection. Quality-adjusted life-years (QALY), relative risk with 95 %CI, Number Needed to Treat (NNT), and incremental cost-effectiveness ratios were calculated.

RESULTS

Strategy IV provided the greatest increase in QALY at nearly identical cost to the cheapest approach, Strategy I. Relative risk of malignancy compared to the current standard of care and nearest competing strategy, Strategy III, was 0.18 (95 %CI 0.06 - 0.53) with an NNT of 56 (95 %CI 34 - 120).

CONCLUSIONS

Use of IMP was the most cost-effective strategy, supporting its routine clinical use.

To cease or 'de-cyst'? The evaluation and management of pancreatic cystic lesions

Due to the widespread use of cross-sectional imaging and advances in imaging technology, pancreatic cystic lesions are increasingly being detected. The diagnosis and management of such cysts remains challenging and continues to evolve. Different pancreatic cyst types have varying malignant potential. Thus, accurate cyst characterization is essential to appropriate management; the most clinically important distinction is differentiating mucinous lesions, which have malignant potential and may benefit from surgical resection, from non-mucinous cystic lesions. Endoscopic ultrasound with fine needle aspiration with cytologic, chemical,, and tumor marker analysis appears to be the best currently available method for accurately characterizing a cyst's malignant potential, and therefore impacts the most important management decision for a pancreatic cyst-continued surveillance or surgical resection.

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.

Management of mucin-producing cystic neoplasms of the pancreas

During the last decade small lesions of the pancreas have been increasingly recognized in clinical practice. Among these lesions, mucin-producing cystic neoplasms represent a recently described and unique entity among pancreatic tumors. In 1996, the World Health Organization distinguished two different types of mucinous cystic tumors: intraductal papillary mucinous neoplasms (IPMNs) of the pancreas, which are characterized by mucin production, cystic dilation of the pancreatic ducts, and intrapapillary growth, and mucinous cystic neoplasms (MCNs), which are defined by ovarian-like stroma and in most cases do not communicate with pancreatic ducts. Further, IPMNs can be subdivided into main-duct type, mixed-type, and branch-duct type tumors. Older data did not distinguish among different subsets of cystic neoplasms of the pancreas, and consequently many databases were inconsistent. Histopathologically, both IPMNs and MCNs demonstrate a wide spectrum of cellular atypia ranging from mild mucinous hyperplasia to invasive adenocarcinoma. Because mucinous cystic neoplasms of the pancreas show significant differences in clinical behavior from patient to patient, knowledge of the clinicopathologic characteristics and natural history of specific subtypes of IPMNs and MCNs has become crucial for physicians working in the field of gastroenterology. The present work offers an overview of current and generally accepted clinical guidelines for the diagnosis and treatment of IPMNs and MCNs.

Proteomic analysis of pancreatic ductal adenocarcinoma compared with normal adjacent pancreatic tissue and pancreatic benign cystadenoma

BACKGROUND

Dual expression of potential biomarkers in both benign and malignant pancreatic tumors was a major obstacle in the development of diagnostic biomarkers of early pancreatic cancer.

METHODS

To better understand the limitations of potential protein biomarkers in pancreatic cancer, we employed two-dimensional difference gel electrophoresis technology and tandem mass spectrometry to study protein expression profiles in pancreatic cancer tissues, benign pancreatic adenoma and normal adjacent pancreas. Seven differently expressed proteins were selected for validation by Western blot and/or immunohistochemistry.

RESULTS

21 spots were overexpressed and 24 spots were downexpressed in pancreatic cancer compared with benign and normal adjacent tissues. Our study demonstrated that three candidate pancreatic ductal adenocarcinoma biomarkers identified in previous studies, fructose-bisphosphate aldolase A, alpha-smooth muscle actin and vimentin, were also overexpressed in pancreatic cystadenoma, which might lower their further utility as biomarkers for pancreatic cancer. Aflatoxin B(1) aldehyde reductase (AKR7A2) was confirmed to be only highly expressed in pancreatic cancer, not in normal adjacent pancreas and benign tumors.

CONCLUSIONS

The protein profile pattern of pancreatic cystadenoma was more similar to normal adjacent pancreas than pancreatic cancer. We identified panels of the upregulated proteins in pancreatic cancer, which have not been reported in prior proteomic studies. AKR7A2 may be a novel potential biomarker for pancreatic cancer.

Incidental cystic neoplasms of pancreas: what is the optimal interval of imaging surveillance?

BACKGROUND

The optimal interval of imaging studies for surveillance of incidental pancreatic cystic neoplasms is not known.

OBJECTIVE

A retrospective analysis of longitudinal medical records of patients with pancreatic cystic neoplasms was performed to examine the natural history of incidentally detected cystic pancreatic neoplasms with respect to the development of significant growth and to identify predictors of such growth.

RESULTS

After excluding patients with small (<10 mm) cysts (N = 144) and inadequate clinical follow-up of less than 6 months (N = 79) and those with a clinical diagnosis of pancreatic pseudocysts, serous cystadenoma, main duct intraductal papillary mucinous neoplasm (N = 29), and neuroendocrine tumor (N = 3), in total, 166 cysts in 150 patients were available for analysis. The working diagnoses on these cysts (based on clinical, radiological features, aspiration cytology, cyst fluid analysis, and surgical pathology data when available) were mucinous cystic neoplasm in 117 and branch-type intraductal papillary mucinous neoplasm in 49. The mean standard error (SE) initial size of these cysts was 2 (0.1) cm. Over a median period of follow-up of 32 (IQR [inter-quartile range] 19-48) months, 89% of all the cysts did not show significant growth during the follow-up. In a multivariate Cox proportional hazards model, the initial size of the cystic lesion was an independent predictor of significant growth during follow-up (relative risk 1.28, 95% confidence interval [CI] 1.08-1.61, P= 0.01); the only other significant variable was the presence of intracystic or mural nodule (relative risk 38.6, 95% CI 2.3-654, P= 0.01).

CONCLUSION

Most incidentally detected cystic neoplasms of the pancreas did not have significant growth during follow-up. Such growth is unlikely to occur before 2 yr of the baseline evaluation, and we suggest that the optimal imaging interval during follow-up of these patients should be at 2 yr from the baseline evaluation, particularly in cystic lesions 3.0 cm or less in size and without intracystic or mural nodules.