Progesterone receptor and PTEN expression predict survival in patients with low- and intermediate-grade pancreatic neuroendocrine tumors

Epidemiological characteristics of neuroendocrine neoplasms in Beijing: a population-based retrospective study

BACKGROUND

The incidence of neuroendocrine neoplasms (NENs) is rising rapidly worldwide. However, there are few reports on these heterogeneous diseases in China. Our study aimed to explore the epidemiological characteristics of NENs in Beijing.

METHODS

We conducted a retrospective cohort study using population-based cancer surveillance data in Beijing, China. All data were extracted from the Beijing Cancer Registry with incidence dates from 1 January 1998 to 31 December 2018; the follow-up period was through 31 December 2021. Segi's world standard population was used to estimate the age-standardized rate. Survival was estimated using the Kaplan-Meier method.

RESULTS

From 1998 to 2018, the incidence of NENs in Beijing initially showed a significant increasing trend, from 1.07/100,000 to 3.53/100,000; this began to plateau after 2013. The age-specific incidence rate increased with age and peaked in the age group 70-74 years. The incidence in men was significantly higher than that in women (4.41/100,000 vs. 1.69/100,000). The most common sites of NENs were the lung (2.38/100,000) and rectum (0.14/100,000). Most NENs were diagnosed at a late stage. We found that NENs originating from the lung had worse overall survival than extrapulmonary NENs, and male patients had worse survival than female patients.

CONCLUSIONS

This study retrospectively analyzed the epidemiological characteristics of NENs in Beijing from 1998 to 2018. Our findings provide a reference regarding the epidemiological statistics of NENs in Beijing to contribute to the prevention, diagnosis, and treatment of these specific tumors.

Gender-related differences in patients with carcinoid syndrome: new insights from an Italian multicenter cohort study

BACKGROUND

The incidence of neuroendocrine neoplasm (NEN) and related carcinoid syndrome (CaS) has increased markedly in recent decades, and women appear to be more at risk than men. As per other tumors, gender may be relevant in influencing the clinical and prognostic characteristics of NEN-associated CS. However, specific data on carcinoid syndrome (CaS) are still lacking.

PURPOSE

To evaluate gender differences in clinical presentation and outcome of CaS.

METHODS

Retrospective analysis of 144 CaS patients from 20 Italian high-volume centers was conducted. Clinical presentation, tumor characteristics, therapies, and outcomes (progression-free survival, PFS, overall survival, OS) were correlated to gender.

RESULTS

Ninety (62.5%) CaS patients were male. There was no gender difference in the site of primary tumor, tumor grade and clinical stage, as well as in treatments. Men were more frequently smokers (37.2%) and alcohol drinkers (17.8%) than women (9.5%, p = 0.002, and 3.7%, p = 0.004, respectively). Concerning clinical presentation, women showed higher median number of symptoms (p = 0.0007), more frequent abdominal pain, tachycardia, and psychiatric disorders than men (53.3% vs 70.4%, p = 0.044; 6.7% vs 31.5%, p = 0.001; 50.9% vs. 26.7%, p = 0.003, respectively). Lymph node metastases at diagnosis were more frequent in men than in women (80% vs 64.8%; p = 0.04), but no differences in terms of PFS (p = 0.51) and OS (p = 0.64) were found between gender.

CONCLUSIONS

In this Italian cohort, CaS was slightly more frequent in males than females. Gender-related differences emerged in the clinical presentation of CaS, as well as gender-specific risk factors for CaS development. A gender-driven clinical management of these patients should be advisable.

Prognostic significance of systemic immune-inflammation index in patients with nonfunction pancreatic neuroendocrine tumor undergoing surgical resection

PURPOSE

The purpose of our study was to investigate the clinical significance and prognostic role of the systemic immune-inflammation index (SII) in patients who underwent surgical resection for nonfunctioning pancreatic neuroendocrine tumors (pNETs).

METHODS

We conducted a retrospective analysis of 364 patients with nonfunctioning pNETs. The association between the SII level and clinical parameters was investigated. The receiver operating characteristic (ROC) curve was used to calculate the optimal SII value. Cox proportional hazard analysis was performed to evaluate the prognostic factors.

RESULTS

Our study included 364 patients with nonfunctioning pNETs who underwent surgery. The median age was 51.0 (43.0, 59.3), and 164 (45.1%) were male. The optimal threshold of SII determined by ROC analysis was 523.95. Higher SII levels were significantly associated with older age (p = 0.001), sex (p = 0.011), tumor size (p = 0.032), and tumor grade (p = 0.002). Recurrence was observed in 70 (19.2%) patients following a median follow-up of 98 months. Univariate analysis showed that higher SII (p < 0.0001), tumor size >4 cm (p = 0.015), and G2/G3 grade (p = 0.002) were significantly associated with disease-free survival (DFS). Multivariate analysis revealed that higher SII (HR: 7.35; 95% CI: 3.44, 15.70; p < 0.0001) and G2/G3 grade (HR: 3.11; 95% CI: 1.42, 6.82; p = 0.005) remained significantly associated with tumor recurrence. Furthermore, 46 (12.6%) patients died during the follow-up. Higher SII (HR: 8.43; 95% CI: 3.19, 22.72; p < 0.0001) and G2/G3 grade (HR: 3.16; 95% CI: 1.01, 9.86; p = 0.048) were independent predictors of overall survival (OS) by multivariate analysis.

CONCLUSION

In conclusion, our study revealed that a higher SII level was associated with tumor-related features (larger tumor size and advanced grade) and subsequent shorter DFS and OS in patients with nonfunctioning pNETs. These results indicated that the SII could serve as an efficient prognostic biomarker for nonfunctioning pNETs.

Incidence and survival of neuroendocrine neoplasms in China with comparison to the United States

BACKGROUND

Neuroendocrine neoplasms (NENs) are rare tumors characterized by variable biology and delayed diagnosis. However, the nationwide epidemiology of NENs has never been reported in China. We aimed to estimate the incidence and survival statistics of NENs in China, in comparison to those in the United States during the same period.

METHODS

Based on the data from 246 population-based cancer registries covering 272.5 million people of China, we calculated age-specific incidence on NENs in 2017 and multiplied by corresponding national population to estimate the nationwide incidence in China. The data of 22 population-based cancer registries were used to estimate the trends of NENs incidence from 2000 to 2017 through the Joinpoint regression model. We used the cohort approach to analyze the 5-year age-standardized relative survival by sex, age group, and urban-rural area between 2008 and 2013, based on data from 176 high-quality cancer registries. We used data from the Surveillance, Epidemiology, and End Results (SEER) 18 program to estimate the comparable incidence and survival of NENs in the United States.

RESULTS

The overall age-standardized rate (ASR) of NENs incidence was lower in China (1.14 per 100,000) than in the United States (6.26 per 100,000). The most common primary sites were lungs, pancreas, stomach, and rectum in China. The ASRs of NENs incidence increased by 9.8% and 3.6% per year in China and the United States, respectively. The overall 5-year relative survival in China (36.2%) was lower than in the United States (63.9%). The 5-year relative survival was higher for female patients than male patients, and was higher in urban areas than in rural areas.

CONCLUSIONS

The disparities in burden of NENs persist across sex, area, age group, and site in China and the United States. These findings may provide a scientific basis on prevention and control of NENs in the two countries.

Sex Differences in Survival from Neuroendocrine Neoplasia in England 2012–2018: A Retrospective, Population-Based Study

Pre-clinical studies have suggested sex hormone signalling pathways may influence tumorigenesis in neuroendocrine neoplasia (NEN). We conducted a retrospective, population-based study to compare overall survival (OS) between males and females with NEN. A total of 14,834 cases of NEN diagnosed between 2012 and 2018, recorded in England’s National Cancer Registry and Analysis Service (NCRAS), were analysed. The primary outcome was OS with 5 years maximum follow-up. Multivariable analysis, restricted mean survival time and mediation analysis were performed. Appendiceal, pulmonary and early-stage NEN were most commonly diagnosed in females; stomach, pancreatic, small intestinal, colonic, rectal and later-stage NEN were more often diagnosed in males. Females displayed increased survival irrespective of the stage, morphology or level of deprivation. On average, they survived 3.62 (95% CI 1.73–5.90) to 10.26 (6.6–14.45) months longer than males; this was statistically significant in NEN of the lung, pancreas, rectum and stomach (p < 0.001). The stage mediated improved survival in stomach, lung, and pancreatic NEN but not in rectal NEN. The reasons underlying these differences are not yet understood. Overall, females diagnosed with NEN tend to survive longer than males, and the stage at presentation only partially explains this. Future research, as well as prognostication and treatment, should consider sex as an important factor.

PTEN regulates invasiveness in pancreatic neuroendocrine tumors through DUSP19-mediated VEGFR3 dephosphorylation

Background

Phosphatase and tensin homolog (PTEN) is a tumor suppressor. Low PTEN expression has been observed in pancreatic neuroendocrine tumors (pNETs) and is associated with increased liver metastasis and poor survival. Vascular endothelial growth factor receptor 3 (VEGFR3) is a receptor tyrosine kinase and is usually activated by binding with vascular endothelial growth factor C (VEGFC). VEGFR3 has been demonstrated with lymphangiogenesis and cancer invasiveness. PTEN is also a phosphatase to dephosphorylate both lipid and protein substrates and VEGFR3 is hypothesized to be a substrate of PTEN. Dual-specificity phosphatase 19 (DUSP19) is an atypical DUSP and can interact with VEGFR3. In this study, we investigated the function of PTEN on regulation of pNET invasiveness and its association with VEGFR3 and DUSP19.

Methods

PTEN was knocked down or overexpressed in pNET cells to evaluate its effect on invasiveness and its association with VEGFR3 phosphorylation. In vitro phosphatase assay was performed to identify the regulatory molecule on the regulation of VEGFR3 phosphorylation. In addition, immunoprecipitation, and immunofluorescence staining were performed to evaluate the molecule with direct interaction on VEGFR3 phosphorylation. The animal study was performed to validate the results of the in vitro study.

Results

The invasion and migration capabilities of pNETs were enhanced by PTEN knockdown accompanied with increased VEGFR3 phosphorylation, ERK phosphorylation, and increased expression of epithelial–mesenchymal transition molecules in the cells. The enhanced invasion and migration abilities of pNET cells with PTEN knockdown were suppressed by addition of the VEGFR3 inhibitor MAZ51, but not by the VEGFR3-Fc chimeric protein to neutralize VEGFC. VEGFR3 phosphorylation is responsible for pNET cell invasiveness and is VEGFC-independent. However, an in vitro phosphatase assay failed to show VEGFR3 as a substrate of PTEN. In contrast, DUSP19 was transcriptionally upregulated by PTEN and was shown to dephosphorylate VEGFR3 via direct interaction with VEGFR3 by an in vitro phosphatase assay, immunoprecipitation, and immunofluorescence staining. Increased tumor invasion into peripheral tissues was validated in xenograft mouse model. Tumor invasion was suppressed by treatment with VEGFR3 or MEK inhibitors.

Conclusions

PTEN regulates pNET invasiveness via DUSP19-mediated VEGFR3 dephosphorylation. VEGFR3 and DUSP19 are potential therapeutic targets for pNET treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-022-00875-2.

Changes in Survival Outcomes of Patients With Neuroendocrine Neoplasms Over the Past 15 Years: A Real-World Study

BACKGROUND

The past 2 decades have observed a number of advances in therapeutic approaches to patients with neuroendocrine neoplasms (NENs). This study aims to assess whether survival outcomes have changed among patients with NENs over the past 15 years, in a real-world, population-based study.

MATERIALS AND METHODS

We accessed administrative databases within the province of Alberta, Canada, and we reviewed patients with invasive NENs diagnosed 2004 to 2019. Patients were classified according to the year of diagnosis into 3 groups: 2004 to 2008; 2009 to 2013; and 2014 to 2019. Kaplan-Meier survival estimates were used to compare overall survival (OS) according to different baseline characteristics (including the year of diagnosis). Multivariable Cox regression modeling was used to examine factors associated with the risk of death in this cohort.

RESULTS

We included a total of 3431 patients in the study cohort. Using multivariable Cox regression analysis, the following factors were associated with worse survival: older age at diagnosis (hazard ratio [HR]: 3.45; 95% CI [confidence interval]: 2.74-4.35), male sex (HR: 1.38; 95% CI: 1.21-1.56), lung primary site (HR for lung vs. appendicular primary: 1.39; 95% CI: 1.01-1.92), Stage 4 disease (HR: 2.80; 95% CI: 2.38-3.30), South zone of the province (HR for South zone vs. Calgary zone: 1.85; 95% CI: 1.49-2.30), and higher comorbidity index (HR for ≥3 vs. 0: 2.66; 95% CI: 2.19-3.24). Although Kaplan-Meier method showed significant difference in OS according to diagnosis period, multivariable regression model showed that the period of diagnosis did not appear to impact OS (HR for diagnosis period 2004 to 2009 vs. 2014 to 2019: 1.04; 95% CI: 0.89-1.22).

CONCLUSIONS

Over the study period (2004 to 2019), patients diagnosed during later periods did not appear to experience better OS compared with patients diagnosed at an earlier time.

Non-functional pancreatic neuroendocrine tumours: ATRX/DAXX and alternative lengthening of telomeres (ALT) are prognostically independent from ARX/PDX1 expression and tumour size

OBJECTIVE

Recent studies have found aristaless-related homeobox gene (ARX)/pancreatic and duodenal homeobox 1 (PDX1), alpha-thalassemia/mental retardation X-linked (ATRX)/death domain-associated protein (DAXX) and alternative lengthening of telomeres (ALT) to be promising prognostic biomarkers for non-functional pancreatic neuroendocrine tumours (NF-PanNETs). However, they have not been comprehensively evaluated, especially among small NF-PanNETs (≤2.0 cm). Moreover, their status in neuroendocrine tumours (NETs) from other sites remains unknown.

DESIGN

An international cohort of 1322 NETs was evaluated by immunolabelling for ARX/PDX1 and ATRX/DAXX, and telomere-specific fluorescence in situ hybridisation for ALT. This cohort included 561 primary NF-PanNETs, 107 NF-PanNET metastases and 654 primary, non-pancreatic non-functional NETs and NET metastases. The results were correlated with numerous clinicopathological features including relapse-free survival (RFS).

RESULTS

ATRX/DAXX loss and ALT were associated with several adverse prognostic findings and distant metastasis/recurrence (p<0.001). The 5-year RFS rates for patients with ATRX/DAXX-negative and ALT-positive NF-PanNETs were 40% and 42% as compared with 85% and 86% for wild-type NF-PanNETs (p<0.001 and p<0.001). Shorter 5-year RFS rates for ≤2.0 cm NF-PanNETs patients were also seen with ATRX/DAXX loss (65% vs 92%, p=0.003) and ALT (60% vs 93%, p<0.001). By multivariate analysis, ATRX/DAXX and ALT status were independent prognostic factors for RFS. Conversely, classifying NF-PanNETs by ARX/PDX1 expression did not independently correlate with RFS. Except for 4% of pulmonary carcinoids, ATRX/DAXX loss and ALT were only identified in primary (25% and 29%) and NF-PanNET metastases (62% and 71%).

CONCLUSIONS

ATRX/DAXX and ALT should be considered in the prognostic evaluation of NF-PanNETs including ≤2.0 cm tumours, and are highly specific for pancreatic origin among NET metastases of unknown primary.

Sex-based differences in the outcomes of patients with lung carcinoids

Objective: To assess the impact of sex on the outcomes of patients with well-differentiated lung neuroendocrine neoplasms in a real-world setting. Methods: The Surveillance, Epidemiology and End Results Research Plus database (2000-2018) was accessed, and patients with a diagnosis of typical or atypical carcinoid of the lung were reviewed. Trends in age-standardized rates (per 100,000) of the incidence of lung carcinoid tumors were reviewed among male and female patients as well as the overall population, and annual percent change (APC) was determined for the three groups. Multivariate Cox regression analysis was then used to assess the factors associated with overall and cancer-specific survival. Results: Among all patients, APC (2000-2018) for lung carcinoid diagnosis was 2.9 (95% CI: 2.4-3.5). Among male patients, APC (2000-2018) for lung carcinoid diagnosis was 1.8 (95% CI: 1.2-2.5). By contrast, among female patients, APC (2000-2018) for lung carcinoid diagnosis was 3.4 (95% CI: 2.8-4.1). Based on Kaplan-Meier survival estimates, female sex was associated with better overall survival compared with male sex (p < 0.001). Based on multivariate Cox regression analysis, the following factors were associated with worse cancer-specific survival: older age (hazard ratio [HR]: 1.036; 95% CI: 1.031-1.041), atypical carcinoid histology (HR: 3.10; 95% CI: 2.71-3.56), stage (distant vs localized stage HR: 4.05; 95% CI: 3.48-4.71), sex (male vs female sex HR: 1.76; 95% CI: 1.56-1.99) and no surgical treatment (HR: 3.77; 95% CI: 3.22-4.42). Conclusion: Female patients with lung carcinoid tumors have better overall survival compared with male patients, particularly among patients with typical carcinoid tumors.

Combined analysis of PTEN, HER2, and hormone receptors status: remodeling breast cancer risk profiling

BACKGROUND

Phosphatase and tensin homolog (PTEN) loss is associated with tumorigenesis, tumor progression, and therapy resistance in breast cancer. However, the clinical value of PTEN as a biomarker in these patients is controversial. We sought to determine whether the benefit of traditional biomarkers testing is improved by the analysis of PTEN status for the identification of high-risk breast cancer.

METHODS

A cohort of 608 patients with breast cancer was included in this study. Based on the expression on the neoplastic cells compared to the normal internal controls by immunohistochemistry (IHC), cases were classified as PTEN-low (PTEN-L) or PTEN-retained (PTEN-WT). The former constituted the study group, while the latter the control group. Analysis of gene expression was performed on publicly available genomic data and included 4265 patients from the METABRIC and MSK cohorts retrieved from cBioPortal. The Shapiro-Wilk test was used to analyze the normal distributions of continuous variables. Relationships between PTEN status and the clinicopathologic and molecular features of the patient population were assessed using Fisher's exact test or Chi-squared/Wilcoxon rank-sum test. Survival curves were built according to the Kaplan-Meier method.

RESULTS

Alteration in PTEN status was significantly different at protein and gene levels, where the reduced protein expression was observed in 280/608 cases (46.1%) from our group, while genetic aberrations in only 315/4265 (7.4%) cases of the METABRIC and MSK cohorts. PTEN-L tumors were significantly enriched for hormone receptors (HR) and HER2 negativity (n = 48, 17.1%) compared to PTEN-WT tumors (n = 22, 6.7%; p = 0.0008). Lack of HR with or without HER2 overexpression/amplification was significantly associated with worse overall survival (OS) in PTEN-L but not in PTEN-WT breast cancers (p < .0001). Moreover, PTEN-L protein expression but not gene alterations was related to the outcome, in terms of both OS and disease-free survival (p = 0.002).

CONCLUSIONS

The combined analysis of PTEN, HER2, and HR status offers relevant information for a more precise risk assessment of patients with breast cancer.

Sex-Based Differences in Prognosis of Patients With Gastroenteropancreatic-Neuroendocrine Neoplasms: A Population-Based Study

OBJECTIVES

The aim of this study was to assess sex-based differences in prognosis of a contemporary cohort of gastroenteropancreatic-neuroendocrine neoplasm (GEP-NEN) patients.

METHODS

Surveillance, Epidemiology, and End Results database was accessed, and cases with GEP-NENs were selected. Rates of GEP-NEN diagnosis from 1975 to 2016 for both male patients and female patients were reviewed. Survival outcomes of GEP-NEN patients diagnosed from 2010 to 2014 were determined through Kaplan-Meier estimates and multivariable Cox regression analysis. Overall survival analyses were stratified by stage and histology.

RESULTS

A total of 20,836 GEP-NEN patients were diagnosed from 2010 to 2014, and they were included in the current analysis. These include 10,336 male patients and 10,500 female patients. Annual percent change for the age-adjusted rate for GEP-NENs in the United States (1975-2016) is 5.0 (95% confidence interval [CI], 4.8-5.2). When stratified by sex, annual percent change for male patients was 4.8 (95% CI, 4.6-5.1), whereas for female patients, it was 5.0 (95% CI, 4.8-5.3). Female patients have better overall survival compared with male patients among all substrata of patients (according to stage, histology, and differentiation) (P for all comparisons <0.01).

CONCLUSIONS

Female sex seems to be associated with better overall survival among patients with GEP-NENs. It is unclear if this is the result of differences in noncancer mortality or is the result of inherent biological differences.

Evolution of the Mesenteric Mass in Small Intestinal Neuroendocrine Tumours

Simple Summary

Around two-thirds of patients with small intestinal neuroendocrine tumours are present with a metastatic mesenteric mass. This mass is known to cause intestinal complications, however, little is known on its development over time in the era of targeted therapy. Therefore, we conducted a retrospective study to assess the growth and response to therapy. We found that the growth of the mesenteric mass was detectable in 13.5% over a median time of 3.4 years and peptide receptor radionuclide therapy resulted in size reduction in only 3.8%. This site-specific static growth behavior is important to note when assessing disease progression and therapeutic options.

Abstract

Background: A metastatic mesenteric mass is a hallmark of small intestinal neuroendocrine tumours (SI-NETs). However, little is known on its development over time. Therefore, we conducted a study to assess the evolution of a SI-NET-associated mesenteric mass over time. Methods: Retrospectively, 530 patients with proven SI-NET were included. The presence and growth of a mesenteric mass was assessed using RECIST 1.1 criteria on every consecutive CT-scan until the end of follow-up or resection. Results: At baseline, a mesenteric mass was present in 64% of the patients, of whom 13.5% showed growth of the mesenteric mass with a median time to growth of 40 months. Male gender was the only independent predictor of growth (OR 2.67). Of the patients without a mesenteric mass at the first evaluation, 2.6% developed a pathological mesenteric mass. Treatment with peptide receptor radionuclide therapy (PRRT; N = 132) resulted in an objective size reduction of the mesenteric mass in 3.8%. Conclusion: The metastatic mesenteric mass in SI-NETs has a static behavior over time. Therefore, site-specific growth behavior should be taken into account when selecting target lesions and assessing disease progression and therapeutic response. PRRT appears not to be effective for size reduction of the mesenteric mass.

A Real-World, Population-Based Study for the Incidence and Outcomes of Neuroendocrine Neoplasms of Unknown Primary

OBJECTIVE

The aim of the study was to provide a real-world, population-based assessment of the incidence and outcomes of neuroendocrine neoplasms (NENs) of unknown primary.

METHODS

Surveillance, Epidemiology, and End Results registry was accessed, and cases with NENs of unknown primary were reviewed. Rates of NENs diagnosis 1975-2017 according to primary tumor site were also reviewed. Survival outcomes of patients with NENs of unknown primary compared to metastatic NENs with known primary were determined through Kaplan-Meier estimates and multivariable Cox regression analysis. Overall and cancer-specific survival analyses were stratified by primary site and histology (neuroendocrine tumor vs. neuroendocrine carcinoma).

RESULTS

A total of 3,550 cases (7%) were diagnosed with NENs of unknown primary within the study duration. The annual percent change for NENs of unknown primary was 3.4 (95% CI: 2.6-4.2). Within the cohort of metastatic neuroendocrine tumor patients (carcinoid tumor histology), the following factors were associated with a lower risk of death; younger age (HR: 0.477; 95% CI: 0.443-0.513), female sex (HR: 0.922; 95% CI: 0.860-0.989), and small intestinal primary (HR for unknown primary vs. small intestinal primary: 1.532; 95% CI: 1.408-1.668). Within the cohort of metastatic neuroendocrine carcinoma, the following factors were associated with a lower risk of death in this cohort; younger age (HR: 0.646; 95% CI: 0.612-0.681), female sex (HR: 0.843; 95% CI: 0.801-0.888), and small intestinal primary (HR for unknown primary vs. small intestinal primary: 2.961; 95% CI: 2.586-3.391).

CONCLUSIONS

The diagnosis of NENs of unknown primary has increased across the past 4 decades. Outcomes of individuals with metastatic small intestinal NENs seem to be better than those with metastatic NENs of unknown primary (for both carcinoid tumors and neuroendocrine carcinomas).

Comprehensive Genomic Profiling of Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs)

PURPOSE

GEP-NENs are rare malignancies with increasing incidence. Their molecular characteristics are still undefined. We explored the underlying biology of GEP-NENs and the differences between gastrointestinal (GI) and pancreatic (PNEN), high-grade (HG), and low-grade (LG) tumors.

EXPERIMENTAL DESIGN

GEP-NENs were analyzed using next-generation sequencing (NGS; MiSeq on 47 genes, NextSeq on 592 genes), IHC, and in situ hybridization. Tumor mutational burden (TMB) was calculated on the basis of somatic nonsynonymous missense mutations, and microsatellite instability (MSI) was evaluated by NGS of known MSI loci.

RESULTS

In total, 724 GEP-NENs were examined: GI (N = 469), PNEN (N = 255), HG (N = 135), and LG (N = 335). Forty-nine percent were female, and median age was 59. Among LG tumors, the most frequently mutated genes were ATRX (13%), ARID1A (10%), and MEN1 (10%). HG tumors showed TP53 (51%), KRAS (30%), APC (27%), and ARID1A (23%). Immune-related biomarkers yielded a lower prevalence in LG tumors compared with HG [MSI-H 0% vs. 4% (P = 0.04), PD-L1 overexpression 1% vs. 6% (P = 0.03), TMB-high 1% vs. 7% (P = 0.05)]. Compared with LG, HG NENs showed a higher mutation rate in BRAF (5.4% vs. 0%, P < 0.0001), KRAS (29.4% vs. 2.6%, P < 0.0001), and PI3KCA (7% vs. 0.3%, P < 0.0001). When compared with GI, PNEN carried higher frequency of MEN1 (25.9% vs. 0.0%, P < 0.0001), FOXO3 (8.6% vs. 0.8%, P = 0.005), ATRX (20.6% vs. 2.0%, P = 0.007), and TSC2 (6.3% vs. 0.0%, P = 0.007), but lower frequency of mutations in APC (1.0% vs. 13.8%, P < 0.0001).

CONCLUSIONS

Significant molecular differences were observed in GEP-NENs by tumor location and grade, indicating differences in carcinogenic pathways and biology.

Pancreatic Neuroendocrine Neoplasms: Does Sex Matter?

Genetic and molecular disparities between men and women have a role in the differing incidence, pathophysiology, clinical signs, and treatment outcome of several cancers. Sex differences in cancer incidence are attributed to regulation at the genetic/molecular level and to sex hormones that in turn modulate gene expression in various cancers. Sex differences in the incidence of cancer, its aggressiveness, and the disease prognosis have been reported for several types of cancer but little is known for pancreatic neuroendocrine neoplasms (PNENs). The aim of this Opinion article is to provide an overview of sex differences in PNENs in terms of epidemiology, pathophysiology, treatment responses, prognosis, and survival. This overview might allow better tailoring of the management of PNENs.

Intratumoral Fibrosis and Tumor Growth Pattern as Prognostic Factors in Optimally Resected Pancreatic Neuroendocrine Neoplasms: An Analysis of 168 Cases

OBJECTIVES

Pancreatic neuroendocrine neoplasms (PanNENs) can recur after curative resection. We sought to establish the significance of tumor fibrosis and tumor growth pattern as predictors of recurrence-free survival and overall survival.

METHODS

A retrospective query of an institutional surgical database was performed from 2000 to 2018 to identify optimally resected PanNENs. All eligible slides were reviewed by an experienced gastrointestinal pathologist for established histopathologic prognostic factors, as well as fibrosis and tumor growth pattern. We evaluated the effect of the interested variables through Cox proportional hazards models.

RESULTS

One hundred sixty-eight cases were considered. The majority of patients (90%) had grade 1 or 2 tumors, 46% showed significant fibrosis, and 22% demonstrated an infiltrative growth pattern. Twenty-one percent of patients had a recurrence. In multivariable analysis, lymphovascular invasion with a hazard ratio (HR) of 5.1 and infiltrative growth pattern (HR, 2.8) were significantly associated with increased risk of recurrence and increased risk of death (HR, 3.6 and 2.7, respectively). There was a significant decrease in recurrence-free survival and overall survival for fibrosis and infiltrative growth pattern.

CONCLUSIONS

In optimally resected PanNENs, the presence of fibrosis and infiltrative growth pattern are significant risk factors for recurrence and/or decreased survival.

Triple-high expression of phosphatase and tensin homolog (PTEN), estrogen receptor (ER) and progesterone receptor (PR) may predict favorable prognosis for patients with Type I endometrial carcinoma

Endometrial carcinoma (EC) is the most common malignant tumors in female derived from the endometrial epithelium. Several previous studies have described estrogen receptors (ER), progesterone Receptor (PR) and phosphatase and tensin homolog (PTEN) are associated with clinicopathological factors and prognosis in EC patients. However, during EC patients follow-up, we found that some EC patients with down-regulation of PTEN, but up-regulation of ER or PR , and some EC patients with down-regulation of ER or PR, but up-regulation of PTEN also had a poor prognosis. Therefore, to reveal the prognosis of EC patients with different phenotypes based on PTEN, ER and PR expression, 120 cases formalin-fixed paraffin-embedded EC tissues and 543 cases uterine corpus endometrial carcinoma (UCEC) patients from the cancer genome atlas (TCGA) UCEC datasets were analyzed. Results showed that EC tissues can be classified to PTEN^LER^LPR^L, PTEN^HER^LPR^L, PTEN^HER^HPR^H, PTEN^LER^HPR^H, PTEN^HER^HPR^L, PTEN^HER^LPR^H, and PTEN^LER^HPR^L phenotypes basing on IHC analysis. Additionally, EC patients with PTEN^LER^LPR^L showed high malignancy, while patients with PTEN^HER^HPR^H showed low malignancy. Therefore, combined detection of PTEN, ER, PR may help identify a small subset of EC with more aggressive behavior and may aid in risk stratification.

Prognostic and predictive factors on overall survival and surgical outcomes in pancreatic neuroendocrine tumors: recent advances and controversies

Introduction: Recent advances in diagnostic modalities and therapeutic agents have raised the importance of prognostic factors in predicting overall survival, as well as predictive factors for surgical outcomes, in tailoring therapeutic strategies of patients with pancreatic neuroendocrine neoplasms (panNENs).Areas covered: Numerous recent studies of panNEN patients report the prognostic values of a number of clinically related factors (clinical, laboratory, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors on long-term survival. In addition, an increasing number of studies showed the usefulness of various factors, specifically biomarkers and molecular makers, in predicting recurrence and mortality related to surgical treatment. Recent findings (from the last 3 years) in each of these areas, as well as recent controversies, are reviewed.Expert commentary: The clinical importance of prognostic and predictive factors for panNENs is markedly increased for both overall outcome and post resection, as a result of recent advances in all aspects of the diagnosis, management and treatment of panNENs. Despite the proven prognostic utility of routinely used tumor grading/classification and staging systems, further studies are required to establish these novel prognostic factors to support their routine clinical use.

Prognostic value of progesterone receptor in solid pseudopapillary neoplasm of the pancreas: evaluation of a pooled case series

Background

The role of progesterone receptor (PR) has been reported in a series of pancreatic cysts. However, the relationship between PR and prognosis of solid pseudopapillary neoplasm of the pancreas (SPNP) has not been elucidated so far. The aim of our study was to evaluate the prognostic value of PR in SPNP.

Methods

A total of 76 patients with SPNP treated in our institution from January 2012 to December 2017 were included. Demographic parameters, laboratory data, pathologic information and clinical outcomes were analyzed by the use of survival analysis. In addition, a pooled case series was performed to evaluate the results.

Results

The institutional data included 76 patients (17 male and 59 female) ranging from 8 to 90 years (median, 30 years) in age. Kaplan-Meier survival analysis confirmed negative PR result was significantly associated with poorer disease-free survival (DFS) and disease-specific survival (DSS) (both P < 0.001). In the pooled analysis, a total of 62 studies comprising 214 patients with SPNP were included. After multivariable cox analysis, negative PR result remained an independent prognostic factor for SPNP (DFS HR: 14.50, 95% CI: 1.98–106.05, P = 0.008; DSS HR: 9.15, 95% CI: 1.89–44.17, P = 0.006).

Conclusion

Our results indicated the role of PR in predicting adverse outcome of patients with SPNP and negative PR result may serve as a potential prognostic factor.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0914-8) contains supplementary material, which is available to authorized users.

Evaluation of endometrial carcinoma prognostic immunohistochemistry markers in the context of molecular classification

Molecular subclassification of endometrial carcinoma (EC) with Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) identifies four subtypes [DNA polymerase epsilon (POLE) mutant, mismatch repair‐deficient, p53 wild‐type (wt), and p53 abnormal]. The aim of this study was to evaluate additional EC biomarkers in the context of these subtypes. Tissue microarrays encompassing 460 previously characterized ECs were assessed for L1‐cell adhesion molecule (L1CAM), progesterone receptor (PR), estrogen receptor (ER) alpha, stathmin, and phosphatase and tensin homolog (PTEN), by immunohistochemistry (IHC). Associations with clinicopathological parameters, molecular subtype, and outcomes were determined. About 413 ECs (75% endometrioid, >15% serous) had complete data. L1CAM overexpression was found in 16%, associated with older age, lower body mass index (BMI), advanced stage, grade 3 (97%), non‐endometrioid histology (84%), deep myometrial invasion, lymphovascular space invasion (LVSI), and ER‐negative, PR‐negative status. Tumours overexpressing L1CAM were associated with poor outcomes {hazard ratio (HR) [95% confidence interval (CI)] 3.35 [2.10–5.23] for disease‐specific survival [DSS], p < 0.0001}. PR positivity was associated with younger women, higher BMI, early stage (77% stage I), low grade (61%), endometrioid histology (90%) without LVSI or nodal disease, ER positivity (90%), p53wt tumours (55%), and favourable outcomes [HR (CI) 0.39 (0.25–0.62) for DSS, p < 0.0001]. ER positive tumours were early stage (73%), low grade, endometrioid histology, with improved DSS. Stathmin and PTEN IHC were not associated with outcomes. There was minimal agreement between IHC and mutation status for PTEN. L1CAM overexpression was significantly associated with the p53 abnormal molecular subtype, which accounted for more than 70% of the tumours overexpressing L1CAM. PR expression also correlated with molecular subtype, with most PR negative tumours being p53 abnormal. Multivariable analysis demonstrated that only ProMisE subtype [overall survival (OS), DSS, and progression‐free survival] and age (OS only) maintained an association with outcomes. The prognostic significance of the single biomarkers tested could be explained based on their being covariable with the ProMisE molecular subtype.

The regulatory role of aberrant Phosphatase and Tensin Homologue and Liver Kinase B1 on AKT/mTOR/c-Myc axis in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumor (pNET) is an uncommon type of pancreatic neoplasm. Low Phosphatase and Tensin Homologue (PTEN) expression and activation of the mechanistic target of rapamycin (mTOR) pathway have been noted in pNETs, and the former is associated with poor survival in pNET patients. Based on the results of the RADIANT-3 study, everolimus, an oral mTOR inhibitor, has been approved to treat advanced pNETs. However, the exact regulatory mechanism for the mTOR pathway in pNETs remains largely unknown. PTEN and liver kinase B1 (LKB1) are well-known for their regulatory role in the mTOR pathway. We evaluated the expression of PTEN and LKB1 in 21 pNET patients, and low PTEN and LKB1 expression levels were noted in 48% and 24% of the patients, respectively. Loss of PTEN and LKB1 synergistically promoted cell proliferation of pNET, attenuated the sensitivity of cells to mTOR inhibitors and enhanced c-Myc expression, which back-regulated PTEN, AKT, mTOR and its downstream effectors. For pNET cells with low expression levels of PTEN and LKB1, silencing the expression of c-Myc by shRNA reduced their proliferative rate, while adding either c-Myc inhibitor or AMP-activated protein kinase activator reversed their resistance to mTOR inhibitors in vitro and in vivo. Furthermore, high c-Myc expression was subsequently identified in 81% of pNETs, suggesting that up-regulation of c-Myc expression in pNETs may occur through PTEN/LKB1-dependent and PTEN/LKB1-independent regulation. The results delineated the regulation of PTEN and LKB1 on the AKT/mTOR/c-Myc axis and suggested that both c-Myc and mTOR are potential therapeutic targets for pNET.

Loss of Progesterone Receptor Expression Is an Early Tumorigenesis Event Associated with Tumor Progression and Shorter Survival in Pancreatic Neuroendocrine Tumor Patients

Background

Pancreatic neuroendocrine tumors (PanNETs) are the second most common pancreatic neoplasms and there is no well-elucidated biomarker to stratify their detection and prognosis. Previous studies have reported that progesterone receptor (PR) expression status was associated with poorer survival in PanNET patients.

Methods

To validate previous studies, PR protein expression was assessed in 21 neuroendocrine microadenomas and 277 PanNETs and compared with clinicopathologic factors including patient survival.

Results

PR expression was gradually decreased from normal islets (49/49 cases, 100%) to neuroendocrine microadenoma (14/21, 66.6%) to PanNETs (60/277, 21.3%; p < .001). PanNETs with loss of PR expression were associated with increased tumor size (p < .001), World Health Organization grade (p = .001), pT classification (p < .001), perineural invasion (p = .028), lymph node metastasis (p = .004), activation of alternative lengthening of telomeres (p = .005), other peptide hormonal expression (p < .001) and ATRX/DAXX expression (p = .015). PanNET patients with loss of PR expression (5-year survival rate, 64.1%) had significantly poorer recurrence-free survival outcomes than those with intact PR expression (90%) by univariate (p = .012) but not multivariate analyses. Similarly, PanNET patients with PR expression loss (5-year survival rate, 76%) had significantly poorer overall survival by univariate (p = .015) but not multivariate analyses.

Conclusions

Loss of PR expression was noted in neuroendocrine microadenomas and was observed in the majority of PanNETs. This was associated with increased grade, tumor size, and advanced pT and pN classification; and was correlated with decreased patient survival time by univariate but not multivariate analyses. Loss of PR expression can provide additional information on shorter disease-free survival in PanNET patients.

Recent Updates on Neuroendocrine Tumors From the Gastrointestinal and Pancreatobiliary Tracts

CONTEXT

-Gastrointestinal (GI) and pancreatobiliary tracts contain a variety of neuroendocrine cells that constitute a diffuse endocrine system. Neuroendocrine tumors (NETs) from these organs are heterogeneous tumors with diverse clinical behaviors. Recent improvements in the understanding of NETs from the GI and pancreatobiliary tracts have led to more-refined definitions of the clinicopathologic characteristics of these tumors. Under the 2010 World Health Organization classification scheme, NETs are classified as grade (G) 1 NETs, G2 NETs, neuroendocrine carcinomas, and mixed adenoneuroendocrine carcinomas. Histologic grades are dependent on mitotic counts and the Ki-67 labeling index. Several new issues arose after implementation of the 2010 World Health Organization classification scheme, such as issues with well-differentiated NETs with G3 Ki-67 labeling index and the evaluation of mitotic counts and Ki-67 labeling. Hereditary syndromes, including multiple endocrine neoplasia type 1 syndrome, von Hippel-Lindau syndrome, neurofibromatosis 1, and tuberous sclerosis, are related to NETs of the GI and pancreatobiliary tracts. Several prognostic markers of GI and pancreatobiliary tract NETs have been introduced, but many of them require further validation.

OBJECTIVE

-To understand clinicopathologic characteristics of NETs from the GI and pancreatobiliary tracts.

DATA SOURCES

-PubMed (US National Library of Medicine) reports were reviewed.

CONCLUSIONS

-In this review, we briefly summarize recent developments and issues related to NETs of the GI and pancreatobiliary tracts.

Progesterone inhibits proliferation and modulates expression of proliferation-Related genes in classical progesterone receptor-negative human BxPC3 pancreatic adenocarcinoma cells

Recent studies suggest that progesterone may possess anti-tumorigenic properties. However, a growth-modulatory role of progestins in human cancer cells remains obscure. With the discovery of a new class of membrane progesterone receptors (mPRs) belonging to the progestin and adipoQ receptor gene family, it becomes important to study the effect of this hormone on proliferation of tumor cells that do not express classical nuclear progesterone receptors (nPRs). To identify a cell line expressing high levels of mPRs and lacking nPRs, we examined mRNA levels of nPRs and three forms of mPRs in sixteen human tumor cell lines of different origin. High expression of mPR mRNA has been found in pancreatic adenocarcinoma BxPC3 cells, while nPR mRNA has not been detected in these cells. Western blot analysis confirmed these findings at the protein level. We revealed specific binding of labeled progesterone in these cells with affinity constant similar to that of human mPR expressed in yeast cells. Progesterone at high concentration of 20 μM significantly reduced the mRNA levels of proliferation markers Ki67 and PCNA, as well as of cyclin D1, and increased the mRNA levels of cyclin dependent kinase inhibitors p21 and p27. Progesterone (1 μM and 20 μM) significantly inhibited proliferative activity of BxPC3 cells. These results point to anti-proliferative effects of the progesterone high concentrations on BxPC3 cells and suggest that activation of mPRs may mediate this action. Our data are a starting point for further investigations regarding the application of progesterone in pancreatic cancer.

A retrospective cohort study of pancreatic neuroendocrine tumors at single institution over 15 years: New proposal for low- and high-grade groups, validation of a nomogram for prognosis, and novel follow-up strategy for liver metastases

PURPOSE

Pancreatic neuroendocrine tumors (PNETs) exhibit various tumor behaviors and symptoms that are difficult for physicians to stage and predict prognosis. We assess prognostic factors combined with staging classifications to optimal the models and try to improve follow-up strategy to monitor liver metastases after surgery.

METHODS

Patients with PNETs treated at Sun Yat-sen Memorial Hospital between 2000 and 2015 were recruited. Patients were regrouped on the basis of functional status and mitotic rates. Nomograms to predict the prognostic values of classifications (AJCC, ENETS, and WHO) were constructed; the accuracy of the nomograms were quantified by the C-index and calibration plots.

RESULTS

We identified 78 PNETs patients with pathological reports. Correlations with OS in univariate analysis included nonfunctional status (P = 0.002), CgA>200 ng/ml (P < 0.001), Ki-67 (3-20%, P = 0.014; >20%, P < 0.001), and mitotic rate (3-20/10HPF, P = 0.011; >20/10HPF, P < 0.001). By multivariate analysis, nonfunctional status and mitotic rate maintained significance (P = 0.039; 3-20/10HPF, P = 0.015; >20/10HPF, P = 0.007). Evaluating the new proposed system, the difference in OS between low- and high-groups was statistically significant (P = 0.001). The C-index of the regrouped nomograms were higher than that of premise ones (AJCC cohort, 0.605 v 0.576, P < 0.01; ENETS cohort, 0.73 v 0.691, P < 0.01; WHO cohort, 0.678 v 0.603, P < 0.01).

CONCLUSION

An prognostic model based on mitotic rates and functional status correlates strongly with survival. PNETs should return visits every 2 months for the first half years, and every 3 months as followed until 2 years after surgery.

Malignant Solitary Fibrous Tumor of the Pancreas

Solitary fibrous tumor (SFT) arising in the pancreas is exceedingly rare, with only 11 cases reported in the English literature. All cases described thus far have exhibited benign histology. We report the first case of malignant SFT of the pancreas. The patient was a 52-year-old woman who presented with obstructive jaundice and a 15-cm pancreatic head mass. The mass showed areas with typical histologic features for SFT including small fibroblastlike cells arranged in the well-characterized "patternless pattern" of architecture, hemangiopericytomalike vessels, areas with dense collagen and infrequent mitoses (0-2 per 10 high-power fields [HPFs]). In addition, multiple areas with an overtly sarcomatous morphology were present, containing large spindle and epithelioid cells with nuclear pleomorphism, marked cellularity, up to17 mitoses per 10 HPFs, and necrosis. Immunohistochemical stains were positive for CD34 and B-cell CLL/lymphoma 2 (Bcl-2) in both benign and malignant components and showed strong, diffuse p53 and p16 staining in the malignant component. At last follow-up (40 months), the patient was alive and well without evidence of disease. However, given that the presence of a malignant component in extrapancreatic SFT has been associated with recurrence/metastasis and death, complete surgical resection and close long-term follow-up is required.

Phase I study of the anti-IGF1R antibody cixutumumab with everolimus and octreotide in advanced well-differentiated neuroendocrine tumors

Preclinical data suggest multiple roles for the IGF1 receptor (IGF1R) in neuroendocrine tumors (NETs), including mediating resistance to mammalian target of rapamycin (mTOR) inhibitors. Everolimus, an oral mTOR inhibitor, and octreotide long-acting repeatable (LAR) are approved for subgroups of well-differentiated NET. The primary objective of the present study was to establish the safety and recommended phase II dose (RP2D) of cixutumumab, a monoclonal antibody (MAB) against IGF1R, with everolimus and octreotide LAR. Patients with well-differentiated NET were treated with 10  mg everolimus p.o. daily, 20  mg octreotide LAR i.m. every 21 days, and escalating doses of cixutumumab. An expansion cohort was enrolled at RP2D. Correlative studies included the evaluation of mTOR pathway inhibition in paired tumor biopsies and the effects of this combination on metabolism via indirect calorimetry. Nineteen patients with progressive disease were enrolled, including nine to the expansion portion. Two patients had dose-limiting toxicities of grade 3 mucositis at 15  mg/kg cixutumumab. Long-term tolerance at RP2D was problematic, and the most common ≥grade 3 adverse event was fatigue. One patient with metastatic insulinoma had a confirmed partial response, whereas 17 had stable disease. The median progression-free survival was 43.6 weeks, and the median overall survival was 25.5 months. The RP2D of this combination per the predefined study protocol of 10  mg/kg cixutumumab i.v., 20  mg octreotide LAR i.m. every 21 days plus 10  mg everolimus p.o. daily is associated with non-dose-limiting toxicities that limit long-term tolerance. Although a signal of activity was noted in the present study, this will need to be reconciled with limited tolerance of the combination and data from larger studies of anti-IGF1R MABs in NET that have been disappointing.

miR-181c promotes proliferation via suppressing PTEN expression in inflammatory breast cancer

Primary inflammatory breast cancer (IBC) accounts for ~6% of new breast cancer cases. Even with multimodality treatment, the 5-year disease-free survival is <45%, thus making IBC the most deadly form of locally advanced breast cancer. Better understanding of the pathogenesis of IBC is essential to the design of effective therapy. We found that miR-181c was upregulated in IBC, implying that it could be a useful prognostic marker for IBC and a novel therapeutic target for the intervention of disease. Elucidating why the gene is overexpressed and how to downregulate it will help us to further understand the pathogenesis and progression of the disease and offer new targets for therapies. In this study, we showed that miR-181c as an oncogene promoted proliferation and it inhibited PTEN protein expression by targeting 3'-UTR of PTEN mRNA in IBC SUM149 cells. Moreover, PTEN was not only downregulated in IBC, but also inhibited proliferation in SUM149 cells and introduction of PTEN cDNA lacking the predicted sites of 3'-UTR abrogated miR-181c cellular function, suggesting that miR-181c inhibited proliferation by downregulating PTEN expression in IBC. Thus, targeting miR-181c and restoration of PTEN can be used in conjunction with other therapies to prevent progression of IBC.

miR-494-3p Regulates Cellular Proliferation, Invasion, Migration, and Apoptosis by PTEN/AKT Signaling in Human Glioblastoma Cells

Malignant gliomas are the most common primary brain tumors, and the molecular mechanisms involving their progression and recurrence are still largely unclear. Substantial data indicate that the oncogene miR-494-3p is significantly elevated in gliomas, but the molecular functions of miR-494-3p in gliomagenesis are largely unknown. The present study aimed to explore the role of miR-494-3p and its molecular mechanism in human brain gliomas, malignant glioma cell lines, and cancer stem-like cells. The expression level of miR-494-3p in 48 human glioma issues and 8 normal brain tissues was determined using stem-loop real-time polymerase chain reaction (PCR). To study the function of miR-494-3p inhibitor in glioma cells, the miR-494-3p inhibitor lentivirus was used to transfect glioma cells. Transwell invasion system was used to estimate the effects of miR-494-3p inhibitor on the invasiveness of glioma cells. A mouse model was used to test the effect of miR-494-3p inhibitor on glioma proliferation and invasion in vivo. Results showed that the expression of miR-494-3p in human brain glioma tissues was higher than in normal brain tissues. Downregulated expression of miR-494-3p can inhibit the invasion and proliferation and promote apoptosis in glioma cells. Quantitative reverse transcription PCR and Western blotting analysis revealed that the expression of PTEN was increased after downexpression of miR-494-3p in glioma cells (U87 and U251). miR-494-3p inhibitor could prevent migration, invasion, proliferation, and promote apotosis in gliomas through PTEN/AKT pathway. Therefore, the study results have shown that miR-494-3p may act as a therapeutic target in gliomas.

The PI3K/Akt Pathway in Tumors of Endocrine Tissues

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is a key driver in carcinogenesis. Defects in this pathway in human cancer syndromes such as Cowden's disease and Multiple Endocrine Neoplasia result in tumors of endocrine tissues, highlighting its importance in these cancer types. This review explores the growing evidence from multiple animal and in vitro models and from analysis of human tumors for the involvement of this pathway in the following: thyroid carcinoma subtypes, parathyroid carcinoma, pituitary tumors, adrenocortical carcinoma, phaeochromocytoma, neuroblastoma, and gastroenteropancreatic neuroendocrine tumors. While data are not always consistent, immunohistochemistry performed on human tumor tissue has been used alongside other techniques to demonstrate Akt overactivation. We review active Akt as a potential prognostic marker and the PI3K pathway as a therapeutic target in endocrine neoplasia.