Circulating Tumor DNA Analysis Guiding Adjuvant Therapy in Stage II Colon Cancer.

BACKGROUND: The role of adjuvant chemotherapy in stage II colon cancer continues to be debated. The presence of circulating tumor DNA (ctDNA) after surgery predicts very poor recurrence-free survival, whereas its absence predicts a low risk of recurrence. The benefit of adjuvant chemotherapy for ctDNA-positive patients is not well understood. METHODS: We conducted a trial to assess whether a ctDNA-guided approach could reduce the use of adjuvant chemotherapy without compromising recurrence risk. Patients with stage II colon cancer were randomly assigned in a 2:1 ratio to have treatment decisions guided by either ctDNA results or standard clinicopathological features. For ctDNA-guided management, a ctDNA-positive result at 4 or 7 weeks after surgery prompted oxaliplatin-based or fluoropyrimidine chemotherapy. Patients who were ctDNA-negative were not treated. The primary efficacy end point was recurrence-free survival at 2 years. A key secondary end point was adjuvant chemotherapy use. RESULTS: Of the 455 patients who underwent randomization, 302 were assigned to ctDNA-guided management and 153 to standard management. The median follow-up was 37 months. A lower percentage of patients in the ctDNA-guided group than in the standard-management group received adjuvant chemotherapy (15% vs. 28%; relative risk, 1.82; 95% confidence interval [CI], 1.25 to 2.65). In the evaluation of 2-year recurrence-free survival, ctDNA-guided management was noninferior to standard management (93.5% and 92.4%, respectively; absolute difference, 1.1 percentage points; 95% CI, -4.1 to 6.2 [noninferiority margin, -8.5 percentage points]). Three-year recurrence-free survival was 86.4% among ctDNA-positive patients who received adjuvant chemotherapy and 92.5% among ctDNA-negative patients who did not. CONCLUSIONS: A ctDNA-guided approach to the treatment of stage II colon cancer reduced adjuvant chemotherapy use without compromising recurrence-free survival. (Supported by the Australian National Health and Medical Research Council and others; DYNAMIC Australian New Zealand Clinical Trials Registry number, ACTRN12615000381583.).

Surveillance for Presumed BD-IPMN of the Pancreas: Stability, Size, and Age Identify Targets for Discontinuation.

BACKGROUND & AIMS: Currently, most patients with branch duct intraductal papillary mucinous neoplasms (BD-IPMN) are offered indefinite surveillance, resulting in health care costs with questionable benefits regarding cancer prevention. This study sought to identify patients in whom the risk of cancer is equivalent to an age-matched population, thereby justifying discontinuation of surveillance. METHODS: International multicenter study involving presumed BD-IPMN without worrisome features (WFs) or high-risk stigmata (HRS) at diagnosis who underwent surveillance. Clusters of individuals at risk for cancer development were defined according to cyst size and stability for at least 5 years, and age-matched controls were used for comparison using standardized incidence ratios (SIRs) for pancreatic cancer. RESULTS: Of 3844 patients with presumed BD-IPMN, 775 (20.2%) developed WFs and 68 (1.8%) HRS after a median surveillance of 53 (interquartile range 53) months. Some 164 patients (4.3%) underwent surgery. Of the overall cohort, 1617 patients (42%) remained stable without developing WFs or HRS for at least 5 years. In patients 75 years or older, the SIR was 1.12 (95% CI, 0.23-3.39), and in patients 65 years or older with stable lesions smaller than 15 mm in diameter after 5 years, the SIR was 0.95 (95% CI, 0.11-3.42). The all-cause mortality for patients who did not develop WFs or HRS for at least 5 years was 4.9% (n = 79), and the disease-specific mortality was 0.3% (n = 5). CONCLUSIONS: The risk of developing pancreatic malignancy in presumed BD-IPMN without WFs or HRS after 5 years of surveillance is comparable to that of the general population depending on cyst size and patient age. Surveillance discontinuation could be justified after 5 years of stability in patients older than 75 years with cysts <30 mm, and in patients 65 years or older who have cysts ≤15 mm.

Prospective, Multi-Institutional, Real-Time Next-Generation Sequencing of Pancreatic Cyst Fluid Reveals Diverse Genomic Alterations That Improve the Clinical Management of Pancreatic Cysts.

BACKGROUND & AIMS: Next-generation sequencing (NGS) of pancreatic cyst fluid is a useful adjunct in the assessment of patients with pancreatic cyst. However, previous studies have been retrospective or single institutional experiences. The aim of this study was to prospectively evaluate NGS on a multi-institutional cohort of patients with pancreatic cyst in real time. METHODS: The performance of a 22-gene NGS panel (PancreaSeq) was first retrospectively confirmed and then within a 2-year timeframe, PancreaSeq testing was prospectively used to evaluate endoscopic ultrasound-guided fine-needle aspiration pancreatic cyst fluid from 31 institutions. PancreaSeq results were correlated with endoscopic ultrasound findings, ancillary studies, current pancreatic cyst guidelines, follow-up, and expanded testing (Oncomine) of postoperative specimens. RESULTS: Among 1933 PCs prospectively tested, 1887 (98%) specimens from 1832 patients were satisfactory for PancreaSeq testing. Follow-up was available for 1216 (66%) patients (median, 23 months). Based on 251 (21%) patients with surgical pathology, mitogen-activated protein kinase/GNAS mutations had 90% sensitivity and 100% specificity for a mucinous cyst (positive predictive value [PPV], 100%; negative predictive value [NPV], 77%). On exclusion of low-level variants, the combination of mitogen-activated protein kinase/GNAS and TP53/SMAD4/CTNNB1/mammalian target of rapamycin alterations had 88% sensitivity and 98% specificity for advanced neoplasia (PPV, 97%; NPV, 93%). Inclusion of cytopathologic evaluation to PancreaSeq testing improved the sensitivity to 93% and maintained a high specificity of 95% (PPV, 92%; NPV, 95%). In comparison, other modalities and current pancreatic cyst guidelines, such as the American Gastroenterology Association and International Association of Pancreatology/Fukuoka guidelines, show inferior diagnostic performance. The sensitivities and specificities of VHL and MEN1/loss of heterozygosity alterations were 71% and 100% for serous cystadenomas (PPV, 100%; NPV, 98%), and 68% and 98% for pancreatic neuroendocrine tumors (PPV, 85%; NPV, 95%), respectively. On follow-up, serous cystadenomas with TP53/TERT mutations exhibited interval growth, whereas pancreatic neuroendocrine tumors with loss of heterozygosity of ≥3 genes tended to have distant metastasis. None of the 965 patients who did not undergo surgery developed malignancy. Postoperative Oncomine testing identified mucinous cysts with BRAF fusions and ERBB2 amplification, and advanced neoplasia with CDKN2A alterations. CONCLUSIONS: PancreaSeq was not only sensitive and specific for various pancreatic cyst types and advanced neoplasia arising from mucinous cysts, but also reveals the diversity of genomic alterations seen in pancreatic cysts and their clinical significance.

Impact of preoperative endoscopic procedures on adverse event rates after surgical resection for main-duct and mixed-type intraductal papillary mucinous neoplasms (IPMNs).

BACKGROUND: Main-duct (MD-) and mixed-type (MT-) IPMNs harbor an increased risk of pancreatic cancer and warrant surgical resection. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) are important in the diagnosis of IPMNs. The aim of this study was to investigate whether endoscopic procedures manipulating the MD impact postoperative adverse events in patients with MD- and MT-IPMNs. METHODS: We performed a retrospective study of 369 patients who underwent resections for MD- or MT-IPMN at two tertiary centers (2000-2019). Multivariable logistic regression analyses were performed for postoperative adverse events to compare the risks between intervention (ERCP, EUS-FNA with branch duct (BD) aspirated, EUS-FNA with MD aspirated from the duct directly or cyst/mass arising from MD) versus no-intervention group. RESULTS: 33.1 % of patients had a preoperative ERCP and 69.4 % had EUS-FNA. Postoperative adverse events included: 30-day readmission (12.7 %), delayed gastric emptying (13.8 %), pancreatic fistula (10.3 %), abdominal abscess (5.7 %), cardiopulmonary adverse events (11.4 %), and mortality (1.4 %). The model was adjusted for potential confounders. There were no significant differences between the ERCP and no-ERCP groups for specific adverse events. Compared to no-EUS-FNA groups, groups of EUS-FNA with BD aspiration and EUS-FNA with MD aspiration from the main pancreatic duct directly or cyst/mass arising from MD did not show a significant increase in specific adverse events. CONCLUSIONS: Postoperative adverse events were not significantly increased among patients who had ERCP or EUS-FNA before surgical resection for MD- or MT-IPMNs. Endoscopic procedures directly sampling the MD can be safely pursued for diagnostic purposes in selected cases.

International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas.

This study group aimed to revise the 2017 international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and mainly focused on five topics; the revision of high-risk stigmata (HRS) and worrisome features (WF), surveillance of non-resected IPMN, surveillance after resection of IPMN, revision of pathological aspects, and investigation of molecular markers in cyst fluid. A new development from the prior guidelines is that systematic reviews were performed for each one of these topics, and published separately to provide evidence-based recommendations. One of the highlights of these new "evidence-based guidelines" is to propose a new management algorithm, and one major revision is to include into the assessment of HRS and WF the imaging findings from endoscopic ultrasound (EUS) and the results of cytological analysis from EUS-guided fine needle aspiration technique, when this is performed. Another key element of the current guidelines is to clarify whether lifetime surveillance for small IPMNs is required, and recommends two options, "stop surveillance" or "continue surveillance for possible development of concomitant pancreatic ductal adenocarcinoma", for small unchanged BD-IPMN after 5 years surveillance. Several other points are also discussed, including identifying high-risk features for recurrence in patients who underwent resection of non-invasive IPMN with negative surgical margin, summaries of the recent observations in the pathology of IPMN. In addition, the emerging role of cyst fluid markers that can aid in distinguishing IPMN from other pancreatic cysts and identify those IPMNs that harbor high-grade dysplasia or invasive carcinoma is discussed.

Real-time evaluation and adaptation to facilitate rapid recruitment in a large, prospective cohort study.

BACKGROUND: Recruiting large cohorts efficiently can speed the translation of findings into care across a range of scientific disciplines and medical specialties. Recruitment can be hampered by factors such as financial barriers, logistical concerns, and lack of resources for patients and clinicians. These and other challenges can lead to underrepresentation in groups such as rural residents and racial and ethnic minorities. Here we discuss the implementation of various recruitment strategies for enrolling participants into a large, prospective cohort study, assessing the need for adaptations and making them in real-time, while maintaining high adherence to the protocol and high participant satisfaction. METHODS: While conducting a large, prospective trial of a multi-cancer early detection blood test at Geisinger, an integrated health system in central Pennsylvania, we monitored recruitment progress, adherence to the protocol, and participants' satisfaction. Tracking mechanisms such as paper records, electronic health records, research databases, dashboards, and electronic files were utilized to measure each outcome. We then reviewed study procedures and timelines to list the implementation strategies that were used to address barriers to recruitment, protocol adherence and participant satisfaction. RESULTS: Adaptations to methods that contributed to achieving the enrollment goal included offering multiple recruitment options, adopting group consenting, improving visit convenience, increasing the use of electronic capture and the tracking of data and source documents, staffing optimization via leveraging resources external to the study team when appropriate, and integrating the disclosure of study results into routine clinical care without adding unfunded work for clinicians. We maintained high protocol adherence and positive participant experience as exhibited by a very low rate of protocol deviations and participant complaints. CONCLUSION: Recruiting rapidly for large studies - and thereby facilitating clinical translation - requires a nimble, creative approach that marshals available resources and changes course according to data. Planning a rigorous assessment of a study's implementation outcomes prior to study recruitment can further ground study adaptations and facilitate translation into practice. This can be accomplished by proactively and continuously assessing and revising implementation strategies.

A Combined DNA/RNA-based Next-Generation Sequencing Platform to Improve the Classification of Pancreatic Cysts and Early Detection of Pancreatic Cancer Arising From Pancreatic Cysts.

OBJECTIVE: We report the development and validation of a combined DNA/RNA next-generation sequencing (NGS) platform to improve the evaluation of pancreatic cysts. BACKGROUND AND AIMS: Despite a multidisciplinary approach, pancreatic cyst classification, such as a cystic precursor neoplasm, and the detection of high-grade dysplasia and early adenocarcinoma (advanced neoplasia) can be challenging. NGS of preoperative pancreatic cyst fluid improves the clinical evaluation of pancreatic cysts, but the recent identification of novel genomic alterations necessitates the creation of a comprehensive panel and the development of a genomic classifier to integrate the complex molecular results. METHODS: An updated and unique 74-gene DNA/RNA-targeted NGS panel (PancreaSeq Genomic Classifier) was created to evaluate 5 classes of genomic alterations to include gene mutations (e.g., KRAS, GNAS, etc.), gene fusions and gene expression. Further, CEA mRNA ( CEACAM5 ) was integrated into the assay using RT-qPCR. Separate multi-institutional cohorts for training (n=108) and validation (n=77) were tested, and diagnostic performance was compared to clinical, imaging, cytopathologic, and guideline data. RESULTS: Upon creation of a genomic classifier system, PancreaSeq GC yielded a 95% sensitivity and 100% specificity for a cystic precursor neoplasm, and the sensitivity and specificity for advanced neoplasia were 82% and 100%, respectively. Associated symptoms, cyst size, duct dilatation, a mural nodule, increasing cyst size, and malignant cytopathology had lower sensitivities (41-59%) and lower specificities (56-96%) for advanced neoplasia. This test also increased the sensitivity of current pancreatic cyst guidelines (IAP/Fukuoka and AGA) by >10% and maintained their inherent specificity. CONCLUSIONS: PancreaSeq GC was not only accurate in predicting pancreatic cyst type and advanced neoplasia but also improved the sensitivity of current pancreatic cyst guidelines.

Predictive ability of pancreatic cyst fluid biomarkers: A systematic review and meta-analysis.

BACKGROUND: Mucinous pancreatic cysts harbor the potential to progress to highly lethal pancreatic ductal adenocarcinoma (PDAC). Since these precursor cysts require cancer surveillance or surgical resection, they need to be reliably distinguished from harmless pancreatic cysts. Current clinical and radiographic assessment is imperfect and the value of cyst fluid analysis for differential diagnosis is unclear. Therefore, we set out to investigate the value of cyst fluid biomarkers in distinguishing pancreatic cysts. METHODS: We performed a systematic review of the current literature to identify articles that evaluated the diagnostic performance of clinically relevant and promising candidate cyst fluid biomarkers, with a particular emphasis on DNA-based biomarkers. Meta-analysis was performed for biomarkers targeted at identifying cyst type and presence of high-grade dysplasia or PDAC. RESULTS: Data from a total of 42 studies was analyzed. Mutations in KRAS and/or GNAS allowed identification of mucinous cysts with a sensitivity of 79% and specificity of 98%. This exceeded the performance of the traditional biomarker carcinoembryonic antigen (CEA; sensitivity 58%, specificity 87%). Mutations in VHL were specific for serous cystadenomas (SCAs; sensitivity 56%, specificity 99%) and help to exclude mucinous cysts. Mutations in CDKN2A, PIK3CA, SMAD4, and TP53 each had high specificities of 97%, 97%, 98%, and 95%, respectively, to identify high-grade dysplasia or PDAC in mucinous cysts. CONCLUSIONS: Cyst fluid analysis can be a valuable tool in the characterization of pancreatic cysts, with relevant clinical implications. Our results support the use of DNA-based cyst fluid biomarkers in the multidisciplinary diagnostic work-up of pancreatic cysts.

Assessing aneuploidy with repetitive element sequencing.

We report a sensitive PCR-based assay called Repetitive Element AneupLoidy Sequencing System (RealSeqS) that can detect aneuploidy in samples containing as little as 3 pg of DNA. Using a single primer pair, we amplified ∼350,000 amplicons distributed throughout the genome. Aneuploidy was detected in 49% of liquid biopsies from a total of 883 nonmetastatic, clinically detected cancers of the colorectum, esophagus, liver, lung, ovary, pancreas, breast, or stomach. Combining aneuploidy with somatic mutation detection and eight standard protein biomarkers yielded a median sensitivity of 80% in these eight cancer types, while only 1% of 812 healthy controls scored positive.

Multiinstitutional Validation Study of Cyst Fluid Protein Biomarkers in Patients With Cystic Lesions of the Pancreas.

OBJECTIVE: Prospective evaluation of 2 clinical-molecular models in patients with unknown pathology who underwent endoscopic ultrasound with fine-needle aspiration (EUS-FNA) for a cystic lesion of the pancreas. SUMMARY OF BACKGROUND DATA: Preoperative prediction of histologic subtype (mucinous vs nonmucinous) and grade of dysplasia in patients with pancreatic cystic neoplasms is challenging. Our group has previously published 2 clinical-molecular nomograms for intraductal papillary mucinous neoplasms (IPMN) that incorporated both clinical/radiographic features and cyst fluid protein markers (sFASL, CA72-4, MMP9, IL-4). METHODS: This multiinstitutional study enrolled patients who underwent EUS-FNA for a cystic lesion of the pancreas. Treatment recommendations regarding resection were based on standard clinical, radiographic, and endoscopic features. Predicted probabilities of high-risk IPMN (high-grade dysplasia/invasive cancer) were calculated using the previously developed clinical-molecular nomograms. RESULTS: Cyst fluid was obtained from 100 patients who underwent diagnostic EUS-FNA. Within this group there were 35 patients who underwent resection, and 65 were monitored radiographically. Within the group that underwent resection, 26 had low-risk IPMN or benign non-IPMN lesions, and 9 had high-risk IPMN. Within the surveillance group, no patient progressed to resection or developed cancer after a median follow-up of 12months (range: 0.5-38). Using the clinical/radiographic nomogram alone, 2 out of 9 patients with high-risk IPMN had a predicted probability >0.5. In the clinical-molecular models, 6 of 9 patients in model 1, and 6 of 9 in model 2, had scores >0.5. CONCLUSIONS: This prospective study of patients with unknown cyst pathology further demonstrates the importance of cyst fluid protein analysis in the preoperative identification of patients with high-risk IPMN. Longer follow-up is necessary to determine if this model will be useful in clinical practice.

Alterations in the Duodenal Fluid Microbiome of Patients With Pancreatic Cancer.

BACKGROUND & AIMS: The tumor microbiome of patients with pancreas ductal adenocarcinoma (PDAC) includes bacteria normally present in the upper gastrointestinal tract. If the predominant source of intratumoral bacteria in patients with PDAC is retrograde migration from the duodenum, duodenal fluid could be a representative biospecimen for determining microbiome profiles of patients with PDAC or at risk of developing PDAC. METHODS: We performed a case-control study comparing bacterial and fungal (16S and 18S rRNA) profiles of secretin-stimulated duodenal fluid collections from 308 patients undergoing duodenal endoscopy including 134 normal pancreas control subjects, 98 patients with pancreatic cyst(s) and 74 patients with PDAC. RESULTS: Alterations in duodenal fluid microbiomes with diminished alpha diversity were significantly associated with age >70 and proton pump inhibitor use. Patients with PDAC had significantly decreased duodenal microbial alpha diversity compared with age-matched control subjects with normal pancreata and those with pancreatic cyst(s). There was evidence of enrichment of Bifidobacterium genera in the duodenal fluid of patients with PDAC compared with control subjects and those with pancreatic cyst(s). There were also enrichment of duodenal fluid Fusobacteria and Rothia bacteria among patients with PDAC with short-term survival. Duodenal fluid microbiome profiles were not significantly different between control subjects and patients with pancreatic cyst(s). CONCLUSION: Patients with PDAC have alterations in their duodenal fluid microbiome profiles compared with patients with pancreatic cysts and those with normal pancreata. ClinicalTrials.gov, Number: NCT02000089.

Serum Carboxypeptidase Activity and Genotype-Stratified CA19-9 to Detect Early-Stage Pancreatic Cancer.

BACKGROUND AND AIMS: Serum diagnostic markers of early-stage pancreatic ductal adenocarcinoma (PDAC) are needed, especially for stage I disease. As tumors grow and cause pancreatic atrophy, markers derived from pancreatic parenchyma such as serum carboxypeptidase A (CPA) activity lose diagnostic performance. We evaluated, with CA19-9, serum CPA as a marker of early pancreatic cancer. METHODS: Serum CPA activity levels were measured in 345 controls undergoing pancreatic surveillance, divided into 2 sets, set 1 being used to establish a reference range. Variants within the CPA1 locus were sought for their association with pancreatic CPA1 expression to determine if such variants associated with serum CPA levels. A total of 190 patients with resectable PDAC were evaluated. RESULTS: Among controls, those having 1 or more minor alleles of CPA1 variants rs6955723 or rs2284682 had significantly higher serum CPA levels than did those without (P = .001). None of the PDAC cases with pancreatic atrophy had an elevated CPA. Among 122 PDAC cases without atrophy, defining serum CPA diagnostic cutoffs by a subject's CPA1 variants yielded a diagnostic sensitivity of 18% at 99% specificity (95% confidence interval [CI], 11.7-26) (vs 11.1% sensitivity using a uniform diagnostic cutoff); combining CPA with variant-stratified CA19-9 yielded a sensitivity of 68.0% (95% CI, 59.0-76.2) vs 63.1% (95% CI, 53.9- 71.7) for CA19-9 alone; and among stage I PDAC cases, diagnostic sensitivity was 51.9% (95% CI, 31.9-71.3) vs 37.0% (95% CI, 19.4-57.6) for CA19-9 alone. In the validation control set, the variant-stratified diagnostic cutoff yielded a specificity of 98.2%. CONCLUSION: Serum CPA activity has diagnostic utility before the emergence of pancreatic atrophy as a marker of localized PDAC, including stage I disease.

Accuracy and agreement of a large panel of endosonographers for endomicroscopy-guided virtual biopsy of pancreatic cystic lesions.

BACKGROUND: Although emerging data evidences that EUS-guided needle-based confocal laser endomicroscopy (nCLE) accurately diagnoses pancreatic cystic lesions (PCLs), there are a lack of interobserver agreement (IOA) studies utilizing reference histopathological diagnosis and for specific PCL subtypes. Hence, we sought to assess the IOA, intra-observer reliability (IOR), and diagnostic performance of EUS-nCLE using a large cohort of patients with histopathological diagnosis amongst a broad panel of international observers. METHODS: EUS-nCLE videos (n = 76) of subjects with PCLs [intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystadenoma (SCA), pseudocyst, and cystic-neuroendocrine tumors/solid pseudopapillary neoplasm (cystic-NET/SPN)], simulating clinical prevalence rates were obtained from 3 prospective studies. An international panel of 13 endosonographers with nCLE experience, blinded to all PCL data, evaluated the video library twice with a two-week washout for PCL differentiation (mucinous vs. non-mucinous) and subtype diagnosis. RESULTS: The IOA (κ = 0.82, 95% CI 0.77-0.87) and IOR (κ = 0.82, 95% CI 0.78-0.85) were "almost perfect" to differentiate mucinous vs. non-mucinous PCLs. For PCL subtype, IOA was highest for SCA (almost perfect; κ = 0.85), followed by IPMN (substantial, κ = 0.72), and cystic-NET/SPN (substantial, κ = 0.73). The IOA was moderate for MCN (κ = 0.47), and pseudocyst (κ = 0.57). Compared to histopathology, observers differentiated mucinous vs. non-mucinous PCLs with high accuracy (94.8%, 95% CI 93.3-96.1). For detecting specific PCLs subtypes, EUS-nCLE was highly accurate in diagnosing non-mucinous cysts (SCA: 98%; cystic-NET/SPN: 96%; pseudocyst: 96%) and slightly less accurate for mucinous lesions (IPMN: 86%; MCN: 84%). CONCLUSION: Diagnosis of PCLs by EUS-nCLE guided virtual biopsy is very accurate and reliable for the most prevalent pancreatic cysts in clinical practice.

Multiregion whole-exome sequencing of intraductal papillary mucinous neoplasms reveals frequent somatic KLF4 mutations predominantly in low-grade regions.

OBJECTIVE: Intraductal papillary mucinous neoplasms (IPMNs) are non-invasive precursor lesions that can progress to invasive pancreatic cancer and are classified as low-grade or high-grade based on the morphology of the neoplastic epithelium. We aimed to compare genetic alterations in low-grade and high-grade regions of the same IPMN in order to identify molecular alterations underlying neoplastic progression. DESIGN: We performed multiregion whole exome sequencing on tissue samples from 17 IPMNs with both low-grade and high-grade dysplasia (76 IPMN regions, including 49 from low-grade dysplasia and 27 from high-grade dysplasia). We reconstructed the phylogeny for each case, and we assessed mutations in a novel driver gene in an independent cohort of 63 IPMN cyst fluid samples. RESULTS: Our multiregion whole exome sequencing identified KLF4, a previously unreported genetic driver of IPMN tumorigenesis, with hotspot mutations in one of two codons identified in >50% of the analyzed IPMNs. Mutations in KLF4 were significantly more prevalent in low-grade regions in our sequenced cases. Phylogenetic analyses of whole exome sequencing data demonstrated diverse patterns of IPMN initiation and progression. Hotspot mutations in KLF4 were also identified in an independent cohort of IPMN cyst fluid samples, again with a significantly higher prevalence in low-grade IPMNs. CONCLUSION: Hotspot mutations in KLF4 occur at high prevalence in IPMNs. Unique among pancreatic driver genes, KLF4 mutations are enriched in low-grade IPMNs. These data highlight distinct molecular features of low-grade and high-grade dysplasia and suggest diverse pathways to high-grade dysplasia via the IPMN pathway.

Recurrent Rearrangements in PRKACA and PRKACB in Intraductal Oncocytic Papillary Neoplasms of the Pancreas and Bile Duct.

BACKGROUND & AIMS: Intraductal oncocytic papillary neoplasms (IOPNs) of the pancreas and bile duct contain epithelial cells with numerous, large mitochondria and are cystic precursors to pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA), respectively. However, IOPNs do not have the genomic alterations found in other pancreatobiliary neoplasms. In fact, no recurrent genomic alterations have been described in IOPNs. PDACs without activating mutations in KRAS contain gene rearrangements, so we investigated whether IOPNs have recurrent fusions in genes. METHODS: We analyzed 20 resected pancreatic IOPNs and 3 resected biliary IOPNs using a broad RNA-based targeted sequencing panel to detect cancer-related fusion genes. Four invasive PDACs and 2 intrahepatic CCAs from the same patients as the IOPNs, were also available for analysis. Samples of pancreatic cyst fluid (n = 5, collected before surgery) and bile duct brushings (n = 2) were analyzed for translocations. For comparison, we analyzed pancreatobiliary lesions from 126 patients without IOPN (controls). RESULTS: All IOPNs evaluated were found to have recurring fusions of ATP1B1-PRKACB (n = 13), DNAJB1-PRKACA (n = 6), or ATP1B1-PRKACA (n = 4). These fusions also were found in corresponding invasive PDACs and intrahepatic CCAs, as well as in matched pancreatic cyst fluid and bile duct brushings. These gene rearrangements were absent from all 126 control pancreatobiliary lesions. CONCLUSIONS: We identified fusions in PRKACA and PRKACB genes in pancreatic and biliary IOPNs, as well as in PDACs and pancreatic cyst fluid and bile duct cells from the same patients. We did not identify these gene fusions in 126 control pancreatobiliary lesions. These fusions might be used to identify patients at risk for IOPNs and their associated invasive carcinomas.

Guidelines on management of pancreatic cysts detected in high-risk individuals: An evaluation of the 2017 Fukuoka guidelines and the 2020 International Cancer of the Pancreas Screening (CAPS) consortium statements.

BACKGROUND: Objectives: Pancreatic cysts are frequently detected in high-risk individuals (HRI) undergoing surveillance for pancreatic cancer. The International Cancer of the Pancreas Screening (CAPS) Consortium developed consensus recommendations for surgical resection of pancreatic cysts in HRI that are similar to the Fukuoka guidelines used for the management of sporadic cysts. We compared the performance characteristics of CAPS criteria for pancreatic cyst management in HRI with the Fukuoka guidelines originally designed for the management of cysts in non-HRI. METHODS: Using prospectively collected data from CAPS studies, we determined for each patient with resected screen-detected cyst(s) whether Fukuoka guidelines or CAPS consensus statements would have recommended surgery. We compared sensitivity, specificity, PPV, NPV, and Receiver Operator Characteristics (ROC) curves of these guidelines at predicting the presence of high-grade dysplasia or invasive cancer in pancreatic cysts. RESULTS: 356/732 HRI had ≥ one pancreatic cyst detected; 24 had surgery for concerning cystic lesions. The sensitivity, specificity, PPV, and NPV for the Fukuoka criteria were 40%, 85%, 40%, and 85%, while those of the CAPS criteria were 60%, 85%, 50%, 89%, respectively. ROC curve analyses showed no significant difference between the Fukuoka and CAPS criteria. CONCLUSIONS: In HRI, the CAPS and Fukuoka criteria are moderately specific, but not sufficiently sensitive for detecting advanced neoplasia in cystic lesions. New approaches are needed to guide the surgical management of cystic lesions in HRI.

Risk factors for lymph node metastasis and survival of patients with nonampullary duodenal carcinoid tumors treated with endoscopic therapy versus surgical resection: analysis of the Surveillance, Epidemiology, and End Results program.

BACKGROUND AND AIMS: Endoscopic therapy (ET) has been used to treat nonampullary duodenal neuroendocrine tumors (NAD-NETs) ≤10 mm in size, but data on long-term outcomes are limited. In addition, management of 11- to 19-mm NAD-NETs is not well defined because of variable estimates of risk of metastasis. We aimed to determine the prevalence and risk factors of metastasis of NAD-NETs ≤19 mm and evaluate the long-term survival of patients after ET as compared with radical surgery. METHODS: The Surveillance Epidemiology and End Result database was used to identify 1243 patients with T1-2 histologically confirmed NAD-NETs ≤19 mm in size. Cancer-specific survival (CSS) and overall survival (OS) were calculated. RESULTS: Overall, 4.8% of cases had metastasis at the time of diagnosis, with lower prevalence in ≤10-mm lesions (3.1%) versus 11- to 19-mm lesions (11.7%, P < .001). The risk factors for metastases included invasion to the muscularis propria (odds ratio, 25.95; 95% confidence interval, 9.01-76.70), age <65 years (odds ratio, 1.93), submucosal involvement (odds ratio, 3.1), and 11 to 19 mm in size (vs ≤10 mm). In patients with well- to moderately differentiated T1-2N0M0 NAD-NETs ≤19 mm confined to the mucosa/submucosa who underwent ET or surgery, the 5-year CSS was 100%. The 5-year OS was similar between the ≤10-mm and 11- to 19-mm groups (86.6% vs 91.0%, P = .31) and the ET and surgery groups (87.4% vs 87.5%, P = .823). CONCLUSIONS: In NAD-NETs, invasion to the muscularis propria is the strongest risk factor for metastasis. In the absence of metastasis, in lesions with well/moderate differentiation and without muscle invasion, ET is adequate for NAD-NETs ≤10 mm and is a viable option for 11- to 19-mm lesions.

Detection of aneuploidy in patients with cancer through amplification of long interspersed nucleotide elements (LINEs).

Aneuploidy is a feature of most cancer cells, and a myriad of approaches have been developed to detect it in clinical samples. We previously described primers that could be used to amplify ∼38,000 unique long interspersed nucleotide elements (LINEs) from throughout the genome. Here we have developed an approach to evaluate the sequencing data obtained from these amplicons. This approach, called Within-Sample AneupLoidy DetectiOn (WALDO), employs supervised machine learning to detect the small changes in multiple chromosome arms that are often present in cancers. We used WALDO to search for chromosome arm gains and losses in 1,677 tumors and in 1,522 liquid biopsies of blood from cancer patients or normal individuals. Aneuploidy was detected in 95% of cancer biopsies and in 22% of liquid biopsies. Using single-nucleotide polymorphisms within the amplified LINEs, WALDO concomitantly assesses allelic imbalances, microsatellite instability, and sample identification. WALDO can be used on samples containing only a few nanograms of DNA and as little as 1% neoplastic content and has a variety of applications in cancer diagnostics and forensic science.

Management of patients with increased risk for familial pancreatic cancer: updated recommendations from the International Cancer of the Pancreas Screening (CAPS) Consortium.

BACKGROUND AND AIM: The International Cancer of the Pancreas Screening Consortium met in 2018 to update its consensus recommendations for the management of individuals with increased risk of pancreatic cancer based on family history or germline mutation status (high-risk individuals). METHODS: A modified Delphi approach was employed to reach consensus among a multidisciplinary group of experts who voted on consensus statements. Consensus was considered reached if ≥75% agreed or disagreed. RESULTS: Consensus was reached on 55 statements. The main goals of surveillance (to identify high-grade dysplastic precursor lesions and T1N0M0 pancreatic cancer) remained unchanged. Experts agreed that for those with familial risk, surveillance should start no earlier than age 50 or 10 years earlier than the youngest relative with pancreatic cancer, but were split on whether to start at age 50 or 55. Germline ATM mutation carriers with one affected first-degree relative are now considered eligible for surveillance. Experts agreed that preferred surveillance tests are endoscopic ultrasound and MRI/magnetic retrograde cholangiopancreatography, but no consensus was reached on how to alternate these modalities. Annual surveillance is recommended in the absence of concerning lesions. Main areas of disagreement included if and how surveillance should be performed for hereditary pancreatitis, and the management of indeterminate lesions. CONCLUSIONS: Pancreatic surveillance is recommended for selected high-risk individuals to detect early pancreatic cancer and its high-grade precursors, but should be performed in a research setting by multidisciplinary teams in centres with appropriate expertise. Until more evidence supporting these recommendations is available, the benefits, risks and costs of surveillance of pancreatic surveillance need additional evaluation.

Comparable Cancer-Specific Mortality of Patients With Early Gastric Cancer Treated With Endoscopic Therapy vs Surgical Resection.

BACKGROUND & AIMS: Endoscopic therapy is used commonly for superficial gastric cancer with very low risk of metastasis to the lymph nodes. However, limited population-based studies from the West have evaluated long-term outcomes of patients who received endoscopic therapy vs surgery. METHODS: We used the Surveillance Epidemiology and End Results database to identify and compare features and outcomes of patients who underwent endoscopic therapy (n = 786) or surgery (n = 2577) for Tis or T1aN0M0 superficial gastric cancer, diagnosed from 1998 to 2014. Multivariate logistic regression was performed to identify factors associated with endoscopic therapy. Overall survival and gastric cancer-specific survival times were compared after we controlled for covariates. RESULTS: Use of endoscopic therapy increased from 15.1% of cases in 1998 to 2000 to 39.0% of cases in 2013 to 2014. Endoscopic therapy was used more frequently in patients who were older, female, or Caucasian, or with lesions that were located in the proximal stomach or were limited in depth (Tis vs T1a) and size, compared with surgery. The median follow-up time was 59 months (interquartile range, 31-102 mo). Percentages of 5-year overall and cancer-specific survival were 57% and 99% in the endoscopic therapy group and 76% and 95% in the surgery group. After we adjusted for clinical factors using a multivariate Cox proportional hazards model, we found no significant difference in gastric cancer-specific mortality between patients who received endoscopic therapy vs surgery (hazard ratio, 1.42; 95% CI, 0.91-2.23; P = .12). CONCLUSIONS: In an analysis of a large population database, we found an increased trend in endoscopic therapy for superficial gastric cancer compared with surgery from 1998 through 2014. Patients who received endoscopic therapy vs surgery had comparable long-term cancer-specific mortality.