Intraductal papillary mucinous neoplasms

Oncogenic GNAS uses PKA-dependent and independent mechanisms to induce cell proliferation in human pancreatic ductal and acinar organoids

Ductal and acinar pancreatic organoids generated from human pluripotent stem cells (hPSCs) are promising models to study pancreatic diseases, including precursor lesions of pancreatic cancer. Genome sequencing studies have revealed that mutations in a G-protein (GNASR201C) are exclusively observed in intraductal papillary mucinous neoplasms (IPMNs), one of the most common cystic pancreatic precancerous lesions. GNASR201C cooperates with oncogenic KRASG12V/D to produce IPMN lesions in mice; however, the biological mechanisms by which oncogenic GNAS affects the ductal and acinar exocrine pancreas are not understood. In this study, we use pancreatic ductal and acinar organoids generated from human embryonic stem cells to investigate mechanisms by which GNASR201C functions. As expected, GNASR201C-induced cell proliferation in acinar organoids was PKA-dependent. Surprisingly, GNASR201C-induced cell proliferation independent of the canonical PKA signaling in short-term and stable, long-term cultures of GNAS-expressing ductal organoids and in an immortalized ductal epithelial cell line, demonstrating that GNASR201C uses PKA-dependent and independent mechanisms to induce cell proliferation in the exocrine pancreas. Co-expression of oncogenic KRASG12V and GNASR201C induced cell proliferation in ductal and acini organoids in a PKA-independent and dependent manner, respectively. Thus, we identify cell lineage-specific roles for PKA signaling driving pre-cancerous lesions and report the development of a human pancreatic ductal organoid model system to investigate mechanisms regulating GNASR201C-induced IPMNs.

State-of-the-art surgical treatment of IPMNs

Background

A “pandemic” of incidentally discovered pancreatic cyst neoplasms (PCNs) is ongoing. Among PCNs, intraductal papillary mucinous cystic neoplasms (IPMNs) are the most common and with their complex biology could represent a precursor lesion of pancreatic cancer. Although multiple guidelines exist to guide their treatment, there are still many “gray areas” on indications for surgery for IPMNs.

Methods

The current indications for surgery of IPMNs were reappraised, considering potential discrepancies between available evidence and guidelines policies. The practice at a high-volume center for the diagnosis and treatment of PCN was presented and discussed.

Results

Most IPMNs do not and will never require surgery, as they won’t progress to malignancy. The current literature is solid in identifying high-grade dysplasia (HGD) as the right and timely target for IPMN resection, but how to precisely assess its presence remains controversial and guidelines lack of accuracy in this regard. Multiple tumorigenic pathways of progression of IPMNs exist, and their knowledge will likely lead to more accurate tests for malignancy prediction in the future.

Conclusions

The surgical management of IPMNs still is a matter of debate. Indication for resection should be considered only in highly selected cases with the ideal target of HGD. Clinicians should critically interpret the guidelines’ indications, refer to a multidisciplinary team discussion, and always consider the outcome of an adequate counselling with the patient.

Analyzing Intraductal Papillary Mucinous Neoplasms Using Artificial Neural Network Methodologic Triangulation

Intraductal papillary mucinous neoplasms (IPMN) are a type of mucinous pancreatic cyst. IPMN have been shown to be pre-malignant precursors to pancreatic cancer, which has an extremely high mortality rate with average survival less than 1 year. The purpose of this analysis is to utilize methodological triangulation using artificial neural networks and regression to examine the impact and effectiveness of a collection of variables believed to be predictive of malignant IPMN pathology. Results indicate that the triangulation is effective in both finding a new predictive variable and possibly reducing the number of variables needed for predicting if an IPMN is malignant or benign.

Intraductal Papillary Mucinous Neoplasm of the Pancreas in Young Patients: Tumor Biology, Clinical Features, and Survival Outcomes

AIM

The aim of this paper is to describe the characteristics of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas in young patients.

METHODS

We evaluated 1693 patients from the Pancreatic Surgery Consortium who underwent resection for IPMN and classified them as younger or older than 50 years of age at the time of surgery. We assessed the relationship of age with clinical, radiological, pathological, and prognostic features.

RESULTS

We identified 90 (5%) young patients. Age was not associated with differences in main pancreatic duct size (P = 0.323), presence of solid components (P = 0.805), or cyst size (P = 0.135). IPMNs from young patients were less likely to be of gastric type (37 vs. 57%, P = 0.005), and more likely to be of oncocytic (15 vs. 4%, P = 0.003) and intestinal types (44 vs. 26%, P = 0.004). Invasive carcinomas arising from IPMN were less common in young patients (17 vs. 27%, P = 0.044), and when present they were commonly of colloid type (47 vs. 31% in older patients, P = 0.261) and had better overall survival than older patients (5-year, 71 vs. 37%, log-rank P = 0.031).

CONCLUSION

Resection for IPMN is infrequent in young patients, but when they are resected, IPMNs from young patients demonstrate different epithelial subtypes from those in older patients and more favorable prognosis.

Intraductal Papillary Mucinous Neoplasms of the Pancreas: Correlation of Helical Computed Tomography (CT) Features With Pathologic Findings

RATIONALE AND OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are precancerous lesions of the pancreas. Computed tomography (CT) has been recommended to screen the malignant potential of IPMNs. However, data evaluating the use of CT to differentiate categories of IPMN based on disease progression are limited. This study aimed to explore the correlation between CT characteristics and pathology in IPMN associated with invasive carcinoma.

MATERIALS AND METHODS

A total of 31 patients with intraductal papillary mucinous carcinoma (IPMC) treated at one local regional hospital in Shanghai, China, were enrolled in this study. Patients were divided into two groups based on invasion component and characterized as follows: group A, an invasive component of less than 50% (IPMC-I); and group B, with invasion of 50% or greater and defined as pancreatic ductal adenocarcinoma associated with IPMN (PDAC-IPMN). First, we analyzed the imaging information of the 31 patients retrospectively. Then, we compared the imaging differences between the two groups.

RESULTS

Fifteen patients with IPMC-1 and 16 patients with PDAC-IPMN were identified. There was no statistically significant difference in sex, age, lesion location, radiologic type, tumor size, mural nodule size, and lymphatic metastasis between the two groups. However, the arterial increased CT values were significantly different between the two groups (P < .01), with values of 29.2 ± 12.4 HU for group A and 14.2 ± 8.8 HU for group B. The venous increased CT values were 44.6 ± 12.0 HU for group A and 28.4 ± 12.3 HU for group B, and these were significantly different between the two groups (P < .01). In group A, 13 cases (86.7%) were classified as T1 or T2 stage, and in group B, eight cases (50.0%) were classified as T1 and T2 stage. There was a statistically significant difference in tumor classification between group A and group B patients (P < .05).

CONCLUSIONS

IPMC-I and PDAC-IPMN have different characteristics in CT imaging, and we demonstrated that CT scans based on blood supply and lymphatic metastasis could be used to evaluate and potentially screen for variation in IPMC disease outcomes.

Intraductal Papillary Mucinous Neoplasm of the Pancreas With High Malignant Potential on FDG PET/MRI

A 57-year-old man underwent FDG PET/CT to evaluate a mass in the head of the pancreas. The imaged revealed mildly, nonuniformly increased activity in the mass, but the exact location of the activity could not be determined on the low-dose noncontrast CT portion of the study. On subsequent PET/MRI images acquired 60 minutes after the FDG PET/CT study, the increased activity was clearly localized on the cystic wall. The pathological examination showed that the lesion was intraductal papillary mucinous neoplasm of the pancreas with high degree of dysplasia.

Pancreatic resection for intraductal papillary mucinous neoplasm- a thirteen-year single center experience

BACKGROUND

The purpose of this study is to review our results for pancreatic resection in patients with intraductal papillary mucinous neoplasm (IPMN) with and without associated carcinoma.

METHODS

A total of 54 patients undergoing pancreatic resection for IPMN in a single university surgical center (Medical University of Graz) were reviewed retrospectively. Their survival rates were compared to those of patients with pancreatic ductal adenocarcinoma.

RESULTS

Twenty-four patients exhibit non-invasive IPMN and thirty patients invasive IPMN with associated carcinoma. The mean age is 67 (+/-11) years, 43 % female. Surgical strategies include classical or pylorus-preserving Whipple procedure (n = 30), distal (n = 13) or total pancreatectomy (n = 11), and additional portal venous resection in three patients (n = 3). Median intensive care stay is three days (range 1 - 87), median in hospital stay is 23 days (range 7 - 87). Thirty-day mortality is 3.7 %. Median follow up is 42 months (range 0 - 127). One-, five- and ten-year overall actuarial survival is 87 %; 84 % and 51 % respectively. Median overall survival is 120 months. Patients with non-invasive IPMN have significantly better survival than patients with invasive IPMN and IPMN-associated carcinoma (p < 0.008). In the subgroup of invasive IPMN with associated carcinoma, a positive nodal state, perineural invasion as well as lymphovascular infiltration are associated with poor outcome (p < 0.0001; <0.0001 and =0.001, respectively). Elevated CA 19-9(>37 U/l) as well as elevated lipase (>60 U/l) serum levels are associated with unfavorable outcome (p = 0.009 and 0.018; respectively). Patients operated for pancreatic ductal adenocarcinoma show significantly shorter long-term survival than patients with IPMN associated carcinoma (p = 0.001).

CONCLUSIONS

Long-term outcome after pancreatic resection for non-invasive IPMN is excellent. Outcome after resection for invasive IPMN with invasive carcinoma is significantly better than for pancreatic ductal adenocarcinoma. In low- and intermediate risk IPMN with no clear indication for immediate surgical resection, a watchful waiting strategy should be evaluated carefully against surgical treatment individually for each patient.

Peroxisome proliferator activated receptors at the crossroad of obesity, diabetes, and pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the fourth cause of cancer death with an overall survival of 5% at five years. The development of PDAC is characteristically associated to the accumulation of distinctive genetic mutations and is preceded by the exposure to several risk factors. Epidemiology has demonstrated that PDAC risk factors may be non-modifiable risks (sex, age, presence of genetic mutations, ethnicity) and modifiable and co-morbidity factors related to the specific habits and lifestyle. Recently it has become evident that obesity and diabetes are two important modifiable risk factors for PDAC. Obesity and diabetes are complex systemic and intertwined diseases and, over the years, experimental evidence indicate that insulin-resistance, alteration of adipokines, especially leptin and adiponectin, oxidative stress and inflammation may play a role in PDAC. Peroxisome proliferator activated receptor-γ (PPARγ) is a nuclear receptor transcription factor that is implicated in the regulation of metabolism, differentiation and inflammation. PPARγ is a key regulator of adipocytes differentiation, regulates insulin and adipokines production and secretion, may modulate inflammation, and it is implicated in PDAC. PPARγ agonists are used in the treatment of diabetes and oxidative stress-associated diseases and have been evaluated for the treatment of PDAC. PPARγ is at the cross-road of diabetes, obesity, and PDAC and it is an interesting target to pharmacologically prevent PDAC in obese and diabetic patients.

Trends in malignant intraductal papillary mucinous neoplasm in US adults from 1990 to 2010: a SEER database analysis

Background: Intraductal papillary mucinous neoplasms (IPMNs) are precancerous lesions with a well-described adenoma-carcinoma sequence. Although the risk of malignant transformation has been well studied, data on trends in long-term survival and important prognostic factors associated with survival in malignant IPMN are lacking.

Methods: The Surveillance, Epidemiology, and End Results (SEER) database was queried to identify patients with confirmed malignant IPMN based upon pathologic diagnosis or radiographic evidence concerning for malignant potential. Median survival and age-adjusted incidence were calculated. Cox proportional hazard regression was used to determine independent mortality factors.

Results: Based upon the SEER database query, 2651 patients were diagnosed with malignant IPMN between 1990 and 2010. The age-adjusted incidence of IPMN in 1990 was 0.361 per 100 000 persons (95% confidence interval [CI]: 0.285–0.451) with a steady decline observed through 2010 (0.135 per 100 000 persons, 95% CI: 0.098–0.186). A total of 564 patients (21.3%) underwent a surgical procedure, though the number of patients who underwent surgery from 1990 to 2010 also decreased (1990–1995, n = 132 to 2006–2010, n = 96, respectively). The overall median survival was 4 months and remained relatively stable from 1990 to 2010. Performance of surgery (HR: 0.45, 95% CI: 0.40–0.53, P < 0.001) was associated with a decreased risk of death.

Conclusion: A significant decrease in the incidence of malignant IPMN was seen from 1990 to 2010. There was also no improvement observed in long-term survival. The small percentage of eligible cases receiving surgical treatment suggests that there is room for further improvement in survival, with increased utilization of surgery.

Molecular Characterization and Pathogenesis of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are noninvasive neoplasms which occur in the main pancreatic duct or its major branches. IPMNs have an important meaning in the clinic and in research since they represent around 20% of all resected pancreatic neoplasms. Morphologically, branch duct, main duct and mixed-type IPMNs can be distinguished. Histologically, they can be divided into gastric, intestinal, pancreatobiliary and oncocytic type. There are different mutations in genes such as KRAS, GNAS, RNF43 and p53. The expression of miRNAs is specific to IPMNs; altogether, 14 miRNAs have been identified so far which are differently expressed in all IPMNs in contrast to normal pancreatic tissue. It has also been observed that methylation levels can be altered in IPMNs. This review summarizes the molecular characteristics of IPMNs of the pancreas and presents currently known markers.