Prevalence of Pancreatic Cystic Lesions Is Associated With Diabetes Mellitus and Obesity: An Analysis of 5296 Individuals Who Underwent a Preventive Medical Examination

Global Prevalence of Pancreatic Cystic Lesions in the General Population on Magnetic Resonance Imaging: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Understanding the burden of pancreatic cystic lesions (PCLs) in the general population is important for clinicians and policymakers. In this systematic review, we sought to estimate the global prevalence of PCLs using magnetic resonance imaging (MRI) and to investigate factors that contribute to its variation.

METHODS

We searched MEDLINE, EMBASE, and Cochrane Central, from database inception through February 2023. We included full-text articles that reported the prevalence of PCLs using MRI in the general population. A proportional meta-analysis was performed, and the prevalence of PCLs was pooled using a random-effects model.

RESULTS

Fifteen studies with 65,607 subjects were identified. The pooled prevalence of PCLs was 16% (95% confidence interval [CI], 13%-18%; I2 = 99%), most of which were under 10 mm. Age-specific prevalence of PCLs increased from 9% (95% CI, 7%-12%) at 50 to 59 years, to 18% (95% CI, 14%-22%) at 60 to 69 years, 26% (95% CI, 20%-33%) at 70 to 79 years, and 38% at 80 years and above (95% CI, 25%-52%). There was no difference in prevalence between sexes. Subgroup analysis showed higher PCL prevalence when imaging findings were confirmed by independent radiologist(s) (25%; 95% CI, 16%-33%) than when chart review alone was used (5%; 95% CI, 4%-7%; P < .01). There was no independent association of PCL prevalence with geographic location (Europe, North America, or Asia), MRI indication (screening vs evaluation of non-pancreatic pathology), enrollment period, sample size, magnet strength (1.5 vs 3 tesla), and MRI sequence (magnetic resonance cholangiopancreatography vs no magnetic resonance cholangiopancreatography).

CONCLUSION

In this systematic review, the global prevalence of PCLs using a highly sensitive noninvasive imaging modality ranged between 13% and 18%.

Rare Pancreatic/Peripancreatic Cystic Lesions Can Be Accurately Characterized by EUS with Through-the-Needle Biopsy-A Unique Pictorial Essay with Clinical and Histopathological Correlations

Due to their aspecific macroscopic appearance, uncommon pancreatic cystic lesions (PCLs) are often misdiagnosed as mucinous lesions and improperly resected. We aimed to evaluate the endoscopic ultrasound (EUS)-guided through-the-needle biopsy (TTNB) capacity of the preoperative diagnosis of uncommon PCLs. Overall, 136 patients with PCLs who underwent EUS-TTNB between 2016 and 2022 were retrospectively identified. Common histotypes (e.g., IPMN, serous cystadenoma, and mucinous cystadenoma) were excluded and 26 (19.1%) patients (15 female, mean age 52.9 ± 10.4) were analyzed. The EUS findings, adverse events (AEs), and TTNB outcomes in uncommon PCLs were evaluated. The cysts histotype was accurately diagnosed by TTNB in 24/26 (92.3%) cases (seven cystic neuroendocrine tumors, four squamoid cysts, three acinar cells cystadenomas, two lymphoepithelial cysts, two mucinous non-neoplastic cysts, two bronchogenic cysts, two cystic lymphangiomas, one solid-pseudopapillary neoplasm, and one schwannoma). In the remaining two cases, lymphangioma was eventually diagnosed after resection. Surgery was performed in 15/26 (57.7%) patients. The mean follow-up of non-surgical patients was 32.5 months. One severe acute case of pancreatitis (3.8%) that required surgery occurred after EUS-TTNB. Uncommon pancreatic/peripancreatic lesions represent the 19.1% of PCLs in our series, with mainly benign histotypes. TTNB demonstrated a high diagnostic performance with a low rate of AEs in this setting, representing a reliable tool with which to avoid useless surgery.

Burden of New Pancreatic Cyst Diagnosis

Pancreatic cysts are an increasingly identified entity with significant health care implications. Although some cysts present with concurrent symptoms that often require operative intervention, the advent of improved cross-sectional imaging has heralded an era of increased incidentally detected pancreatic cysts. Although the rate of malignant progression in pancreatic cysts remains low, the poor prognosis of pancreatic malignancy has driven recommendations for ongoing surveillance. A uniform consensus has not been reached on the management and surveillance of pancreatic cysts leading clinicians to grapple with the burden of how best to approach pancreatic cysts from a health, psychosocial, and cost perspective.

Glycemic Abnormalities in Pancreatic Cystic Lesions—A Single-Center Retrospective Analysis

Background and Objectives: Glucose metabolism alterations are very common in solid pancreatic lesions, particularly in pancreatic cancer. Similarly, diabetes and especially new-onset diabetes (NOD) have been associated with the malignant transformation of pancreatic cysts. We aimed to assess the prevalence and relevant associations of glycemic abnormalities in pancreatic cystic lesions (PCLs) in a retrospective analysis. Materials and Methods: We retrospectively recruited all patients who underwent endoscopic ultrasound for a PCL over a period of 36 months (January 2018 to December 2021). Final diagnosis was set by means of tissue acquisition, surgery, follow-up, or board decision. Demographic and clinical data, laboratory workup, and imaging features were extracted from the patients’ charts according to a predefined protocol. We considered fasting blood glucose (FBG) and HbA1c values and stratified the patients as nondiabetic (FBG ≤ 99 mg/dL, HbA1c ≤ 5.6%, no history of glycemic abnormalities), prediabetic (FBG 100–125 mg/dL, HbA1c 5.7–6.4%), or diabetic (long-lasting diabetes or NOD). Results: Altogether, 81 patients were included, with a median age of 66 years, and 54.3% of them were male. The overall prevalence of fasting hyperglycemia was 54.3%, comprising 34.6% prediabetes and 22.2% diabetes, of which 16.7% had NOD. The mean FBG and HbA1c levels were higher in malignant and premalignant PCLs (intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), cystadenocarcinoma, and cystic neuroendocrine tumor) compared to the benign lesions (pseudocysts, walled-off necrosis, and serous cystadenoma): 117.0 mg/dL vs. 108.3 mg/dL and 6.1% vs. 5.5%, respectively. Conclusions: Hyperglycemia and diabetes are common in PCLs, with a high prevalence in premalignant and malignant cysts. Screening and follow-up for glycemic abnormalities should be routinely conducted for PCLs, as they can contribute to a tailored risk assessment of cysts.

The Role of Magnetic Resonance Imaging (MRI) in the Diagnosis of Pancreatic Cystic Lesions (PCLs)

Pancreatic cystic lesions (PCLs) are a common incidental finding on cross-sectional imaging. Given the high signal to noise and contrast resolution, multi-parametric capability and lack of ionizing radiation, magnetic resonance imaging (MRI) has become the non-invasive method of choice to predict cyst type, risk stratify the presence of neoplasia, and monitor changes during surveillance. In many patients with PCLs, the combination of MRI and the patient's history and demographics will suffice to stratify lesions and guide treatment decisions. In other patients, especially those with worrisome or high-risk features, a multimodal diagnostic approach that includes endoscopic ultrasound (EUS) with fluid analysis, digital pathomics, and/or molecular analysis is often necessary to decide on management options. The application of radiomics and artificial intelligence in MRI may improve the ability to non-invasively stratify PCLs and better guide treatment decisions. This review will summarize the evidence on the evolution of MRI for PCLs, the prevalence of PCLs using MRI, and the MRI features to diagnose specific PCL types and early malignancy. We will also describe topics such as the utility of gadolinium and secretin in MRIs of PCLs, the limitations of MRI for PCLs, and future directions.

Pancreatic Cystic Tumors: A Single-Center Observational Study

Background and Objectives: The aim of the study was to analyze the prevalence and characteristics of pancreatic cystic tumors (PCTs). Material and Methods: A retrospective analysis of the medical records of 124 patients, 102 (69%) women and 46 (31%) men, who had undergone surgery for pancreatic cystic tumors in 2014-2018. Among 148 pancreatic cysts, 24 (16%) were non-neoplasmatic and 124 (84%) were neoplasmatic. The neoplasmatic cysts (n = 124) were included in our analysis. There were five main types of PCTs: IPMN (intraductal papillary mucinous neoplasm) (n = 45), MCN (mucinous cystic neoplasm) (n = 30), SCN (serous cystic neoplasm) (n = 28), SPN (solid pseudopapillary neoplasm) (n = 8), and CPEN (cystic pancreatic endocrine neoplasm) (n = 8), as well as mixed-type tumors (n = 5). Results: A statistically significant dependency between PCT type and age was proven (p= 0.0001): IPMNs were observed in the older group of patients with an average age of 66.12 (40-79) years while SPNs were noted in the youngest group of patients with an average age of 36.22 (22-55) years. A statistically significant association between PCT type and gender (p = 0.0001) was found: IPMNs occurred among 24 (53.33%) men and 21 (46.6%) women. In the MCN and SPN groups, all patients were female (100%). Among the SCN group, the majority were women (27 (96.43%)), and there was only 1 (3.57%) man. A statistically significant dependency between PCT type and size was proven (p = 0.0007). The mean size of IPMNs was the smallest 2.95 (0.6-10 cm) and the mean size of MCNs was the largest 6.78 (1.5-19 cm). A statistically significant dependency between PCT type and tumor location was proven (p = 0.000238). The most frequent location of IPMN was the pancreatic head: 27 (60%). MCN was most frequently located in the pancreatic tail (18 (60%)). Most (10/28) SCNs were found in the pancreatic tail (10 (35.71%)). CPENs were most frequently located in the pancreatic tail (three (37.5%)) and pancreatic body and tail (three (37.5%)). SPNs were located commonly in the pancreatic head (five (62.5%)). The type of surgery depended on the tumor location. The most frequent surgery for IPMNs was pancreatoduodenectomy (44.4%), while for MCNs and SCNs, it was distal pancreatectomy (81%). The postoperative morbidity and mortality were 34.68% and 1.61%, respectively. Postoperative pancreatic fistula (POPF) was the most frequent (29%) complication. Conclusions: IPMN was the most frequent resected PCT in our material. A statistically significant association between the type of cyst and location within the pancreas, size, local lymph node involvement, and patient's age and sex was proved. POPF was the most frequent postoperative complication. In patients with PCTs, due to substantial postoperative morbidity, adequate patient selection, considering both the surgical risk as well as the long-term risk of malignant transformation, is very important during qualification for surgery.

New-Onset Diabetes Is a Potential Marker for the Malignant Transformation of Pancreatic Cysts: A Real-World Population Cohort Study

OBJECTIVES

New-onset diabetes mellitus has been shown to be associated with pancreatic cancer (PC) in the general population. Our objective was to leverage real-world data to assess the association of new-onset diabetes (NODM) with malignant transformation in a large longitudinal cohort of pancreatic cyst patients.

METHODS

A retrospective longitudinal cohort study was conducted using IBM's MarketScan claims databases from 2009 to 2017. From 200 million database subjects, we selected patients with newly diagnosed cysts without prior pancreatic pathology.

RESULTS

Of the 137,970 patients with a pancreatic cyst, 14,279 had a new diagnosis. Median follow-up was 41.6 months. Patients with NODM progressed to PC at nearly 3 times the rate of patients without a diabetes history (hazard ratio, 2.80; 95% confidence interval, 2.05-3.83) and at a significantly higher rate than patients with preexisting diabetes (hazard ratio, 1.59; 95% confidence interval, 1.14-2.21). The mean interval between NODM and cancer diagnosis was 7.5 months.

CONCLUSIONS

Cyst patients who developed NODM progressed to PC at 3 times the rate of nondiabetics and at a greater rate than preexisting diabetics. The diagnosis of NODM preceded cancer detection by several months. These results support the inclusion of diabetes mellitus screening in cyst surveillance algorithms.

New Screening System Using Forward-Viewing Radial Endoscopic Ultrasound and Magnetic Resonance Imaging for High-Risk Individuals With Familial History of Pancreatic Cancer

Background and Aims

Attention is increasingly being paid to family history of pancreatic cancer (PC) as a risk factor for developing PC. It is mandatory to develop a screening system for early detection of PC; however, the relationship between a family history of PC and the incidence of pancreatic abnormalities, such as pancreatic cyst and chronic pancreatitis (CP), in the Japanese population remains unknown.

Patients and Methods

Individuals with a family history of PC were prospectively enrolled in a screening program using forward-viewing radial endoscopic ultrasound (FR-EUS) and magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) as the diagnostic modalities.

Results

In total, forty-three individuals in 37 families were enrolled (mean age, 54 years). All individuals underwent FR-EUS and MRI with no complications. FR-EUS revealed resectable PC (n = 1, 2.3%), pancreatic cysts (n = 24, 55.8%), intraductal papillary mucinous neoplasm (IPMN; n = 13, 30.2%), and early CP-like appearance (n = 15, 34.9%). The detection rate of early CP-like appearance was significantly higher by EUS than by MRI. Pancreatic cysts and IPMN detected by FR-EUS were significantly correlated to age (≥60 years) and less correlated to men (hazard ratio [HR] 22.4; 95% confidence interval [CI], 2.10–236.0; p < 0.01 and HR 0.092; 95% CI, 0.01–0.83; p = 0.033, respectively). Early CP-like appearance detected by FR-EUS was significantly correlated with men and smoking (HR 5.0; 95% CI, 1.3–19.3; p = 0.02 and HR 4.02; 95% CI, 0.991–16.3; p = 0.05, respectively).

Conclusion

A screening system using FR-EUS and MRI/MRCP for individuals with a family history of PC was useful for identifying curable PC and pancreatic abnormalities. The incidence of pancreatic cysts, such as IPMN and early CP-like appearance, was also high in the Japanese cohort.

Opportunistic Detection for Pancreatic Cystic Lesions During Chest Multidetector CT Scans for Lung Cancer Screening

Purpose

The purpose of this study was to analyze the prevalence of and risk factors for incidental pancreatic cystic lesions (PCLs) in the Chinese general population. Furthermore, the association between baseline imaging findings and PCL progression was also investigated.

Patients and Methods

A total of 9826 individuals who underwent computed tomography (CT) examinations for lung cancer screening between January 1, 2018 and January 1, 2019 were included in this study. The participants’ CT imaging findings and biochemical biomarker levels were reviewed and analyzed. PCLs detected during the screening were followed up for 12 months. Associations between imaging findings and clinical factors with PCL progression were explored.

Results

PCLs were observed in 172 of the 9826 participants. The crude prevalence of PCLs in total population was 1.75%. In subjects aged >60 years, the prevalence of PCLs was 3.2% (102/3151). The occurrence of PCLs was significantly increased with an increase of age in both men and women (p < 0.001). High-risk PCLsL commonly located in pancreatic head showed extrapancreatic growth, and had high urea levels (p = 0.005, p = 0.015, p = 0.002, respectively) compared with low-risk PCLs. Location in the pancreatic head (odds ratio (OR) = 6.286, 95% confidence interval (CI): 1.842–21.452) and extrapancreatic growth (OR = 4.049, 95% CI: 1.235–13.333) were risk factors for PCL progression.

Conclusion

PCLs are not uncommon in the Chinese general population. Location in the pancreatic head and extrapancreatic growth are the independent predictors of high-risk of PCLs and PCL progression.

Coexisting Type 1 Autoimmune Pancreatitis and Mixed-type Intraductal Papillary Mucinous Neoplasm

An 84-year-old man was referred to our hospital for a cystic lesion of the pancreatic head, swelling of the pancreatic tail and hilar biliary stricture, resulting in elevated liver enzyme levels. We suspected branch duct-type intraductal papillary mucinous neoplasm (IPMN) and type I autoimmune pancreatitis (AIP) associated with sclerosing cholangitis because of the high serum IgG4 levels. The main pancreatic duct on the tail side of the AIP lesion was moderately dilated. Although the biliary stricture and pancreatic swelling improved after prednisolone treatment, the pancreatic enzyme levels increased rapidly. The entire main pancreatic duct exhibited remarkable dilatation, which led to the diagnosis of mixed-type IPMN. The clinical characteristics of IPMN in the main pancreatic duct appear to have been initially masked by AIP.

High-Risk Characteristics Associated with Advanced Pancreatic Cystic Lesions: Results from a Retrospective Surgical Cohort

BACKGROUND AND AIM

The management of pancreatic cystic lesions (PCLs) remains controversial. We performed a retrospective study to determine characteristics associated with advanced PCLs (A-PCLs) and whether these characteristics vary in different pathological types of PCLs. The additional diagnostic value of endoscopic ultrasound (EUS) was also evaluated.

METHODS

Patients who underwent surgical resection for an identified PCLs by imaging modalities were included. A logistic regression model was developed to identify significant characteristics for A-PCLs. EUS data was assessed separately.

RESULTS

Three hundred and fifty-three patients were included, and 125 patients (35.4%) were A-PCLs. The presence of main pancreatic duct (MPD) diameter ≥ 10 mm (odds ratio [OR], 11.7; 95% confidence interval [CI], 1.53-89.2; P = 0.018), mural nodules ≥ 5 mm (OR, 11.67; 95% CI, 2.3-59.05; P = 0.003), solid components within cysts (OR, 30.87; 95% CI, 7.23-131.7; P < 0.0001) and high serum CA19-9 levels (OR, 1.006; 95% CI, 1.001-1.011; P = 0.02) were independently associated with the presence of A-PCLs. The presence of septa was independently associated with the presence of non-A-PCLs (OR, 0.147; 95% CI, 0.04-0.6; P = 0.008). Males who had a history of tobacco abuse (P < 0.0001) and had a greatly dilated MPD (P < 0.0001) were more common in advanced intraductal papillary mucinous neoplasms (IPMC) patients. Solid pseudopapillary neoplasm (SPT) often occurred in young women (P < 0.0001), mostly asymptomatically (P < 0.0001) and with lower serum CA19-9 levels (P < 0.0001). In the 124 patients who underwent EUS-guided fine-needle aspiration (EUS-FNA), five additional characteristics (4 mural nodules and 1 MPD involvement) were identified by EUS imaging and 17 patients were identified with abnormal cytological results (13 atypical cells and 4 suspicious for malignancy cells) by EUS-FNA.

CONCLUSION

On the basis of a retrospective study with large sample size, the presence of MPD ≥ 10 mm, mural nodules, solid components, and high serum CA19-9 levels were independently associated with the presence of A-PCLs. The high-risk characteristics may vary across different types of A-PCLs. EUS and EUS-FNA could provide additional diagnostic information for PCLs.

Screening Strategy of Pancreatic Cancer in Patients with Diabetes Mellitus

The incidence of pancreatic cancer (PCa) is increasing worldwide and has become one of the leading causes of cancer-related death. Screening for high risk populations is fundamental to overcome this intractable malignancy. Diabetes mellitus (DM) is classically known as a risk factor for PCa. Recently the reverse causality is in the spotlight, that is to say, DM is considered to be a manifestation of PCa. Numbers of epidemiological studies clarified that new-onset DM (≤2-year duration) was predominant in PCa patients and the relative risk for PCa inversely correlated with duration of DM. Among patients with new-onset DM, elder onset, weight loss, and rapid exacerbation of glycemic control were reported to be promising risk factors and signs, and the model was developed by combining these factors. Several pilot studies disclosed the possible utility of biomarkers to discriminate PCa-associated DM from type 2 DM. However, there is no reliable biomarkers to be used in the practice. We previously reported the application of a multivariate index for PCa based on the profile of plasma free amino acids (PFAAs) among diabetic patients. We are further investigating on the PFAA profile of PCa-associated DM, and it can be useful for developing the novel biomarker in the near future.

Pancreatic cystic lesions in diabetes mellitus patients

Introduction

According to the literature exocrine pancreatic insufficiency is relatively common among patients with diabetes mellitus (DM). Pseudocysts are the most common cystic lesions and may be formed in the setting of acute or chronic pancreatitis. However, whether DM is involved or not in pancreatic cyst formation is still not well established.

Aim

To investigate the frequency and risk factors of cystic lesions in diabetic patients.

Material and methods

One hundred and sixty-one patients with DM, with no previous history of pancreatic diseases, were prospectively included in the study. Endosonography followed by fine needle aspiration biopsy was then performed.

Results

Finally, 33 of 161 patients (20.5%) were recognized with cystic lesions of the pancreas. Among them 5 patients were classified as cystic neoplasms, and 28 as pseudocysts. In the group of patients with pseudocysts, cystic lesions were significantly more prevalent in individuals with DM lasting less than 3 years. Prevalence of cystic lesions was significantly higher in metformin users in comparison to other diabetic patients (p < 0.05). Cystic lesions were more frequent in patients above 50 years of age (p < 0.05).

Conclusions

The prevalence of cystic lesions in the diabetic population is higher than in the general population. DM seems to play a major role in the process of cyst development, especially in patients without previous history of pancreatitis. Higher prevalence of cystic lesions in early diabetes seems to be the first stage of pancreatic injury. The exact role of diabetes duration and type of treatment should be established.

Progression of pancreatic cystic lesions without any risk features is associated with initial cyst size and obesity

BACKGROUND AND AIM

The clinical significance of incidental pancreatic cystic lesions (PCLs) remains unclear in those that are not accompanied by worrisome features or high-risk stigmata. We aimed to investigate the natural course of PCLs without any risk features and examine the clinical factors associated with their progression.

METHODS

We conducted a retrospective cohort study of 427 patients with PCLs, which were incidentally detected by computed tomography between January 2003 and December 2012. Progression of PCLs without any risk features and the clinical factors associated with their progression were investigated. The length of time to significant growth was also evaluated.

RESULTS

Ninety-four (22.0%) of the 427 patients had asymptomatic PCLs that showed significant growth after a median surveillance period of 5.3 years; approximately 27.7% of the patients showed significant size changes in the first 5 years, while the remaining 72.3% showed significant changes after 5 years. The cumulative rate of patients with significant growth was associated with initial cyst size and high body mass index. In the growth group, additional treatments were required for 12 patients, one of whom developed malignancy. Four patients in the stable group underwent additional treatment and showed no malignant change.

CONCLUSIONS

One-fifth of the asymptomatic PCLs significantly increased in size after a long-term follow-up period, which was associated with initial cyst size and obesity. The size of PCLs mostly increased after 5 years; although the malignancy risk of PCLs was low, it was still a concern.

Negative effect of fatty liver on visualization of pancreatic cystic lesions at screening transabdominal ultrasonography

RATIONALE, AIMS, AND OBJECTIVES

The aim of this observational study is to identify factors by which some pancreatic cystic lesions (PCLs) were undetectable at transabdominal ultrasonography (TAUS), using magnetic resonance imaging (MRI) as reference standard.

METHODS

The database for 781 consecutive subjects who underwent a health checkup including fat computed tomography and upper abdominal MRI as option was searched. The presence of fatty liver and fatty pancreas was diagnosed by TAUS, and atrophic pancreas was determined by reevaluating the image of the pancreas in the chest computed tomography for screening. Subjects with PCL detected and those undetected at TAUS were statistically compared in clinical characteristics.

RESULTS

The prevalence of PCL detected at MRI was 17.8% in the general population. Multivariate logistic regression analysis showed that fatty liver, body mass index, and the size of PCL were significantly associated with the factors influencing the visualization of PCL at TAUS (odds ratio [OR]: 0.337, 95% confidence interval [CI]: 0.154-0.734, P = 0.006; OR: 0.852, 95% CI: 0.737-0.985, P = 0.030; OR:1.120, 95% CI: 1.045-1.200, P = .001). Thirty-six PCLs (64.3%) in a total of 56 PCLs were undermeasured by TAUS. Additionally, nine (56%) out of 16 PCLs (≥ 15 mm) were undermeasured by 5 mm or more by TAUS, although a significantly higher detection rate was observed for PCLs (≥ 15 mm) in comparison with that for PCLs (< 15 mm) (80% vs 33.6%, P = .000).

CONCLUSIONS

It should be noted that coexisting fatty liver may lower the detection of PCL, and its size may be underestimated by TAUS.

Long-term Risk of Malignancy in Branch-Duct Intraductal Papillary Mucinous Neoplasms

BACKGROUND & AIMS

Long-term outcomes of patients with branch-duct intraductal papillary mucinous neoplasms (IPMNs), particularly those after 5 years of surveillance, have not been fully evaluated in large studies. We analyzed incidences of IPMN-derived carcinoma and concomitant ductal adenocarcinoma (pancreatic ductal adenocarcinoma [PDAC]) over 20 years in a large population of patients.

METHODS

We identified 1404 consecutive patients (52% women; mean age, 67.5 years) with a diagnosis of branch-duct IPMN, from 1994 through 2017, at the University of Tokyo in Japan. Using a competing risk analysis, we estimated cumulative incidence of pancreatic carcinoma, overall and by carcinoma type. We used competing risks proportional hazards models to estimate subdistribution hazard ratios (SHRs) for incidences of carcinomas. To differentiate IPMN-derived and concomitant carcinomas, we collected genomic DNA from available paired samples of IPMNs and carcinomas and detected mutations in GNAS and KRAS by polymerase chain reaction and pyrosequencing.

RESULTS

During 9231 person-years of follow-up, we identified 68 patients with pancreatic carcinomas (38 patients with IPMN-derived carcinomas and 30 patients with concomitant PDACs); the overall incidence rates were 3.3%, 6.6%, and 15.0% at 5, 10, and 15 years, respectively. Among 804 patients followed more than 5 years, overall cumulative incidence rates of pancreatic carcinoma were 3.5% at 10 years and 12.0% at 15 years from the initial diagnosis. The size of the IPMN and the diameter of the main pancreatic duct associated with incidence of IPMN-derived carcinoma (SHR 1.85; 95% confidence interval 1.38-2.48 for a 10-mm increase in the IPMN size and SHR 1.56; 95% confidence interval 1.33-1.83 for a 1-mm increase in the main pancreatic duct diameter) but not with incidence of concomitant PDAC.

CONCLUSIONS

In a large long-term study of patients with branch-duct IPMNs, we found the 5-year incidence rate of pancreatic malignancy to be 3.3%, reaching 15.0% at 15 years after IPMN diagnosis. We observed heterogeneous risk factor profiles between IPMN-derived and concomitant carcinomas.

Single-session esophagogastroduodenoscopy and endoscopic ultrasound using a forward-viewing radial scan ultrasonic endoscope

BACKGROUND

Endoscopic ultrasound is useful for obtaining high-resolution images of pancreaticobiliary diseases, but is not readily available for physical checkups. In this study, we evaluated the safety and efficacy of single-session esophagogastroduodenoscopy and endoscopic ultrasound in the detection of upper-gastrointestinal and pancreaticobiliary diseases using a forward-viewing radial scan ultrasonic endoscope.

METHODS

A total of 148 patients who were scheduled for upper-gastrointestinal screening using an endoscope were prospectively included. All patients were examined by EUS in combination with EGD using a forward-viewing radial scan ultrasonic endoscope. The primary endpoint was the safety of the procedures. The secondary endpoints were the prevalence of diseases, the basal imaging capability of EUS, the procedure time, total dose of propofol, and the correlation between background factors and the prevalence of pancreatic disease. The imaging capability at each region was scored as 0 (invisible) to 2 (sufficient visualization to evaluate the organs).

RESULTS

Intraoperative hypotension occurred as an adverse event of intravenous anesthesia in one patient. There were 82 pancreaticobiliary findings and 165 upper-gastrointestinal findings (malignancy not included). Follicular lymphoma of the intra-abdominal lymph nodes was detected in one patient. The mean imaging scores of each section were 1.95 (pancreatic head and papilla), 2.0 (pancreatic body), 1.99 (pancreatic tail), and 1.89 (common bile duct and gallbladder). Age, history of diabetes mellitus, and smoking history were significantly associated with the prevalence of pancreatic diseases.

CONCLUSION

The simultaneous performance of EGD and EUS using a new ultrasonic endoscope is tolerable and safe for upper-gastrointestinal and pancreaticobiliary screening.

Association between macroscopically visible tissue samples and diagnostic accuracy of EUS-guided through-the-needle microforceps biopsy sampling of pancreatic cystic lesions

BACKGROUND AND AIMS

EUS-guided through-the-needle biopsy (TTNB) sampling has been reported to improve diagnostic yield compared with cytology for the evaluation of pancreatic cystic lesions (PCLs). The number of macroscopically visible tissue samples needed to reach an adequate diagnosis is still unknown.

METHODS

This is a retrospective, single-center study on consecutive patients with PCLs with risk features (cyst >3 cm, thickened wall, cyst growth during follow-up, and mural nodules) who underwent TTNB sampling. The capability of differentiating mucinous versus nonmucinous cysts, ability to obtain a cyst-lining epithelium, definition of the grade of dysplasia, and specific diagnosis of cyst histotype were evaluated for 1, 2, or 3 TTNB macroscopically visible specimens.

RESULTS

Sixty-one patients were evaluated. A 100% histologic adequacy was reached by 2 samples (P = .05 versus 1). Compared with cytology, 1 TTNB specimen improved the possibility of defining cyst histotype (P < .0001), whereas 2 specimens increased all 4 diagnostic categories (P < .003). Two specimens also increased diagnostic yield compared with 1 sample (P < .085). The collection of a third sample did not improve the value of any diagnostic categories. A specific diagnosis was reached in 74% of patients with 2 histologic samples. The diagnostic reliability of TTNB sampling compared with surgical histology was 90%, with a 22.9% rate of adverse events.

CONCLUSIONS

Two TTNB macroscopically visible specimens reached 100% histologic adequacy and a specific diagnosis in 74% of patients. The collection of a third specimen did not add any additional information and should be avoided to possibly decrease the risk of adverse events.

Development of a stratification tool to identify pancreatic intraductal papillary mucinous neoplasms at lowest risk of progression

BACKGROUND

Because most pancreatic intraductal papillary mucinous neoplasms (IPMNs) will never become malignant, currently advocated long-term surveillance is low-yield for most individuals.

AIM

To develop a score chart identifying IPMNs at lowest risk of developing worrisome features or high-risk stigmata.

METHODS

We combined prospectively maintained pancreatic cyst surveillance databases of three academic institutions. Patients were included if they had a presumed side-branch IPMN, without worrisome features or high-risk stigmata at baseline (as defined by the 2012 international Fukuoka guidelines), and were followed ≥ 12 months. The endpoint was development of one or more worrisome features or high-risk stigmata during follow-up. We created a multivariable prediction model using Cox-proportional logistic regression analysis and performed an internal-external validation.

RESULTS

875 patients were included. After a mean follow-up of 50 months (range 12-157), 116 (13%) patients developed worrisome features or high-risk stigmata. The final model included cyst size (HR 1.12, 95% CI 1.09-1.15), cyst multifocality (HR 1.49, 95% CI 1.01-2.18), ever having smoked (HR 1.40, 95% CI 0.95-2.04), history of acute pancreatitis (HR 2.07, 95% CI 1.21-3.55), and history of extrapancreatic malignancy (HR 1.34, 95% CI 0.91-1.97). After validation, the model had good discriminative ability (C-statistic 0.72 in the Mayo cohort, 0.71 in the Columbia cohort, 0.64 in the Erasmus cohort).

CONCLUSION

In presumed side branch IPMNs without worrisome features or high-risk stigmata at baseline, the Dutch-American Risk stratification Tool (DART-1) successfully identifies pancreatic lesions at low risk of developing worrisome features or high-risk stigmata.

Prevalence of pancreatic cystic lesions detected by magnetic resonance imaging in the Chinese population

BACKGROUND AND AIM

Incidental pancreatic cystic lesions (PCLs) are being diagnosed more frequently. However, little is known about the prevalence of PCLs in the Chinese population. The aim of the study was to assess the crude prevalence of PCLs in individuals who underwent magnetic resonance imaging (MRI).

METHODS

Data from consecutive patients who underwent MRI without pancreatic indications were included. MRI images were reviewed for the presence of pancreatic cysts. The prevalence of PCLs and high-risk PCLs in different gender and age groups was calculated. To assess the crude prevalence, the prevalence and demographic data were standardized on the basis of Chinese national population data in 2017.

RESULTS

A total of 10 987 individuals were included (7344 men). Incidental PCLs were identified in 212 individual (128 men). The prevalence of PCLs was 1.93%, and PCLs were more often discovered in women (1.74% vs 2.31%, P = 0.043). Prevalence increased with age (r = 0.804, P < 0.001). The prevalence of high-risk PCLs was 0.12% (n = 13). Gender predominance and age distribution showed no difference between high-risk PCLs and low-risk PCLs (P = 0.234 and P = 0.855), but cysts located in the pancreatic head were more likely to develop into high-risk PCLs (P = 0.001). After data standardization, the crude prevalence of PCLs was 1.31%, and PCLs were more often discovered in women (1.11% vs 1.5%, P < 0.001). The crude prevalence of high-risk PCLs was 0.07%.

CONCLUSION

Pancreatic cystic lesions in the Chinese population are not rare. The prevalence of PCLs increased with age and is higher in the female population. The prevalence of high-risk PCLs should not be ignored.

Current Status of Endoscopic Ultrasound Techniques for Pancreatic Neoplasms

Endoscopic ultrasound (EUS) now plays an important role in the management of pancreatic neoplasms. There are various types of pancreatic neoplasms, from benign to malignant lesions, and the role of EUS ranges from the imaging diagnosis to treatment. EUS is useful for the detection, characterization, and tissue acquisition of pancreatic lesions. Recent advancement of contrast-enhanced harmonic EUS and elastography enables better characterization of pancreatic lesions. In addition to these enhanced EUS imaging techniques, EUS-guided tissue acquisition is now the standard procedure to establish the pathological diagnosis of pancreatic neoplasms. While these diagnostic roles of EUS have been established, EUS-guided interventions such as ablation and drainage are also increasingly utilized in the management of pancreatic neoplasms. However, most of these EUS-guided interventions are not yet standardized in terms of techniques and devices and thus need further investigations.

Testing for Verification Bias in Reported Malignancy Risks for Side-Branch Intraductal Papillary Mucinous Neoplasms: A Simulation Modeling Approach

OBJECTIVE

The objective of our study was to test for the possibility that published malignancy risks for side-branch intraductal papillary mucinous neoplasms (IPMNs) are overestimates, likely due to verification bias.

MATERIALS AND METHODS

We tested for possible verification bias using simulation modeling techniques. First, in age-defined hypothetical cohorts of 10 million persons, we projected the frequency of pancreatic ductal adenocarcinoma (PDAC) arising from side-branch IPMNs over 5 years using published estimates of their prevalence (4.4%) and rate of malignant transformation (1.9%). Second, we projected the total number of PDAC cases in corresponding cohorts over the same time horizon using national cancer registry data. For each cohort, we determined whether the percentage of all PDAC cases that arose from side-branch IPMNs (i.e., side-branch IPMN-associated PDAC cases) was clinically plausible using an upper limit of 10% to define plausibility, as estimated from the literature. Model assumptions and parameter uncertainty were evaluated in sensitivity analysis.

RESULTS

Across all cohorts, percentages of side-branch IPMN-associated PDACs greatly exceeded 10%. In the base case (mean age = 55.7 years), 80% of PDAC cases arose from side-branch IPMNs (7877/9786). In the oldest cohort evaluated (mean age = 75 years), this estimate was 76% (14,227/18,714). In a secondary analysis, we found that if an upper limit threshold of 10% for side-branch IPMN-associated PDAC was imposed, the model-predicted rate of malignancy for side-branch IPMNs would be less than 0.24% over a 5-year time horizon, substantially lower than most literature-based estimates.

CONCLUSION

Our results suggest that reported malignancy risks associated with side-branch IPMNs are likely to be overestimates and imply the presence of verification bias.

Systematic review and meta-analysis: Prevalence of incidentally detected pancreatic cystic lesions in asymptomatic individuals

BACKGROUND & AIMS

Pancreatic cystic lesions (PCLs) are frequent incidental findings. As most PCLs require costly diagnostic evaluation and active surveillance, it is important to clarify their prevalence in asymptomatic individuals. We therefore aimed at performing a systematic review and meta-analysis to determine it.

METHODS

a systematic search was conducted and studies meeting inclusion criteria were included. The prevalence of PCLs was pooled across studies. A random effect model was used with assessment of heterogeneity.

RESULTS

17 studies, with 48,860 patients, were included. Only 3 were prospective; 5 studies were conducted in the US, 7 in Europe, 4 in Asia and 1 in Brazil. The pooled prevalence of PCLs was 8% (95% CI 4-14) with considerable heterogeneity (I² = 99.5%). This prevalence was higher in studies of higher quality, examining older subjects, smaller cohorts, and employing MRCP (24.8% vs 2.7% with CT-scan). The pooled rate of PCLs was four times higher in studies conducted in the US than in Asia (12.6% vs 3.1%). 7 studies reported the prevalence of mucinous lesions, with a pooled rate of 4.3% (95% CI 2-10; I² = 99.2%), but of 0.7% only for worrisome features or high risk stigmata.

CONCLUSION

The rate of incidentally detected PCLs is of 8%. Mucinous lesions are the most common incidentally detected PCLs, although they rarely present with potential indication for surgery. The observed different rates in the US and other geographic Areas suggest that different protocols might be necessary to help balancing costs and effectiveness of follow-up investigations in asymptomatic subjects.

Prevention of pancreatic acinar cell carcinoma by Roux-en-Y Gastric Bypass Surgery

Roux-en-Y Gastric Bypass Surgery (RYGB) prevents the occurrence of pancreatic cell acinar carcinoma (ACC) in male and female Ngn3-Tsc1-/- mice. Ngn3 directed Cre deletion of Tsc1 gene induced the development of pancreatic ACC. The transgenic mice with sham surgery demonstrated a cancer incidence of 96.7 ± 3.35% and survival rate of 67.0 ± 1.4% at the age of 300 days. Metastasis to liver and kidney was observed in 69.7 ± 9.7% and 44.3 ± 8.01% of these animals, respectively. All animals with RYGB performed at the age of 16 weeks survived free of pancreatic ACC up to the age of 300 days. RYGB significantly attenuated the activation of mTORC1 signaling and inhibition of tumor suppressor genes: p21, p27, and p53 in pancreatic ACC. Our studies demonstrate that bariatric surgery may limit the occurrence and growth of pancreatic ACC through the suppression of mTORC1 signaling in pancreas. RYGB shows promise for intervention of both metabolic dysfunction and organ cancer.

Pancreatic Fat Content Detected by Computed Tomography and Its Significant Relationship With Intraductal Papillary Mucinous Neoplasm

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant lesions of pancreatic ductal adenocarcinomas (PDACs). Fat accumulation in the pancreas is increasingly recognized as a cause of PDAC. We aimed to identify factors that are relevant between IPMN and metabolic-related factors, including pancreatic fat.

METHODS

The database for 781 subjects who underwent a health checkup and upper abdominal magnetic resonance imaging was searched and computed tomography attenuation indexes (pancreatic and spleen attenuation, pancreas-to-spleen attenuation ratio) were decided by measuring the regions of interest in the pancreas and spleen on nonenhanced images, using Hounsfield units. Eighty-five subjects from each of the IPMN and noncyst groups were matched for age, sex, and glycemic status and statistically compared in clinical characteristics.

RESULTS

There was no difference in metabolic-related factors except for apolipoprotein A1 and high-density lipoprotein cholesterol between the 2 groups in univariate analysis. Multivariate logistic regression analysis showed that both indexes were significantly associated with IPMN (odds ratio, 0.905 [95% confidence intervals, 0.851-0.963; P = 0.002]; odds ratio, 0.006 [95% confidence intervals, 0.000-0.152; P = 0.002]).

CONCLUSIONS

Pancreatic fat content measured by computed tomography was significantly associated with IPMN. These results suggest that IPMN may develop secondary to pancreatic steatosis that could be an overlapping risk factor for PDAC and IPMN.