Evaluating no fixation, endoscopic suture fixation, and an over-the-scope clip for anchoring fully covered self-expanding metal stents in benign upper gastrointestinal conditions: a comparative multicenter international study (With Video).

BACKGROUND AND AIMS: Fully covered self-expandable metal stents (FCSEMSs) are widely used in benign upper gastrointestinal (GI) conditions, but stent migration remains a limitation. An over-the-scope clip (OTSC) device (Stentfix {SF], Ovesco Endoscopy) for stent anchoring has recently been developed. The aim of this study was to evaluate the effect of OTSC fixation on FCSEMS migration rate. METHODS: In this retrospective review of consecutive patients who underwent FCSEMS placement for benign upper GI conditions from January 2011 to October 2022 at 16 centers, the primary outcome was rate of stent migration. The secondary outcomes were clinical success and adverse events. RESULTS: A total of 311 (no fixation [NF] 122, SF 94, endoscopic suturing [ES] 95) patients underwent 316 stenting procedures. Compared with the NF group (n = 49, 39%), the rates of stent migration were significantly lower in the SF (n = 16, 17%, P = .001) and ES (n = 23, 24%, P = .01) groups. The rates of stent migration were not different between the SF and ES groups (P = .2). On multivariate analysis, SF (odds ratio [OR], 0.34, 95% CI, 0.17-0.70, P < .01) and ES (OR, 0.46, 95% CI, 0.23-0.91; P = .02) were independently associated with decreased risk of stent migration. Compared with the NF group (n = 64; 52%), there were higher rates of clinical success in the SF (n = 64; 68%; P = .03) and ES (n = 66; 69%; P = .02) groups. There was no significant difference in the rates of adverse events among the 3 groups. CONCLUSION: Stent fixation using OTSCs is safe and effective at preventing stent migration and may also result in improved clinical response.

Advanced endoscopy meets molecular diagnosis of cholangiocarcinoma.

Cholangiocarcinoma remains an aggressive and deadly malignancy that is often diagnosed late. Intrinsic tumour characteristics and the growth pattern of cancer cells contribute to the challenges of diagnosis and chemoresistance. However, establishing an early and accurate diagnosis, and in some instances identifying targetable changes, has the potential to impact survival. Primary sclerosing cholangitis, a chronic cholangiopathy prodromal to the development of a minority of cholangiocarcinomas, poses a particular diagnostic challenge. We present our diagnostic and theranostic approach to the initial evaluation of cholangiocarcinomas, focusing on extrahepatic cholangiocarcinoma. This involves a multipronged strategy incorporating advanced imaging, endoscopic methods, multiple approaches to tissue sampling, and molecular markers. We also provide an algorithm for the sequential use of these tools.

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.

The Use of Integrated Molecular Testing in the Assessment and Management of Pancreatic Cysts.

PURPOSE OF REVIEW: As abdominal imaging becomes more sensitive and regularly used, pancreatic cystic lesions (PCLs) are being diagnosed more frequently. A small but clinically significant minority of these lesions have a predisposition to either harbor malignancy or undergo malignant transformation. This review highlights the current state and performance of cystic fluid biomarkers and how they may be incorporated into management. RECENT FINDINGS: Among the major domains of molecular testing for PCLs, DNA based analyses have demonstrated the highest accuracy in identifying cyst type and have the most data to support their clinical use. However, epigenetic and protein biomarker based molecular assessments have emerged with the potential to complement DNA based approaches. In addition, recent studies have increasingly demonstrated the value associated with combinations of mutations and other biomarkers in identifying higher grade mucinous cystic lesions. We present the performance of individual biomarkers in cyst fluid analysis with an emphasis on an algorithmic approach to improve the accurate identification of both cyst type and risk of malignant transformation.

Standardization of EUS imaging and reporting in high-risk individuals of pancreatic adenocarcinoma: consensus statement of the Pancreatic Cancer Early Detection Consortium.

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma is an aggressive disease most often diagnosed after local progression or metastatic dissemination, precluding resection and resulting in a high mortality rate. For individuals with elevated personal risk of the development of pancreatic cancer, EUS is a frequently used advanced imaging and diagnostic modality. However, variability in the expertise and definition of EUS findings exists among gastroenterologists, as well as a lack of standardized reporting of relevant findings at the time of examination. Adoption of standardized EUS reporting, using a universally accepted and agreed on terminology, is needed. METHODS: A consensus statement designed to create a standardized reporting template was authored by a multidisciplinary group of experts in pancreatic diseases that includes gastroenterologists, radiologists, surgeons, oncologists, and geneticists. This statement was developed using a modified Delphi process as part of the Pancreatic Cancer Early Detection Consortium, and >75% agreement was required to reach consensus. RESULTS: We identified reporting elements and present standardized reporting templates for EUS indications, procedural data, EUS image capture, and descriptors of findings, tissue sampling, and postprocedural assessment of adequacy. CONCLUSIONS: Adoption of this standardized EUS reporting template should improve consistency in clinical decision-making for individuals with elevated risk of pancreatic cancer by providing complete and accurate reporting of pancreatic abnormalities. Standardization will also help to facilitate research and clinical trial design by using clearly defined and consistent imaging descriptions, thus allowing for comparison of results across different centers.

Interleukin-1ß-induced pancreatitis promotes pancreatic ductal adenocarcinoma via B lymphocyte-mediated immune suppression.

OBJECTIVE: Long-standing chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC). Interleukin-1ß (IL-1ß) has been associated in PDAC with shorter survival. We employed murine models to investigate the mechanisms by which IL-1ß and chronic pancreatitis might contribute to PDAC progression. DESIGN: We crossed LSL-Kras+/G12D;Pdx1-Cre (KC) mice with transgenic mice overexpressing IL-1ß to generate KC-IL1ß mice, and followed them longitudinally. We used pancreatic 3D in vitro culture to assess acinar-to-ductal metaplasia formation. Immune cells were analysed by flow cytometry and immunohistochemical staining. B lymphocytes were adoptively transferred or depleted in Kras-mutant mice. B-cell infiltration was analysed in human PDAC samples. RESULTS: KC-IL1ß mice developed PDAC with liver metastases. IL-1ß treatment increased Kras+/G12D pancreatic spheroid formation. CXCL13 expression and B lymphocyte infiltration were increased in KC-IL1ß pancreata. Adoptive transfer of B lymphocytes from KC-IL1ß mice promoted tumour formation, while depletion of B cells prevented tumour progression in KC-IL1ß mice. B cells isolated from KC-IL1ß mice had much higher expression of PD-L1, more regulatory B cells, impaired CD8+ T cell activity and promoted tumorigenesis. IL-35 was increased in the KC-IL1ß pancreata, and depletion of IL-35 decreased the number of PD-L1+ B cells. Finally, in human PDAC samples, patients with PDAC with higher B-cell infiltration within tumours showed significantly shorter survival. CONCLUSION: We show here that IL-1ß promotes tumorigenesis in part by inducing an expansion of immune-suppressive B cells. These findings point to the growing significance of B suppressor cells in pancreatic tumorigenesis.

Missing links - epigenetic regulators of the pancreatic cancer-associated inflammation.

Pancreatic ductal adenocarcinoma (PDAC) features a hostile tumor microenvironment (TME) that renders it remarkably resistant to most therapeutic interventions. Consequently, survival remains among the poorest compared with other gastrointestinal cancers. Concerted efforts are underway to decipher the complex PDAC TME, break down barriers to efficacious therapies and identify novel treatment strategies. In the recent Clinical Science, Li and colleagues identify the long noncoding RNA KLHDC7B-DT as a crucial epigenetic regulator of IL-6 transcription in PDAC and illustrate its potent influences on the pancreatic TME. In this commentary, we introduce epigenetics in pancreatic cancer and put the findings by Li et al. in context with current knowledge.

Characteristics and Outcomes of Patients Undergoing Endoscopy During the COVID-19 Pandemic: A Multicenter Study from New York City.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted the practice of endoscopy, but characteristics of COVID patients undergoing endoscopy have not been adequately described. AIMS: To compare findings, clinical outcomes, and patient characteristics of endoscopies performed during the pandemic in patients with and without COVID-19. METHODS: This was a retrospective multicenter study of adult endoscopies at six academic hospitals in New York between March 16 and April 30, 2020. Patient and procedure characteristics including age, sex, indication, findings, interventions, and outcomes were compared in patients testing positive, negative, or untested for COVID-19. RESULTS: Six hundred and five endoscopies were performed on 545 patients during the study period. There were 84 (13.9%), 255 (42.2%), and 266 (44.0%) procedures on COVID-positive, negative, and untested patients, respectively. COVID patients were more likely to undergo endoscopy for gastrointestinal bleeding or gastrostomy tube placement, and COVID patients with gastrointestinal bleeding more often required hemostatic interventions on multivariable logistic regression. COVID patients had increased length of stay, intensive care unit admission, and intubation rate. Twenty-seven of 521 patients (5.2%) with no or negative COVID testing prior to endoscopy later tested positive, a median of 13.5 days post-procedure. CONCLUSIONS: Endoscopies in COVID patients were more likely to require interventions, due either to more severe illness or a higher threshold to perform endoscopy. A significant number of patients endoscoped without testing were subsequently found to be COVID-positive. Gastroenterologists in areas affected by the pandemic must adapt to changing patterns of endoscopy practice and ensure pre-endoscopy COVID testing.

Donning a New Approach to the Practice of Gastroenterology: Perspectives From the COVID-19 Pandemic Epicenter.

The COVID-19 pandemic seemingly is peaking now in New York City and has triggered significant changes to the standard management of gastrointestinal diseases. Priorities such as minimizing viral transmission, preserving personal protective equipment, and freeing hospital beds have driven unconventional approaches to managing gastroenterology (GI) patients. Conversion of endoscopy units to COVID units and redeployment of GI fellows and faculty has profoundly changed the profile of most GI services. Meanwhile, consult and procedural volumes have been reduced drastically. In this review, we share our collective experiences regarding how we have changed our practice of medicine in response to the COVID surge. Although we review our management of specific consults and conditions, the overarching theme focuses primarily on noninvasive measures and maximizing medical therapies. Endoscopic procedures have been reserved for those timely interventions that are most likely to be therapeutic. The role of multidisciplinary discussion, although always important, now has become critical. The support of our faculty and trainees remains essential. Local leadership can encourage well-being by frequent team check-ins and by fostering trainee development through remote learning. Advancing a clear vision and a transparent process for how to organize and triage care in the recovery phase will allow for a smooth transition to our new normal.

New onset diabetes predicts progression of low risk pancreatic mucinous cysts.

BACKGROUND: Patients with low-risk lesions require ongoing surveillance since the rate of progression to pancreatic cancer (PC), while small, is much greater than in the general population. Our objective was to study the relationship between new onset diabetes (NODM) and progression in patients with low risk mucinous cysts. METHODS: We evaluated a prospectively maintained cohort of 442 patients with a suspected mucinous cyst without worrisome features (WF) or high-risk stigmata (HRS). Multivariable Cox models were developed for progression to WF and HRS, with diabetes status formulated as both time independent and dependent covariates. The adjusted cumulative risk of progression was calculated using the corrected group prognosis method. RESULTS: The 5-year cumulative progression rates to WFs and HRS were 12.8 and 3.6%, respectively. After controlling for other risk factors, the development of NODM was strongly associated with progression to HRS (HR = 11.6; 95%CI, 3.5-57.7%), but not WF. Among patients with the smallest cysts (<10 mm) at baseline, those who developed NODM had a 5-year adjusted cumulative risk of progression to HRS of 8.6% (95%CI, 0.0%-20.2%), compared to only 0.8% (95%CI, 0.0%-2.3%) for patients without NODM. Among patients with the largest cysts (20-29 mm), those who developed NODM during surveillance had a 5-year adjusted cumulative risk of progression of 53.5% (95%CI, 19.6%-89.9%) compared to only 7.5% (95%CI, 1.6%-15.2%) for patients without NODM. CONCLUSION: New onset diabetes may predict progression in patients with low risk mucinous cysts. Pending validation with large-scale studies, these findings support regular diabetes screening among patients surveilled for suspected IPMNs or MCNs.

Pancreatic cyst surveillance imposes low psychological burden.

BACKGROUND/OBJECTIVES: For the currently recommended pancreatic cyst surveillance to be feasible, participant adherence is a prerequisite. Our objective was to evaluate the psychological burden of pancreatic cyst surveillance from a participant's perspective. METHODS: The present participant survey is part of an international cohort study (PACYFIC study, www.pacyfic.net), which prospectively records the outcome of surveillance of asymptomatic pancreatic cysts. Participants are invited to complete questionnaires before and during cyst surveillance. RESULTS: 109 participants, 31 enrolled before and 78 during surveillance (median time since cyst diagnosis 16.5 (IQR 36) months), returned a total of 179 questionnaires. The majority indicated that surveillance reduces concerns of developing pancreatic cancer (82%), gives a sense of certainty (81%) and is a good method to detect cancer (91%). Participants already undergoing surveillance reported more negative aspects than those still to commence, like sleeping worse (30% vs 13%, P = 0.035), postponing plans (32% vs 13%, P = 0.031), and finding the follow-up burdensome (33% vs 13%, P = 0.044). Overall, the vast majority (94%) deemed advantages to outweigh disadvantages. Anxiety and depression scores were low (median Hospital Anxiety and Depression Scale 4 for anxiety (IQR 6), 2 for depression (IQR 5)). CONCLUSION: The psychological burden of pancreatic cyst surveillance is low. Therefore, participant adherence is expected to be high and annual surveillance seems feasible.

Incremental value of DNA analysis in pancreatic cysts stratified by clinical risk factors.

BACKGROUND AND AIMS: We determined the incremental predictive value of pancreatic cyst fluid molecular analysis to assessing malignancy risk over long-term follow-up of a well-characterized cohort, given the underlying predictive value of imaging parameters routinely used to triage such patients. METHODS: Patients who lacked initial cytologic malignancy in cyst fluid and had final pathology or a follow-up period of more than 2 years were included. Patient outcomes determined the malignancy-free survival of patients with high-risk stigmata (HRS), worrisome features (WFs), and DNA abnormalities. DNA analysis included 3 abnormalities: loss of heterozygosity mutations among a panel of tumor suppressor genes, Kras mutation, and elevated DNA quantity. RESULTS: Included were 478 patients; 209 had surgical pathology-derived outcomes and 269 had clinical follow-up of >2 years. Eleven percent had malignant outcome. Forty-two patients had HRS, 272 lacked both HRS and WFs, and 164 lacked HRS but had WFs. DNA abnormalities did not statistically change long-term malignancy risk in patients with HRS or in patients lacking both HRS and WFs. Among patients with WFs, the presence of ≥2 DNA abnormalities significantly increased malignancy risk (relative risk, 5.2; P = .002) and the absence of all DNA abnormalities significantly decreased risk (relative risk, .4; P = .040). Sensitivity analysis confirmed results of survival analysis over differing baseline malignancy probabilities. CONCLUSIONS: Our study defines the clinical characteristic of patients in which DNA abnormality testing has the greatest impact on patient outcomes. Use of DNA abnormality testing is supported in a carefully selected patient population limited to cysts with WFs.

Comparison of Endoscopic Ultrasound-Fine-Needle Aspiration and Endoscopic Ultrasound-Fine-Needle Biopsy for Solid Lesions in a Multicenter, Randomized Trial.

BACKGROUND & AIMS: Endoscopic ultrasound with fine-needle aspiration (FNA) is the standard of care for tissue sampling of solid lesions adjacent to the gastrointestinal tract. Fine-needle biopsy (FNB) may provide higher diagnostic yield with fewer needle passes. The aim of this study was to assess the difference in diagnostic yield between FNA and FNB. METHODS: This is a multicenter, prospective randomized clinical trial from 6 large tertiary care centers. Patients referred for tissue sampling of solid lesions were randomized to either FNA or FNB of the target lesion. Demographics, size, location, number of needle passes, and final diagnosis were recorded. RESULTS: After enrollment, 135 patients were randomized to FNA (49.3%), and 139 patients were randomized to FNB (50.7%).The following lesions were sampled: mass (n = 210, 76.6%), lymph nodes (n = 46, 16.8%), and submucosal tumors (n = 18, 6.6%). Final diagnosis was malignancy (n = 192, 70.1%), reactive lymphadenopathy (n = 30, 11.0%), and spindle cell tumors (n = 24, 8.8%). FNA had a diagnostic yield of 91.1% compared with 88.5% for FNB (P = .48). There was no difference between FNA and FNB when stratified by the presence of on-site cytopathology or by type of lesion sampled. A median of 1 needle pass was needed to obtain a diagnostic sample for both needles. CONCLUSIONS: FNA and FNB obtained a similar diagnostic yield with a comparable number of needle passes. On the basis of these results, there is no significant difference in the performance of FNA compared with FNB in the cytologic diagnosis of solid lesions adjacent to the gastrointestinal tract. ClinicalTrials.gov identifier: NCT01698190.

Role of Fluorescent In Situ Hybridization, Cholangioscopic Biopsies, and EUS-FNA in the Evaluation of Biliary Strictures.

BACKGROUND AND AIMS: Our goal was to compare the diagnostic accuracy of FISH in the detection of malignancy compared with other standard diagnostic modalities, including brush cytology and biopsy specimens over a 10-year period of prospective data collection. METHODS: We conducted a review of all consecutive biliary strictures evaluated between 2006 and 2016. Patients with a final pathologic diagnosis or conclusive follow-up were included. We evaluated the performance of FISH polysomy (CEP 3, 7, and 17) and 9p21 deletion as well as cholangioscopic biopsy (CBx) and EUS-FNA. Statistical analysis was performed with the Mann-Whitney U and Fisher's exact tests. RESULTS: Of 382 patients with indeterminate strictures, 281 met inclusion criteria. Forty-nine percent were malignant. Cytology, FISH polysomy, and FISH polysomy/9p21 showed a specificity of 99.3%. FISH polysomy/9p21 as a single modality was the most sensitive at 56% (p < 0.001). The sensitivity of FISH polysomy/9p21 and cytology was significantly higher than cytology alone at 63 versus 35% (p < 0.05). EUS-FNA for distal strictures and CBx for proximal strictures increased sensitivity from 33 to 93% (p < 0.001) and 48-76% (p = 0.05) in cytology-negative strictures. CONCLUSIONS: The high specificity of FISH polysomy/9p21 suggests that a positive result is sufficient for diagnosing malignancy in indeterminate strictures. The significantly higher sensitivity of FISH polysomy/9p21 compared to cytology supports the use of FISH in all non-diagnostic cases. Although both EUS-FNA and CBx were complimentary, our results suggest that distal strictures should be evaluated by EUS initially. Proximal strictures may be evaluated by FISH first and then by CBx if inconclusive.

Mutation Profile and Fluorescence In Situ Hybridization Analyses Increase Detection of Malignancies in Biliary Strictures.

BACKGROUND & AIMS: It is a challenge to detect malignancies in biliary strictures. Various sampling methods are available to increase diagnostic yield, but these require additional procedure time and expertise. We evaluated the combined accuracy of fluorescence in situ hybridization (FISH) and polymerase chain reaction-based DNA mutation profiling (MP) of specimens collected using standard brush techniques. METHODS: We performed a prospective study of 107 consecutive patients treated for biliary strictures by endoscopic retrograde cholangiopancreatography from June 2012 through June 2014. We performed routine cytology and FISH analyses on cells collected by standard brush techniques, and analyzed supernatants for point mutations in KRAS and loss-of-heterozygosity mutations in tumor-suppressor genes at 10 loci (MP analysis was performed at Interpace Diagnostics). Strictures were determined to be nonmalignant based on repeat image analysis or laboratory test results 12 months after the procedure. Malignant strictures were identified based on subsequent biopsy or cytology analyses, pathology analyses of samples collected during surgery, or death from biliary malignancy. We determined the sensitivity and specificity with which FISH and MP analyses detected malignancies using the exact binomial test. RESULTS: Our final analysis included 100 patients; 41% had biliary malignancies. Cytology analysis identified patients with malignancies with 32% sensitivity and 100% specificity. Addition of FISH or MP results to cytology results increased the sensitivity of detection to 51% (P < .01) without reducing specificity. The combination of cytology, MP, and FISH analyses detected malignancies with 73% sensitivity (P < .001). FISH identified an additional 9 of the 28 malignancies not detected by cytology analysis, and MP identified an additional 8 malignancies. FISH and MP together identified 17 of the 28 malignancies not detected by cytology analysis. CONCLUSIONS: Addition of FISH and mutation analyses to cytology analysis significantly increased the level of sensitivity with which we detected malignancy in biliary strictures, with 100% specificity. These techniques can be performed using standard brush samples collected during endoscopic retrograde cholangiopancreatography, with mutations detected in free DNA in supernatant fluid of samples. The tests are complementary and therefore should be used sequentially in the diagnostic evaluation of biliary strictures.

Endoscopic septotomy: an effective approach for internal drainage of sleeve gastrectomy-associated collections.

Background and study aims Staple-line leaks occur in 1 % - 7 % of patients who undergo sleeve gastrectomy, and can be challenging to treat. The success of endoscopic approaches decreases as leaks develop into chronic sinus tracts. Endoscopic septotomy has been used to facilitate healing of refractory leaks by incision and enlargement of the tract to allow direct communication with the gastric lumen and internal drainage. Patients and methods We reviewed the technique and outcomes among patients who underwent endoscopic septotomy at two centers for the management of sleeve gastrectomy-associated gastric fistulas and perigastric collections refractory to occlusive endoscopic therapies. Results Nine patients underwent endoscopic septotomy at a mean of 8.6 weeks after leak diagnosis, following failure of percutaneous and conventional endoscopic modalities. Perigastric collections ranged from 3 cm to 10 cm in size. The mean procedure time for endoscopic septotomy was 87.2 minutes. Multiple endoscopic septotomy procedures (mean 2.3, range 1 - 4) were required to achieve radiological resolution. The mean follow-up period was 21.2 weeks, and all nine patients achieved symptom resolution without the need for surgery. Bleeding at the time of endoscopic septotomy occurred in three patients, and was managed with endoscopic clips and did not require transfusion. No other adverse events or delayed complications were recorded. Conclusions Endoscopic septotomy appears to be a safe and effective technique for the management of sleeve gastrectomy-associated fistulae and collections, including those refractory to other endoscopic and percutaneous methods.

Long-Term Surveillance and Timeline of Progression of Presumed Low-Risk Intraductal Papillary Mucinous Neoplasms.

OBJECTIVE: The purpose of this study was to assess risk of progression and rate of growth of presumed low-risk branch duct intraductal papillary mucinous neoplasms surveyed for more than 4 years. MATERIALS AND METHODS: A keyword search of electronic medical charts was performed for the years 2001-2013. Cystic lesions that met the criteria for clinical branch duct intraductal papillary mucinous neoplasm, lacked baseline high-risk or worrisome features, and had more than 4 years of surveillance were included in this study. Two radiologists performed cyst size measurements to assess interreader variability. Cyst progression was defined either as 2-mm or greater or 20% or greater increase in diameter or as development of worrisome features. Kaplan-Meier curves were generated to evaluate cyst progression time and linear mixed models to evaluate growth rates. RESULTS: The search revealed 2423 patients with cystic pancreatic lesions. Among these patients 228 had imaging follow-up for 4 or more years, and 131 met the clinical criteria for branch duct intraductal papillary mucinous neoplasms. Among the 131 cysts, 73 (55.7%) progressed: 61 (46.6%) increased in size, 10 (7.6%) increased in size and developed worrisome features, and two (1.5%) developed worrisome features only. Of the 71 cysts that increased in size, 50 (70.4%) did so within the first 5 years, and 21 (29.6%) grew after 5 years. No patient had adenocarcinoma. There was no significant difference in growth rate based on cyst size within the first 50 months. After 50 months, cysts larger than 20 mm continued to increase in size (p < 0.05) and had faster growth rates. CONCLUSION: Among presumed low-risk branch duct intraductal papillary mucinous neoplasms, most increased in size, approximately 30% after 5 years. Cysts with baseline size larger than 20 mm continued to grow beyond 5 years at a faster rate.