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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The additive value of CA19.9 monitoring in a pancreatic cyst surveillance program

BACKGROUND

Surveillance of pancreatic cysts focuses on the detection of (mostly morphologic) features warranting surgery. European guidelines consider elevated CA19.9 as a relative indication for surgery. We aimed to evaluate the role of CA19.9 monitoring for early detection and management in a cyst surveillance population.

METHODS

The PACYFIC-registry is a prospective collaboration that investigates the yield of pancreatic cyst surveillance performed at the discretion of the treating physician. We included participants for whom at least one serum CA19.9 value was determined by a minimum follow-up of 12 months.

RESULTS

Of 1865 PACYFIC participants, 685 met the inclusion criteria for this study (mean age 67 years, SD 10; 61% female). During a median follow-up of 25 months (IQR 24, 1966 visits), 29 participants developed high-grade dysplasia (HGD) or pancreatic cancer. At baseline, CA19.9 ranged from 1 to 591 kU/L (median 10 kU/L [IQR 14]), and was elevated (≥37 kU/L) in 64 participants (9%). During 191 of 1966 visits (10%), an elevated CA19.9 was detected, and these visits more often led to an intensified follow-up (42%) than those without an elevated CA19.9 (27%; p < 0.001). An elevated CA19.9 was the sole reason for surgery in five participants with benign disease (10%). The baseline CA19.9 value was (as continuous or dichotomous variable at the 37 kU/L threshold) not independently associated with HGD or pancreatic cancer development, whilst a CA19.9 of ≥ 133 kU/L was (HR 3.8, 95% CI 1.1-13, p = 0.03).

CONCLUSIONS

In this pancreatic cyst surveillance cohort, CA19.9 monitoring caused substantial harm by shortening surveillance intervals (and performance of unnecessary surgery). The current CA19.9 cutoff was not predictive of HGD and pancreatic cancer, whereas a higher cutoff may decrease false-positive values. The role of CA19.9 monitoring should be critically appraised prior to implementation in surveillance programs and guidelines.

Mutation Analysis of Pancreatic Juice and Plasma for the Detection of Pancreatic Cancer

Molecular profiling may enable earlier detection of pancreatic cancer (PC) in high-risk individuals undergoing surveillance and allow for personalization of treatment. We hypothesized that the detection rate of DNA mutations is higher in pancreatic juice (PJ) than in plasma due to its closer contact with the pancreatic ductal system, from which pancreatic cancer cells originate, and higher overall cell-free DNA (cfDNA) concentrations. In this study, we included patients with pathology-proven PC or intraductal papillary mucinous neoplasm (IPMN) with high-grade dysplasia (HGD) from two prospective clinical trials (KRASPanc and PACYFIC) for whom both PJ and plasma were available. We performed next-generation sequencing on PJ, plasma, and tissue samples and described the presence (and concordance) of mutations in these biomaterials. This study included 26 patients (25 PC and 1 IPMN with HGD), of which 7 were women (27%), with a median age of 71 years (IQR 12) and a median BMI of 23 kg/m2 (IQR 4). Ten patients with PC (40%) were (borderline) resectable at baseline. Tissue was available from six patients (resection n = 5, biopsy n = 1). A median volume of 2.9 mL plasma (IQR 1.0 mL) and 0.7 mL PJ (IQR 0.1 mL, p < 0.001) was used for DNA isolation. PJ had a higher median cfDNA concentration (2.6 ng/μL (IQR 4.2)) than plasma (0.29 ng/μL (IQR 0.40)). A total of 41 unique somatic mutations were detected: 24 mutations in plasma (2 KRAS, 15 TP53, 2 SMAD4, 3 CDKN2A 1 CTNNB1, and 1 PIK3CA), 19 in PJ (3 KRAS, 15 TP53, and 1 SMAD4), and 8 in tissue (2 KRAS, 2 CDKN2A, and 4 TP53). The mutation detection rate (and the concordance with tissue) did not differ between plasma and PJ. In conclusion, while the concentration of cfDNA was indeed higher in PJ than in plasma, the mutation detection rate was not different. A few cancer-associated genetic variants were detected in both biomaterials. Further research is needed to increase the detection rate and assess the performance and suitability of plasma and PJ for PC (early) detection.

An 8q24 Gain in Pancreatic Juice Is a Candidate Biomarker for the Detection of Pancreatic Cancer

Secretin-stimulated pancreatic juice (PJ), collected from the duodenum, presents a valuable biomarker source for the (earlier) detection of pancreatic cancer (PC). Here, we evaluate the feasibility and performance of shallow sequencing to detect copy number variations (CNVs) in cell-free DNA (cfDNA) from PJ for PC detection. First, we confirmed the feasibility of shallow sequencing in PJ (n = 4), matched plasma (n = 3) and tissue samples (n = 4, microarray). Subsequently, shallow sequencing was performed on cfDNA from PJ of 26 cases (25 sporadic PC, 1 high-grade dysplasia) and 19 controls with a hereditary or familial increased risk of PC. 40 of the 45 PJ samples met the quality criteria for cfDNA analysis. Nine individuals had an 8q24 gain (oncogene MYC; 23%; eight cases (33%) and one control (6%), p = 0.04); six had both a 2q gain (STAT1) and 5p loss (CDH10; 15%; four cases (7%) and two controls (13%), p = 0.72). The presence of an 8q24 gain differentiated the cases and controls, with a sensitivity of 33% (95% CI 16-55%) and specificity of 94% (95% CI 70-100%). The presence of either an 8q24 or 2q gain with a 5p loss was related to a sensitivity of 50% (95% CI 29-71%) and specificity of 81% (95% CI 54-96%). Shallow sequencing of PJ is feasible. The presence of an 8q24 gain in PJ shows promise as a biomarker for the detection of PC. Further research is required with a larger sample size and consecutively collected samples in high-risk individuals prior to implementation in a surveillance cohort.

Protein biomarkers in pancreatic juice and serum for identification of pancreatic cancer

BACKGROUND AND AIMS

To date, surveillance of high-risk individuals for pancreatic ductal adenocarcinoma (PDAC) has not lived up to expectations, as identification of curable stages through imaging remains challenging. Biomarkers are therefore needed. Pancreatic juice (PJ) may be a promising source, because it is in direct contact with the ductal epithelial lining from which PDAC arises. We aimed to develop a panel of biomarkers from serum and PJ to detect PDAC for future surveillance purposes.

METHODS

All patients who underwent PJ collection on secretin stimulation at the Erasmus MC were included. Both PJ and serum were evaluated. Protein levels were determined by the Lowry assay. Potential biomarkers (interleukin-8, interferon-γ, neutrophil gelatinase-associated lipocalin [NGAL], mucin 5, subtype AC [MUC5AC], mucin 2, phospholipase A2 group IB) were selected based on previously reported outcomes and assessed with enzyme-linked immunosorbent assay. Serum carbohydrate antigen 19-9 (CA19-9) values were determined by electrochemiluminescence immunoassay.

RESULTS

This study included 59 cases and 126 surveilled control subjects (who underwent PJ collection), of whom 71 had a hereditary predisposition (35 genetic, 36 familial) and 55 had (suspected neoplastic) pancreatic cysts. CA19-9 values were available for 53 cases and 48 control subjects. Serum CA19-9, as well as PJ interleukin-8, NGAL and MUC5AC, were associated with PDAC independent of age, gender, and presence of diabetes mellitus. Serum CA19-9 had a significantly higher area under the curve (AUC; .86; 95% confidence interval [CI], .79-.94) than individual PJ markers (AUC, .62-.70). A combination of PJ markers and serum CA19-9 (panel 2: sensitivity 42% [95% CI, 29-57] and specificity 96% [95% CI, 86-100]) did not improve diagnostic performance compared with CA19-9 alone (sensitivity 70% [95% CI, 56-82] and specificity 85% [95% CI, 72-94]).

CONCLUSIONS

High levels of serum CA19-9 and PJ-derived proteins are associated with PDAC. Prospective surveillance studies including individuals at risk of developing PDAC are required to validate these findings.

Extracellular vesicle-derived microRNAs in pancreatic juice as biomarkers for detection of pancreatic ductal adenocarcinoma

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is usually diagnosed in an advanced stage, with minimal likelihood of long-term survival. Only a small subset of patients are diagnosed with early (T1) disease. Early detection is challenging due to the late onset of symptoms and limited visibility of sub-centimeter cancers on imaging. A novel approach is to support the clinical diagnosis with molecular markers. MicroRNA derived from extracellular vehicles (EVs) in blood has shown promise as a potential biomarker for pancreatic neoplasia, but microRNA derived from pancreatic juice (PJ) may be a more sensitive biomarker, given that is in close contact with ductal cells from which PDAC arises. This study aims to evaluate and compare the performance of PJ- and serum-derived EV-miRNA for the detection of PDAC.

METHODS

PJ was collected from the duodenum during EUS after secretin stimulation from 54 patients with PDAC and 118 non-malignant controls. Serum was available for a subset of these individuals. MiR-16, miR-21, miR-25, miR-155 and miR-210 derived from EVs isolated from PJ and serum were analyzed by qPCR, and serum CA19-9 levels were determined by electrochemiluminescence immunoassay. For statistical analysis, either a Mann-Whitney U test or a Wilcoxon Signed Rank test was performed. ROC curves and AUC were used to assess the sensitivity and specificity of miR expression for PDAC detection.

RESULTS

Expression of EV-miR-21, EV-miR-25 and EV-miR-16 were increased in cases vs controls in PJ, while only EV-miR-210 was increased in serum. The potential to detect PC was good for a combination of PJ EV-miR-21, EV-miR-25, EV-miR-16 and serum miR-210, CA-19-9, with an area under the curve of 0.91, a specificity of 84.2% and a sensitivity of 81.5%.

CONCLUSION

Detection of miRNA from EVs in PJ is feasible. A combined panel of PJ EV-miR-21, EV-miR-25, EV-miR-16, and serum EV-miR-210 and CA19-9 distinguishes cases with PDAC from controls undergoing surveillance with a specificity of 81.5% and sensitivity of 84.2%.

Long-term yield of pancreatic cancer surveillance in high-risk individuals

OBJECTIVE

We aimed to determine the long-term yield of pancreatic cancer surveillance in hereditary predisposed high-risk individuals.

DESIGN

From 2006 to 2019, we prospectively enrolled asymptomatic individuals with an estimated 10% or greater lifetime risk of pancreatic ductal adenocarcinoma (PDAC) after obligatory evaluation by a clinical geneticist and genetic testing, and subjected them to annual surveillance with both endoscopic ultrasonography (EUS) and MRI/cholangiopancreatography (MRI/MRCP) at each visit.

RESULTS

366 individuals (201 mutation-negative familial pancreatic cancer (FPC) kindreds and 165 PDAC susceptibility gene mutation carriers; mean age 54 years, SD 9.9) were followed for 63 months on average (SD 43.2). Ten individuals developed PDAC, of which four presented with a symptomatic interval carcinoma and six underwent resection. The cumulative PDAC incidence was 9.3% in the mutation carriers and 0% in the FPC kindreds (p<0.001). Median PDAC survival was 18 months (range 1-32). Surgery was performed in 17 individuals (4.6%), whose pathology revealed 6 PDACs (3 T1N0M0), 7 low-grade precursor lesions, 2 neuroendocrine tumours <2 cm, 1 autoimmune pancreatitis and in 1 individual no abnormality. There was no surgery-related mortality. EUS detected more solid lesions than MRI/MRCP (100% vs 22%, p<0.001), but less cystic lesions (42% vs 83%, p<0.001).

CONCLUSION

The diagnostic yield of PDAC was substantial in established high-risk mutation carriers, but non-existent in the mutation-negative proven FPC kindreds. Nevertheless, timely identification of resectable lesions proved challenging despite the concurrent use of two imaging modalities, with EUS outperforming MRI/MRCP. Overall, surveillance by imaging yields suboptimal results with a clear need for more sensitive diagnostic markers, including biomarkers.

Longitudinal changes of serum protein N-Glycan levels for earlier detection of pancreatic cancer in high-risk individuals

BACKGROUND

Surveillance of individuals at risk of developing pancreatic ductal adenocarcinoma (PDAC) has the potential to improve survival, yet early detection based on solely imaging modalities is challenging. We aimed to identify changes in serum glycosylation levels over time to earlier detect PDAC in high-risk individuals.

METHODS

Individuals with a hereditary predisposition to develop PDAC were followed in two surveillance programs. Those, of which at least two consecutive serum samples were available, were included. Mass spectrometry analysis was performed to determine the total N-glycome for each consecutive sample. Potentially discriminating N-glycans were selected based on our previous cross-sectional analysis and relative abundances were calculated for each glycosylation feature.

RESULTS

165 individuals ("FPC-cohort" N = 119; Leiden cohort N = 46) were included. In total, 97 (59%) individuals had a genetic predisposition (77 CDKN2A, 15 BRCA1/2, 5 STK11) and 68 (41%) a family history of PDAC without a known genetic predisposition (>10-fold increased risk of developing PDAC). From each individual, a median number of 3 serum samples (IQR 3) was collected. Ten individuals (6%) developed PDAC during 35 months of follow-up; nine (90%) of these patients carried a CDKN2A germline mutation. In PDAC cases, compared to all controls, glycosylation characteristics were increased (fucosylation, tri- and tetra-antennary structures, specific sialic linkage types), others decreased (complex-type diantennary and bisected glycans). The largest change over time was observed for tri-antennary fucosylated glycans, which were able to differentiate cases from controls with a specificity of 92%, sensitivity of 49% and accuracy of 90%.

CONCLUSION

Serum N-glycan monitoring may support early detection in a pancreas surveillance program.

Timeline of Development of Pancreatic Cancer and Implications for Successful Early Detection in High-Risk Individuals

BACKGROUND & AIMS

To successfully implement imaging-based pancreatic cancer (PC) surveillance, understanding the timeline and morphologic features of neoplastic progression is key. We aimed to investigate the progression to neoplasia from serial prediagnostic pancreatic imaging tests in high-risk individuals and identify factors associated with successful early detection.

METHODS

We retrospectively examined the development of pancreatic abnormalities in high-risk individuals who were diagnosed with PC or underwent pancreatic surgery, or both, in 16 international surveillance programs.

RESULTS

Of 2552 high-risk individuals under surveillance, 28 (1%) developed neoplastic progression to PC or high-grade dysplasia during a median follow-up of 29 months after baseline (interquartile range [IQR], 40 months). Of these, 13 of 28 (46%) presented with a new lesion (median size, 15 mm; range 7-57 mm), a median of 11 months (IQR, 8; range 3-17 months) after a prior examination, by which time 10 of 13 (77%) had progressed beyond the pancreas. The remaining 15 of 28 (54%) had neoplastic progression in a previously detected lesion (12 originally cystic, 2 indeterminate, 1 solid), and 11 (73%) had PC progressed beyond the pancreas. The 12 patients with cysts had been monitored for 21 months (IQR, 15 months) and had a median growth of 5 mm/y (IQR, 8 mm/y). Successful early detection (as high-grade dysplasia or PC confined to the pancreas) was associated with resection of cystic lesions (vs solid or indeterminate lesions (odds ratio, 5.388; 95% confidence interval, 1.525-19.029) and small lesions (odds ratio, 0.890/mm; 95% confidence interval 0.812-0.976/mm).

CONCLUSIONS

In nearly half of high-risk individuals developing high-grade dysplasia or PC, no prior lesions are detected by imaging, yet they present at an advanced stage. Progression can occur before the next scheduled annual examination. More sensitive diagnostic tools or a different management strategy for rapidly growing cysts are needed.

Neoantigen Quantity and Quality in Relation to Pancreatic Cancer Survival

Introduction

Factors underlying antitumor immunity in pancreatic cancer (PC) are poorly understood. We hypothesized that not neoantigen quantity, but quality, is related to immune cell infiltration and survival.

Methodology

We performed genomic and transcriptomic profiling of paired normal, tumor tissue of 13 patients with PC with distinct survival times. Additionally, neoantigens prediction and immunological profiling were performed.

Results

The proportion of neoantigens with a low similarity-to-self score was higher in short-term survivors (p < 0.0001), while mutational load and burden, similarity-to-known-pathogens, and immunogenicity of neoantigens were not associated with immune cell infiltration or survival.

Discussion

No tumor mutational load or neoantigen quantity, but low similarity-to-self score, was associated with immune cell infiltration and survival.

Barrett's Epithelial Thickness, Assessed by Volumetric Laser Endomicroscopy, Is Associated With Response to Radiofrequency Ablation

BACKGROUND & AIMS

Radiofrequency ablation (RFA) is the most common treatment for flat Barrett's esophagus (BE), but reasons for varying outcomes are poorly understood. A recently developed contrast-enhancement algorithm allows reliable measurement of Barrett's epithelial thickness (BET) from volumetric laser endomicroscopy (VLE) images and correlation with response to RFA. Using this algorithm, we investigated whether patients with thicker Barrett's mucosa are less likely to respond to RFA. In the future, this algorithm may guide choice of RFA dosing or endoscopic resection.

METHODS

We performed a retrospective analysis on all patients with BE who received a baseline VLE scan between May 2015 and October 2016, followed by RFA and 1 follow-up exam, from 14 institutions participating in the United States VLE registry. We measured BET on equidistant locations by estimating the distance between the esophageal surface and the superficial edge of the deepest lamina propria. The primary outcome variable was the percentage reduction in Prague length; secondary outcome variables were complete remission of intestinal metaplasia (CRIM) and presence of strictures after 12 months.

RESULTS

Images from 61 patients were included in our final analysis. Mean BET per patient ranged from 224 μm to 705 μm. A 100 μm thicker mean BET per patient resulted in a 12% lower response to treatment, measured by a reduction of Prague length (P = .03), after adjustment for confounders. We found an association between mean BET and CRIM, but not with stricture formation.

CONCLUSIONS

Based on measurements on contrast-enhanced VLE images, we found that BET correlates with response to RFA. For clinical implementation, larger studies with a standardized follow-up and development of computer-aided image analysis systems are needed.

Volumetric laser endomicroscopy in the biliary and pancreatic ducts: a feasibility study with histological correlation

BACKGROUND

Volumetric laser endomicroscopy (VLE) provides circumferential images 3 mm into the biliary and pancreatic ducts. We aimed to correlate VLE images with the normal and abnormal microstructure of these ducts.

METHODS

Samples from patients undergoing hepatic or pancreatic resection were evaluated. VLE images were collected using a low-profile VLE catheter inserted manually into the biliary and pancreatic ducts ex vivo. Histological correlation was assessed by two unblinded investigators.

RESULTS

25 patients (20 liver and 5 pancreatic samples) and 111 images were analyzed. VLE revealed three histological layers: epithelium, connective tissue, and parenchyma. It identified distinctive patterns for primary sclerosing cholangitis (PSC), pancreatic cysts, neuroendocrine tumor, and adenocarcinoma adjacent to the pancreatic duct or ampulla. VLE failed to identify dysplasia in a dominant stricture and inflammatory infiltrates in PSC. Reflectivity measurements of the liver parenchyma diagnosed liver cirrhosis with high sensitivity.

CONCLUSIONS

VLE can identify histological changes in the biliary and pancreatic ducts allowing real-time diagnosis. Further studies are needed to measure the accuracy of VLE in a larger sample and to validate our findings in vivo.