Predictors of Malignancy in "Pure" Branch-Duct Intraductal Papillary Mucinous Neoplasm of the Pancreas without Enhancing Mural Nodules on CT Imaging: A Nationwide Multicenter Study

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pancreatic Cyst Size Measurement on Magnetic Resonance Imaging Compared to Pathology

BACKGROUND

While multiple cyst features are evaluated for stratifying pancreatic intraductal papillary mucinous neoplasms (IPMN), cyst size is an important factor that can influence treatment strategies. When magnetic resonance imaging (MRI) is used to evaluate IPMNs, no universally accepted sequence provides optimal size measurements. T2-weighted coronal/axial have been suggested as primary measurement sequences; however, it remains unknown how well these and maximum all-sequence diameter measurements correlate with pathology size. This study aims to compare agreement and bias between IPMN long-axis measurements on seven commonly obtained MRI sequences with pathologic size measurements.

METHODS

This retrospective cohort included surgically resected IPMN cases with preoperative MRI exams. Long-axis diameter tumor measurements and the presence of worrisome features and/orhigh-risk stigmata were noted on all seven MRI sequences. MRI size and pathology agreement and MRI inter-observer agreement involved concordance correlation coefficient (CCC) and intraclass correlation coefficient (ICC), respectively. The presence of worrisome features and high-risk stigmata were compared to the tumor grade using kappa analysis. The Bland-Altman analysis assessed the systematic bias between MRI-size and pathology.

RESULTS

In 52 patients (age 68 ± 13 years, 22 males), MRI sequences produced mean long-axis tumor measurements from 2.45-2.65 cm. The maximum MRI lesion size had a strong agreement with pathology (CCC = 0.82 (95% CI: 0.71-0.89)). The maximum IPMN size was typically observed on the axial T1 arterial post-contrast and MRCP coronal series and overestimated size versus pathology with bias +0.34 cm. The radiologist interobserver agreement reached ICCs 0.74 to 0.91 on the MRI sequences.

CONCLUSION

The maximum MRI IPMN size strongly correlated with but tended to overestimate the length compared to the pathology, potentially related to formalin tissue shrinkage during tissue processing.

Systematic review of challenging issues in pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are a cystic precursor to pancreatic cancer. IPMNs deemed clinically to be at high-risk for malignant progression are frequently treated with surgical resection, and pathological examination of the pancreatectomy specimen is a key component of the clinical care of IPMN patients.

METHODS

Systematic literature reviews were conducted around eight topics of clinical relevance in the examination of pathological specimens in patients undergoing resection of IPMN.

RESULTS

This review provides updated perspectives on morphological subtyping of IPMNs, classification of intraductal oncocytic papillary neoplasms, nomenclature for high-grade dysplasia, assessment of T stage, distinction of carcinoma associated or concomitant with IPMN, role of molecular assessment of IPMN tissue, role of intraoperative assessment by frozen section, and preoperative evaluation of cyst fluid cytology.

CONCLUSIONS

This analysis provides the foundation for data-driven approaches to several challenging issues in the pathology of IPMNs.

The clinical impact of endoscopic ultrasound-guided fine-needle aspiration on the patients with low-risk pancreatic cystic lesions

Background and aims

Endoscopic ultrasound (EUS) is playing a more and more important role in the management of pancreatic cystic lesion (PCLs). The aim of our study was to evaluate the clinical impact of EUS and EUS guided fine needle aspiration (FNA) on patients with low-risk PCLs.

Materials and methods

Low-risk PCL patients who underwent EUS-FNA in 2 edoscopic centers were retrospectively collected and analyzed. The clinical impact of EUS-FNA on these patients was analyzed and the predictors for significance EUS-FNA (defined by diagnosis and treatment method change, new high-risk feature identified after imaging scans) were analyzed by logistic regression analyses.

Results

From July 2004 to February 2017, 186 patients with low-risk PCLs were included. The study cohort had a mean age of 52.4 ± 15.9 years (range: 19-86 years) with 89 (47.8%) male patients included. The clinical significance of EUS-FNAs was observed in 74 patients (39.8%). The presumed diagnoses of PCLs by imaging were changed in 51 (51/74, 68.9%) patients. Nineteen (19/74, 25.7%) new high-risk features were identified by EUS-FNA, and four patients (4/74, 5.4%) underwent surgery due to suspicious or malignant cytology. Based on multivariate analysis, large cyst size [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.02–1.19, P = 0.033], young age (OR: 0.94, 95% CI: 0.91–0.99, P = 0.041) and BMI over 25 (OR: 3.15, 95% CI: 1.29–7.86, P = 0.013) were independent predictors of clinical significance for EUS-FNA. The optimal age and cyst size to predict significance EUS-FNA was 46.0 years and 2.3cm.

Conclusions

On the basis of a 2-center retrospective study, EUS-FNA was clinically significant in about 40% of low-risk PCLs, especially in young, large cyst size, and overweight patients.

Long-term follow-up of Branch-Duct Intraductal Papillary Mucinous Neoplasms with negative Sendai Criteria: the therapeutic challenge of patients who convert to positive Sendai Criteria

BACKGROUND

The management of Branch-Duct Intraductal Papillary Mucinous Neoplasm (BD-IPMN) is still controversial. Our objective was to assess the long-term follow-up (FU) of patients with "low-risk" BD-IPMN according to the Sendai-International Consensus Guidelines (ICG-I).

METHODS

We retrospectively analyzed a cohort of patients with BD-IPMN and Negative Sendai-Criteria (NSC) from January 2004 to October 2019. A univariate analysis was performed to determine factors associated with conversion to Positive Sendai-Criteria (PSC) and malignancy. Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of the IGC-I were assessed for the development of malignancy.

RESULTS

A total of 219 patients were selected and underwent a median 58-month FU. Thirty-seven (17%) patients developed PSC during FU including 12 (5.5%) with malignant lesions. Conversely, 182 patients (83%) did not develop malignancy. The NPV and PPV of ICG-I for malignancy were 100% and 32.4%, respectively. Among patients who developed PSC, those with cancer were >65years (OR = 3.57;p = 0.015) and had significantly higher serum CA-19-9 levels (OR = 5.27;p = 0.007).

CONCLUSION

The ICG-I is a safe strategy for FU of patients with BD-IPMN. The absence of PSC exclude malignancy. Among patients who develops PSC, the risk of cancer remains low and surgery should be decided according to their surgical risk and life expectancy.

Surgical indication for intraductal papillary mucinous neoplasm without mural nodule ≥5 mm

BACKGROUND

In intraductal papillary mucinous neoplasm, a mural nodule ≥5 mm is an important predictor of malignancy. Surgical indication is less clear in cases of intraductal papillary mucinous neoplasm without mural nodule ≥5 mm. This is a retrospective study evaluating predictors of high-grade dysplasia or invasive intraductal papillary mucinous carcinoma for intraductal papillary mucinous neoplasm without mural nodule ≥5 mm.

METHODS

Among consecutive patients who underwent surgery for intraductal papillary mucinous neoplasm between 1999 and 2018, 174 had intraductal papillary mucinous neoplasm with mural nodule ≥5 mm (mural nodule[+] ≥5 mm group). The remaining 155 patients had intraductal papillary mucinous neoplasm but did not have mural nodule ≥5 mm: 24 patients with mural nodule <5 mm (mural nodule[+] <5 mm group) and 131 patients without mural nodule (mural nodule[-] group). We investigated predictors of high-grade dysplasia or invasive intraductal papillary mucinous neoplasm in cases of intraductal papillary mucinous neoplasm without mural nodule ≥5 mm.

RESULTS

The frequency of high-grade dysplasia invasive intraductal papillary mucinous neoplasm was significantly higher in the mural nodule(+) ≥5 mm group (87.4%) than in the mural nodule(+) <5 mm group (37.5%, P < .001) and mural nodule(-) group (45.0%, P < .001). However, frequency was not significantly different between mural nodule(+) <5 mm and mural nodule(-) groups (P = .494). Multivariate analysis showed three independent predictors of high-grade dysplasia invasive intraductal papillary mucinous carcinoma in intraductal papillary mucinous neoplasm without mural nodule ≥5 mm: branch cyst ≥40 mm (P = .038, odds ratio 3.704; 95% confidence interval, 1.075-12.821), positive cytology of pancreatic juice (P = .039, odds ratio 16.792; 95% confidence interval, 1.152-244.744), and carcinoembryonic antigen in pancreatic juice ≥30 mg/mL (P < .001, odds ratio 14.925; 95% confidence interval, 4.525-50.0).

CONCLUSION

For cases of intraductal papillary mucinous neoplasm without mural nodule ≥5 mm, large cysts, positive cytology of the pancreatic juice, and high levels of carcinoembryonic antigen in pancreatic juice may be useful to determine surgical indication, although further studies are needed to confirm these results.

What is the Outcome of Patients Affected by Intraductal Papillary Mucinous Neoplasms Without High-Risk Stigmata?: A Single-Center Retrospective Study

OBJECTIVES

The objectives of the study were to define the natural history of intraductal papillary mucinous neoplasms (IPMNs) without high-risk stigmata (HRS) and to identify factors capable of influencing outcome and management.

METHODS

This is a retrospective study of patients affected by IPMNs without HRS. Survival analyses included overall survival, disease-specific survival, and years of life lost. Uni- and multivariate analyses were carried out to identify factors capable of predicting years of life lost.

RESULTS

Three hundred fifty-six patients were analyzed. Fifty-three patients (14.9%) died: no postoperative mortality, 6 (1.7%) patients from pancreatic cancer and 47 (13.2%) from reasons not related to the disease. Mean overall survival and disease-specific survival were 199.4 (SD, 16.6) and 281 months (SD, 6.9), respectively. The years of life lost of the sample observed with respect to the general population were 2 years and 3 months (15 years and 3 months vs 17 years and 6 months). Younger age, length of follow-up more than 3 years, and surgery significantly increased the years of life lost.

CONCLUSIONS

The patients affected by IPMNs without HRS rarely died from the disease. Young age (<65 years) and follow-up more than 3 years seemed to be the only factors capable of influencing the outcome and management.