Natural history of branch duct intraductal papillary mucinous neoplasms of the pancreas: a multicenter study in Japan

Clinicopathological and prognostic significance of MUC13 and AGR2 expression in intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a primary pancreatic ductal epithelial neoplasm with the potential to develop into an invasive adenocarcinoma. This study aimed to investigate the clinicopathologic and prognostic significance of four potential biomarkers for the preoperative evaluation of patients with IPMN.

MATERIALS AND METHODS

Clinicopathologic materials from 104 patients with IPMN who underwent surgical resection at Jichi Medical University Hospital were analyzed. IPMNs (110 lesions in total) were histologically classified into low-grade IPMN (Group 1; n = 68), high-grade IPMN (Group 2; n = 16), or IPMN with an associated invasive carcinoma (Group 3; n = 26). We evaluated the immunohistochemical expression of MUC13, AGR2, FUT8, and FXYD3, which were previously reported to be overexpressed in pancreatic ductal adenocarcinoma.

RESULTS

The expression of MUC13 was more common in Group 3 compared with groups 1 and 2 (p < 0.001) and was associated with poor prognosis (p = 0.004). The expression of MUC13 was not associated with age, sex, tumor location, histological subtype, lymphatic or vascular invasion, or neural invasion. In most cases of IPMN, the loss of expression of AGR2 appeared to show an association with tumor recurrence and poorly differentiated histology of invasive carcinoma; however, this association was not statistically significant. The expressions of FUT8 and FXYD3were not associated with the clinicopathological features of IPMNs.

CONCLUSIONS

The results suggest that MUC13 overexpression and loss of expression of AGR2 may predict the progression of IPMN and an unfavorable prognosis in patients with IPMN.

Utility of transabdominal ultrasound for surveillance of known pancreatic cystic lesions: prospective evaluation with MRI as reference standard

OBJECTIVES

To prospectively assess the utility of transabdominal ultrasound in surveillance of known pancreatic cystic lesions (PCL) using same day MRI as reference standard.

METHODS

In an IRB-approved study with written informed consent, patients with known PCL underwent pancreas US on same day as surveillance MRI. US was performed blinded to same date MRI results. Transverse (TR), antero-posterior (AP), cranio-caudal (CC), and longest any plane diameter, were measured for each PCL at US and MRI. Visualization was correlated with patient (weight, abdominal diameter, thickness of abdominal fat, sex) and cyst (location, size, internal complexity) factors.

RESULTS

252 PCLs evaluated in 57 subjects (39 females; mean age 67 (range 39-86) yrs). Mean maximum PCL diameter 8.5 (range 2-92) mm. US identified 100% (5/5) of cysts ≥3 cm; 92% (12/13) ≥2 and <3 cm; 78% (43/55) ≥1 and <2 cm; 35% (27/78) ≥5 mm and <1 cm; and 16% (16/101) <5 mm. US visualization correlated with PCL location (<0.0001), size (p < 0.0001), patient gender (p = 0.005), participation of attending radiologist (p = 0.03); inversely with patient weight (p = 0.012) and AP abdominal diameter (p = 0.01).

CONCLUSION

Many PCLs are visualized and accurately measured at follow-up with transabdominal ultrasound. Visualization correlates with lesion size, location, patient sex, weight, and abdominal diameter.

Intraductal Papillary Mucinous Neoplasm of the Pancreas as the Main Focus for Early Detection of Pancreatic Adenocarcinoma

For early detection of pancreatic cancer, interests are now focused on the detection of high-risk individuals to undergo screening examinations. Intraductal papillary mucinous neoplasm (IPMN) is a unique dual precursor of pancreatic cancer, characterized by progression to invasive cancer and the development of pancreatic adenocarcinoma either concomitantly (synchronous occurrence) or even after resection of IPMN (metachronous occurrence). Careful examination and surveillance of patients with IPMN may therefore lead to early detection of pancreatic cancer. By reviewing only reports describing detailed breakdown of the morphological types of IPMN and numbers of patients with noninvasive and invasive carcinoma in each type, the rough frequencies of noninvasive carcinoma in main duct IPMNs and branch duct IPMNs (BD-IPMNs) are 20% and 10%, respectively, and those of invasive carcinoma are 40% and 13%, respectively. Roughly 5% of all patients with IPMN had concomitant adenocarcinoma. The real frequency of carcinoma in BD-IPMNs would be far lower because most patients with small asymptomatic BD-IPMNs do not undergo resection. Intraductal papillary mucinous neoplasm can be the main focus for early detection of pancreatic cancer to achieve favorable prognosis after surgical resection. The optimal protocol for surveillance and method for early detection of pancreatic cancer are to be determined.

ACG Clinical Guideline: Diagnosis and Management of Pancreatic Cysts

Pancreatic cysts are very common with the majority incidentally identified. There are several types of pancreatic cysts; some types can contain cancer or have malignant potential, whereas others are benign. However, even the types of cysts with malignant potential rarely progress to cancer. At the present time, the only viable treatment for pancreatic cysts is surgical excision, which is associated with a high morbidity and occasional mortality. The small risk of malignant transformation, the high risks of surgical treatment, and the lack of high-quality prospective studies have led to contradictory recommendations for their immediate management and for their surveillance. This guideline will provide a practical approach to pancreatic cyst management and recommendations for cyst surveillance for the general gastroenterologist.

Early Diagnosis to Improve the Poor Prognosis of Pancreatic Cancer

Pancreatic cancer (PC) has a poor prognosis due to delayed diagnosis. Early diagnosis is the most important factor for improving prognosis. For early diagnosis of PC, patients with clinical manifestations suggestive of PC and high risk for developing PC need to be selected for examinations for PC. Signs suggestive of PC (e.g., symptoms, diabetes mellitus, acute pancreatitis, or abnormal results of blood examinations) should not be missed, and the details of risks for PC (e.g., familial history of PC, intraductal mucin producing neoplasm, chronic pancreatitis, hereditary pancreatitis, or life habit) should be understood. Multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) can be performed for diagnosing PC, but the diagnostic ability of these examinations for PC is limited. Endoscopic diagnostic procedures, such as endoscopic ultrasonography, including fine-needle aspiration, and endoscopic retrograde pancreatocholangiography, including Serial Pancreatic-juice Aspiration Cytologic Examination (SPACE), could be recommended for a detailed examination to diagnose pancreatic carcinoma earlier.

Meta-analysis of mortality in patients with high-risk intraductal papillary mucinous neoplasms under observation

BACKGROUND

Although consensus guidelines suggest that patients with high-risk intraductal papillary mucinous neoplasms (IPMNs) should have surgery, a non-operative strategy is often selected in patients who are poor surgical candidates. The aim was to determine the risk of disease-related death from IPMN in patients with worrisome features or high-risk stigmata who were kept under observation.

METHODS

A PubMed literature search was undertaken of articles published from August 1992 to June 2016 (updated October 2017). The methodology was developed from PRISMA and MOOSE checklists. Incidence proportions and rates of overall and IPMN-related deaths were calculated, with subgroup analyses for main-duct/mixed-type and branch-duct IPMNs. Quality of the studies, publication bias and heterogeneity were explored.

RESULTS

Six studies reported data on overall mortality and eight described disease-specific mortality for 556 patients during follow-up ranging from 24·9 to 60·0 months. Pooled rates of overall and IPMN-related mortality were 30·9 (95 per cent c.i. 19·6 to 45·1) and 11·6 (6·0 to 21·2) per cent respectively. The pooled incidence rate for overall mortality was substantially higher than that for IPMN-related mortality: 78 (95 per cent c.i. 44 to 111) and 23 (9 to 37) per 1000 patient-years respectively. The pooled incidence rate for disease-specific mortality was considerably lower for branch-duct than for main-duct or mixed-type IPMNs: 5 (0 to 10) and 32 (12 to 52) per 1000 patient-years respectively.

CONCLUSION

In patients unfit for surgery, IPMN-related mortality among patients with worrisome features and high-risk stigmata is low, and the risk of death from other causes much higher.

Predictive performance of factors associated with malignancy in intraductal papillary mucinous neoplasia of the pancreas

Background

Estimation of the risk of malignancy in intraductal papillary mucinous neoplasia (IPMN) of the pancreas is a clinical challenge. Several routinely used clinical factors form the basis of the current consensus guidelines. This study aimed to determine the predictive values of the most commonly assessed risk factors.

Methods

A meta-analysis of individual risk factors of malignancy in IPMN was performed. Contingency tables were derived from these data, and sensitivity, specificity, negative and positive predictive values, and diagnostic odds ratios (DOR) were determined. Hierarchical summary receiver operating characteristic (HSROC) curves for each factor were calculated and the respective area under the curve (AUC) was assessed.

Results

A total of 3443 studies were screened initially. Analysis of recent literature revealed 60 studies with 13 relevant risk factors including clinical, serological and radiological parameters. The largest area under the HSROC curve was found for weight loss (0·84) and jaundice/raised bilirubin level (0·80), followed by increased carcinoembryonic antigen (CEA) (0·79) or carbohydrate antigen (CA) 19-9 (0·78) levels. The most sensitive factors were patient age (71 per cent) and mural nodules (65 per cent), and jaundice/raised bilirubin level (97 per cent) and increased CEA level (95 per cent) were most specific. None of the analysed factors reached a positive or negative level of prediction beyond 90 per cent.

Conclusion

None of the established criteria safely distinguishes malignant from non-malignant lesions.

An elevated expression of serum exosomal microRNA-191, - 21, -451a of pancreatic neoplasm is considered to be efficient diagnostic marker

BACKGROUND

Pancreatic cancer is associated with an extremely poor prognosis, so new biomarkers that can detect the initial stages are urgently needed. The significance of serum microRNA (miR) levels in pancreatic neoplasm such as pancreatic cancer and intraductal papillary mucinous neoplasm (IPMN) diagnosis remains unclear. We herein evaluated the usefulness of miRs enclosed in serum exosomes (ExmiRs) as diagnostic markers.

METHODS

The ExmiRs from patients with pancreatic cancer (n = 32) or IPMN (n = 29), and patients without neoplasms (controls; n = 22) were enriched using ExoQuick-TC™. The expression of ExmiRs was evaluated using a next-generation sequencing analysis, and the selected three miRs through this analysis were confirmed by a quantitative real-time polymerase chain reaction.

RESULTS

The expression of ExmiR-191, ExmiR-21 and ExmiR-451a was significantly up-regulated in patients with pancreatic cancer and IPMN compared to the controls (p < 0.05). A receiver operating characteristic curve analysis showed that the area under the curve and the diagnostic accuracy of ExmiRs were 5-20% superior to those of three serum bulky circulating miRs (e.g.; ExmiR-21: AUC 0.826, accuracy 80.8%. Circulating miR-21: AUC 0.653, accuracy 62.3%). In addition, high ExmiR-451a was associated with mural nodules in IPMN (p = 0.010), and high ExmiR-21 was identified as a candidate prognostic factor for the overall survival (p = 0.011, HR 4.071, median OS of high-ExmiR-21: 344 days, median OS of low-ExmiR-21: 846 days) and chemo-resistant markers (p = 0.022).

CONCLUSIONS

The level of three ExmiRs can thus serve as early diagnostic and progression markers of pancreatic cancer and IPMN, and considered more useful markers than the circulating miRs (limited to these three miRs).

Natural history of pancreatic cystic lesions: A multicenter prospective observational study for evaluating the risk of pancreatic cancer

BACKGROUND AND AIM

The aim of this study is to elucidate the natural history of pancreatic cystic lesions (PCLs), including branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN), via midterm follow-up analysis of a multicenter prospective observational study (NSPINAL study).

METHODS

From July 2011 to October 2016, 881 patients with PCLs were enrolled in NSPINAL study, and 664 patients with > 12 months of follow up were analyzed. Every patient was asymptomatic, and endoscopic ultrasound was performed at the initial diagnosis to exclude high-risk individuals. Follow up included endoscopic ultrasound, computed tomography, or magnetic resonance imaging at least once a year. Serial morphological changes and the pancreatic cancer (PC) incidence, including malignant progression of PCLs, were evaluated.

RESULTS

The 664 patients (358 men) were followed for a median of 33.5 months (interquartile range 29). The cyst and main pancreatic duct sizes were 16.6 ± 9.3 and 2.3 ± 1.0 mm, respectively. Morphologically, 518 cases were multilocular, 137 were unilocular, and 9 had a honeycomb pattern; 269 cases involved multifocal lesions. Ninety-six patients (14.5%) showed worsening progression on imaging. There were two resectable and four unresectable cases of pancreatic ductal adenocarcinoma and three cases of malignant BD-IPMN. The 3-year risk of developing PC was 1.2%. The standardized incidence ratio for PC among PCLs was 10.0 (95% confidence interval 3.5-16.5), and the standardized incidence ratio among BD-IPMN was 16.6 (95% confidence interval 5.1-28.1). Multivariate analysis showed that development of symptoms and worsening progression were significant predictors of PC.

CONCLUSIONS

Malignant progression of PCLs, including PC development, is not uncommon. Patients with PCLs should be carefully monitored to detect pancreatic ductal adenocarcinoma at early stages.

Surveillance of patients with intraductal papillary mucinous neoplasm with and without pancreatectomy with special reference to the incidence of concomitant pancreatic ductal adenocarcinoma

BACKGROUND

The presence of an intraductal papillary mucinous neoplasm is important in the detection of concomitant pancreatic ductal adenocarcinoma. The aim of this study was to elucidate the incidence and timing of development of concomitant pancreatic ductal adenocarcinoma in patients with and without pancreatectomy for intraductal papillary mucinous neoplasm.

METHODS

We reviewed retrospectively the surveillance data for 22 patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma concomitant with intraductal papillary mucinous neoplasm (pancreatic ductal adenocarcinoma-resection group), 180 who underwent pancreatectomy for intraductal papillary mucinous neoplasm (intraductal papillary mucinous neoplasm-resection group), and 263 whose intraductal papillary mucinous neoplasms were left untreated (nonresection group). The incidence and timing of the development of a concomitant pancreatic ductal adenocarcinoma during the surveillance of patients with and without partial pancreatectomy for intraductal papillary mucinous neoplasm were investigated using the Kaplan-Meier method.

RESULTS

During a median surveillance period of 40 months (range 6-262 months), 5 patients in the pancreatic ductal adenocarcinoma-resection group, 6 in the intraductal papillary mucinous neoplasm-resection group, and 8 in the nonresection group developed concomitant pancreatic ductal adenocarcinoma. The estimated 5-year (17%) and 10-year (56%) cumulative incidences of secondary pancreatic ductal adenocarcinoma in the pancreatic ductal adenocarcinoma-resection group were significantly greater than those in the other two groups (P < .01). Conversely, the difference in the estimated cumulative incidence of concomitant pancreatic ductal adenocarcinoma between the intraductal papillary mucinous neoplasm-resection and nonresection groups was not significant (5-year, 5.0% vs 2.2%; 10-year, 5.0% vs 8.7%; P = .87).

CONCLUSION

Long-term (≥5-year) surveillance in patients with intraductal papillary mucinous neoplasm is necessary and important because of the potential for development of concomitant pancreatic ductal adenocarcinoma. Those with a history of resection of concomitant pancreatic ductal adenocarcinoma at the time of the initial operation are at quite high risk for the development of secondary pancreatic ductal adenocarcinoma.

Effect of low-dose aspirin use on pancreatic cancer development and morphological changes on imaging in IPMN: A long-term cohort study

Background

Aspirin use may reduce the incidence of pancreatic cancer (PC), but no data are available regarding its chemopreventive effects on intraductal papillary mucinous neoplasm (IPMN). We aimed to determine whether low-dose aspirin (LDA) reduces PC development and morphological changes on imaging in IPMN patients.

Methods

A cohort of 448 IPMN patients periodically followed up with imaging tests was analyzed. We used one-to-two propensity score matching to adjust for differences between an LDA group (n = 63) and a non-LDA group (n = 385). Outcomes included increasing cyst diameter, increasing main pancreatic duct (MPD) diameter, mural nodule (MN) appearance and PC development.

Results

After matching, 63 LDA and 126 non-LDA patients were selected. During follow-up (median, 5.5 years), no significant differences were found in increasing cyst diameter, MN appearance, or PC development. However, there were significantly fewer cases of increasing MPD diameter in the LDA group (4.8% vs. 12.7%; p = 0.02). After adjustment for age and sex, LDA still decreased the risk of increasing MPD diameter (hazard ratio, 0.17; p = 0.02).

Conclusion

Our results do not support a chemopreventive effect of LDA on PC development. However, LDA reduces further MPD dilation in IPMN patients.

Long-term Risk of Pancreatic Malignancy in Patients With Branch Duct Intraductal Papillary Mucinous Neoplasm in a Referral Center

BACKGROUND & AIMS

Little is known about the development of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs). We evaluated long-term outcomes of a large cohort of patients with BD-IPMNs to determine risk of malignancy and define a subset of low-risk BD-IPMNs.

METHODS

We performed a retrospective analysis of data from 577 patients with suspected or presumed BD-IPMN under surveillance at the Massachusetts General Hospital. Patients underwent cross-sectional imaging analysis at 3 months or later after their initial diagnosis. The diagnosis of BD-IPMN was based on the presence of unilocular or multilocular cysts of the pancreas and a non-dilated main pancreatic duct (<5 mm). We collected demographic, clinical, and pathology data. Cysts were characterized at the time of diagnosis and during the follow-up period. Follow-up duration was time between initial cyst diagnosis and date of last visit or death for patients without development of pancreatic cancer, date of surgery for patients with histologically confirmed malignancy, or date of first discovery of malignancy by imaging analysis for patients with unresectable tumors or who underwent neoadjuvant treatment before surgery. The primary outcome was risk of malignancy, with a focus on patients followed for 5 years or more, compared with that of the US population, based on standardized incidence ratio.

RESULTS

Of the 577 patients studied, 479 (83%) were asymptomatic at diagnosis and 363 (63%) underwent endoscopic ultrasound at least once. The median follow-up time was 82 months (range, 6-329 months) for the entire study cohort; 363 patients (63%) underwent surveillance for more than 5 years, and 121 (21%) for more than 10 years. Malignancies (high-grade dysplasia or invasive neoplasm) developed after 5 years in 20 of 363 patients (5.5%), and invasive cancer developed in 16 of 363 patients (4.4%). The standardized incidence ratio for patients with BD-IPMNs without worrisome features of malignancy at 5 years was 18.8 (95% confidence interval, 9.7-32.8; P < .001). One hundred and eight patients had cysts ≤1.5 cm for more than 5 years of follow-up; only 1 of these patients (0.9%) developed a distinct ductal adenocarcinoma. By contrast, among the 255 patients with cysts >1.5 cm, 19 (7.5%) developed malignancy (P = .01).

CONCLUSIONS

In a retrospective analysis of patients with BD-IPMNs under surveillance, their overall risk of malignancy, almost 8%, lasted for 10 years or more, supporting continued surveillance after 5 years. Cysts that remain ≤1.5 cm for more than 5 years might be considered low-risk for progression to malignancy.

Incidences of Pancreatic Malignancy and Mortality in Patients With Untreated Branch-Duct Intraductal Papillary Mucinous Neoplasms Undergoing Surveillance: A Systematic Review

OBJECTIVE

The aim of this study was to pool incidences of increased cyst size, malignant branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs), pancreatic malignancy, and pancreatic malignancy-related death during follow-up (FU) of BD-IPMN patients.

METHODS

Searches were performed from January 2010 to April 2016. All hits were checked on inclusion criteria, and outcomes were extracted. Incidences were pooled. Three subgroups were defined: (1) including only BD-IPMN patients, (2) short-interval FU (maximum 6 months), and (3) long-interval FU (>6 months).

RESULTS

Thirty-one articles were enrolled, including 8455 patients (mean age, 66.4 years). Twenty-two studies included subgroup 1; 10 and 6 studies included, respectively, subgroups 2 and 3. Incidence of increased cyst size was 17.4%. In subgroups 1, 2, and 3, incidences were, respectively, 20.0%, 17.2%, and 31.7%. Incidence of malignant BD-IPMN was 2.5. In subgroups 1, 2, and 3, incidences were, respectively, 3.0%, 2.4%, and 3.3%. Incidence of pancreatic malignancy was 2.6%. In subgroups 1, 2, and 3, incidences were, respectively, 2.3%, 1.2%, and 4.0%. Incidence of death was 0.5%. In subgroups 1, 2, and 3, incidences were, respectively, 0.4%, 0.04%, and 0.12%.

CONCLUSIONS

Although not significant, all incidences on long-interval FU were higher; therefore, short-interval FU seems necessary to find resectable lesions.

Endoscopic Ultrasound Imaging for Diagnosing and Treating Pancreatic Cysts

Cystic pancreatic lesions are increasingly diagnosed owing to the abundant use of cross-sectional imaging. Given their malignant potential, true pancreatic cysts should be considered for resection or periodic follow-up. Cystic lesions of the pancreas (CLPs) require further evaluation and management. Therefore, it is important to establish a solid diagnosis at the time of detection. Endoscopic ultrasound examination is the imaging modality of choice. Fine needle aspiration provides fluid for cytologic, biochemical, and molecular assays to classify lesions and predict biological behavior. This review provides an overview of the diagnosis and management of various types of commonly encountered true CLPs.

Fukuoka criteria accurately predict risk for adverse outcomes during follow-up of pancreatic cysts presumed to be intraductal papillary mucinous neoplasms

OBJECTIVE

Fukuoka consensus guidelines classify pancreatic cystic lesions (PCLs) presumed to be intraductal papillary mucinous neoplasms (IPMNs) into Fukuoka positive (FP) (subgroups of high-risk (HR) and worrisome features (WFs)) and Fukuoka negative (FN) (non-HR feature/WF cysts). We retrospectively estimated 5-year risk of pancreatic cancer (PC) in FN, WF and HR cysts of patients with PCL-IPMN.

DESIGN

From Mayo Clinic databases, we randomly selected 2000 patients reported to have a PCL; we excluded inflammatory or suspected non-IPMN cysts and those without imaging follow-up. We re-reviewed cross-sectional imaging and abstracted clinical and follow-up data on PCL-IPMNs. The study contained 802 patients with FN cysts and 358 with FP cysts.

RESULTS

Patients with PCL-IPMN had median (IQR) follow-up of 4.2 (1.8-7.1) years. Among FN cysts, 5-year PC risk was low (2-3%) regardless of cyst size (p=0.67). After excluding events in the first 6 months, 5-year PC risk remained low (0-2%) regardless of cyst size (p=0.61). Among FP cysts, HR cysts (n=66) had greater 5-year PC risk than WF cysts (n=292) (49.7% vs 4.1%; p<0.001). In HR cysts, 3-year PC risk was greatest for obstructive jaundice versus enhancing solid component or main pancreatic duct >10 mm (79.8% vs 37.3% vs 39.4%, respectively; p=0.01).

CONCLUSIONS

Fukuoka guidelines accurately stratify PCL-IPMNs for PC risk, with FN cysts having lowest and HR cysts having greatest risk. After 6-month follow-up, WF and FN cysts had a low 5-year PC risk. Surveillance strategies should be tailored appropriately.

Validation of the American Gastroenterological Association guidelines on management of intraductal papillary mucinous neoplasms: more than 5 years of follow-up

OBJECTIVES

Recent guidelines suggest that imaging surveillance be conducted for 5 years for patients with at most one high-risk feature. If there were no significant changes, surveillance is stopped. We sought to validate this follow-up strategy.

METHODS

In study 1, data were analysed for 392 patients with intraductal papillary mucinous neoplasms (IPMNs) and at most one high-risk feature who were periodically followed up for more than 1 year with imaging tests. In study 2, data were analysed for 159 IPMN patients without worsening high-risk features after 5 years (stop surveillance group).

RESULTS

In study 1, pancreatic cancer (PC) was identified in 12 patients (27.3%) in the endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) indication group and none in the non-EUS-FNA indication group (P < 0.01). In the EUS-FNA indication group, 11 patients (25%) died, whereas 29 (8.3%) died in the non EUS-FNA indication group (P < 0.01). In study 2 (stop surveillance group), PC was identified in three patients (1.9%) at 84, 103 and 145 months.

CONCLUSIONS

PC risk and mortality for IPMNs not showing significant change for 5 years is likely to be low, and the non-EUS-FNA indication can provide reasonable decisions. However, three patients without worsening high-risk features for 5 years developed PC. The stop surveillance strategy should be reconsidered.

KEY POINTS

• The AGA guidelines provide reasonable clinical decisions for the EUS-FNA indication. • In stop surveillance group, PC was identified in 3 patients (1.9%). • In stop surveillance group, 2 of 3 PC patients died from PC. • Risk of pancreatic cancer in "stop surveillance" group is not negligible.

Surveillance and Outcomes of Nonresected Presumed Branch-Duct Intraductal Papillary Mucinous Neoplasms: A Meta-analysis

OBJECTIVES

Guidelines regarding the surveillance of intraductal papillary mucinous neoplasms (IPMNs) are controversial because of uncertain risk of malignancy, agnosticism regarding the use of endoscopic ultrasound, and their recommendation to stop surveillance after 5 years. We present a systematic review and meta-analysis of the risk of malignancy and other end points and estimate the value of endoscopic ultrasound for surveillance.

METHODS

We systematically searched MEDLINE for studies with a cohort of patients with presumed branch-duct IPMN who initially were managed nonsurgically. Data regarding study characteristics, surveillance, and outcomes were extracted. Incidence rates of morphologic progression, malignancy, surgery, and death were calculated with a random effects model.

RESULTS

Twenty-four studies with 3440 patients and 13,097 patient-years of follow-up were included. Rates of morphologic progression, surgery, malignancy, and death were 0.0379, 0.0250, 0.0098, and 0.0043 per patient-year, respectively. Endoscopic ultrasound was not associated with significantly different rates of these outcomes.

CONCLUSIONS

The risk of malignancy calculated in this study was low and in line with recent systematic reviews. Endoscopic ultrasound does not have marginal use in surveillance. Given the limitations of a systematic review of nonrandomized studies, further studies are needed to determine the optimal surveillance of branch-duct IPMNs.

Editorial: Management of the Small Asymptomatic Pancreatic Cyst: Somehow Along the Way We Forgot About the Patient

The incidentally identified pancreatic cyst is an increasing burden for both physicians and patients alike. Although we recognize that most of these lesions are benign and may not progress, a subset of these lesions are premalignant, may have frank cancer, and may progress over time. Most occur in older patients who have associated comorbidity. Recent studies highlight neoplastic features of these cysts that when present may warrant surgery or close long-term follow-up; however, there has been little study on the natural history factoring in patient comorbidity and pancreatic cancer-free survival. This retrospective cohort study underscores the importance of patient comorbidity in our management algorithm, and these data should prompt subsequent guidelines to factor in such comorbidity.

Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas

The management of intraductal papillary mucinous neoplasm (IPMN) continues to evolve. In particular, the indications for resection of branch duct IPMN have changed from early resection to more deliberate observation as proposed by the international consensus guidelines of 2006 and 2012. Another guideline proposed by the American Gastroenterological Association in 2015 restricted indications for surgery more stringently and recommended physicians to stop surveillance if no significant change had occurred in a pancreatic cyst after five years of surveillance, or if a patient underwent resection and a non-malignant IPMN was found. Whether or not it is safe to do so, as well as the method and interval of surveillance, has generated substantial debate. Based on a consensus symposium held during the meeting of the International Association of Pancreatology in Sendai, Japan, in 2016, the working group has revised the guidelines regarding prediction of invasive carcinoma and high-grade dysplasia, surveillance, and postoperative follow-up of IPMN. As the working group did not recognize the need for major revisions of the guidelines, we made only minor revisions and added most recent articles where appropriate. The present guidelines include updated information and recommendations based on our current understanding, and highlight issues that remain controversial or where further research is required.

Pancreatic Cysts - Part 2: Should We Be Less Cyst Centric?

The management of pancreatic cysts is a common problem faced by physicians and surgeons. Pancreatic cysts are important because some of them are mucin-producing cysts (MPCs), which may harbor or develop pancreatic ductal adenocarcinoma. Thus, accurate classification of pancreatic cysts and diagnosis of MPCs offer a potential for the prevention or early detection of pancreatic cancer. However, the diagnosis and management of asymptomatic pancreatic cysts are complicated by 2 factors. First, incidentally detected pancreatic cysts are often misdiagnosed as branch duct intraductal papillary mucinous neoplasms. Although most are MPCs, there are other types of cysts, such as serous cystadenomas, which are managed differently. Second, only a minority of MPCs will ultimately develop into invasive pancreatic ductal adenocarcinoma. Thus, on the one hand, pancreatic cysts offer a unique opportunity to identify precursors to pancreatic cancer and improve outcomes. On the other hand, misdiagnosis and overzealous testing or unnecessary surgery may lead to high cost and harm to patients. Several guidelines have been developed by various groups for the management of pancreatic cysts. In this article, we review the strengths and weaknesses of the American Gastroenterology Association guidelines, highlight key recommendations requiring further validation, and provide our balanced approach to diagnosing and managing pancreatic cysts.

Endoscopic Management of Pancreatic Cysts

Management of pancreatic cystic lesions relies on patients' clinical presentation, imaging, and endoscopic ultrasound. Current research in basic science, radiology, and endoscopy is evolving and making progress in this condition which is relatively common in the general population. This review focuses on the recent endoscopic ultrasound approaches to the diagnosis of these pancreatic disorders.

Management of Incidental Pancreatic Cysts: A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee (IFC) presents recommendations for managing pancreatic cysts that are incidentally detected on CT or MRI. These recommendations represent an update from the pancreatic component of the JACR 2010 white paper on managing incidental findings in the adrenal glands, kidneys, liver, and pancreas. The Pancreas Subcommittee-which included abdominal radiologists, a gastroenterologist, and a pancreatic surgeon-developed this algorithm. The recommendations draw from published evidence and expert opinion, and were finalized by informal iterative consensus. Algorithm branches successively categorize pancreatic cysts based on patient characteristics and imaging features. They terminate with an ascertainment of benignity and/or indolence (sufficient to discontinue follow-up), or a management recommendation. The algorithm addresses most, but not all, pathologies and clinical scenarios. Our goal is to improve quality of care by providing guidance on how to manage incidentally detected pancreatic cysts.

Pancreatic juice cytology with immunohistochemistry to detect malignancy and histologic subtypes in patients with branch duct type intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND AND AIMS

The aim of this study was to elucidate the efficacy of pancreatic juice cytology with the cell-block method (CB-PJC) for the determination of surgery in patients with branch duct intraductal papillary mucinous neoplasm (BD-IPMN).

METHODS

In 138 patients with BD-IPMN from whom pancreatic juice was collected under ERCP for CB-PJC, we retrospectively evaluated the following: (1) the rate of successfully evaluated CB-PJC; (2) the ability of CB-PJC to diagnose malignancy and to identify pathologic subtypes in resected BD-IPMNs; (3) the rate of development into invasive cancer and progression of BD-IPMNs in patients with BD-IPMNs diagnosed as benignancy by CB-PJC; and (4) post-ERCP adverse events.

RESULTS

(1) The success rate of CB-PJC was 89.9%. (2) The sensitivity and specificity of CB-PJC for preoperative diagnosis of malignancy were 50% and 100%, respectively, with only hematoxylin and eosin staining, whereas they were 79% and 100%, respectively, by adding immunohistologic staining. The agreement rate of the preoperative subtypes by CB-PJC with the subtypes of resected specimens was 93%. (3) The onset of invasive cancer was not detected at all on imaging studies, whereas the progression of IPMN was detected in 14 patients. Multivariate analysis revealed the risk factor of progression to be non-gastric type. The cumulative 5-year progression rate in this group was 89%. (4) Post-ERCP pancreatitis developed in 13 patients (7.7%).

CONCLUSIONS

The diagnostic efficacy of preoperative CB-PJC for malignant BD-IPMN was excellent. The results may suggest the feasibility of applying preoperative subtyping by CB-PJC for decisions as to whether surgery is indicated.

Early diagnosis of pancreatic cancer: Current trends and concerns

Early detection of pancreatic cancer (PC) is essential for a better prognosis. Some recent studies have demonstrated that a slight dilatation of the main pancreatic duct (MPD) and small cystic lesions were detected initially in most cases diagnosed at an early stage. Detecting these abnormal findings in cases with high risk factors through an effective screening system including image diagnosis, some biological markers, or familial cancer registrations should contribute to early diagnosis of PC. It has been reported that endoscopic ultrasonography (EUS) is essential for detecting tumors <10 mm with a favorable prognosis. Additionally, EUS‐guided fine‐needle aspiration biopsy is useful for confirming final histological diagnosis. For the diagnosis of stage 0 PC, local irregular stenosis of MPD should be an important initial abnormal sign detected by EUS or magnetic resonance cholangiopancreatography. Cytodiagnosis multiple times using pancreatic juice obtained by endoscopic nasopancreatic drainage should be essential for the final diagnosis. Recently, activities of regional networks between specialist doctors in medical centers and general practitioners for early diagnosis of PC have been reported in Japan. In the future, these activities may play an important role in the early diagnosis of PC.

Diversity of Precursor Lesions For Pancreatic Cancer: The Genetics and Biology of Intraductal Papillary Mucinous Neoplasm

Pancreatic ductal adenocarcinoma (PDA), one of the most lethal cancers worldwide, is associated with two main types of morphologically distinct precursors—pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). Although the progression of PanIN into invasive cancer has been well characterized, there remains an urgent need to understand the biology of IPMNs, which are larger radiographically detectable cystic tumors. IPMNs comprise a number of subtypes with heterogeneous histopathologic and clinical features. Although frequently remaining benign, a significant proportion exhibits malignant progression. Unfortunately, there are presently no accurate prognosticators for assessing cancer risk in individuals with IPMN. Moreover, the fundamental mechanisms differentiating PanIN and IPMN remain largely obscure, as do those that distinguish IPMN subtypes. Recent studies, however, have identified distinct genetic profiles between PanIN and IPMN, providing a framework to better understand the diversity of the precursors for PDA. Here, we review the clinical, biological, and genetic properties of IPMN and discuss various models for progression of these tumors to invasive PDA.

Natural courses of branch duct intraductal papillary mucinous neoplasm

PURPOSE

The study was done to elucidate the clinico-radiologic predictive factors for cancerous change detected by disease progression (PD) mainly defined by interval increase in cyst size and change of cyst morphology, for branch duct intraductal papillary mucinous neoplasm (BD-IPMN) patients with relatively long-term follow-up.

METHODS

Retrospective analysis of medical records and imaging findings were performed on 107 patients with BD-IPMN enrolled from July 2005 to May 2013, in whom the communication between the cystic lesion and pancreatic duct was confirmed by either endoscopic ultrasonography (EUS), magnetic resonance cholangiopancreatography (MRCP), or endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

During the mean ± SD follow-up period of 51.5 ± 24.5 months, PD was noticed in 43 (40.2%) of 107 BD-IPMN patients. Among these 107 patients, 21 (19.6%) displayed cancerous change. By univariate analyses, septated/multilocular cyst morphology, cyst size larger than 30 mm, cyst wall thickening, mural nodules, and the presence of symptoms were significant predictive factors for cancerous changes in BD-IPMN patients. A Cox forward stepwise linear regression model revealed that cyst wall thickening (OR 9.187, 95% CI 1.883~44.820, P < 0.01) and mural nodules (OR 6.224, 95% CI 1.311~29.549, P = 0.021) were significant and independent predictive factors for cancerous change in BD-IPMN patients.

CONCLUSIONS

A significant proportion of patients with BD-IPMN showed PD and cancerous change during the long-term follow-up. Cyst wall thickening and mural nodules were significant and independent predictive factors of cancerous change in patients with BD-IPMN.

A resected case of two branch duct-type intraductal papillary mucinous neoplasms showing different clinical courses after a two-year follow-up

The patient was a 60-year-old man without any particular complaints, but he underwent abdominal computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) due to a fatty liver, which revealed two similar cystic lesions regarded as branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) in the pancreatic body [BD-IPMN (b), 16 mm in size] and tail [BD-IPMN (t), 13 mm in size] without a “high-risk stigmata” or “worrisome features”. He subsequently received follow-up by MRCP every 6 months. Two years later, MRCP showed prominent dilation of the main pancreatic duct (MPD) and mural nodule formation within the dilated MPD adjacent to the BD-IPMN (b). Distal pancreatectomy specimens revealed that the BD-IPMN (b) was lined by low-papillary gastric mucinous epithelium with low-to-intermediate-grade dysplasia and involved the MPD, forming a malignant mural nodule showing pancreatobiliary-type IPMN. In contrast, the BD-IPMN (t) was lined by flat, monolayer columnar gastric mucinous epithelium without atypia, which suggested the possibility of a “simple mucinous cyst”. A genetic analysis showed KRAS mutation only in BD-IPMN (b). Differences in the histological and genetic findings between two similar BD-IPMNs in the present case may suggest what kinds of examinations should be performed in patients with BD-IPMNs without any worrisome features.

International Intraductal Papillary Mucinous Neoplasms Registry: Long-Term Results Based on the New Guidelines

OBJECTIVE

The aim of this study was to analyze the outcomes of a long-term intraductal papillary mucinous neoplasm (IPMN) registry and evaluate new guidelines.

METHODS

A prospectively maintained IPMN registry involving 6 centers in Europe and the United States was used to collect the data. Patients with more than 1-year follow-up and no malignancy diagnosed within the first 3 months of surveillance were included.

RESULTS

From 1999 to 2014, 620 patients were included. The median follow-up time was 3 years. Thirty-seven (6%) patients developed malignancy with a median time from IPMN diagnosis to malignancy of 10.3 months. The 1-, 5-, and 10-year actuarial rates of disease-free survival were 97%, 93%, and 92% respectively. Four hundred thirty-one patients met criteria for low-risk branch duct IPMN consisting of cyst size less than 3 cm, with no solid component or main duct dilation. Eight malignancies were diagnosed in this subgroup, all of them within the first 5 years. From this subcohort, 112 patients had a follow-up time of more than 5 years, and no malignancy was diagnosed.

CONCLUSIONS

In IPMN lesions with low-risk features at baseline, the risk of progression to malignancy after the first 5 years of follow-up was minimal. Furthermore, the main cyst characteristics remained unchanged during their surveillance.

The Sendai and Fukuoka consensus criteria for the management of branch duct IPMN - A meta-analysis on their accuracy

INTRODUCTION

The risk of malignancy in branch duct intraductal papillary mucinous neoplasia of the pancreas (BD-IPMN) is controversially debated. An increasing number of studies report on outcomes using the Sendai or Fukuoka consensus criteria for treatment decision-making. The objective of this work was to evaluate the diagnostic accuracy of the Sendai and Fukuoka criteria.

METHODS

We systematically reviewed studies on Sendai or Fukuoka criteria-guided management of BD-IPMN. Pooled sensitivity, specificity and diagnostic odds ratios as compound measures of diagnostic accuracy were calculated from studies matching the inclusion criteria. The meta-analysis was performed using a random effects model.

RESULTS

Fifteen studies with a total of 2710 patients were included. Twelve of these used the Sendai criteria. In these studies, 23% of Sendai-negative patients had a high grade dysplastic lesion or an invasive carcinoma in final histology. Pooled sensitivity was 56%, specificity was 74% and the diagnostic odds ratio for malignancy in Sendai-positive lesions was 7.45. When the results of follow-up examinations were included, diagnostic accuracy improved significantly (14.66, p < 0.001). Three studies were identified that used the Fukuoka criteria for decision making. Of 200 patients with Fukuoka-negative lesions who underwent surgery, 22 had a malignant lesion in final histology (11%). Pooled sensitivity was 83%, specificity was 53% and the diagnostic odds ratio was 8.76.

CONCLUSION

The Fukuoka criteria have considerably improved sensitivity but still lack adequate specificity. For further reduction of a potential surgical overtreatment of BD-IPMN, the development of criteria with an increased specificity is required.

Intraductal papillary mucinous neoplasms and mucinous cystadenomas: current status and recommendations

The real prevalence of pancreatic cystic lesions remains unknown. The malignant potential of some of these lesions remains a cause for significant concern. Thus, it is mandatory to develop a strategy to clearly discriminate those cysts with a potential for malignant transformation from those that do not carry any significant risk. Intraductal papillary mucinous neoplasms and mucinous cystadenomas are mucinous cystic neoplasms with a known malignant potential that have gained greater recognition in recent years. However, despite the numerous studies that have been carried out, their differential diagnosis among other cysts subtypes and their therapeutic approach continue to be a challenge for clinicians. This review contains a critical approach of the current recommendations and management strategies regarding intraductal papillary mucinous neoplasms and mucinous cystadenomas, as well as highlighting the limitations exposed in current guidelines.

A novel approach for selecting combination clinical markers of pathology applied to a large retrospective cohort of surgically resected pancreatic cysts

OBJECTIVE

Our objective was to develop an approach for selecting combinatorial markers of pathology from diverse clinical data types. We demonstrate this approach on the problem of pancreatic cyst classification.

MATERIALS AND METHODS

We analyzed 1026 patients with surgically resected pancreatic cysts, comprising 584 intraductal papillary mucinous neoplasms, 332 serous cystadenomas, 78 mucinous cystic neoplasms, and 42 solid-pseudopapillary neoplasms. To derive optimal markers for cyst classification from the preoperative clinical and radiological data, we developed a statistical approach for combining any number of categorical, dichotomous, or continuous-valued clinical parameters into individual predictors of pathology. The approach is unbiased and statistically rigorous. Millions of feature combinations were tested using 10-fold cross-validation, and the most informative features were validated in an independent cohort of 130 patients with surgically resected pancreatic cysts.

RESULTS

We identified combinatorial clinical markers that classified serous cystadenomas with 95% sensitivity and 83% specificity; solid-pseudopapillary neoplasms with 89% sensitivity and 86% specificity; mucinous cystic neoplasms with 91% sensitivity and 83% specificity; and intraductal papillary mucinous neoplasms with 94% sensitivity and 90% specificity. No individual features were as accurate as the combination markers. We further validated these combinatorial markers on an independent cohort of 130 pancreatic cysts, and achieved high and well-balanced accuracies. Overall sensitivity and specificity for identifying patients requiring surgical resection was 84% and 81%, respectively.

CONCLUSIONS

Our approach identified combinatorial markers for pancreatic cyst classification that had improved performance relative to the individual features they comprise. In principle, this approach can be applied to any clinical dataset comprising dichotomous, categorical, and continuous-valued parameters.

Evolution of incidental branch-duct intraductal papillary mucinous neoplasms of the pancreas: A study with magnetic resonance imaging cholangiopancreatography

AIM

To investigate the type and timing of evolution of incidentally found branch-duct intraductal papillary mucinous neoplasms (bd-IPMN) of the pancreas addressed to magnetic resonance imaging cholangiopancreatography (MRCP) follow-up.

METHODS

We retrospectively evaluated 72 patients who underwent, over the period 2006-2016, a total of 318 MRCPs (mean 4.4) to follow-up incidental, presumed bd-IPMN without signs of malignancy, found or confirmed at a baseline MRCP examination. Median follow-up time was 48.5 mo (range 13-95 mo). MRCPs were acquired on 1.5T and/or 3.0T systems using 2D and/or 3D technique. Image analysis assessed the rates of occurrence over the follow-up of the following outcomes: (1) imaging evolution, defined as any change in cysts number and/or size and/or appearance; and (2) alert findings, defined as worrisome features and/or high risk stigmata (e.g., thick septa, parietal thickening, mural nodules and involvement of the main pancreatic duct). Time to outcomes was described with the Kaplan-Meir approach. Cox regression model was used to investigate clinical or initial MRCP findings predicting cysts changes.

RESULTS

We found a total of 343 cysts (per-patient mean 5.1) with average size of 8.5 mm (range 5-25 mm). Imaging evolution was observed in 32/72 patients (44.4%; 95%CI: 32-9-56.6), involving 47/343 cysts (13.7%). There was a main trend towards small (< 10 mm) increase and/or decrease of cysts size at a median time of 22.5 mo. Alert findings developed in 6/72 patients (8.3%; 95%CI: 3.4-17.9) over a wide interval of time (13-63 mo). No malignancy was found on endoscopic ultrasound with fine-needle aspiration (5/6 cases) or surgery (1/6 cases). No clinical or initial MRCP features were significantly associated with changes in bd-IPMN appearance (P > 0.01).

CONCLUSION

Changes in MRCP appearance of incidental bd-IPNM were frequent over the follow-up (44.4%), with relatively rare (8.3%) occurrence of non-malignant alert findings that prompted further diagnostic steps. Changes occurred at a wide interval of time and were unpredictable, suggesting that imaging follow-up should be not discontinued, though MRCPs might be considerably delayed without a significant risk of missing malignancy.

The safety and benefit of pancreatic juice cytology under ERCP in IPMN patients

BACKGROUND

International consensus guidelines 2012 for intraductal papillary mucinous neoplasia (IPMN), defined two characteristics: high-risk stigmata (HRS) and worrisome features (WF). Patients with WF require detailed examination including cytology. However, routine endoscopic retrograde cholangiopancreatography (ERCP) for cytology is not recommended in the guidelines due to risk of post-ERCP pancreatitis (PEP). Our aim was to clarify what types of IPMN were susceptible for PEP and gain benefit of ERCP.

PATIENTS/METHODS

We examined 138 consecutive IPMN patients who underwent ERCP in our hospital, retrospectively. Patients were classified into HRS, WF and the others (N) based on imaging findings before ERCP. We assessed pancreatic juice cytology, PEP frequency and rate of malignant IPMN at 12 months after ERCP.

RESULTS

The rates of cytological malignancy were 0% (N), 4.8% (WF) and 19.5% (HRS). The PEP frequency was 14.5%, and these risk factors were branch duct (BD)-IPMN, body/tail cysts and brush cytology by multivariate logistic analysis. The rates of malignant IPMN were 0% (N), 16.4% (WF) and 48.8% (HRS). Furthermore, we examined patients with WF in detail. The PEP frequency/rate of malignancy were 3.6%/23.1% in patients with main pancreatic duct (MPD) dilatation (5-9 mm), and the sensitivity of cytology was 33.3%. On the other hand, the PEP frequency/rate of malignancy were 17.2%/0% in patients with BD-IPMN fulfilling only cyst size over 30 mm.

CONCLUSIONS

Routine ERCP for IPMN, especially for BD-IPMN, is not recommended. ERCP may be beneficial for WF patients with MPD dilatation based on a balance between PEP risk and presence of malignancy.

Prevalence, Diagnosis and Management of Pancreatic Cystic Neoplasms: Current Status and Future Directions

Cystic neoplasms of the pancreas are found with increasing prevalence, especially in elderly asymptomatic individuals. Although the overall risk of malignancy is very low, the presence of these pancreatic cysts is associated with a large degree of anxiety and further medical investigation due to concerns about malignancy. This review discusses the different cystic neoplasms of the pancreas and reports diagnostic strategies based on clinical features and imaging data. Surgical and nonsurgical management of the most common cystic neoplasms, based on the recently revised Sendai guidelines, is also discussed, with special reference to intraductal papillary mucinous neoplasm (IPMN; particularly the branch duct variant), which is the lesion most frequently identified incidentally. IPMN pathology, its risk for development into pancreatic ductal adenocarcinoma, the pros and cons of current guidelines for management, and the potential role of endoscopic ultrasound in determining cancer risk are discussed. Finally, surgical treatment, strategies for surveillance of pancreatic cysts, and possible future directions are discussed.

Risk of pancreatic malignancy and mortality in branch-duct IPMNs undergoing surveillance: A systematic review and meta-analysis

BACKGROUND

Safety of non-operative management for low-risk branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) is debated.

AIM

To perform a systematic review/meta-analysis to determine their risk of developing pancreatic malignancy and of pancreatic malignancy-related deaths.

METHODS

A MEDLINE search was performed and methodology was based on PRISMA statement. Incidence rates of overall pancreatic malignancy, malignant BD-IPMN, IPMN-distinct PDAC, and of pancreatic malignancy-related death rates were calculated by dividing the total number of events by the total number of person-years (pyrs) of follow-up. Heterogeneity was determined by I(2) statistic.

RESULTS

20 studies including 2177 patients were included. Mean follow-up ranged from 29.3 to 76.7 months. Overall, 82 patients (3.7%) developed a pancreatic malignancy with a pooled estimate rate of 0.007/pyrs (I(2)=32.8%). The pooled estimate rate of malignant IPMN was 0.004/pyrs (I(2)=40.8%), and the pooled estimate rate of distinct PDAC 0.002/pyrs (I(2)=0%). The rate of death due to pancreatic malignancy during follow-up was 0.9%, with an overall pooled estimate rate of death of 0.002/pyrs (I(2)=0%).

CONCLUSION

Non-operative management of low-risk BD-IPMN is safe, with a very low risk of malignant transformation of IPMN and of distinct PDAC. The rate of pancreatic malignancy-related mortality is low, particularly when compared with the mortality of pancreatic surgery.

Progression of Incidental Intraductal Papillary Mucinous Neoplasms of the Pancreas in Liver Transplant Recipients

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant pancreatic cysts commonly found incidentally. Immunosuppression accelerates carcinogenesis.Thus, we aimed to compare IPMN progression in liver transplant (LT) recipients on chronic immunosuppression to progression among an immunocompetent population.

METHODS

We retrospectively assessed adult LT recipients between 2008 and 2014 for imaging evidence of IPMN. Diagnosis of IPMN was based on history, imaging, and cyst fluid analysis. The immunocompetent control group consisted of nontransplant patients from our pancreatic cyst surveillance program with IPMN under surveillance for greater than 12 months between 1997 and 2013. Four hundred fifty-four patients underwent LT in the study period and had cross-sectional imaging.

RESULTS

The prevalence of suspected IPMN was 6.6% (30 of 454). Compared with 131 controls, the transplant cohort was younger, with increased prevalence of diabetes and smoking. The prevalence of other risk factors for IPMN progression (history of pancreatitis, family history of pancreatic cancer) was similar. After an average follow-up of 31 months, most cysts increased in diameter, with a similar increase of dominant cyst (0.4 cm vs 0.5 cm; P = 0.6). Type of immunosuppression was not associated with the increased rate of cyst growth.

CONCLUSIONS

Our findings suggest that LT recipients with incidental IPMN can be managed under similar guidelines as immunocompetent patients.

Determining the natural history of pancreatic cystic neoplasms: a Manitoban cohort study

BACKGROUND

Most pancreatic cystic neoplasms (PCN) are thought to harbor a low malignant potential. This historical cohort study attempts to describe the natural history of these lesions in a provincial cohort, to assess the safety of non-surgical management. Pathological diagnosis of malignancy was the primary outcome measure of interest.

METHODS

All adult patients (age 18+) with PCN seen between 2000 and 2012 by the two main institutions in Manitoba were included in this study. PCN were graded as high and low risk, which dictated initial treatment plan (surgery or observation). Predictors of initial surgical treatment, delayed surgery in the observation group and the clinical/radiological predictors of malignancy were determined.

RESULTS

497 patients were included in this study. 43 (8.7%) high-risk lesions underwent initial surgery, with 13 (30.2%) cases of malignancy discovered. 450 (90.5%) low-risk cysts were observed for a median of 17.3 months (range: 0.00-142.3). 29 (6.4%) cases of delayed surgery occurred, with malignancy discovered in five (17.2%).

CONCLUSIONS

This study supports current selection criteria for management of PCNs. Due to the low incidence of malignancy in low-risk PCN, it appears that long-term observation is safe and should be the treatment modality of choice in the absence of high-risk features.

Intraductal papillary mucinous neoplasm presenting with recurrent pancreatitis: a report of a painful 3-decade-long history

Intraductal papillary mucinous neoplasm represents the most common pancreatic cystic neoplasm and harbours significant malignant potential. Duct obliteration can lead to recurrent episodes of pancreatic inflammation mimicking acute and chronic pancreatitis. We report a case of a patient with multiple episodes of idiopathic pancreatitis occurring over a period of three decades. Following admission with severe upper gastrointestinal bleeding, the patient was diagnosed as having invasive pancreatic adenocarcinoma. Examination of the surgical specimen confirmed an intraductal papillary mucinous neoplasm with multiple foci of invasive adenocarcinoma. This case is of significant interest, highlighting the long delay until diagnosis seen in this situation. Intraductal papillary mucinous neoplasm should be considered in the presence of recurrent acute or chronic pancreatitis of unknown aetiology.

Validation of international consensus guideline 2012 for intraductal papillary mucinous neoplasm of pancreas

Purpose

Intraductal papillary mucinous neoplasm (IPMN) has variable malignant potential ranging from premalignant intraductal lesions to malignant neoplasms with invasive carcinoma. To help physicians managing patients with IPMN, International consensus guidelines was made in 2006 and revised in 2012. This study was designed to evaluate the clinical usefulness of guidelines and to validate.

Methods

From October 1996 to December 2011, we retrospectively reviewed the data of 230 patients who underwent pancreatic resection for IPMN. Univariate and multivariable analyses were used to identify significant predictors of malignancy in IPMN.

Results

Of the 230 patients, 62 patients (27%) were diagnosed with invasive carcinoma. Jaundice (P < 0.001; 95% confidence interval [CI], 3.086–40.010) main pancreatic duct diameter equal to or greater than 10 mm (P < 0.001; 95% CI, 1.723–6.673) and also abdominal pain (P < 0.001; 95% CI, 4.363–22.600) show statistical significance in univariate and multivariate analysis. "High-risk stigmata" was statistical powerful predictors of malignancy than "worrisome features". International consensus guidelines 2012 had improvement on specificity but deterioration of sensitivity.

Conclusion

Revised guidelines seemed to bring about an improvement of weak side of Sendai criteria. Abdominal pain, jaundice, main pancreas duct greater than 10 mm can be clinical variables to predict malignancy.

Patterns of Recurrence After Resection of IPMN: Who, When, and How?

OBJECTIVE

To describe the patterns of recurrence after resection of intraductal papillary mucinous neoplasms (IPMN) of the pancreas.

BACKGROUND

IPMNs represent an increasing indication for pancreatic resection, but little is known about the actual incidence and the patterns of recurrence after surgical excision.

METHODS

Retrospective review of 412 resected IPMNs from 1990 to 2013 who have had near-complete follow-up.

RESULTS

Median age of the cohort was 68 years, 56% had branch duct (BD)-IPMN and 21% had invasive cancers. Nineteen patients (5%) had distinct pancreatic ductal adenocarcinoma (PDAC) and were excluded from the recurrence analysis. After a median of 58 months, 65 of 381 patients (17%) experienced recurrence of the IPMN, and 5- and 10-year disease-free survival (DFS) was 82% and 78%, respectively. Only 2 patients (0.5%) developed metachronous PDAC. In 33 patients (9%), a residual BD-IPMN was left in the pancreatic remnant, but none of these significantly grew or required reoperation. Invasive component and resection margin positive for IPMN were predictors of recurrence (P < 0.05). Invasive IPMN recurred in 45% of cases, whereas noninvasive in only 9% and later (P < 0.001), but patterns depended on IPMN subtypes. Only 9 patients required reoperation for recurrence, with good long-term outcome particularly for oncocytic IPMNs.

CONCLUSIONS

Recurrence of noninvasive BD-IPMN is infrequent and surveillance may be avoided in selected cases. In invasive IPMN recurrence depends on N status, pancreatic margin, and invasive type.

Effectiveness of contrast-enhanced endoscopic ultrasound for detecting mural nodules in intraductal papillary mucinous neoplasm of the pancreas and for making therapeutic decisions

Background and Objectives:

There have been few studies to date evaluating the effectiveness of contrast-enhanced endoscopic ultrasound (CE-EUS) for detecting mural nodules in patients with branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) of the pancreas. We aim to evaluate the effectiveness of CE-EUS for detecting mural nodules in BD-IPMN.

Patients and Methods:

Of the 427 BD-IPMN patients, 21 patients (4.9%) in whom the presence of mural nodules was suggested by CE computed tomography (CT) or magnetic resonance imaging (MRI), or in whom the presence of nodule-like lesions as shown by fundamental EUS, were examined by CE-EUS.

Results:

The mean diameter of cystic lesions was 29.8 ± 12.8 mm. The mean diameter of mural nodules was 9.5 ± 5.7 mm. BD-IPMN was detected in the pancreatic head in 16 cases, pancreatic body in 2 cases, and pancreatic tail in 3 cases. The mean follow-up period was 17.2 ± 11.9 months. The detection rates of mural nodule-like lesions in BD-IPMN patients on CT, MRI, and fundamental EUS were 36.8%, 63.2%, and 100%, respectively. The detection rates of true mural nodules in BD-IPMN patients on CT, MRI, and fundamental EUS were 85.7%, 71.4%, and 100%, respectively. The echo levels of mural nodule-like lesions on fundamental EUS were hyperechoic in 6 patients, isoechoic in 9 patients, and hypoechoic in 6 patients. The final diagnosis was mucus lumps in 14 patients and mural nodules in 7 patients. The contrast patterns observed were avascular, isovascular, and hypervascular in 14, 3, and 4 patients, respectively. No patients showed a hypovascular pattern. Fourteen patients showing an avascular pattern were diagnosed as having mucus lumps, and they were able to avoid surgical resection. Of the 7 patients who were diagnosed as having mural nodules, 5 underwent surgical resection. The pathological findings were adenocarcinoma in 2 patients and adenoma in 3 patients. Of the 3 adenoma patients, fundamental EUS demonstrated a hypoechoic area in 1 patient and an isoechoic area in 2 patients. Of the 2 adenocarcinoma patients, 1 each showed a hypoechoic area and a hyperechoic area. It was difficult to distinguish between patients with adenoma and patients with adenocarcinoma using the echo levels obtained from fundamental EUS.

Conclusions:

CE-EUS may be useful for avoiding the overdiagnosis of BD-IPMN with mural nodule-like lesions. However, it has difficulty in distinguishing between clearly benign and malignant lesions in BD-IPMN.

International consensus on the management of intraductal papillary mucinous neoplasm of the pancreas

International consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas revised in 2012 (Fukuoka consensus) seem to be accepted well worldwide. Division of various factors to predict malignant transformation into two categories, i.e., "high-risk stigmata" and "worrisome features", is also accepted as practically useful for stratifying the risk factors. Our current interest resides in the development of noninvasive and/or invasive pancreatic cancer in areas of the pancreas distinct from IPMN. Invasive pancreatic cancers derived from and concomitant with IPMN should be distinguished to clarify the incidence of each entity, although some more definitive method for differentiation has to be devised in some cases where histological distinction is obscure. IPMN is a clue to early detection of pancreatic cancer. The optimal surveillance protocol for IPMN on observation should be determined in consideration of both of these different pancreatic cancers.

What Is the Best Way to Identify Malignant Transformation Within Pancreatic IPMN: A Systematic Review and Meta-Analyses

OBJECTIVES

Pancreatic intraductal papillary mucinous neoplasias (IPMNs) represent 25% of all cystic neoplasms and are precursor lesions for pancreatic ductal adenocarcinoma. This study aims to identify the best imaging modality for detecting malignant transformation in IPMN, the sensitivity and specificity of risk features on imaging, and the usefulness of tumor markers in serum and cyst fluid to predict malignancy in IPMN.

METHODS

Databases were searched from November 2006 to March 2014. Pooled sensitivity and specificity of diagnostic techniques/imaging features of suspected malignancy in IPMN using a hierarchical summary receiver operator characteristic (HSROC) approach were performed.

RESULTS

A total of 467 eligible studies were identified, of which 51 studies met the inclusion criteria and 37 of these were incorporated into meta-analyses. The pooled sensitivity and specificity for risk features predictive of malignancy on computed tomography/magnetic resonance imaging were 0.809 and 0.762 respectively, and on positron emission tomography were 0.968 and 0.911. Mural nodule, cyst size, and main pancreatic duct dilation found on imaging had pooled sensitivity for prediction of malignancy of 0.690, 0.682, and 0.614, respectively, and specificity of 0.798, 0.574, and 0.687. Raised serum carbohydrate antigen 19-9 (CA19-9) levels yielded sensitivity of 0.380 and specificity of 0903. Combining parameters yielded a sensitivity of 0.743 and specificity of 0.906.

CONCLUSIONS

PET holds the most promise in identifying malignant transformation within an IPMN. Combining parameters increases sensitivity and specificity; the presence of mural nodule on imaging was the most sensitive whereas raised serum CA19-9 (>37 KU/l) was the most specific feature predictive of malignancy in IPMNs.

Morphological differentiation and follow-up of pancreatic cystic neoplasms using endoscopic ultrasound

Endoscopic ultrasound (EUS) is a key modality for the evaluation of suspected pancreatic cystic neoplasms (PCNs), as the entire pancreatic gland can be demonstrated with high spatial resolution from the stomach and duodenum. Detailed information can be acquired about the internal contents of the cyst(s) [septum, capsule, mural nodules (MNs)], its relation with the main pancreatic duct (MPD), and any parenchymal changes in the underlying gland. PCNs comprise true cysts and pseudocysts. True cysts can be neoplastic or nonneoplastic. Here, we describe serous cystic neoplasm (SCN), mucinous cystic neoplasm (MCN), and intraductal papillary mucinous neoplasm (IPMN) as prototype neoplastic cysts, along with nonneoplastic lymphoepithelial cysts (LECs).

Effective screening for early diagnosis of pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery should improve long-term patient outcome. At present, improving survival should lie in identifying those cases with high-risk factors or precursor lesions through an effective screening including ultrasonography, some biological markers, or national familial pancreatic cancer registration. Recently, cases with PC < 10 mm with a favorable prognosis have been reported. For the diagnoses of cases with PC < 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on CT or other modalities, and EUS-guided fine needle aspiration was helpful in confirming the histologic diagnosis. Additionally, for the diagnosis of cases with PC in situ, EUS and magnetic resonance cholangiopancreatography (MRCP) may play important roles in detecting the local irregular stenosis of the pancreatic duct. Cytodiagnosis of pancreatic juice using endoscopic nasopancreatic drainage multiple times may be useful in the final diagnosis.

A Revised Classification System and Recommendations From the Baltimore Consensus Meeting for Neoplastic Precursor Lesions in the Pancreas

International experts met to discuss recent advances and to revise the 2004 recommendations for assessing and reporting precursor lesions to invasive carcinomas of the pancreas, including pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm, and other lesions. Consensus recommendations include the following: (1) To improve concordance and to align with practical consequences, a 2-tiered system (low vs. high grade) is proposed for all precursor lesions, with the provision that the current PanIN-2 and neoplasms with intermediate-grade dysplasia now be categorized as low grade. Thus, "high-grade dysplasia" is to be reserved for only the uppermost end of the spectrum ("carcinoma in situ"-type lesions). (2) Current data indicate that PanIN of any grade at a margin of a resected pancreas with invasive carcinoma does not have prognostic implications; the clinical significance of dysplasia at a margin in a resected pancreas with IPMN lacking invasive carcinoma remains to be determined. (3) Intraductal lesions 0.5 to 1 cm can be either large PanINs or small IPMNs. The term "incipient IPMN" should be reserved for lesions in this size with intestinal or oncocytic papillae or GNAS mutations. (4) Measurement of the distance between an IPMN and invasive carcinoma and sampling of intervening tissue are recommended to assess concomitant versus associated status. Conceptually, concomitant invasive carcinoma (in contrast with the "associated" group) ought to be genetically distinct from an IPMN elsewhere in the gland. (5) "Intraductal spread of invasive carcinoma" (aka, "colonization") is recommended to describe lesions of invasive carcinoma invading back into and extending along the ductal system, which may morphologically mimic high-grade PanIN or even IPMN. (6) "Simple mucinous cyst" is recommended to describe cysts >1 cm having gastric-type flat mucinous lining at most minimal atypia without ovarian-type stroma to distinguish them from IPMN. (7) Human lesions resembling the acinar to ductal metaplasia and atypical flat lesions of genetically engineered mouse models exist and may reflect an alternate pathway of carcinogenesis; however, their biological significance requires further study. These revised recommendations are expected to improve our management and understanding of precursor lesions in the pancreas.