Intraductal Papillary Mucinous Neoplasm of the Pancreas: Current State of the Art and Ongoing Controversies

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Reoperation for heterochronic intraductal papillary mucinous neoplasm of the pancreas after bile duct neoplasm resection: A case report

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) and intraductal papillary mucinous neoplasm (IPMN) of the pancreas have similar pathological manifestations. However, they often develop separately and it is rare for both to occur together. Patients presenting with heterochronic IPMN after IPNB are prone to be misdiagnosed with tumor recurrence.

CASE SUMMARY

A 67-year-old male patient was admitted 8.5 years after IPNB carcinoma and 4 years after the discovery of a pancreatic tumor. A left hepatic bile duct tumor with distal bile duct dilatation was found 8.5 years ago by the computed tomography; therefore, a left hepatectomy was performed. The postoperative pathological diagnosis was malignant IPNB with negative cutting edge and pathological stage T1N0M0. Magnetic resonance imaging 4 years ago showed cystic lesions in the pancreatic head with pancreatic duct dilatation, and carcinoembryonic antigen continued to increase. Positron emission tomography showed a maximum standard uptake value of 11.8 in the soft tissue mass in the pancreatic head, and a malignant tumor was considered. Radical pancreatoduodenectomy was performed. Postoperative pathological diagnosis was pancreatic head IPMN with negative cutting edge, pancreaticobiliary type, stage T3N0M0. He was discharged 15 d after the operation. Follow-up for 6 mo showed no tumor recurrence, and quality of life was good.

CONCLUSION

IPNB and IPMN are precancerous lesions with similar pathological characteristics and require active surgery and long-term follow-up.

Innovation in the Surgical Management of Pancreatic Cystic Neoplasms: Same Operations, Narrower Indications, and an Individualized Approach to Decision-Making

Historically, the management of pancreatic cystic neoplasms (PCN) has been operative. Early intervention for premalignant lesions, including intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN), offers an opportunity to prevent pancreatic cancer-with potential decrement to patients' short-term and long-term health. The operations performed have remained fundamentally the same, with most patients undergoing pancreatoduodenectomy or distal pancreatectomy using oncologic principles. The role of parenchymal-sparing resection and total pancreatectomy remains controversial. We review innovations in the surgical management of PCN, focusing on the evolution of evidence-based guidelines, short-term and long-term outcomes, and individualized risk-benefit assessment.

Pre-emptive resection for intraductal papillary mucinous neoplasia - Long-term outcome is similar between non-invasive and early invasive lesions in a tertiary single center

BACKGROUND

Pre-emptive resection for intraductal papillary mucinous neoplasm (IPMN) aims to reduce the risk before invasive transformation has taken place. Pancreatic resections are highly associated with major morbidity and mortality. Long-term overall survival (OS) after resection for invasive IPMN (inv-IPMN) in early stages is favorable. Comparison of long-term OS for resected non-invasive IPMN and early staged inv-IPMN is poorly delineated. This study aims to compare outcomes for resected non-invasive IPMN and T1-staged inv-IPMN.

METHODS

All patients ≥18 years of age resected for IPMN up to stage T1 at Karolinska University Hospital between 2008 and 2020 were included. Two-year OS were compared between groups by chi-squared test, and 5-year OS was estimated using Kaplan-Meier method. Covariates associated with death was assessed in multivariable Cox regression model.

RESULTS

We included 284 patients, 264 (93%) non-invasive IPMN and 20 (7%) T1-staged inv-IPMN. Dysplasia of low grade (LGD) and high grade, i.e., tumor in situ (Tis) were present in 190 (67%) and 75 (26%) patients respectively. The 2-year OS for the entire cohort was 96%, and there were no differences between non-invasive and inv-IPMN (96% vs 92%, p = 0.203), nor between IPMN with LGD and Tis-T1b-staged IPMN (96% vs 95%, p = 0.734).

CONCLUSION

Two thirds of the specimen from pre-emptive resections were of LGD and did not involve superior OS than in situ or early cancer. Due to high complication burden, efforts should be made to avoid resection when LGD is probable and rather identify more accurate predictors for surgery.

Outcome after surgery for invasive intraductal papillary mucinous neoplasia compared to conventional pancreatic ductal adenocarcinoma - A Swedish nationwide register-based study

BACKGROUND

The clinical importance of intraductal papillary mucinous neoplasm (IPMN) have increased last decades. Long-term survival after resection for invasive IPMN (inv-IPMN) compared to conventional pancreatic ductal adenocarcinoma (PDAC) is not thoroughly delineated.

OBJECTIVE

This study, based on the Swedish national pancreatic and periampullary cancer registry aims to elucidate the outcome after resection of inv-IPMN compared to PDAC.

METHODS

All patients ≥18 years of age resected for inv-IPMN and PDAC in Sweden between 2010 and 2019 were included. Clinicopathological variables were retrieved from the national registry. The effect on death was assessed in two multivariable Cox regression models, one for patients resected 2010-2015, one for patients resected 2016-2019. Median overall survival (OS) was estimated using the Kaplan-Meier method.

RESULTS

We included 1909 patients, 293 inv-IPMN and 1616 PDAC. The most important independent predictors of death in multivariable Cox regressions were CA19-9 levels, venous resection, tumour differentiation, as well as T-, N-, M-stage and surgical margin. Tumour type was an independent predictor for death in the 2016-2019 cohort, but not in the 2010-2015 cohort. In Kaplan-Meier survival analysis, inv-IPMN was associated with longer median OS in stage N0-1 and in stage M0 compared to PDAC. However, in stage T2-4 and stage N2 median OS was similar, and in stage M1 even shorter for inv-IPMN compared to PDAC.

CONCLUSION

In this population-based nationwide study, outcome after resected inv-IPMN compared to PDAC is more favourable in lower stages, and similar to worse in higher.

Outcome after resection for invasive intraductal papillary mucinous neoplasia is similar to conventional pancreatic ductal adenocarcinoma

BACKGROUND/OBJECTIVES

Resections for intraductal papillary mucinous neoplasm (IPMN) have increased last decades. Overall survival (OS) for conventional pancreatic ductal adenocarcinoma (PDAC) is well known but OS for invasive IPMN (inv-IPMN) is not as conclusive. This study aims to elucidate potential differences in clinicopathology and OS between these tumor types and to investigate if the raised number of resections have affected outcome.

METHODS

Consecutive patients ≥18 years of age resected for inv-IPMN and PDAC at Karolinska University Hospital between 2009 and 2018 were included. Clinicopathological variables were analyzed in multivariable regression models. Outcome was assessed calculating two-year OS, estimating OS using the Kaplan-Meier model and comparing survival functions with log-rank test.

RESULTS

513 patients were included, 122 with inv-IPMN and 391 with PDAC. During the study period both the proportion resected inv-IPMN and two-year OS, irrespective of tumor type, increased (2.5%-45%; p < 0.001 and 44%-57%; p = 0.005 respectively). In Kaplan-Meier survival analysis inv-IPMN had more favorable median OS (mOS) compared to PDAC (33.6 months vs 19.3 months, p = 0.001). However, in multivariable Cox Regression analysis, tumor type was not a predictor for death, but so were resection period, tumor subtype and N-stage (all p < 0.001).

CONCLUSION

In this large single center observational cohort study, inv-IPMN seemed to have favorable survival outcome compared to PDAC, but after adjusting for predictors for death this benefit vanished. The combination of a pronounced increase in resected inv-IPMN and a concurrent hazard abatement for death within 2 years during the study period proved to be a principal factor.

Pancreas Cystic Lesions

This article outlines the principles behind the management of pancreatic cystic lesions. We outline what the general surgeon needs to know in managing and triaging these patients. It is our feeling that the general surgeon is often the first line of evaluation of these complex patients and a working knowledge of the different types of cysts is critical to safe care of the patient.

Collagenase Nanoparticles Enhance the Penetration of Drugs into Pancreatic Tumors

Overexpressed extracellular matrix (ECM) in pancreatic ductal adenocarcinoma (PDAC) limits drug penetration into the tumor and is associated with poor prognosis. Here, we demonstrate that a pretreatment based on a proteolytic-enzyme nanoparticle system disassembles the dense PDAC collagen stroma and increases drug penetration into the pancreatic tumor. More specifically, the collagozome, a 100 nm liposome encapsulating collagenase, was rationally designed to protect the collagenase from premature deactivation and prolonged its release rate at the target site. Collagen is the main component of the PDAC stroma, reaching 12.8 ± 2.3% vol in diseased mice pancreases, compared to 1.4 ± 0.4% in healthy mice. Upon intravenous injection of the collagozome, ∼1% of the injected dose reached the pancreas over 8 h, reducing the level of fibrotic tissue to 5.6 ± 0.8%. The collagozome pretreatment allowed increased drug penetration into the pancreas and improved PDAC treatment. PDAC tumors, pretreated with the collagozome followed by paclitaxel micelles, were 87% smaller than tumors pretreated with empty liposomes followed by paclitaxel micelles. Interestingly, degrading the ECM did not increase the number of circulating tumor cells or metastasis. This strategy holds promise for degrading the extracellular stroma in other diseases as well, such as liver fibrosis, enhancing tissue permeability before drug administration.

Cytologic Analysis of Pancreatic Juice Increases Specificity of Detection of Malignant IPMN-A Systematic Review

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas can progress to cancer. Biomarkers have been identified that were reported to increase the accuracy of identification of malignant lesions; we performed a systematic review of the accuracy of these markers.

METHODS

We performed a systematic review of published studies on biomarkers of malignant IPMNs by searching MEDLINE and Web of Science databases from January 2005 through December 2017. Our methods were developed based on the Meta-analysis Of Observational Studies in Epidemiology guidelines. Pooled sensitivity, specificity, receiver operating characteristic curves, and their respective areas under the curve (AUC) were calculated from groups of markers (cell-, protein-, or DNA-based) measured in samples collected before and after surgery. A hypothetical test model was developed to determine how to meaningfully amend the revised Fukuoka guidelines, focusing on increasing test specificity for patients with IPMNs that have worrisome features.

RESULTS

We collected data from 193 published studies, comprising 12,297 patients, that analyzed 7 preoperative and 21 postoperative markers of IPMNs. The 3 biomarkers that identified malignant IPMNs with the largest AUC values were pancreatic juice cytology (AUC, 0.84; sensitivity, 0.54; specificity, 0.91), serum protein carbohydrate antigen 19-9 (AUC, 0.81; sensitivity, 0.45; specificity, 0.90), and cyst fluid cytology (AUC, 0.82; sensitivity, 0.57; specificity, 0.84). A combination of cytologic and immunohistochemical analysis of MUC1 and MUC2 in pancreatic juice samples identified malignant IPMNs with the largest AUC and sensitivity values (AUC, 0.85; sensitivity, 0.85; specificity, 0.65). In a test model, inclusion of cytologic analysis of pancreatic juice in the guideline algorithm significantly increased the specificity of detection of malignant IPMNs.

CONCLUSIONS

In a systematic review, we found cytologic analysis of pancreatic juice to have the greatest effect in increasing the specificity of detection of malignant IPMNs. We propose addition of this test to the Fukuoka guidelines for assessment of patients with IPMNs with worrisome features.

Pancreatic fat content may increase the risk of imaging progression in low-risk branch duct intraductal papillary mucinous neoplasm

OBJECTIVE

To identify risk factors of imaging progression (increase in cyst size or main pancreatic duct size, or a new mural nodule) in low-risk branch duct intraductal papillary mucinous neoplasm (BD-IPMN), including obesity-related factors such as pancreatic fat content.

METHODS

Our hospital databases were searched for patients who had completed health checkup, including upper abdominal magnetic resonance imaging (MRI) over 48 months (August 2012 to July 2016). Individuals with BD-IPMN without worrisome features and high-risk stigmata who underwent surveillance with at least one follow-up MRI, irrespective of the follow-up period, were included. Pancreatic computed tomography attenuation indexes were defined as the difference between the pancreas and spleen attenuation (P - S) and the pancreas to spleen attenuation ratio (P/S).

RESULTS

Among 75 patients diagnosed as having low-risk BD-IPMN, during a median follow-up of 36 months, 11 (15%) had imaging progression in cyst size, including two with worrisome features. A multivariate logistic analysis showed that the initial cyst size and both indexes (P - S, or P/S) were significantly associated with imaging progression in IPMN, respectively (Model 1: odds ratio [OR] 1.188, 95% confidence interval [CI] 1.060-1.331, P = 0.003; OR 0.871, 95% CI 0.776-0.977, P = 0.019; Model 2: OR 1.186, 95% CI 1.064-1.322, P = 0.002; OR 0.002, 95% CI 0.000-0.970, P = 0.049).

CONCLUSIONS

Pancreatic fat content and initial cyst size were significantly associated with imaging progression in low-risk BD-IPMN. Revisions of international consensus Fukuoka guidelines might be customized based on initial cyst size and pancreatic fat content.

The clinical value of ERCP-guided cholangiopancreatoscopy using a single-operator system

BACKGROUND

Single-operator, per-oral cholangiopancreatoscopy (SOPCP) enables direct biliopancreatic ductal visualization, targeted tissue sampling, and therapeutic intervention. At Karolinska University Hospital, SOPCP was introduced early and has since been extensively utilized according to a standardized protocol. We analysed the clinical value of SOPCP in the diagnosis and treatment of biliopancreatic diseases in a single high volume center.

METHODS

All SOPCP procedures performed between March 2007 and December 2014 were retrospectively reviewed. Each procedure's diagnostic yield and therapeutic value was evaluated using a predefined 4 grade scale; 1 - no diagnostic or therapeutic value, 2 - information gained did not impact clinical decision-making and in case of a therapeutic intervention, did not alter the clinical course of the patient, 3 - information gained had an impact on clinical decision-making and in the case of a therapeutic intervention, assisted subsequent disease management, and finally, 4 - information gained was essential and critical for clinical decision-making and in case of a therapeutic intervention, solved the clinical problem requiring no further therapeutic actions. Descriptive statistics were used to analyse results, with uni- and multivariate analyses completed to assess risk of adverse events.

RESULTS

During the study period, 365 SOPCP procedures were performed. We found SOPCP of pivotal importance (grade 4) in 19% of cases, and of great clinical significance (grade 3) in 44% of cases. SOPCP did not affect clinical decision-making or alter clinical course (grade 1 and 2) in 37% of cases.

CONCLUSION

SOPCP offers direct access to the biliopancreatic ducts for both diagnostic and therapeutic purposes, adding significant clinical value in 64% of cases.

TRIAL REGISTRATION

As this is a purely observational and retrospectively registered study in which the assignment of the medical intervention was not at the discretion of the investigator, it has not been registered in a registry.

Progression Patterns in the Remnant Pancreas after Resection of Non-Invasive or Micro-Invasive Intraductal Papillary Mucinous Neoplasms (IPMN)

BACKGROUND

Although IPMN are thought to represent a whole-gland disease, segmental resection remains the most frequently performed treatment. We sought to determine the rates, patterns, and predictors of IPMN progression in the pancreatic remnant following segmental resection of noninvasive or microinvasive IPMN.

METHODS

A prospectively maintained database was queried to identify all patients who underwent resection of noninvasive or microinvasive IPMN (≤ 10 mm of invasive component) between 1989 and 2015. Progression (recurrence) was defined as either the development of cancer, a new IPMN cystic lesion > 1 cm or ≥ 50% increase in the diameter of residual IPMN lesions in the remnant. Univariate and multivariate cox regression models were created to determine predictors of progression.

RESULTS

A total of 319 patients underwent resection for noninvasive and microinvasive IPMN. The median age was 68, 53% had branch-duct (BD) IPMN, and 6% had microinvasive disease. After a median follow-up of 42 months, 71 patients (22%) experienced IPMN progression. Within this group of 71 patients, 11 (16% of recurrence) developed invasive cancer in the pancreatic remnant after a median of 28 months. Twelve patients (17%) experienced progression > 5 years following initial resection. On multivariate analysis, a distal location of the initial lesion was associated with an increased risk of progression (multivariate hazards ratio = 2.43, confidence interval 1.47-4.0, p < 0.001).

CONCLUSIONS

In this study, 22% of patients had disease progression following resection of noninvasive or microinvasive IPMN; 16% of these progressions represented invasive disease. These patients represent a high-risk group and should undergo long-term radiographic surveillance.

The Clinical Management of Main Duct Intraductal Papillary Mucinous Neoplasm of the Pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas comprise a heterogeneous group of intraductal mucin-producing neoplasms representing a typical adenoma-to-carcinoma sequence. The involvement of the main pancreatic duct (MPD) is a feature of paramount importance, directly related to a more aggressive biology and a higher malignancy rate.

METHOD

We review and discuss the clinical management of IPMNs with a MPD involvement, recalling the different consensus guidelines and addressing recent controversies in literature, presenting the current clinical practice in Verona Pancreas Institute.

RESULTS

All the aspects of surgical management were discussed, from the indication for surgery to the intraoperative management and the follow-up strategies.

CONCLUSION

The management of presumed IPMNs involving the MPD at our Institution is in line with the International Association of Pancreatology 2012 guidelines, revised in 2016. Surgical resection proposed should achieve the complete removal of the tumor with negative margins. Despite a good prognosis in terms of survival of overall resected main duct intraductal papillary mucinous neoplasms, follow-up should not be discontinued.

Health-related Quality of Life and Functional Outcomes in 5-year Survivors After Pancreaticoduodenectomy

OBJECTIVE

Our aim was to assess quality of life (QOL) and functionality in a large cohort of patients ≥5-years after pancreaticoduodenectomy (PD).

BACKGROUND

Long-term QOL outcomes after PD for benign or malignant disease are largely undocumented.

METHODS

We administered the EORTC QLQ-C30 questionnaire to patients who underwent PD for neoplasms from 1998 to 2011 and compared their scores with an age- and sex-matched normal population. Clinical relevance (CR) of differences was scored as small (5-10), moderate (10-20), or large (>20) based on validated interpretation of clinically important differences.

RESULTS

Of 305 PD survivors, 245 (80.3%) responded, of whom 157 (64.1%) underwent PD for nonmalignant lesions. Median follow-up was 9.1 years (range 5.1 -21.2 yrs). New-onset diabetes developed in 10.6%; 50.4% reported taking pancreatic enzymes; 54.6% reported needing antacids. Compared with the age- and sex-adjusted controls, PD survivors demonstrated higher global QOL (78.7 vs 69.7, CR small, P < 0.001), physical (86.7 vs 77.9, CR small, P < 0.001) and role-functioning scores (86.3 vs 74.1, CR medium, P < 0.001). Using linear regression and adjusting for socioeconomic variables, there were no differences in QOL or functional scores in the benign versus malignant subgroups. Older age at operation was associated with worse physical-functioning (-0.4/yr, P = 0.008). Taking pancrelipase (-6.8, P = 0.035) or antacids (-6.3, P = 0.044) were both associated with lower social-functioning scores.

CONCLUSIONS

Patients who had a PD demonstrated better global QOL, physical- and role-functioning scores at 5-years when compared with age- and sex-matched controls. Approximately half of the patients required pancreatic enzyme replacement, while only 11% developed new-onset diabetes.

Natural History of Pancreatic Cysts

Pancreatic cystic neoplasms are discovered with increasing frequency. Accurate knowledge of the natural history of cystic neoplasms is crucial to develop useful and cost-effective strategies for surveillance and surgical resection. To date, the natural history of cystic neoplasms is still incomplete due to lack of adequate diagnostic accuracy in the absence of surgical pathology. Nevertheless, current evidence points to risk factors for malignant transformation to help clinical management. New biomarkers that accurately distinguish cyst neoplasms and those most likely to progress to cancer would help clarify the natural history of cystic neoplasms.