Patients with a resected pancreatic mucinous cystic neoplasm have a better prognosis than patients with an intraductal papillary mucinous neoplasm: A large single institution series

Multiregion Genomic Analysis of Human Pancreatic Mucinous Cystic Neoplasms

Mucinous cystic neoplasms (MCNs) are precursors to invasive pancreatic cancer. Conflicting clinical management recommendations call for better molecular characterization to improve our understanding of their tumorigenesis and risk assessment. We sampled epithelial tissue from a total of 18 surgically resected MCNs and performed dedicated multiregion analysis of somatic genetic alterations by targeted next-generation sequencing of 25 driver genes. In addition, we performed whole-exome sequencing and immunohistochemistry on selected samples to supplement our analyses. In total, 128 samples of epithelial MCN tissue were sequenced and analyzed, including samples from 13 small MCNs with low-grade (LG) dysplasia, 1 small MCN with high-grade (HG) dysplasia (HGD), and 4 large MCNs with HGD. Eight of 13 (61.5%) comprehensively sampled small LG MCNs lacked somatic driver gene mutations in all tissue blocks. These MCNs were lined by predominantly flat epithelium. In contrast, the majority of MCNs with driver gene mutations were predominantly lined by mucin-rich epithelium. No heterogeneity in KRAS mutations was seen across the sampled regions. Multiregion genetic analysis of 4 large MCNs with HGD provide insights into neoplastic progression, with shared somatic alterations suggesting that HGD arises from LG mucin-rich epithelium. These findings were supported by complementary whole-exome sequencing studies in 26 MCN epithelium samples. The neoplastic epithelium in the majority of small MCNs does not harbor somatic mutations in pancreatic driver genes. The genetic findings from multiregion analysis on MCNs contrast previous investigations in other mucin-producing pancreatic cysts, indicating distinct mechanisms in early tumorigenesis. This calls for a more nuanced risk assessment in MCNs, requiring improved preoperative assessment tools.

Cost-effectiveness of Operative Intervention for Mucinous Cystic Neoplasm: The Role of Postoperative Diabetes

OBJECTIVES

Small mucinous cystic neoplasms (MCNs) of the pancreas are managed with operative resection in otherwise healthy patients; however, postoperative diabetes development is not considered in recommendations for resection.

MATERIALS AND METHODS

Via probabilistic microsimulation Markov modeling, we assessed clinical and economic implications of laparoscopic distal pancreatectomy (LDP) versus surveillance for non-diabetes mellitus (DM) patients with suspected MCN of 2 cm without high-risk or worrisome features. Primary outcomes included quality-adjusted life years (QALYs), medical costs (2021 USD), and incremental cost-effectiveness ratios. We conducted sensitivity analyses to evaluate the robustness of our model to changes in input parameters. All analyses were repeated for a population with pre-DM.

RESULTS

Surveillance resulted in 6.52 QALYs and $61,200, while LDP accumulated 6.12 QALYs and $63,700. Almost 20% of the LDP cohort developed DM over the first 10 years, compared with 11% of the surveillance cohort. In a pre-DM cohort, LDP remained dominated in the base case, with over 40% developing DM postoperatively. In sensitivity analyses, surveillance remained the preferred strategy in most iterations for both cohorts.

CONCLUSIONS

Surveillance for small suspected MCNs without high-risk features is the preferred strategy from a clinical and economic standpoint. Consensus guidelines should consider the long-term implications of postoperative diabetes development after LDP.

Cross-Sectional Imaging Characteristics of Pancreatic Intraductal Oncocytic Papillary Neoplasms

PURPOSE

Pancreatic intraductal oncocytic papillary neoplasms (IOPN) are rare precursors to pancreatic ductal adenocarcinoma. We report cross-sectional computed tomography and magnetic resonance imaging (where available) findings of pancreatic IOPNs.

MATERIALS AND METHODS

Consecutive cases of pancreatic IOPNs identified on pathology between 2008 and 2020 at University of Pittsburgh and Johns Hopkins University were included in the study. Cross-sectional imaging of all patients was reviewed by two subspecialty trained abdominal radiologists. Patient demographics, cross-sectional imaging appearances and growth characteristics were evaluated.

RESULTS

In this dual-center study, 14 patients with IOPNs were included. Median age was 64 years, and 64% were male. The median size of the lesions was 5.4 cm (range, 1.4-12.3 cm). All patients had either an enhancing mural nodule (93% of patients) and/or thick internal septations (29%). Thin/imperceptible outer wall was seen in 93%. Main duct was involved in 64% of the cases. Only 14% of the cases did not demonstrate abutment of the main duct. Histologic evaluation of surgical specimen showed high-grade dysplasia without invasive carcinoma in 57% and invasive carcinoma in 43% of cases. Lesions with invasive carcinoma were larger (7.1 cm vs 4.3 cm, P = 0.05) and tended to have larger mural nodule (3.7 cm vs 1.8 cm) compared with those without invasive carcinoma.

CONCLUSION

Pancreatic IOPNs are rare cystic premalignant lesions, which among resected cases, are predominantly seen in middle aged men, are often large, have enhancing mural nodules and frequently harbor invasive carcinoma.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Comprehensive characterisation of acinar cystic transformation of the pancreas: a systematic review

AIMS

Acinar cystic transformation (ACT) of the pancreas is a rare pancreatic cystic lesion. Owing to its rarity, comprehensive histomolecular characterisation of this entity is still lacking. We aim to perform a systematic review on this controversial entity.

METHODS

We searched PubMed, SCOPUS and Embase through May 2023 to identify all studies on ACTs. Clinicopathological, immunohistochemical (IHC) and molecular data have been extracted and analysed.

RESULTS

Overall, there were 121 cases of ACTs in the literature. ACT had a female predominance (65.3% of patients), and a mean size of 4.8 cm. ACT was more often unifocal (71.9%) and multiloculate (61.2%). Histologically, the cysts were lined by an acinar epithelium, sometimes harbouring ductal-like areas (18.2%). In five cases (4.1%), an intralesional pancreatic intraepithelial neoplasia (PanIN) was reported. Preoperative diagnosis is challenging. After surgical resection, all patients were alive and disease free during follow-up except one patient who developed a second ACT after resection. By IHC, all lesions were positive for acinar markers; cytokeratin 7 and 8/18/19 were usually positive, and Ki-67 was invariably ≤3%. At the molecular level, three cases demonstrated genetic alterations: one showed multiple chromosomal gains, and other two harboured somatic mutations of KRAS and SMO genes (one mutation per case).

CONCLUSIONS

Globally considered, our findings demonstrated that ACT is a benign entity, without the need of surgical resection with the exception of symptomatic lesions. The rare occurrence of intracystic PanINs and driver mutations suggest considering follow-up if a preoperative diagnosis of ACT can be made.

It is not necessary to resect all mucinous cystic neoplasms of the pancreas: current guidelines do not reflect the actual risk of malignancy

BACKGROUND

Mucinous Cystic Neoplasms (MCN) of the pancreas are premalignant cysts for which current guidelines support pancreatic resection. The primary aim of this systematic review and meta-analysis is to define the pooled rate of malignancy for MCN.

METHODS

A systematic review of eligible studies published between 2000 and 2021 was performed on PubMed and Embase. Primary outcome was rate of malignancy. Data regarding high-risk features, including cyst size and mural nodules, were collected and analyzed.

RESULTS

A total of 40 studies and 3292 patients with resected MCN were included in the final analysis. The pooled rate of malignancy was 16.1% (95%CI 13.1-19.0). The rate of malignant MCN in studies published before 2012 was significantly higher than that of studies published after recent guidelines were published (21.0% vs 14.9%, p < 0.001). Malignant MCN were larger than benign (mean difference 25.9 mm 95%CI 14.50-37.43, p < 0.001) with a direct correlation between size and presence of malignant MCN (R2 = 0.28, p = 0.020). A SROC identified a threshold of 65 mm to be associated with the diagnosis of malignant MCN. Presence of mural nodules was associated with the diagnosis of a malignant MCN (OR = 4.34, 95%CI 3.00-6.29, p < 0.001).

CONCLUSION

Whereas guidelines recommend resection of all MCN, the rate of malignancy in resected MCN is 16%, implying that surveillance has a role in most cases, and that surgical selection criteria are warranted. Size and presence of mural nodules are significantly associated with an increased risk of malignant degeneration, small MCN and without mural nodules can be considered for surveillance.

Case Report: Early detection of pancreatic pre-cancer lesion in multimodal approach with exosome liquid biopsy

Background

The detection of pancreatic ductal adenocarcinoma (PDAC) lesions at pre-cancerous or early-stages is critical to improving patient survival. We have developed a liquid biopsy test (ExoVita^®) based on the measurement of protein biomarkers in cancer-derived exosomes. The high sensitivity and specificity of the test for early-stage PDAC has the potential to improve a patient's diagnostic journey in hopes to impact patient outcomes.

Methods

Exosome isolation was performed using alternating current electric (ACE) field applied to the patient plasma sample. Following a wash to eliminate unbound particles, the exosomes were eluted from the cartridge. A downstream multiplex immunoassay was performed to measure proteins of interest on the exosomes, and a proprietary algorithm provided a score for probability of PDAC.

Results

We describe the case of a 60-year-old healthy non-Hispanic white male with acute pancreatitis who underwent numerous invasive diagnostic procedures that failed to detect radiographic evidence of pancreatic lesions. Following the results of our exosome-based liquid biopsy test showing "High Likelihood of PDAC", in addition to KRAS and TP53 mutations, the patient decided to undergo a robotic pancreaticoduodenectomy (Whipple) procedure. Surgical pathology confirmed the diagnosis of high-grade intraductal papillary mucinous neoplasm (IPMN), which was consistent with the results of our ExoVita^® test. The patient's post-operative course was unremarkable. At five-month follow-up, the patient continued to recover well without complications, in addition to a repeat ExoVita test which demonstrated "Low Likelihood of PDAC".

Conclusion

This case report highlights how a novel liquid biopsy diagnostic test based on the detection of exosome protein biomarkers allowed early diagnosis of a high-grade precancerous lesion for PDAC and improved patient outcome.

Pancreatic Cystic Neoplasms: Diagnosis and Management

Pancreatic cancer is one of the most lethal cancers, largely related to the difficulties with early detection, as it typically presents in later stages. Pancreatic cystic neoplasms (PCN) are commonly diagnosed as incidental findings on routine imaging. PCN is becoming more frequently detected with the increasing ease and frequency of obtaining cross-sectional images. Certain subtypes of pancreatic cysts have the potential to progress to malignancy, and therefore, clinicians are tasked with creating a patient-centered management plan. The decision of whether to undergo surgical resection or interval surveillance can be challenging given the criteria, including PCN size, pancreatic duct dilation, presence of a mural nodule, and clinical symptoms that play a potential role in risk stratification. Furthermore, the guidelines available from the major gastrointestinal societies all differ in their management recommendations. In this review, we detail an overview of the different types of PCNs and compare major guidelines for both diagnosis and management. We include emerging evidence for next-generation sequencing as well as confocal needle endomicroscopy to aid in the diagnosis and determination of malignancy potential and diagnosis.

Laparoscopic pancreatic enucleation: cystic lesions and proximity to the Wirsung duct increase postoperative pancreatic fistula

BACKGROUND

Risk factors for postoperative pancreatic fistula (POPF) following pancreatic enucleation by the open approach (OpenEN) are well known. However, ENs are more frequently performed laparoscopically (LapEN). The aim of this study was to analyze the risk factors of POPF following LapEN.

METHODS AND PATIENTS

All patients in our prospective database who underwent LapEN were evaluated. We report the demographics, surgical, early and long-term outcomes. Numerous variables were analyzed to identify the risk factors of POPF.

RESULTS

From 2008 to 2020, 650 laparoscopic pancreatic resections were performed including 64 EN (10%). The median age was 51 years old (17-79), median BMI was 24 (19-48), and 44 patients were women (69%). The main presentation was an incidental diagnosis (n = 40; 62%), pain (n= 10;16%), and hypoglycemia (n = 8;12%). The main indications were neuroendocrine tumors (40; 63%), mucinous cystadenomas (15; 23%), intraductal papillary mucinous neoplasie (3; 5%), and other benign cysts (6; 9%). Lesions were located on the distal pancreas (43; 67%), head (n = 17; 27%), and neck (4; 6%). The median size was 20 mm (9-110); 30 mm (20-110) for mucinous cystadenoma and 18 mm (8-33) for NET. The median operative time was 90 mn (30-330), median blood loss was 20 ml (0-800) ml, and there were no transfusions and one conversion. There were no mortalities and overall morbidity (n = 22; 34%) included grades B and C POPF (10;16%) and post-pancreatectomy hemorrhage (4; 6%). The median hospital stay was 7 days (3-42). There were no invaded lymph nodes and all cystic lesions were nonmalignant. After a mean follow-up of 24 months, there was no recurrence. The risk factors for grades B/C POPF were mucinous cystadenoma and proximity to the Wirsung duct < 3 mm.

CONCLUSION

In this series, the outcome of LapEN was excellent with no mortality and a low rate of morbidity. However, the risk of POPF is increased with cystic lesions and those close to the Wirsung duct.

Comparison of clinicopathologic characteristics and survival outcomes between invasive IPMN and invasive MCN: A population-based analysis

Background

Intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm (MCN) are two main histological subtypes of pancreatic cystic neoplasms with rapidly increasing incidence recently. The natural histories, treatment patterns, and survival outcomes of invasive IPMN and invasive MCN have not been well explored.

Methods

Patients with a diagnosis of invasive IPMN and invasive MCN in the SEER database from 2000 through 2018 were retrospectively identified. Multivariable Cox regression analysis was conducted to determine the independent risk factors associated with overall survival (OS). Subgroup analyses of survival outcomes for invasive IPMN and invasive MCN were conducted. The OS for invasive IPMN was compared between patients who underwent surgery alone and those who received surgery plus chemotherapy by propensity score matching (PSM).

Results

A total of 2,505 patients were included, of whom 2,300 were diagnosed with invasive IPMN and 205 were diagnosed with invasive MCN. Half of the invasive IPMN (48.4%) and three-quarters of the invasive MCN (76.1%) patients were female. Of all patients, both the OS and cancer-specific survival were significantly better in the invasive MCN cohort compared to the invasive IPMN cohort. In subgroup analyses, while invasive MCN experienced better OS compared to invasive IPMN in the subgroups of patients with local–regional disease, the survival advantages disappeared in patients at a distant stage. In addition, surgery plus chemotherapy in invasive IPMN patients was associated with significantly better survival compared to surgery alone after PSM.

Conclusion

We examined the demographic and clinical characteristics between invasive IPMN and invasive MCN patients using a large-population-based analysis. Although the OS is significantly better for invasive MCN versus invasive IPMN, the difference disappeared in patients with distant disease. A combination of surgery and chemotherapy in selected invasive IPMN patients could confer survival benefits compared to surgery alone.

Pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) represent a unique opportunity to treat and prevent a curable neoplasm before it has the chance to progress to incurable cancer. This prospect, however, has to be balanced with the real risk of over treating patients with lesions that would, in fact, never progress during the life of the patient.

PURPOSE

Informed clinical decisions in the treatment of IPMNs are first and foremost based on a deep understanding of the pathology of these lesions.

CONCLUSIONS

Here we review the pathology of IPMNs, with an emphasis on the clinical relevance of the important features that characterize these lesions.

Visual Analytics of a Computer-Aided Diagnosis System for Pancreatic Lesions

Machine learning is a powerful and effective tool for medical image analysis to perform computer-aided diagnosis (CAD). Having great potential in improving the accuracy of a diagnosis, CAD systems are often analyzed in terms of the final accuracy, leading to a limited understanding of the internal decision process, impossibility to gain insights, and ultimately to skepticism from clinicians. We present a visual analytics approach to uncover the decision-making process of a CAD system for classifying pancreatic cystic lesions. This CAD algorithm consists of two distinct components: random forest (RF), which classifies a set of predefined features, including demographic features, and a convolutional neural network (CNN), which analyzes radiological (imaging) features of the lesions. We study the class probabilities generated by the RF and the semantical meaning of the features learned by the CNN. We also use an eye tracker to better understand which radiological features are particularly useful for a radiologist to make a diagnosis and to quantitatively compare with the features that lead the CNN to its final classification decision. Additionally, we evaluate the effects and benefits of supplying the CAD system with a case-based visual aid in a second-reader setting.

Loss of Jag1 cooperates with oncogenic Kras to induce pancreatic cystic neoplasms

Notch signaling exerts both oncogenic and tumor-suppressive functions in the pancreas. In this study, deletion of Jag1 in conjunction with oncogenic Kras ^G12D expression in the mouse pancreas induced rapid development of acinar-to-ductal metaplasia and early stage pancreatic intraepithelial neoplasm; however, culminating in cystic neoplasms rather than ductal adenocarcinoma. Most cystic lesions in these mice were reminiscent of serous cystic neoplasm, and the rest resembled intraductal papillary mucinous neoplasm. Jag1 expression was lost or decreased in cystic lesions but retained in adenocarcinoma in these mice, so was the expression of Sox9. In pancreatic cancer patients, JAG1 expression is higher in cancerous tissue, and high JAG1 is associated with poor overall survival. Expression of SOX9 is correlated with JAG1, and high SOX9 is also associated with poor survival. Mechanistically, Jag1 regulates expression of Lkb1, a tumor suppressor involved in the development of pancreatic cystic neoplasm. Collectively, Jag1 can act as a tumor suppressor in the pancreas by delaying precursor lesions, whereas loss of Jag1 promoted a phenotypic switch from malignant carcinoma to benign cystic lesions.

The pathological features and prognoses of intraductal papillary mucinous neoplasm and mucinous cystic neoplasm after surgical resection: a single institution series

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) represent the tumors with malignant transformation potential. The objective of the study was to verify their pathological characteristics, prognoses, and recurrence factors.

METHODS

Two hundred eighteen IPMNs and 27 MCNs resected at a single institution were included. The demographic, preoperative, histopathological, and follow-up data of the patients were recorded and analyzed. Overall survival (OS) and disease-free survival (DFS) were defined as the interval from the date of initial surgery to death or the last follow-up (OS) and to diagnosis of recurrence or death at follow-up (DFS).

RESULTS

Of the 218 IPMN and 27 MCN patients, 93 (42.7%) and 8 (29.6%) cases were malignant, respectively. IPMNs occurred in older patients compared with MCN patients (median 63 years vs 54 years, P < 0.0001), and MCNs occurred exclusively in females (100%). Of the overall study cohort, the pathological specimens presented peripheral invasion in 37 (15.1%) patients and incisal margin invasion was observed in 46 (18.8%) patients. After a median follow-up of 34 months, 37 (14.9%) patients relapsed. The 5-year OS and DFS rates of IPMNs were 97.5% and 80.6%; and the OS and DFS rates of MCNs were 95.7% and 87.0%, respectively. There were four independent risk factors associated with recurrence: pathological diagnoses with malignancy (odds ratio, OR = 3.65), presence of oncocytic type for IPMN (OR = 1.69), peripheral invasion (OR = 12.87), and incisal margin invasion (OR = 1.99).

CONCLUSIONS

IPMNs and MCNs are indolent tumors with favorable prognoses after surgical resection in terms of their relatively high OS and DFS rate. Patients with malignant pathological-related diagnoses should accept strict tumor surveillance in view of their higher risk of recurrence.

Clinical implication of serum CA125 for the prediction of malignancy in mucinous cystic neoplasms of the pancreas

Mucinous cystic neoplasms (MCNs) of the pancreas have malignant potential. Carbohydrate antigen 125 (CA125) is a common widely used biomarker for cancers. However, the role of CA125 in predicting the malignant change of MCNs is currently unidentified. Patients with resected and pathologically confirmed MCN were identified from a prospectively maintained database. The predictive role of serum CA125 in assessing malignant change of MCNs was analyzed and compared with serum carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA). This study included 164 patients with MCN (low/moderate grade, 153 cases; high grade and invasive, 11 cases). The serum levels of CA125 in the high grade and invasive group (45.1±42.1 U/ml) was significantly higher than those in the low/moderate grade group (21.0±46.2 U/ml, P=0.006). The area under the receiver operating characteristic (ROC) curve of CA125 (0.75) for predicting malignancy of MCNs was higher than that of CA19-9 (0.68) or CEA (0.72). The prediction value of CA125 was improved when combined with CEA (CA125 alone, sensitivity 36.4%, specificity 90.6%, accuracy 86.6%; combined with CEA, sensitivity 45.5%, specificity 88.2%, accuracy 85.0%). It was concluded that serum CA125 shows value in predicting the malignant change of MCNs, especially when combined with serum CEA.

Endosonographic diagnosis of advanced neoplasia in intraductal papillary mucinous neoplasms

Pancreatic cancer has a high mortality rate with minimal proven interventions. Intraductal Papillary Mucinous Neoplasms (IPMNs) are known precursor lesions for pancreatic cancer. Identification of pancreatic cysts has improved from advances in abdominal imaging. Despite multiple revisions of the international consensus recommendations and various guidelines by other major societies, successful risk stratification of the malignant potential of mucinous pancreatic cysts remains challenging. Specifically, detection and accurate classification of advanced neoplasia (high-grade dysplasia and/or adenocarcinoma) in IPMNs is suboptimal with current diagnostic strategies. Development of interventional techniques utilizing endoscopic ultrasound include - through-the-needle microforceps biopsy, next-generation or whole genome molecular analysis of cyst fluid, and needle-based confocal laser endomicroscopy. These techniques suffer from a series of limitations in technical success, diagnostic yield, and clinical feasibility, but a combination approach may offer a solution that optimizes their cyst evaluation and risk stratification. Assessment and comparison of these techniques is restricted by lack of adequate surgical specimens for testing of diagnostic accuracy, resulting in a possible sample bias. Additional large-scale multicenter studies are needed to accumulate evidence for the utility and feasibility of their translation into clinical practice. Great strides have been made in pancreatic cyst evaluation, but further research is required to improve diagnostic accuracy and clinical management of IPMNs.

Pancreatic mucinous cystic neoplasms: a clinicopathological study of 11 cases and detailed review of literature

Background

Mucinous cystic neoplasms (MCNs) of pancreas are relatively rare, occur almost exclusively in middle-aged females, and are overwhelmingly located in the body and tail of the pancreas, histologically show an ovarian type stroma. MCNs are premalignant, low aggressive tumors. Here we describe the clinicopathologic and radiologic features and follow up of cases diagnosed in our practice. We also present a detailed review of recent literature.

Materials and methods

Based on strict criteria, 11 cases diagnosed between 2002 and 2016 were included in the study.

Results

All cases were reviewed histologically. Mean and median age was 46.7 and 46 years respectively. All patients were females and 9 out of 11 cases were located in the body and/or tail of the pancreas. Mean tumor size was 8 cm. Grossly, cysts were uni or multilocular and ranged from a few millimeters to several centimeters in diameter. Microscopically, all cases showed characteristic tall columnar, mucin producing epithelium and ovarian type stroma. Atypia was mild in 8 cases and severe in 3 cases. The latter 3 cases were classified as non-invasive MCNs with high grade dysplasia (2 cases) and MCN with an associated invasive carcinoma (1 case). On immunohistochemistry, all cases showed epithelial positivity for cytokeratin AE1/AE3 and stromal positivity for vimentin and smooth muscle actin. Follow up was available in 7 cases. All patients were alive and well with no recurrence.

Conclusions

Our cases show features similar to those described in other published studies although cases in our series tended to be larger in number. Since these tumors are relatively rare, premalignant and have strict diagnostic criteria, they must always be considered in the differential diagnosis of pancreatic mucinous cystic lesions. Larger studies incorporating greater number of patients and more detailed follow up will help in increasing our understanding of MCNs.

A multimodality test to guide the management of patients with a pancreatic cyst

Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.

Fibroblasts in Pancreatic Ductal Adenocarcinoma: Biological Mechanisms and Therapeutic Targets

The desmoplastic reaction of pancreas cancer may begin as a wound healing response to the nascent neoplasm, but it soon creates an insidious shelter that can sustain the growing tumor and rebuff therapy. Among the many cell types subverted by transformed epithelial cells, fibroblasts are recruited and activated to lay a foundation of extracellular matrix proteins and glycosaminoglycans that alter tumor biophysics and signaling. Their near-universal presence in pancreas cancer and ostensible support of disease progression make fibroblasts attractive therapeutic targets. More recently, however, it has also become apparent that diverse subpopulations of fibroblasts with distinct phenotypes and secretomes inhabit the stroma, and that targeted depletion of particular fibroblast subsets could either provide substantial therapeutic benefit or accelerate disease progression. An improved characterization of these fibroblast subtypes, along with their potential relationships to tumor subtypes and mutational repertoires, is needed in order to make anti-fibroblast therapies clinically viable.

Cystic tumors of the pancreas. An update of the surgical experience in a single institution

BACKGROUND

the aim of the present study was to analyze the clinicopathological features of patients undergoing pancreatic surgical resections due to cystic neoplasms of the pancreas.

MATERIAL AND METHODS

demographic data, form of presentation, radiologic images and location of the tumors within the pancreas were analyzed. Data was also collected on the type of surgery (open/laparoscopic), postoperative complications and their severity and oncologic outcomes.

RESULTS

eighty-two pancreatic resections were performed. The mean age of patients was 57 years and 49 (59%) were female. Forty-one tumors (50%) were incidental and the most frequent symptoms in the group of symptomatic patients were abdominal pain (63.4%) and weight loss (36.5%). Thirty-two tumors (39%) were located in the tail of the pancreas, 25 (30.5%) in the head and 20 (24.4%) in the body. Thirty-nine (47.5%) distal pancreatectomies, 16 central, ten duodenal pancreatectomies and one enucleation were performed; 40 (48.5%) were carried out laparoscopically. Mean hospital stay was ten days and eight patients (7%) experienced severe complications, one was a pancreatic fistula. Sixty-six tumors (80.5%) were recorded as non-invasive and 16 (19.5%) as invasive: seven intraductal mucinous papillary tumors, one cystic mucinous tumor, four solid pseudopapillary tumors and four cystic neuroendocrine tumors. There was a median follow-up of 64 months; disease-free survival at five and ten years was 97.4% in the patients with non-invasive tumors and 84.6% and 70.5% in the invasive tumors group (p < 0.01).

CONCLUSIONS

fifty percent of cystic neoplasms of the pancreas are incidental. Two phenotypes exist, invasive and non-invasive.

Pancreatic Cytology

The diagnostic approach to pancreaticobiliary disease requires a multidisciplinary team in which the cytopathologist plays a crucial role. Fine-needle aspiration, obtained by endoscopic ultrasound, is the diagnostic test of choice for pancreatic lesions. Preoperative clinical management depends on many factors, many of which rely on accurate cytologic assessment. Pancreaticobiliary cytology is wrought with diagnostic pitfalls. Clinical history, imaging studies, cytology samples, and ancillary tests, including immunohistochemistry, biochemical analysis, and genetic sequencing, are integral to forming a complete diagnosis and guiding optimal patient management. This article reviews clinical aspects and the diagnostic work-up of commonly encountered diagnostic entities within the field of pancreatic cytology.

ACG Clinical Guideline: Diagnosis and Management of Pancreatic Cysts

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

New Developments in the Molecular Mechanisms of Pancreatic Tumorigenesis

Pancreatic cancer is an aggressive disease with a dismal prognosis in dire need of novel diagnostic and therapeutic approaches. The past decade has witnessed an explosion of data on the genetic alterations that occur in pancreatic cancer, as comprehensive next-generation sequencing analyses have been performed on samples from large cohorts of patients. These studies have defined the genomic landscape of this disease and identified novel candidates whose mutations contribute to pancreatic tumorigenesis. They have also clarified the genetic alterations that underlie multistep tumorigenesis in precursor lesions and provided insights into clonal evolution in pancreatic neoplasia. In addition to these important insights into pancreatic cancer biology, these large scale genomic studies have also provided a foundation for the development of novel early detection strategies and targeted therapies. In this review, we discuss the results of these comprehensive sequencing studies of pancreatic neoplasms, with a particular focus on how their results will impact the clinical care of patients with pancreatic cancer.

[Cystic pancreatic tumors: diagnostics and new biomarkers]

Mortality due to pancreatic ductal adenocarcinoma (PDAC) will increase in the near future. The only curative treatment for PDAC is radical resection; however, even small carcinomas exhibit micrometastases leading to early relapse. Accordingly, detection of premalignant precursor lesions is important. In essence, PDAC develops from three precursor lesions: pancreatic intraepithelial lesions (PanIN), intraductal papillary-mucinous neoplasia (IPMN) and mucinous-cystic neoplasia (MCN). Together with serous cystic neoplasia (SCN) and solid pseudopapillary neoplasia (SPN), these cystic lesions constitute the most common cystic neoplasms in the pancreas. In the case of IPMN, main and branch duct IPMN have to be differentiated because of a markedly different malignancy potential. While main duct IPMN and MCN have a high malignancy transformation rate, branch duct IPMNs are more variable with respect to malignant transformation. This shows that differential diagnosis of cystic lesions is important; however, this is often very difficult to accomplish using conventional imaging. Novel biomarkers and diagnostic tools based on the molecular differences of cystic pancreatic lesions could be helpful to differentiate these lesions and facilitate early diagnosis. The aim is to distinguish the premalignant cysts from strictly benign cystic lesions and a timely detection of malignant transformation. This article provides an overview on the molecular characteristics of cystic pancreatic lesions as a basis for improved diagnostics and the development of new biomarkers.