"Trivial" Cysts Redefine the Risk of Cancer in Presumed Branch-Duct Intraductal Papillary Mucinous Neoplasms of the Pancreas: A Potential Target for Follow-Up Discontinuation?

Systematic review on surveillance for non-resected branch-duct intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

The management of branch-duct type intraductal papillary mucinous neoplasms (BD-IPMN) varies in existing guidelines. This study investigated the optimal surveillance protocol and safe discontinuation of surveillance considering natural history in non-resected IPMN, by systematically reviewing the published literature.

METHODS

This review was guided by PRISMA. Research questions were framed in PICO format "CQ1-1: Is size criteria helpful to determine surveillance period? CQ1-2: How often should surveillance be carried out? CQ1-3: When should surveillance be discontinued? CQ1-4: Is nomogram predicting malignancy useful during surveillance?". PubMed was searched from January-April 2022.

RESULTS

The search generated 2373 citations. After screening, 83 articles were included. Among them, 33 studies were identified for CQ1-1, 19 for CQ1-2, 26 for CQ1-3 and 12 for CQ1-4. Cysts <1.5 or 2 cm without worrisome features (WF) were described as more indolent, and most studies advised an initial period of surveillance. The median growth rate of cysts <2 cm ranged from 0.23 to 0.6 mm/year. Patients with cysts <2 cm showing no morphological changes and no WF after 5-years of surveillance have minimal malignancy risk of 0-2%. Two nomograms created with over 1000 patients had AUCs of around 0.8 and appear to be feasible in a real-world practice.

CONCLUSIONS

For patients with suspected BD-IPMN <2 cm and no other WF, less frequent surveillance is recommended. Surveillance may be discontinued for cysts that remain stable during 5-year surveillance, with consideration of patient condition and life expectancy. With this updated surveillance strategy, patients with non-worrisome BD-IPMN should expect more streamlined management and decreased healthcare utilization.

Impact of age, comorbidities and relevant changes on surveillance strategy of intraductal papillary mucinous neoplasms: a competing risk analysis

OBJECTIVE

Cost-effectiveness of surveillance for branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) is debated. We combined different categories of risks of IPMN progression and of IPMN-unrelated mortality to improve surveillance strategies.

DESIGN

Retrospective analysis of 926 presumed BD-IPMNs lacking worrisome features (WFs)/high-risk stigmata (HRS) under surveillance. Charlson Comorbidity Index (CACI) defined the severity of comorbidities. IPMN relevant changes included development of WF/HRS, pancreatectomy or death for IPMN or pancreatic cancer. Pancreatic malignancy-unrelated death was recorded. Cumulative incidence of IPMN relevant changes were estimated using the competing risk approach.

RESULTS

5-year cumulative incidence of relevant changes was 17.83% and 1.6% developed pancreatic malignancy. 5-year cumulative incidences for IPMN relevant changes were 13.73%, 19.93% and 25.04% in low-risk, intermediate-risk and high-risk groups, respectively. Age ≥75 (HR: 4.15) and CACI >3 (HR: 3.61) were independent predictors of pancreatic malignancy-unrelated death. 5-year cumulative incidence for death for other causes was 15.93% for age ≥75+CACI >3 group and 1.49% for age <75+CACI ≤3. 5-year cumulative incidence of IPMN relevant changes were 13.94% in patients with age <75+CACI ≤3 compared with 29.60% in those with age ≥75+CACI >3. In this group 5-year rate of malignancy-free patients was 95.56% with a 5-year survival of 79.51%.

CONCLUSION

Although it is not uncommon the occurrence of changes considered by current guidelines as relevant during surveillance of low risk BD-IPMNs, malignancy rate is low and survival is significantly affected by competing patients' age and comorbidities. IPMN surveillance strategy should be tailored based on these features and modulated over time.

Optimal Follow-up of Incidental Pancreatic Cystic Lesions without Worrisome Features: Clinical Outcome after Long-term Follow-up

Background/Aims

: The optimal duration and interval of follow-up for cystic lesions of the pancreas (CLPs) is not well established. This study was performed to investigate the optimal duration and interval of follow-up for CLPs in clinical practice.

Methods

: Patients with CLPs without worrisome features or high-risk stigmata underwent follow-up with computed tomography at 6, 12, 18, and 24 months and then every 12 months thereafter. A retrospective analysis of prospectively collected data was performed.

Results

: A total of 227 patients with CLPs detected from 2000 to 2008 (mean initial diameter, 1.3±0.6 cm) underwent follow-up for a median of 120 months. Twenty-two patients (9.7%) underwent surgery after a median of 47.5 months. Malignancies developed in four patients (1.8%), one within 5 years and three within 10 years. One hundred and fourteen patients (50.2%) were followed up for more than 10 years. No malignancy developed after 10 years of follow-up. During surveillance, 37 patients (16.3%) experienced progression to surgical indication. In patients with CLPs less than 2 cm in diameter, development of surgical indications did not occur within 24 months of follow-up.

Conclusions

: CLPs should be continuously monitored after 5 years because of the persistent potential for malignant transformation of CLPs. An interval of 24 months for initial follow-up might be enough for CLPs with initial size of less than 2 cm in clinical practice.

International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas

This study group aimed to revise the 2017 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and mainly focused on five topics; the revision of high-risk stigmata (HRS) and worrisome features (WF), surveillance of non-resected IPMN, surveillance after resection of IPMN, revision of pathological aspects, and investigation of molecular markers in cyst fluid. A new development from the prior guidelines is that systematic reviews were performed for each one of these topics, and published separately to provide evidence-based recommendations. One of the highlights of these new "evidence-based guidelines" is to propose a new management algorithm, and one major revision is to include into the assessment of HRS and WF the imaging findings from endoscopic ultrasound (EUS) and the results of cytological analysis from EUS-guided fine needle aspiration technique, when this is performed. Another key element of the current guidelines is to clarify whether lifetime surveillance for small IPMNs is required, and recommends two options, "stop surveillance" or "continue surveillance for possible development of concomitant pancreatic ductal adenocarcinoma", for small unchanged BD-IPMN after 5 years surveillance. Several other points are also discussed, including identifying high-risk features for recurrence in patients who underwent resection of non-invasive IPMN with negative surgical margin, summaries of the recent observations in the pathology of IPMN. In addition, the emerging role of cyst fluid markers that can aid in distinguishing IPMN from other pancreatic cysts and identify those IPMNs that harbor high-grade dysplasia or invasive carcinoma is discussed.

Intracystic injection of large surface area microparticle paclitaxel for chemoablation of intraductal papillary mucinous neoplasms: Insights from an expanded access protocol

AIMS

A novel large surface area microparticle paclitaxel (LSAM-PTX) has unique properties of long retention in cystic spaces while maintaining high drug concentration. We prospectively evaluated the safety and response of EUS-guided fine needle injection (EUS-FNI) of LSAM-PTX to chemoablate branch duct (BD)-IPMNs.

METHODS

Subjects diagnosed with BD-IPMNs exhibiting at least one worrisome criteria and considered non-surgical were enrolled in a multicenter clinical trial (NCT03188991) and subsequently included in an Expanded Access Protocol (EAP) where they received EUS-FNI of LSAM-PTX (15 mg/mL).

RESULTS

Six BD-IPMNs measuring (mean ± SD) 3.18 ± 0.76 cm in diameter among 5 subjects (mean age: 66 years) were treated by EUS-FNI of LSAM-PTX. A mean of 4 doses of LSAM-PTX (mean dose/cyst: 73 ± 31 mg) were administered, and subjects were followed for up to 32 months. The mean volume reduction/cyst ranged from 42 to 89% (9.58 ± 5.1 ml to 2.2 ± 1.1 ml (p = 0.016)). The mean surface area reduction ranged from 31 to 83% (21.9 ± 8.7 cm2 to 5.7 ± 2.5 cm2 (p = 0.009)). Higher dosing-frequency of EUS-FNI of LSAM-PTX significantly correlated with a reduction in cyst volume (R2 = 0.87, p = 0.03) and surface area (R2 = 0.83, p = 0.04). Comparing pre- and post-ablation samples, molecular analysis of the cyst fluid revealed a loss of IPMN-associated mutations in 5 cases (83.3%), while reemergence was observed in 1 case and persistence in 1 case. Intracystic changes (fibrosis/calcification) were observed in 83.3% (n = 5). One subject developed mild acute pancreatitis (1 of 22 EUS-FNIs of LSAM-PTX).

CONCLUSION

In this EAP, EUS-FNI of LSAM-PTX into BD-IPMNs was safe and resulted in volume and surface area reduction, morphological changes, and loss of pathogenic mutations.

Association of high-risk stigmata and worrisome features with advanced neoplasia in intraductal papillary mucinous neoplasms (IPMN): A systematic review

BACKGROUND

This systematic review aimed to assess the diagnostic accuracy of the International Consensus Fukuoka Guidelines (ICG2017) in identifying high-risk lesions of Intraductal Papillary Mucinous Neoplasms (IPMNs).

METHODS

The ICG2017 revision committee conducted a comprehensive literature review to establish evidence-based statements on IPMNs. The review focused on articles examining the diagnostic value of imaging features (e.g., cyst or main pancreatic duct diameter), clinical symptoms associated with IPMN, and serum biomarkers. Five clinical questions regarding high-risk stigmata (HRS) and worrisome features (WF) in the ICG2017 guidelines were addressed.

RESULTS

A total of 210 articles were reviewed. The findings revealed a significant association between the presence of mural nodules ≥5 mm in diameter or solid components with contrast enhancement and the diagnosis of high-grade dysplasia or invasive carcinoma. Contrast-enhanced diagnostic tools, such as CT, MRI, or EUS, demonstrated the highest prediction rate and were recommended. Positive cytology was identified as an HRS, while symptoms like acute pancreatitis and cyst diameter growth ≥2.5 mm per year were considered WFs. The use of nomograms and multiple diagnostic factors was recommended for optimal IPMN management.

CONCLUSIONS

This systematic review provides evidence supporting the improved diagnostic accuracy of ICG2017 in identifying high-risk lesions of IPMN. The multidisciplinary incorporation of HRS and WF based on imaging findings and clinical symptoms is crucial. These findings should inform the revision of ICG2017, enhancing the evaluation and management of IPMN patients. By implementing these recommendations, clinicians can make more informed decisions, leading to better diagnosis and treatment outcomes for high-risk IPMN cases.

Tracking incidentally discovered pancreatic cysts smaller than 30 mm: Natural course and predictors of malignancy

BACKGROUND AND AIMS

The aim of this study was to assess the natural course and predictors of malignancy in incidentally detected small pancreatic cysts (PCs).

METHOD

We retrospectively included patients with PCs smaller than 30 mm followed up with the same cross-sectional imaging modality at least 12 months apart between January 2010 and December 2019 in three academic institutions. Cyst growth, pancreatic cancer incidence, and associated factors associated with pancreatic cancer were analyzed.

RESULTS

A total of 1109 patients were followed up for a median of 34 months (range, 12‒118 months). Cyst growth and rapid cyst growth (≥ 5 mm/2 years) during follow-up were observed in 20.7% and 8.3%, respectively, both with higher rates for 15‒30 mm sized PCs. Eight patients were diagnosed with pancreatic cancer. The standardized incidence ratio for pancreatic cancer in small PCs was calculated as 5.2 [95% Confidence interval (CI): 1.3‒20.5].  The development of pancreatic cancer was associated with rapid growth [hazard ratio (HR): 8.1, 95% CI: 1.5‒43.4, p = 0.015] and newly developed worrisome features (HR: 11.7, 95% CI: 1.7‒79.6, p = 0.012) in competing risk analysis.

CONCLUSIONS

One-fifth of small incidentally detected PCs increased in size. Rapid growth and newly developed worrisome features were predictors of malignancy.

Intraductal Papillary Mucinous Neoplasms in High-Risk Individuals: Incidence, Growth Rate, and Malignancy Risk

BACKGROUND AND AIMS

In high-risk individuals (HRIs), we aimed to assess the cumulative incidence of intraductal papillary mucinous neoplasms (IPMNs) and compare IPMN growth, neoplastic progression rate, and the value of growth as predictor for neoplastic progression to these in sporadic IPMNs.

METHODS

We performed annual surveillance of Dutch HRIs, involving carriers of germline pathogenic variants (PVs) and PV-negative familial pancreatic cancer kindreds. HRIs with IPMNs were compared with Italian individuals without familial risk under surveillance for sporadic IPMNs.

RESULTS

A total of 457 HRIs were followed for 48 (range 2-172) months; the estimated cumulative IPMN incidence was 46% (95% confidence interval, 28%-64%). In comparison with 442 control individuals, IPMNs in HRIs were more likely to grow ≥2.5 mm/y (31% vs 7%; P < .001) and develop worrisome features (32% vs 19%; P = .010). PV carriers with IPMNs more often displayed neoplastic progression (n = 3 [11%] vs n = 6 [1%]; P = .011), while familial pancreatic cancer kindreds did not (n = 0 [0%]; P = 1.000). The malignancy risk in a PV carrier with an IPMN was 23% for growth rates ≥2.5 mm/y (n = 13), 30% for ≥5 mm/y (n = 10), and 60% for ≥10 mm/y (n = 5).

CONCLUSIONS

The cumulative incidence of IPMNs in HRIs is higher than previously reported in the general population. Compared with sporadic IPMNs, they have an increased growth rate. PV carriers with IPMNs are suggested to be at a higher malignancy risk. Intensive follow-up should be considered for PV carriers with an IPMN growing ≥2.5 mm/y, and surgical resection for those growing ≥5 mm/y.

The role of intraoperative pancreatoscopy in the surgical management of intraductal papillary mucinous neoplasms of the pancreas: a systematic scoping review

BACKGROUND

The type and the extent of surgery is still debatable for intraductal papillary mucinous neoplasm (IPMN). Intraoperative pancreatoscopy (IOP) allows the visualization of the main pancreatic duct (MPD) in its entire length and could help determine the extent of MPD involvement and the type and extent of pancreatic resection. However, current guidelines do not advise its routine use as there is a lack of evidence supporting its safety and feasibility. The present study aims to perform a scoping review of published evidence on the safety and feasibility of IOP in IPMN surgical management.

METHODS

We systematically searched PubMed, Cochrane, Medline and EMbase to identify studies reporting the use of IOP in IPMN surgical management. The research was completed in June 2023. Data extracted included patient selection criteria, demographics, safety of the procedure, intraoperative findings, impact on surgical strategy, histology results and postoperative outcomes.

RESULTS

Four retrospective and one prospective study were included in this scoping review. A total of 142 patients had IOP. The selection criteria for inclusion were heterogenous, with one out of five studies including branch duct (BD), main duct (MD) and mixed type IPMN. Indications for IOP and surgical resection were only reported in two studies. A median of seven outcomes (range 5-8) was described, including the type of surgical resection, additional lesions and change of surgical plan, and complications after IOP. IOP showed additional lesions in 48 patients (34%) and a change of surgical plan in 48(34%). No IOP-related complications were reported.

CONCLUSIONS

This scoping review suggests IOP is safe and identifies additional lesions impacting the surgical strategy for IPMN. However, the included studies were small and heterogeneous regarding IPMN definition and indications for surgery and IOP. There is a need for a large multi-centre prospective study to determine the role of IOP and its impact on surgical strategy for IPMN.

Pancreatic cystic neoplasms: Still high rates of preoperative misdiagnosis in the guidelines and endoscopic ultrasound era

BACKGROUND

A wrong diagnosis of nature is common in pancreatic cystic neoplasms. The aim of the current study is to reappraise the diagnostic errors for presumed pancreatic cystic neoplasms in patients undergoing surgery.

METHODS

All pancreatic resections for presumed pancreatic cystic neoplasms following international guidelines between 2011 and 2020 were analyzed. Misdiagnosis was defined as the discrepancy between preoperative diagnosis of nature and final pathology. Mismatch was defined as the discrepancy between the preoperative suspect of malignancy (or its absence) and final pathology.

RESULTS

A total of 601 patients were included. Endoscopic ultrasound was performed in 301 (50%) patients. Overall misdiagnosis and mismatch were 19% and 34%, respectively, with no significant benefit for those patients who underwent endoscopic ultrasound. The highest rate of misdiagnosis was reached for cystic neuroendocrine tumors (61%) and the lowest for solid pseudopapillary tumors (6%). Several diagnostic errors had clinical relevance, including 7 (13%) presumed serous cystic neoplasms eventually found to be other malignant entities, 50 (24%) intraductal papillary mucinous neoplasms with high-risk stigmata revealed to be non-malignant, and 38 (33%) intraductal papillary mucinous neoplasms without high-risk stigmata revealed to be malignant at final pathology. A preoperative presumption of malignant mucinous cystic neoplasm was correct in only 20 (16%) patients.

CONCLUSIONS

Despite not always being clinically relevant, diagnostic errors are still common among resected pancreatic cystic neoplasms when applying international guidelines. New diagnostic tools beyond endoscopic ultrasound are needed to refine the diagnosis of those lesions at higher risk for unnecessary surgery or accidentally observed, nevertheless being malignant.

Long-term surveillance of branch-duct intraductal papillary mucinous neoplasms without worrisome or high-risk features

INTRODUCTION

Long-term data evaluating clinical outcomes in patients with branch-duct Intraductal papillary mucinous neoplasms (BD-IPMN) without high-risk stigmata (HRS) or worrisome features (WF) remain limited.

METHODS

This observational cohort study included all patients diagnosed with BD-IPMN without HRS or WF between 2003 and 2019 who were enrolled in a prospective surveillance program. Time-to-progression analysis was performed using a cumulative incidence function plot and survival analysis was conducted using Kaplan-Meier.

RESULTS

The median follow-up time for the 267 patient cohort was 44.5 months (interquartile range [IQR]: 24.1-72.2). Radiographic cyst growth was observed in 123 (46.1%) patients; 65 (24.3%) patients progressed to WF/HRS. Twenty-six (9.7%) patients were selected for resection during surveillance: 21 (80.8%) WF, 4 (15.4%) HRS; 1 (3.9%) transformed to mixed-duct. Of all the patients who underwent resection, 5 (19.2%) had adenocarcinoma, and 1 (3.8%) had carcinoma-in-situ. The probability of any radiographic progression was 21.3% (5-year) and 51.3% (10-year). For the entire cohort, there was 1.1% mortality secondary to pancreatic adenocarcinoma and 8.2% all-cause mortality. The 5-year overall survival rate was 91.5%, and at 10 years, 81.5%.

CONCLUSION

Approximately one in four patients with nonworrisome BD-IPMN have progression to WF/HRS stigmata during surveillance. However, the risk of malignant transformation remains low. Surveillance strategy remains prudent in this patient population.

Comparison of outcomes of EUS-guided ablation and surveillance only for pancreatic cystic lesions: a propensity score-matching study (with videos)

BACKGROUND AND AIMS

EUS-guided ethanol ablation is a recently introduced treatment approach for pancreatic cystic lesions (PCLs), including branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). However, the utility of this procedure is limited because of its relatively low efficacy in treating PCLs.

METHODS

We retrospectively reviewed patients with PCLs, including those with enlarging suspected BD-IPMNs or those with PCLs measuring >3 cm, who were suboptimal candidates for surgery and had been managed using EUS-guided rapid ethanol lavage (EUS-REL; immediate ethanol lavage performed 4 times, 2015-2022) or surveillance only (SO; 2007- 2022). Propensity score matching (PSM) was performed to minimize bias. The primary outcome was the cumulative incidence rate of BD-IPMN progression. Secondary outcomes were the efficacy and safety of EUS-REL, surgical resection rate (SR), overall survival (OS), and disease-specific survival (DSS) in both groups.

RESULTS

Overall, 169 and 610 patients were included in the EUS-REL and SO groups, respectively. PSM created 159 matched pairs. The radiologic complete resolution rate after EUS-REL was 74%. Procedure-related pancreatitis in the EUS-REL group was 13.0% (n = 22; 19 mild and 3 moderate grade); no severe adverse events were reported. The 10-year cumulative incidence rate of BD-IPMN progression was significantly lower in the EUS-REL group than in the SO group (1.6% vs 21.2%; hazard ratio, 12.35; P = .003). EUS-REL showed a lower tendency of SR compared with that associated with SO. The rates of 10-year OS and 10-year DSS were comparable in both groups.

CONCLUSIONS

EUS-REL was associated with a significantly lower 10-year cumulative incidence rate of BD-IPMN progression and a lower tendency of SR, whereas its 10-year OS and DSS rates were similar to those of SO for PCLs. EUS-REL may be a viable alternative to SO for managing patients with enlarging suspected BD-IPMNs or those with PCLs >3 cm who are suboptimal candidates for surgery.

Surveillance for Presumed BD-IPMN of the Pancreas: Stability, Size, and Age Identify Targets for Discontinuation

BACKGROUND & AIMS

Currently, most patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMN) are offered indefinite surveillance, resulting in health care costs with questionable benefits regarding cancer prevention. This study sought to identify patients in whom the risk of cancer is equivalent to an age-matched population, thereby justifying discontinuation of surveillance.

METHODS

International multicenter study involving presumed BD-IPMN without worrisome features (WFs) or high-risk stigmata (HRS) at diagnosis who underwent surveillance. Clusters of individuals at risk for cancer development were defined according to cyst size and stability for at least 5 years, and age-matched controls were used for comparison using standardized incidence ratios (SIRs) for pancreatic cancer.

RESULTS

Of 3844 patients with presumed BD-IPMN, 775 (20.2%) developed WFs and 68 (1.8%) HRS after a median surveillance of 53 (interquartile range 53) months. Some 164 patients (4.3%) underwent surgery. Of the overall cohort, 1617 patients (42%) remained stable without developing WFs or HRS for at least 5 years. In patients 75 years or older, the SIR was 1.12 (95% CI, 0.23-3.39), and in patients 65 years or older with stable lesions smaller than 15 mm in diameter after 5 years, the SIR was 0.95 (95% CI, 0.11-3.42). The all-cause mortality for patients who did not develop WFs or HRS for at least 5 years was 4.9% (n = 79), and the disease-specific mortality was 0.3% (n = 5).

CONCLUSIONS

The risk of developing pancreatic malignancy in presumed BD-IPMN without WFs or HRS after 5 years of surveillance is comparable to that of the general population depending on cyst size and patient age. Surveillance discontinuation could be justified after 5 years of stability in patients older than 75 years with cysts <30 mm, and in patients 65 years or older who have cysts ≤15 mm.

Surveillance of Pancreatic Cystic Neoplasms

Pancreatic cystic neoplasms (PCNs) are increasingly detected because of the widespread use of cross-sectional imaging and overall aging population. While the majority of these cysts are benign, some can progress to advanced neoplasia (defined as high-grade dysplasia and invasive cancer). As the only widely accepted treatment for PCNs with advanced neoplasia is surgical resection, accurate preoperative diagnosis, and stratification of malignant potential for deciding about surgery, surveillance or doing nothing remains a clinical challenge. Surveillance strategies for pancreatic cysts (PCNs) combine clinical evaluation and imaging to assess changes in cyst morphology and symptoms that may indicate advanced neoplasia. PCN surveillance heavily relies on various consensus clinical guidelines that focus on high-risk morphology, surgical indications, and surveillance intervals and modalities. This review will focus on current concepts in the surveillance of newly diagnosed PCNs, especially on low-risk presumed intraductal papillary mucinous neoplasms (those without worrisome features and high-risk stigmata), and appraise current clinical surveillance guidelines.

Risk Models for Pancreatic Cyst Diagnosis

The overall prevalence of pancreatic cysts (PCs) is high in the general population. In clinical practice PCs are often incidentally discovered and are classified into benign, premalignant, and malignant lesions according to the World Health Organization. For this reason, in the absence of reliable biomarkers, to date clinical decision-making relies mostly on risk models based on morphological features. The aim of this narrative review is to present the current knowledge regarding PC's morphologic features with related estimated risk of malignancy and discuss available diagnostic tools to minimize clinically relevant diagnostic errors.

Feasibility of Surveillance for Mucinous Cystic Neoplasm of the Pancreas: A Multi-Institutional Retrospective Study of 328 Patients by the Japanese Pancreatic Society

OBJECTIVE

We aimed to elucidate the feasibility of surveillance of patients with mucinous cystic neoplasm (MCN).

METHODS

We performed a retrospective, multi-institutional study of 328 patients who underwent surgery for MCN at 18 Japanese institutions. Patients with MCN were divided into an immediate surgery group and a surveillance group, which underwent surgery after surveillance.

RESULTS

The median surveillance period until surgery in the surveillance group was 27 months (range, 7-165 months). Compared with the immediate surgery group, the surveillance group showed smaller tumor diameter (46 vs 50 mm, P = 0.01), more frequent laparoscopic approach (58% vs 37%, P < 0.01), and less frequent malignancy (7% vs 15%, P = 0.03). The new appearance of mural nodules and elevation of serum tumor markers were associated with malignancy in the surveillance group. Two patients in the surveillance group experienced postoperative recurrence, although there was no significant difference in recurrence or disease-free survival between the two groups. In the surveillance group, the 1-, 5-, and 10-year cumulative incidence rates of malignant MCN were 0.8%, 5.6%, and 36.5%, respectively.

CONCLUSION

As the risk of progression to malignant MCNs increases over the long term, MCNs should be resected rather than subjected to unnecessary surveillance.

Long-term (10-year) outcomes and prognostic factors in resected intraductal papillary mucinous neoplasm tumors in Finland: A nationwide retrospective study

BACKGROUND

The degree of dysplasia is the most important prognostic factor for patients with resected intraductal papillary mucinous neoplasms. Intraductal papillary mucinous neoplasms are predominantly premalignant conditions; in most cases, surveillance is an adequate treatment. If worrisome features are present, surgery should be considered. However, there is limited data on the long-term prognosis of resected intraductal papillary mucinous neoplasms. We aimed to ascertain the nationwide survival of patients with resected intraductal papillary mucinous neoplasms and identify factors associated with survival.

METHODS

This is a retrospective nationwide cohort study. All intraductal papillary mucinous neoplasms operated on in Finland between 2000 and 2008 were identified. Patient records were evaluated, and original radiologic data and histologic samples were re-evaluated. Survival data were collected after a 10-year follow-up period.

RESULTS

Out of 2,024 pancreatic resections, 88 were performed for intraductal papillary mucinous neoplasm. The median age of the patients was 65 years. Histologic diagnoses were main duct intraductal papillary mucinous neoplasm 47/88 (53,4%), mixed-type intraductal papillary mucinous neoplasm 27/88 (30.7%), and branchduct intraductal papillary mucinous neoplasm 14/88 (15.9%). Of the tumors, 40/88 (45.5%) were low-grade dysplasia, 9/88 (10.2%) high-grade, and 39/88 (44.3%) were invasive cancer. The median survival was 121 (range 0-252) months. Ten-year survival was 72.5%, 66.7%, and 23.1% in the low-grade dysplasia, high-grade dysplasia, invasive cancer groups, respectively. Ten-year mortality for pancreatic cancer was 5%, 9.1%, and 71.8% in the low-grade dysplasia, high-grade dysplasia, invasive cancer groups, respectively.

CONCLUSION

Overall, 44.3% of the patients had a malignant tumor, and three-quarters (74.5%) of the main duct intraductal papillary mucinous neoplasms were malignant or high-grade dysplasia at the time of surgery. Ten-year survival was significantly better in patients operated on at the stage of a premalignant tumor (low-grade dysplasia + high-grade dysplasia) than in patients operated on at the stage of a malignant tumor.

When to Stop Surveillance: Pancreatic Cysts

Surveillance of mucinous pancreatic cysts is a key to reducing pancreatic cancer risk and detecting malignancy early. However, while the management of cysts with high-risk and worrisome features is fairly straightforward, surveillance of patients with low-risk branch-duct intraductal papillary mucinous neoplasms has long presented gastroenterologists with the challenging question of discontinuation of surveillance. Up-to-date evidence supports the cessation of follow-up in these patients depending on both interval stability of the cyst and cyst size. Based on these criteria, discontinuation of surveillance at either 5 years or 10 years is recommended. Oversurveillance of patients with pancreatic cysts in the absence of high-risk and worrisome features is discouraged.

The Landmark Series: Intraductal Papillary Mucinous Neoplasms of the Pancreas-From Prevalence to Early Cancer Detection

Modern series report a prevalence of pancreatic cysts in the general population of up to 50% in prospective studies. Of these, about half will be pancreatic cystic neoplasms (PCNs) that have varying degrees of malignant potential. Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are the most common PCNs and are known predecessors of pancreatic adenocarcinoma. Critically, they are one of the only radiographically identifiable precursors of pancreatic cancer and thus provide an opportunity for early cancer detection and surgical resection with curative intent. The combination of high prevalence and potential for malignant degeneration underscore the relevance of discussing the best management of IPMNs and improving the existing standard of care. Landmark data on IPMN prevalence, guidelines, surveillance, biomarkers, and immune landscape are highlighted.

New Diagnostic Modality Combining Mass Spectrometry and Machine Learning for the Discrimination of Malignant Intraductal Papillary Mucinous Neoplasms

BACKGROUND

An intraductal papillary mucinous neoplasm (IPMN) is a pancreatic tumor with malignant potential. Although we anticipate a sensitive method to diagnose the malignant conversion of IPMN, an effective strategy has not yet been established. The combination of probe electrospray ionization-mass spectrometry (PESI-MS) and machine learning provides a promising solution for this purpose.

METHODS

We prospectively analyzed 42 serum samples obtained from IPMN patients who underwent pancreatic resection between 2020 and 2021. Based on the postoperative pathological diagnosis, patients were classified into two groups: IPMN-low grade dysplasia (n = 17) and advanced-IPMN (n = 25). Serum samples were analyzed by PESI-MS, and the obtained mass spectral data were converted into continuous variables. These variables were used to discriminate advanced-IPMN from IPMN-low grade dysplasia by partial least square regression or support vector machine analysis. The areas under receiver operating characteristics curves were obtained to visualize the difference between the two groups.

RESULTS

Partial least square regression successfully discriminated the two disease classes. From another standpoint, we selected 130 parameters from the entire dataset by PESI-MS, which were fed into the support vector machine. The diagnostic accuracy was 88.1%, and the area under the receiver operating characteristics curve was 0.924 by this method. Approximately 10 min were required to perform each method.

CONCLUSION

PESI-MS combined with machine learning is an easy-to-use tool with the advantage of rapid on-site analysis. Here, we show the great potential of our system to diagnose the malignant conversion of IPMN, which would be a promising diagnostic tool in clinical settings.

Real-world costs and dynamics of surveillance in patients who underwent surgery for low-risk branch duct intraductal papillary mucinous neoplasms

Surveillance costs and appropriateness of surgery of "low-risk" BD-IPMNs are relevant issues. In this study we evaluated the rate of correct indication for pancreatectomy defined as high grade dysplasia (HGD) at histology in 961 patients who underwent surveillance for a median of 5.1 years. Undertreatment and overtreatment were defined as invasive cancer and low grade dysplasia (LGD) at histology, respectively. Of the 66 patients (6.9%) who were operated, only 16 (23.8%) had a HGD while 40 (59.7%) had a LGD and 10 (14.9%) an invasive cancer, without differences regarding timing of surgery. The mean surveillance cost was € 194.9 ± 107.6 per patient-year, with a median cost of € 277.1 ± 148.2 in the correct surgery group compared with € 222.7 ± 111.6 and € 197 ± 102.7 in the overtreatment and undertreatment groups. The surveillance mean cost from diagnosis to surgery was € 854.8. Rate of appropriate surgery in BD-IPMNs under surveillance is low.

Pancreatic Cystic Neoplasms

Early detection of high-risk pancreatic cystic lesions enables potentially curative surgical resection, and early detection of lesions without worrisome features may lead to appropriate surveillance. Regrettably, differentiating premalignant and malignant cysts from nonmalignant ones remains challenging. However, emerging additional diagnostic tools, including the needle biopsy with microforceps and needle-based confocal laser endomicroscopy, are of exciting potential along with cyst fluid analysis".

Identification of patients with branch-duct intraductal papillary mucinous neoplasm and very low risk of cancer: multicentre study

BACKGROUND

Different surveillance strategies for patients with low-risk branch-duct (BD) intraductal papillary neoplasm (IPMN) have been described. The aim of this study was to describe the natural history of low-risk BD-IPMN, and to identify risk factors for the development of worrisome features (WF)/high-risk stigmata (HRS) and of pancreatic malignancies.

METHODS

This was a multicentre retrospective study of patients with BD-IPMN who were under active surveillance between January 2006 and December 2015. Patients were eligible if they had a low-risk lesion and had a minimum follow-up of 24 months. Outcomes were development of WF/HRS or cytologically/histologically confirmed malignant IPMN.

RESULTS

Of 837 patients included, 168 (20 per cent) developed WF/HRS. At the end of the observation time, 132 patients (79 per cent) with WF/HRS were still under surveillance without progression to pancreatic cancer. Factors associated with the development of WF or HRS in multivariable analysis included localized nodules (versus diffuse: hazard ratio (HR) 0.43, 95 per cent c.i. 0.26 to 0.68), cyst size 15-19 mm (versus less than 15 mm: HR 1.88, 1.23 to 2.87) or at least 20 mm (versus less than 15 mm: HR 3.25, 2.30 to 4.60), main pancreatic duct size over 3 mm (versus 3 mm or less: HR 2.17, 1.41 to 3.34), and symptoms at diagnosis (versus no symptoms: HR 2.29, 1.52 to 3.45). Surveillance in an endoscopy-oriented centre was also associated with increased detection of WF or HRS (versus radiology-oriented: HR 2.46, 1.74 to 3.47).

CONCLUSION

Conservative management of patients with low-risk BD-IPMN is safe and feasible.

Benefit of Extended Surveillance of Low-Risk Pancreatic Cysts After 5-Year Stability: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Low-risk branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) lacking worrisome features (WF) and high-risk stigmata (HRS) warrant surveillance. However, their optimal duration, especially among cysts with initial 5 years of size stability, warrants further investigation. We systematically reviewed the surveillance of low-risk BD-IPMNs and investigated the incidence of WF/HRS and advanced neoplasia, high-grade dysplasia, and pancreatic cancer during the initial (<5 years) and extended surveillance period (>5-years).

METHODS

A systematic search (CRD42020117120) identified studies investigating long-term IPMN surveillance outcomes of low-risk IPMN among the Cochrane Library, Embase, Google Scholar, Ovid Medline, PubMed, Scopus, and Web of Science, from inception until July 9, 2021. The outcomes included the incidence of WF/HRS and advanced neoplasia, disease-specific mortality, and surveillance-related harm (expressed as percentage per patient-years). The meta-analysis relied on time-to-event plots and used a random-effects model.

RESULTS

Forty-one eligible studies underwent systematic review, and 18 studies were meta-analyzed. The pooled incidence of WF/HRS among low-risk BD-IPMNs during initial and extended surveillance was 2.2% (95% CI, 1.0%-3.7%) and 2.9% (95% CI, 1.0%-5.7%) patient-years, respectively, whereas the incidence of advanced neoplasia was 0.6% (95% CI, 0.2%-1.00%) and 1.0% (95% CI, 0.6%-1.5%) patient-years, respectively. The pooled incidence of disease-specific mortality during initial and extended surveillance was 0.3% (95% CI, 0.1%-0.6%) and 0.6% (95% CI, 0.0%-1.6%) patient-years, respectively. Among BD-IPMNs with initial size stability, extended surveillance had a WF/HRS and advanced neoplasia incidence of 1.9% (95% CI, 1.2%-2.8%) and 0.2% (95% CI, 0.1%-0.5%) patient-years, respectively.

CONCLUSIONS

A lower incidence of advanced neoplasia during extended surveillance among low-risk, stable-sized BD-IPMNs was a key finding of this study. However, the survival benefit of surveillance among this population warrants further exploration through high-quality studies before recommending surveillance cessation with certainty.

State-of-the-Art Update of Pancreatic Cysts

Andrew Canakis.

Comorbidities Drive the Majority of Overall Mortality in Low-Risk Mucinous Pancreatic Cysts Under Surveillance

BACKGROUND & AIMS

The Charlson Comorbidity Index (CACI) has been suggested as a tool to determine comorbidity burden and guide management for patients with mucinous pancreatic cysts (Intrapapillary Mucinous Neoplasms and Mucinous Cystic Neoplasms), but has not been studied well among "low-risk" mucinous pancreatic cysts i.e. without worrisome features (WF) and high-risk stigmata (HRS). This study sought to determine the comorbidity burden among surveillance population of low-risk pancreatic cysts and provide their follow-up mortality outcomes.

METHODS

A single center study retrospectively reviewed a prospective pancreatic cyst database and included individuals with low-risk cysts undergoing serial imaging during 2016. Electronic medical records were reviewed to determine their baseline age-adjusted CACI (age-CACI). After 4 years, their progression to WF, disease specific (pancreatic malignancy-related, DSM), extra-pancreatic (EPM), and overall mortalities (OM) were determined using Kaplan-Meir Survival Analysis.

RESULTS

502 individuals underwent prospective surveillance. The study included 440 individuals with low-risk suspected or presumed mucinous cysts and excluded 50 and 12 individuals with WF and HRS respectively. Over a median follow-up of 56 months, 12 WF progressions, 2 DSMs, 42 EPMs, and 44 OMs were observed. Baseline age-CACI had good predictive capacity for 4-year EPM (Area-Under Curve: 0.87; p< .0001). The median age-CACI of 4 enabled cohort stratification into Low (age-CACI <4) and High CACI (age-CACI ≥4) groups. A significantly higher OM (p< .001) was observed among the High CACI group as compared to the Low CACI group.

CONCLUSION

Through real-time application of CACI to patient outcomes, our analysis supports incorporation of this comorbidity assessment tool in making shared surveillance decisions among low-risk pancreatic cyst population.

International external validation of a stratification tool to identify branch-duct intraductal papillary mucinous neoplasms at lowest risk of progression

Background

Identifying branch‐duct intraductal papillary mucinous neoplasms (BD‐IPMNs) at lowest risk of progression may allow for a reduced intensity of surveillance.

Objective

We aimed to externally validate the previously developed Dutch‐American Risk stratification Tool (DART‐1; https://rtools.mayo.edu/DART/), which identifies cysts at low risk of developing worrisome features (WFs) or high‐risk stigmata (HRS).

Methods

Three prospective cohorts of individuals under surveillance for BD‐IPMNs were combined, independent from the original development cohort. We assessed the performance (discrimination and calibration) of DART‐1, a multivariable Cox‐proportional logistic regression model with five predictors for the development of WFs or HRS.

Results

Of 832 individuals (mean age 77 years, SD 11.5) under surveillance for a median of 40 months (IQR 44), 163 (20%) developed WFs or HRS. DART‐1's discriminative ability (C‐statistic 0.68) was similar to that in the development cohort (0.64–0.72) and showed moderate calibration. DART‐1 adequately estimated the risk for patients in the middle risk quintile, and slightly underestimated it in the lowest quintiles. Their range of predicted versus observed 3‐year risk was 0%–0% versus 0%–3.7% for Q1; 0.3%–0.4% versus 3%–11% for Q2; and 2.6%–3% versus 2.4%–9.8% for Q3. The development of WFs or HRS was associated with pancreatic cancer (p < 0.001). Vice versa, in absence of WFs or HRS, the risk of malignancy was low (0.3%).

Conclusions

The performance of DART‐1 to predict the development of WFs or HRS in BD‐IPMN was validated in an external international cohort, with a discriminative ability equal as in the development cohort. Risk estimations were most accurate for patients with BD‐IPMNs in the middle risk quintile and slightly underestimated in the lowest quintiles.

Clinical Implication of Preoperative C-Reactive Protein/Albumin Ratio in Malignant Transformation of Intraductal Papillary Mucinous Neoplasm: A Propensity Score Analysis

Background: Inflammation-based scoring has been reported to be useful for predicting the recurrence and prognosis of various carcinomas. This study retrospectively investigated the relationship between inflammation-based score and intraductal papillary mucinous neoplasms (IPMNs). Methods: Between January 2013 and October 2018, we enrolled 417 consecutive patients with pancreatic tumors who received surgical resections at our hospital. The main outcome was the association between the preoperative inflammation-based score and their accuracy in predicting malignant transformation of IPMN. Results: Seventy six patients were eligible. Pathological findings indicated that 35 patients had low-grade dysplasia, 18 had high-grade dysplasia, and 23 had invasive carcinomas. As the C-reactive protein albumin ratio (CAR) was higher, malignant transformation of IPMNs also increased (p = 0.007). In comparing CAR^high and CAR^low using cutoff value, the results using a propensity score analysis showed that the CAR^high group predicted malignant transformation of IPMNs (odds ratio, 4.18; 95% confidence interval, 1.37–12.8; p = 0.01). In the CAR^high group, disease-free survival (DFS) was significantly shorter (p = 0.04). In the worrisome features, the AUC for the accuracy of malignant transformation with CAR^high was 0.84 when combining with the MPD findings. Conclusions: Preoperative CAR could be a predictive marker of malignant transformation of IPMNs.

Surgery for Intraductal Papillary Mucinous Neoplasms of the Pancreas: Preoperative Factors Tipping the Scale of Decision-Making

Background

Decision-making in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas depends on scaling the risk of malignancy with the surgical burden of a pancreatectomy. This study aimed to develop a preoperative, disease-specific tool to predict surgical morbidity for IPMNs.

Methods

Based on preoperative variables of resected IPMNs at two high-volume institutions, classification tree analysis was applied to derive a predictive model identifying the risk factors for major morbidity (Clavien–Dindo ≥3) and postoperative pancreatic insufficiency.

Results

Among 524 patients, 289 (55.2%) underwent pancreaticoduodenectomy (PD), 144 (27.5%) underwent distal pancreatectomy (DP), and 91 (17.4%) underwent total pancreatectomy (TP) for main-duct (18.7%), branch-duct (12.6%), or mixed-type (68.7%) IPMN. For 98 (18.7%) of the patients, major morbidity developed. The classification tree distinguished different probabilities of major complications based on the type of surgery (area under the surve [AUC] 0.70; 95% confidence interval [CI], 0.63–0.77). Among the DP patients, the presence of preoperative diabetes identified two risk classes with respective probabilities of 5% and 25% for the development of major morbidity, whereas among the PD/TP patients, three different classes with respective probabilities of 15%, 20%, and 36% were identified according to age and body mass index (BMI). Overall, history of diabetes, age, and cyst size segregated three different risk classes for new-onset/worsening diabetes.

Conclusions

In presumed IPMNs, the disease-specific risk of major morbidity and pancreatic insufficiency can be determined in the preoperative setting and used to personalize the possible surgical indication. Age and overweight status in case of PD/TP and diabetes in case of DP tip the scale toward less aggressive clinical management in the absence of features suggestive for malignancy.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-022-11326-5.

A retrospective study of intraductal papillary neoplasia of the pancreas (IPMN) under surveillance

BACKGROUND AND OBJECTIVE

The growing number of identified intraductal papillary mucinous neoplasm (IPMN) patients places greater pressure on healthcare systems. Only a minority of patients have IPMN-related symptoms. Thus, more precise surveillance is required.

METHODS

In this retrospective single-center cross-sectional study, patients with an active diagnosis of branch duct IPMN (BD-IPMN) and >6 months of surveillance were classified as follows: presence/absence of worrisome features (WF) or high-risk stigmata (HRS), newly developed WF/HRS, under/over 15 mm cyst, growing/not growing <15 mm cyst, and elevated serum carbohydrate antigen 19-9 (CA 19-9).

RESULTS

In all, 377 patients with BD-IPMN were followed for a median of 5.4 years, 28% with WF at diagnosis, and 14% who developed WF/HRS during surveillance. Half had a <15 mm primary cyst, 40% of which did not grow during surveillance. CA 19-9 was elevated in 12%. None of the patients with normal CA 19-9 levels developed cancer or high-grade dysplasia (HGD).

CONCLUSIONS

No carcinomas or HGDs appeared with normal CA 19-9 levels. Patients with <15 mm cysts that do not grow and have no WF/HRS could undergo imaging less frequently.

The use of a mobile application to disseminate guidelines on cystic neoplasms of the pancreas - A snapshot study of 1000 case-simulations

BACKGROUND

No data exist on the actual application of pancreatic cystic neoplasm (PCN) guidelines in clinical practice.

AIM

Disseminate knowledge on existing PCN guidelines and determine which guidelines are prospectively chosen by iCyst app users for different case scenarios.

METHODS

iCyst is a digital tool providing access to the three main existing guidelines (European, IAP, and AGA). Through a case simulation system, for one year, the app prospectively registered users' guideline choices.

RESULTS

During the study period, 276 users downloaded iCyst and entered 1020 completed simulations. Most users were European (88%) and were either surgeons (69%) or gastroenterologists (29%). Six different representative scenarios were identified. Overall, the European guidelines were the most commonly preferred (52%). In 16% of cases, the users did not choose any of the available guidelines.

CONCLUSION

Digital apps can be used to disseminate guidelines in clinical practice. Guideline dissemination might serve as the basis for future research lines on specific clinical scenarios that iCyst identifies as critical.

State-of-the-art surgical treatment of IPMNs

Background

A “pandemic” of incidentally discovered pancreatic cyst neoplasms (PCNs) is ongoing. Among PCNs, intraductal papillary mucinous cystic neoplasms (IPMNs) are the most common and with their complex biology could represent a precursor lesion of pancreatic cancer. Although multiple guidelines exist to guide their treatment, there are still many “gray areas” on indications for surgery for IPMNs.

Methods

The current indications for surgery of IPMNs were reappraised, considering potential discrepancies between available evidence and guidelines policies. The practice at a high-volume center for the diagnosis and treatment of PCN was presented and discussed.

Results

Most IPMNs do not and will never require surgery, as they won’t progress to malignancy. The current literature is solid in identifying high-grade dysplasia (HGD) as the right and timely target for IPMN resection, but how to precisely assess its presence remains controversial and guidelines lack of accuracy in this regard. Multiple tumorigenic pathways of progression of IPMNs exist, and their knowledge will likely lead to more accurate tests for malignancy prediction in the future.

Conclusions

The surgical management of IPMNs still is a matter of debate. Indication for resection should be considered only in highly selected cases with the ideal target of HGD. Clinicians should critically interpret the guidelines’ indications, refer to a multidisciplinary team discussion, and always consider the outcome of an adequate counselling with the patient.

Intraductal Papillary Mucinous Neoplasms of the Pancreas: A Review of Their Genetic Characteristics and Mouse Models

Simple Summary

Pancreatic cancer is one of the deadliest cancers with the lowest survival rate. Little progress has been achieved in prolonging the survival for patients with pancreatic adenocarcinoma. Hence, special attention should be paid to pre-cancerous lesions, for instance, an intraductal papillary mucinous neoplasm (IPMN). Here, we reviewed its genetic characteristics and the mouse models involving mutations in specific pathways, and updated our current perception of how this lesion develops into a precursor of invasive cancer.

Abstract

The intraductal papillary mucinous neoplasm (IPMN) is attracting research attention because of its increasing incidence and proven potential to progress into invasive pancreatic ductal adenocarcinoma (PDAC). In this review, we summarized the key signaling pathways or protein complexes (GPCR, TGF, SWI/SNF, WNT, and PI3K) that appear to be involved in IPMN pathogenesis. In addition, we collected information regarding all the genetic mouse models that mimic the human IPMN phenotype with specific immunohistochemistry techniques. The mouse models enable us to gain insight into the complex mechanism of the origin of IPMN, revealing that it can be developed from both acinar cells and duct cells according to different models. Furthermore, recent genomic studies describe the potential mechanism by which heterogeneous IPMN gives rise to malignant carcinoma through sequential, branch-off, or de novo approaches. The most intractable problem is that the risk of malignancy persists to some extent even if the primary IPMN is excised with a perfect margin, calling for the re-evaluation and improvement of diagnostic, pre-emptive, and therapeutic measures.

Risk Factors for the Development of High-risk Stigmata in Branch-duct Intraductal Papillary Mucinous Neoplasms

Objective Strict follow-up is recommended for branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) to avoid missing the development of high-risk stigmata (HRS) at a premalignant stage. This study explored the risk factors associated with the development of HRS during follow-up. Methods We performed a retrospective analysis of 283 patients with BD-IPMN, treated at Okayama University Hospital in Japan between January 2009 and December 2016. Only patients with imaging studies indicative of classical features of BD-IPMN without HRS and followed for over one year were included in the study. We performed radiological follow-up every six months and collected patients' demographic data, cyst characteristics, and clinical outcomes and used univariate logistic regression models to determine the odds of developing HRS. Results Ten patients (3.5%) developed HRS after a median surveillance period of 55.8 months. The main pancreatic duct (MPD) size (5-9 mm) and cyst growth rate (>2.5 mm/year) were both suggested to be possible risk factors for the development of HRS [odds ratio, 14.2; 95% confidence interval (CI), 3.1-65.2, p=0.0006, and odds ratio, 6.1; 95% CI 1.5-25.5, p=0.014]. Regarding the number of worrisome features (WFs), the rate of HRS development was 2.0% (4/199) in cases with no WF, 1.6% (1/62) in cases with single WF and 22.7% (5/22) in cases with multiple WFs, respectively. The rate of HRS development was significantly higher in cases with multiple WFs than in the other cases (p<0.0001). Conclusion MPD dilation, rapid cyst growth, and multiple WFs were significant risk factors for the development of HRS. In the presence of such features, it is necessary to closely follow the development of HRS and avoid missing the best opportunity to perform surgical intervention.

Updates in diagnosis and management of pancreatic cysts

Incidental pancreatic cysts are commonly encountered with some cysts having malignant potential. The most common pancreatic cystic neoplasms include serous cystadenoma, mucinous cystic neoplasm and intraductal papillary mucinous neoplasm. Risk stratifying pancreatic cysts is important in deciding whether patients may benefit from endoscopic ultrasound (EUS) or surgical resection. Surgery should be reserved for patients with malignant cysts or cysts at high risk for developing malignancy as suggested by various risk features including solid mass, nodule and dilated main pancreatic duct. EUS may supplement magnetic resonance imaging findings for cysts that remain indeterminate or have concerning features on imaging. Various cyst fluid markers including carcinoembryonic antigen, glucose, amylase, cytology, and DNA markers help distinguish mucinous from nonmucinous cysts. This review will guide the practicing gastroenterologist in how to evaluate incidental pancreatic cysts and when to consider referral for EUS or surgery. For presumed low risk cysts, surveillance strategies will be discussed. Managing pancreatic cysts requires an individualized approach that is directed by the various guidelines.

Progression vs Cyst Stability of Branch-Duct Intraductal Papillary Mucinous Neoplasms After Observation and Surgery

Importance

The progression of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas to malignant disease is still poorly understood. Observational and surgical series have failed to provide comprehensive information.

Objective

To identify dynamic variables associated with the development of malignant neoplasms by combining pathological features with data from preoperative repeated observations.

Design, Setting, and Participants

The Crossover Observational Multicentric Study included a retrospective cohort of patients with branch-duct IPMNs (BD IPMNs) enrolled in a surveillance program from January 1, 2000, to December 31, 2019. Patients were enrolled from 5 referral centers: the Pancreas Institute, Verona, Italy; Seoul National University Hospital, Seoul, South Korea; Singapore General Hospital, Singapore; Johns Hopkins School of Medicine, Baltimore, Maryland; and University of Texas MD Anderson Cancer Center, Houston. Patients underwent a minimum of 12 months of preoperative surveillance (median, 37 [interquartile range (IQR), 20-68] months).

Main Outcomes and Measures

Dynamic variables associated with malignant disease were explored to estimate the presence of high-grade dysplasia (HGD) and invasive cancer at final pathological examination.

Results

A total of 292 patients were included in the analysis (137 women [46.9%] and 155 men [53.1%]; median age, 64 [IQR, 56-71] years). During surveillance, 27 patients (9.2%) developed a worrisome feature after 5 years, and 46 of 276 (16.7%) developed high-risk stigmata (HRS). At final pathological evaluation, 107 patients (36.6%) had HGD or invasive cancer, and 16 (5.5%) had IPMNs with concomitant pancreatic ductal adenocarcinoma. Rates of HGD and invasive cancer at pathological evaluation significantly differed between those without worrisome features and those developing HRS from a previous worrisome feature (9 [27.3%] vs 13 [61.9%]; P < .001). Developing an additional worrisome feature during surveillance (odds ratio [OR], 3.24 [95% CI, 1.38-7.60]; P = .007) or an HRS from a baseline worrisome feature (OR, 2.87 [95% CI, 1.01-8.17]; P = .048) was associated with HGD at final pathological evaluation. Among HRS, development of jaundice on a low-risk cyst was independently associated with invasive cancer (OR, 16.04 [95% CI, 2.94-87.40]; P = .001).

Conclusions and Relevance

These findings suggest that in BD IPMNs under surveillance, harboring a stable worrisome feature carries the lowest risk of malignant disease. Development of additional worrisome features or HRS is associated with the presence of HGD, whereas the occurrence of jaundice is associated with invasive cancer.

The faith of non-surveilled pancreatic cysts: a bicentric retrospective study

BACKGROUND

Incidental discovery of pancreatic cystic neoplasms (PCLs) is a common and steadily increasing occurrence. The aim of this study was to investigate a cohort of patients presenting with incidentally detected PCLs which were not included in a surveillance protocol, and to compare their risk of malignant evolution with that of systematically surveilled lesions.

MATERIALS AND METHODS

A population of PCLs which did not receive surveillance over a period >10 years (population A) was selected at the Medical University of Vienna. A group of "low risk" branch duct intraductal papillary mucinous neoplasm ≤15 mm in size upon diagnosis undergoing a regular follow-up of at least 5 years at the University of Verona was selected as control (population B). The incidence of pancreatic cancer (PC), cumulative risk of PC and disease-specific survival were compared.

RESULTS

Overall, 376 patients with non-surveilled PCLs were included in study group A and compared to 299 patients in group B. This comparison resulted in similar incidence rates of PC (1.6% vs 1.7%, p = 0.938), a strong similarity in terms of disease-specific mortality rates (1.3% vs 0.3%, p = 0.171) and the 5- and 10-year cumulative risk of PC (≅ 1% and 2%, p = 0.589) and DSS (≅ 100% and 98%, p = 0.050).

CONCLUSION

The "price to pay" for a negligence-based policy in the population of non-surveilled PCLs was reasonable, and the incidence of PC was comparable to that reported for a population of low-risk cysts enrolled to a standardized surveillance protocol.

Actual malignancy risk of either operated or non-operated presumed mucinous cystic neoplasms of the pancreas under surveillance

BACKGROUND

Despite the low malignant potential of pancreatic mucinous cystic neoplasms (MCNs), surgery is still performed. The aim of this pragmatic study was to assess the outcome of surgery and surveillance for patients presenting with a presumed MCN at the first evaluation.

METHODS

Data for patients with a presumed MCN observed from 2000 to 2016 at the Verona Pancreas Institute and San Raffaele Hospital were extracted from prospective databases. The endpoints were risk of malignancy at pathology and rate of misdiagnosis for the surgical series, expressed as an odds ratio (OR) with 95 per cent confidence interval, and disease-specific survival (DSS) for the surveillance cohort investigated by the Kaplan-Meier method.

RESULTS

A total of 424 patients were identified. In the surgical series (229 patients), the rate of misdiagnosis was 19.2 per cent. The rate of malignant MCNs was 10.9 per cent (25 patients). The overall rate of malignancy, including misdiagnoses, was 11.3 per cent (26 patients). Predictors of malignancy were mural nodules (OR 27.75, 95 per cent c.i. 4.44-173.61; P < 0.001), size at least 50 mm (OR 13.39, 2.01 to 89.47; P = 0.007), and carbohydrate antigen 19.9 level (OR 3.98, 1.19 to 13.30; P = 0.025). In the absence of mural nodules and enhancing walls, none of the resected presumed MCNs smaller than 50 mm were malignant. Only patients with high-risk stigmata undergoing surgery experienced a significantly reduced 5-year DSS compared with all other patients (88 versus 100 per cent; P = 0.031).

CONCLUSION

Presumed MCNs with mural nodules, enhancing walls or cysts of 50 mm or larger should be considered for upfront surgical resection owing to the high risk of malignancy. In the absence of these features, the incidence of malignancy is negligible, favouring surveillance in selected patients given the low risk of malignancy and the high rate of misdiagnosis.

GRAPHICAL ABSTRACT

Pancreatic mucinous cystic neoplasms (MCNs) are well known preneoplastic lesions. Despite the low rate of cancer, lesions without radiological features of malignancy are resected systematically. In the absence of mural nodules, enhancing walls or cyst size 50 mm or more, the incidence of malignancy is negligible. Given the high risk of misdiagnosis, in the absence of such radiological features, surveillance of presumed MCNs seems safer.

Systematic review and meta-analysis of observational studies on BD-IPMNS progression to malignancy

BACKGROUND

The vast majority of presumed branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas are referred to a surveillance program due to the relatively low risk of malignancy. We aim to evaluate all available data from observational studies focused on the risks of BD-IPMN progression and malignancy to provide vital insights into its management in clinical practice.

METHODS

A comprehensive search was conducted at PubMed, Cochrane, Web of Science and Embase for observational studies published before January 1st, 2020. The progression of BD-IPMN was defined as the development of worrisome features (WFs) or high-risk stigmata (HRS) during surveillance. Overall malignancy was defined as all malignancies, such as malignant IPMN, concomitant pancreatic ductal adenocarcinoma (PDAC) and other malignancies, including BD-IPMN with high-grade sec. Baltimore consensus 2015 or BD-IPMN with high-grade dysplasia (carcinoma in situ) sec. WHO 2010. A meta-analysis was performed to investigate the presence of a mural nodule as a possible predictor of malignancy.

RESULTS

Twenty-four studies were included, with a total of 8941 patients with a presumed BD-IPMN. The progression rate was 20.2%, and 11.8% underwent surgery, 29.5% of whom showed malignancy at the final pathology. Of those, 78% had malignant IPMNs, and 22% had concomitant pancreatic cancer. Overall, 0.5% had distant metastasis. The meta-analysis showed that the risk of malignancy in the presence of a mural nodule >5 mm had a RR of 5.457 (95% CI 1.404-21.353), while a nonenhancing mural nodule or an enhancing mural nodule < 5 mm had a RR of 5.286 (95% CI 1.805-15.481) of harboring malignancy.

CONCLUSION

Most presumed BD-IPMNs entering surveillance do not become malignant. Of those submitted to surgery, concomitant PDAC adds to the overall risk of detecting malignancy.

ABO Blood Group and Risk of Pancreatic Carcinogenesis in Intraductal Papillary Mucinous Neoplasms

BACKGROUND

ABO blood group has been associated with risks of various malignancies, including pancreatic cancer. No study has evaluated the association of ABO blood group with incidence of pancreatic carcinogenesis during follow-up of patients with intraductal papillary mucinous neoplasms (IPMN).

METHODS

Among 3,164 patients diagnosed with pancreatic cysts at the University of Tokyo (Tokyo, Japan) from 1994 through 2019, we identified 1,815 patients with IPMN with available data on ABO blood group. We studied the association of ABO blood group with incidence of pancreatic carcinoma, overall and by carcinoma types [IPMN-derived carcinoma or concomitant pancreatic ductal adenocarcinoma (PDAC)]. Utilizing competing-risks proportional hazards models, we estimated subdistribution hazard ratios (SHR) for incidence of pancreatic carcinoma with adjustment for potential confounders, including cyst characteristics.

RESULTS

During 11,518 person-years of follow-up, we identified 97 patients diagnosed with pancreatic carcinoma (53 with IPMN-derived carcinoma and 44 with concomitant PDAC). Compared with patients with blood group O, patients with blood groups A, B, and AB had multivariable SHRs (95% confidence intervals) for pancreatic carcinoma of 2.25 (1.25-4.07; P = 0.007), 2.09 (1.08-4.05; P = 0.028), and 1.17 (0.43-3.19; P = 0.76), respectively. We observed no differential association of ABO blood group with pancreatic carcinoma incidence by carcinoma types.

CONCLUSIONS

In this large long-term study, patients with IPMN with blood group A or B appeared to be at higher risk of pancreatic carcinoma compared with those with blood group O.

IMPACT

ABO blood group can be a biomarker for pancreatic cancer risk among patients with IPMNs.

A Review of the Diagnosis and Management of Premalignant Pancreatic Cystic Lesions

Pancreatic cystic lesions are an increasingly common clinical finding. They represent a heterogeneous group of lesions that include two of the three known precursors of pancreatic cancer, intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN). Given that approximately 8% of pancreatic cancers arise from these lesions, careful surveillance and timely surgery offers an opportunity for early curative resection in a disease with a dismal prognosis. This review summarizes the current evidence and guidelines for the diagnosis and management of IPMN/MCN. Current pre-operative diagnostic tests in pancreatic cysts are imperfect and a proportion of patients continue to undergo unnecessary surgical resection annually. Balancing cancer prevention while preventing surgical overtreatment, continues to be challenging when managing pancreatic cysts. Cyst fluid molecular markers, such as KRAS, GNAS, VHL, PIK3CA, SMAD4 and TP53, as well as emerging endoscopic technologies such as needle-based confocal laser endomicroscopy and through the needle microbiopsy forceps demonstrate improved diagnostic accuracy. Differences in management and areas of uncertainty between the guidelines are also discussed, including indications for surgery, surveillance protocols and if and when surveillance can be discontinued.