Role of Ki-67 proliferation index in the assessment of patients with neuroendocrine neoplasias regarding the stage of disease

Neuroendocrine liver metastases treated using transarterial radioembolization: Identification of prognostic parameters at 68Ga-DOTATATE PET/CT

PURPOSE

To identify prognostic clinical and imaging parameters for patients with neuroendocrine liver metastases (NELMs) undergoing transarterial radioembolization (TARE).

MATERIALS AND METHODS

Forty-seven patients (27 men; mean age, 64 years) with NELMs who received TARE, along with pre-procedure liver MRI and 68Ga-DOTATATE positron emission tomography/computed tomography were included. Apparent diffusion coefficient and standardized uptake value (SUV) of three liver metastases, normal spleen and liver were measured. SUVmax or SUVmean were used for the calculation of tumor-to-organ ratios (tumor-to-spleen and tumor-to-liver ratios) using all possible combinations (including SUVmax/SUVmax, SUVmax/SUVmean, and SUVmean/SUVmean). Clinical parameters (hepatic tumor-burden, presence of extra-hepatic metastases, chromograninA, Ki-67 and bilirubin levels) were assessed. Overall survival, progression-free survival (PFS) and hepatic progression-free survival (HPFS) were calculated using Kaplan-Meier curves.

RESULTS

Median overall survival, PFS and HPFS were 49.6, 13.1 and 28.3 months, respectively. In multivariable Cox regression analysis, low Ki-67 (≤ 5%), low hepatic tumor-burden (< 10%), absence of extrahepatic metastases, and increased Tmean/Lmax ratio were significant prognostic factors of longer overall survival and HPFS. High baseline chromograninA (> 1330 ng/mL) was associated with shorter HPFS. Tmean/Lmax > 1.9 yielded a median overall survival of 69 vs. 33 months (P < 0.04), and a median HPFS of 30 vs. 19 months (P = 0.09). For PFS, high baseline SUVmax of NELMs was the single significant parameter in the multivariable model. SUVmax > 28 resulted in a median PFS of 16.9 vs. 6.5 months, respectively (P = 0.001).

CONCLUSION

High preinterventional Tmean/Lmax ratios, and high SUVmax on 68Ga-DOTATATE positron emission tomography/computed tomography seem to have prognostic value in patients with NELMs undergoing TARE, potentially aiding patient selection and management alongside conventional variables.

Long-Term Outcomes of Liver Transplantation for the Management of Neuroendocrine Neoplasms: A Systematic Review

Liver transplantation is an uncommonly used, controversially debated therapeutic approach for highly selected individuals with neuroendocrine liver metastases. Synthesising evidence regarding outcomes from this approach is crucial to understand its position within the broad neuroendocrine liver metastases armamentarium. In this narrative systematic review of studies published in PubMed, Scopus and OVID until 1 July 2021, we summarise and critically appraise the existing literature regarding this modality, with a special focus on long-term outcomes data where possible. Fourteen studies were identified that reported outcomes from the use of liver transplantation for metastatic neuroendocrine neoplasms. No randomised trials were identified. Generally, indications and selection criteria were poorly articulated, with the notable exception of studies using the Milan criteria. The median 5-year overall survival was 65% (ranging from 36% to 97.2%, 11 studies), and the median 10-year overall survival was 50% (ranging from 46.1% to 88.8%, 3 studies). One additional study focussed on treatments and outcomes following post-transplant recurrence. No studies reported outcomes past 10 years. Further follow-up of the largest series with explicit selection criteria will deepen our understanding of the role that transplantation has to play in this setting.

Management of Small Bowel Neuroendocrine Tumours: 10 Years' Experience at a Tertiary Referral Centre

BACKGROUND

Neuroendocrine tumours (NET) arising from the small bowel are clinically challenging and are often diagnosed at advanced stages. Disease control with surgery alone can be demanding. Multimodal treatment concepts integrating surgery and non-surgical modalities could be of benefit.

METHOD

Retrospective review of consecutive adult patients with SB NET treated at Imperial College Healthcare NHS Trust between 1 January 2010 and 31 December 2019. Data regarding clinicopathological characteristics, treatments, and disease trajectory were extracted and summarised. Overall and progression/recurrence-free survival were estimated at 5 and 10 years.

RESULTS

154 patients were identified, with a median age of 64 years (range 33-87); 135/154 (87.7%) had stage III/IV disease at diagnosis. Surgery was used in 125 individuals (81.2%), typically with either segmental small bowel resection (60.8%) or right hemicolectomy (33.6%) and mesenteric lymphadenectomy for the primary tumour. Systemic and/or liver-directed therapies were used in 126 (81.8%); 60 (47.6%) had more than one line of non-surgical treatment. Median follow-up was 67.2 months (range 3.1-310.4); overall survival at 5 and 10 years was 91.0% (95% CI: 84.9-94.7%) and 82.5% (95% CI: 72.9-88.9%), respectively. Imaging-based median progression-free survival was 42.7 months (95% CI: 24.7 to 72.4); 5-year progression-free survival was 63.4% (95% CI: 55.0-70.6%); 10-year progression-free survival was 18.7% (95% CI: 12.4-26.1). Nineteen patients (12.3%) reached 10 years follow-up without disease recurrence and therefore were considered cured.

CONCLUSIONS

Most patients with SB NET present in a metastasised stage. Multimodal treatment concepts may be associated with excellent clinical outcomes. Future work should explore optimal approaches to treatment sequencing and patient selection.

Imaging of Small-Bowel Neuroendocrine Neoplasms: AJR Expert Panel Narrative Review

Neuroendocrine neoplasms (NENs) of the small bowel are typically slow-growing lesions that remain asymptomatic until reaching an advanced stage. Imaging modalities for lesion detection, staging, and follow-up in patients with known or suspected NEN include CT enterography, MR enterography, and PET/CT using a somatostatin receptor analog. FDG PET/CT may have a role in the evaluation of poorly differentiated NENs. Liver MRI, ideally with a hepatocyte-specific contrast agent, should be used in the evaluation of hepatic metastases. Imaging informs decisions regarding both surgical approaches and systematic therapy (specifically, peptide receptor radionuclide therapy). This AJR Expert Panel Narrative Review describes the multimodality imaging features of small-bowel NENs; explores the optimal imaging modalities for their diagnosis, staging, and follow-up; and discusses how imaging may be used to guide therapy.

Prognostic Implications of PET-Derived Tumor Volume and Uptake in Patients with Neuroendocrine Tumors

Historically, molecular imaging of somatostatin receptor (SSTR) expression in patients with neuroendocrine tumors (NET) was performed using SSTR scintigraphy (SRS). Sustained advances in medical imaging have led to its gradual replacement with SSTR positron-emission tomography (SSTR-PET). The higher sensitivity in comparison to SRS on the one hand and conventional cross-sectional imaging, on the other hand, enables more accurate staging and allows for image quantification. In addition, in recent years, a growing body of evidence has assessed the prognostic implications of SSTR-PET-derived prognostic biomarkers for NET patients, with the aim of risk stratification, outcome prognostication, and prediction of response to peptide receptor radionuclide therapy. In this narrative review, we give an overview of studies examining the prognostic value of advanced SSTR-PET-derived (semi-)quantitative metrics like tumor volume, uptake, and composite metrics. Complementing this analysis, a discussion of the current trends, clinical implications, and future directions is provided.

Assessment of the Role of Leptin and Adiponectinas Biomarkers in Pancreatic Neuroendocrine Neoplasms

Data on the possible connection between circulating adipokines and PanNENs are limited. This novel study aimed to assess the serum levels of leptin and adiponectin and their ratio in patients with PanNENs and to evaluate the possible relationship between them and PanNEN's grade or stage, including the presence of metastases. The study group consisted of PanNENs (n = 83), and healthy controls (n = 39). Leptin and adiponectin measurement by an ELISA assay was undertaken in the entire cohort. The serum concentration of adiponectin was significantly higher in the control group compared to the study group (p < 0.001). The concentration of leptin and adiponectin was significantly higher in females than in males (p < 0.01). Anincreased leptin-adiponectin ratio was observed in well-differentiated PanNENs (G1) vs. moderatelydifferentiated PanNENs (G2) (p < 0.05). An increased leptin-adiponectin ratio was found in PanNENs with Ki-67 < 3% vs. Ki-67 ≥ 3% (p < 0.05). PanNENs with distal disease presented lower leptin levels (p < 0.001) and a decreased leptin-adiponectin ratio (p < 0.01) compared with the localized disease group. Leptin, adiponectin, and the leptin-adiponectin ratio may serve as potential diagnostic, prognostic, and predictive biomarkers for PanNENs. Leptin levels and the leptin-adiponectin ratio may play an important role as predictors of malignancy and metastasis in PanNENs.

Spatial and temporal heterogeneity of digestive neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) are initially monoclonal neoplasms that progressively become polyclonal, with very different genotypic and phenotypic characteristics leading to biological differences, including the Ki-67 proliferation index, morphology, or sensitivity to treatments. Whereas inter-patient heterogeneity has been well described, intra-tumor heterogeneity has been little studied. However, NENs present a high degree of heterogeneity, both spatially within the same location or between different lesions, and through time. This can be explained by the emergence of tumor subclones with different behaviors. These subpopulations can be distinguished by the Ki-67 index, but also by the expression of hormonal markers or by differences in the intensity of uptake on metabolic imaging, such as ⁶⁸Ga-somatostatin receptor and Fluorine-18 fluorodeoxyglucose positron emission tomography. As these features are directly related to prognosis, it seems mandatory to move toward a standardized, improved selection of the tumor areas to be studied to be as predictive as possible. The temporal evolution of NENs frequently leads to changes in tumor grade over time, with impact on prognosis and therapeutic decision-making. However, there is no recommendation regarding systematic biopsy of NEN recurrence or progression, and which lesion to sample. This review aims to summarize the current state of knowledge, the main hypotheses, and the main implications regarding intra-tumor spatial and temporal heterogeneity in digestive NENs.

Transplantation for metastatic liver disease

The liver is a common site of metastases from many cancers, particularly those originating in the gastrointestinal tract. Liver transplantation is an uncommonly used but promising and at times controversial treatment option for neuroendocrine and colorectal liver metastases. Transplantation with meticulous patient selection has been associated with excellent long-term outcomes in individuals with neuroendocrine liver metastases, but questions remain regarding the role of transplantation in those who could also be eligible for hepatectomy, the role of neoadjuvant/adjuvant treatments in minimising recurrence, and the optimal timing of the procedure. A prospective pilot study of liver transplantation for unresectable colorectal liver metastases that reported a 5-year overall survival rate of 60% reinvigorated interest in this area following initially dismal outcomes. This has been followed by larger studies, and prospective trials are ongoing to quantify the potential benefits of liver transplantation over palliative chemotherapy. This review provides a critical summary of currently available knowledge on liver transplantation for neuroendocrine and colorectal liver metastases, and highlights avenues for further study to address gaps in the evidence base.

The Surgical and Therapeutic Activities of Non-Functional Pancreatic Neuroendocrine Tumors at a High-Volume Institution

BACKGROUND

This study aimed to summarize the surgical and therapeutic activities of non-functional pancreatic neuroendocrine tumors (NF-PanNETs) and perform survival analyses of a 15-year single-institutional cohort of NF-PanNETs.

METHODS

In total, 1001 patients with neuroendocrine neoplasms treated at Fudan University Shanghai Cancer Center were screened for inclusion, and 509 patients with NF-PanNETs from 2006 to 2020 were included. For time trend analyses, the 15-year study period was randomly divided into three periods. Survival analyses used the Kaplan-Meier method and Cox regression models.

RESULTS

The total number of resected NF-PanNETs increased over the 15-year study period, from 5 resections in 2006 to 94 resections in 2020. A significant decrease in the tumor size was observed, from a mean of 4.0 cm to 3.3 cm, and to 3.0 cm in the most recent period (p = 0.006). Minimally invasive techniques gradually increased from 3.5% to 12.9%, and finally to 46.4% in the most recent period (p < 0.001). In non-metastatic and resected tumors, the tumor size (p < 0.001), positive lymph node (p < 0.001), adjuvant treatment (p = 0.048), and tumor grade (p < 0.001) were independent prognostic factors for recurrence-free survival (RFS). The microvascular invasion (p = 0.024) and tumor grade (p = 0.013) were independent prognostic factors for overall survival (OS). A malignant transformation from NET into neuroendocrine carcinoma was observed.

CONCLUSIONS

An increasing number of NF-PanNETs resection and minimally invasive surgery was shown. In non-metastatic and resected tumors NF-PanNETs, tumor size, positive lymph node, adjuvant treatment, and tumor grade were independent predictors of RFS. Microvascular invasion and tumor grade were independent prognostic factors for OS.

Tumour Heterogeneity and the Consequent Practical Challenges in the Management of Gastroenteropancreatic Neuroendocrine Neoplasms

Tumour heterogeneity is a common phenomenon in neuroendocrine neoplasms (NENs) and a significant cause of treatment failure and disease progression. Genetic and epigenetic instability, along with proliferation of cancer stem cells and alterations in the tumour microenvironment, manifest as intra-tumoural variability in tumour biology in primary tumours and metastases. This may change over time, especially under selective pressure during treatment. The gastroenteropancreatic (GEP) tract is the most common site for NENs, and their diagnosis and treatment depends on the specific characteristics of the disease, in particular proliferation activity, expression of somatostatin receptors and grading. Somatostatin receptor expression has a major role in the diagnosis and treatment of GEP-NENs, while Ki-67 is also a valuable prognostic marker. Intra- and inter-tumour heterogeneity in GEP-NENS, however, may lead to inaccurate assessment of the disease and affect the reliability of the available diagnostic, prognostic and predictive tests. In this review, we summarise the current available evidence of the impact of tumour heterogeneity on tumour diagnosis and treatment of GEP-NENs. Understanding and accurately measuring tumour heterogeneity could better inform clinical decision making in NENs.

A real-life treatment cohort of pancreatic neuroendocrine tumors: High-grade increase in metastases confers poor survival

BACKGROUND

Tumor grade determined by the Ki67 index is the best prognostic factor for pancreatic neuroendocrine tumors (PanNETs). However, we often observe that the grade of metastases differs from that of their primary tumors. This study aimed to investigate the frequency of grade changes between primary tumors and metastases, explore its association with clinical characteristics, and correlate the findings with the prognosis.

METHODS

Six hundred forty-eight patients with pancreatic neuroendocrine neoplasms treated at Fudan University Shanghai Cancer Center were screened for inclusion, and 103 patients with PanNETs who had paired primary tumors and metastases with an available Ki67 index were included. Re-evaluation of Ki67 was performed on 98 available samples from 69 patients.

RESULTS

Fifty cases (48.5%) had a Ki67 index variation, and 18 cases (17.5%) displayed a grade increase. Metachronous metastases showed significantly higher Ki67 index variation than synchronous metastases (P=0.028). Kaplan-Meier analyses showed that high-grade metastases compared to low-grade primary tumors were significantly associated with decreased progression-free survival (PFS, P=0.012) and overall survival (OS, P=0.027). Multivariable Cox regression analyses demonstrated that a low-grade increase to high-grade was an unfavorable and independent prognostic factor for PFS and OS (P=0.010, and P=0.041, respectively).

CONCLUSIONS

A high-grade increase in metastases was an unfavorable predictor of PanNETs, which emphasized the importance of accurate pathological grading and could provide a reference for clinical decision-making.

Presentation and survival of gastro-entero-pancreatic neuroendocrine tumors in young adults versus older patients

BACKGROUND

A minority of patients with gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) is diagnosed at younger age. This population-based study explores the broad clinical and pathologic features of the youngest 5% of adult patients with GEP-NETs.

METHODS

A retrospective study of the National Cancer Database (NCDB) of patients with a primary GEP-NET was performed. Patients were stratified by age. Kaplan-Meier and multivariate Cox proportional hazards analyses were performed.

RESULTS

We identified 31,983 patients with a diagnosis of a GEP-NET and only 5% of patients were under the age of 35. Young patients were found to have greater proportions of localized, well differentiated disease. On multivariate analysis, young age, well differentiated histology, early stage, and surgical intervention were associated with lower risk of mortality.

CONCLUSIONS

Young patients with GEP-NETs tend to have earlier stage of presentation and well differentiated tumors, which may be most amenable to surgical intervention.

Distinctive features of pancreatic neuroendocrine neoplasms exhibiting an increment in proliferative activity during the course of the disease

PURPOSE

Neuroendocrine neoplasms (NENs) differ in their biological behavior and growth potential in a way that can be predicted using histological classification and grading systems. A subset of pancreatic NENs (pNENs) may develop a more aggressive phenotype during the course of the disease, associated with an increase in the Ki-67 proliferation index (PI). The purpose of the study was to present the clinical characteristics of these patients.

METHODS

Using re-biopsy of growing lesions, we investigated the increase in Ki-67 PI sufficient to change initial grading (G).

RESULTS

Of 264 patients with well differentiated (WD) pNENs who showed progressive disease during follow-up, 15 (6%) exhibited an increase in Ki-67 PI at a median time 36.8 (9.3-255.8) months. All neoplasms had WD-morphology: five had G1 (Ki-67 median value 1%), nine G2 (median value 5%), one G3 (25%) grades. Upon change of Ki-67 PI, 3 patients had G2 (8%) and 12 G3 (57.5%) NENs, while all retained their WD-morphology. At last follow-up, eight patients were alive with a median overall survival (OS) of 52.5 (9.5-264.3) months. Μedian OS was shorter in patients who had a change in Ki-67 PI before 36 months compared to those who had a change of Ki-67 PI at a later stage (27.5 95%CI: 11.88-43.06 vs. 120.87 95%CI: 96.05-145.69; log-rank p = 0.018).

CONCLUSIONS

During the course of their disease, 6% patients with progressive pNENs develop an increase in Ki-67 PI resulting in an increase in grading status while maintaining their morphology. This process is associated with worse OS when it occurs at an early stage.

Semiautomatic Tumor Delineation for Evaluation of 64Cu-DOTATATE PET/CT in Patients with Neuroendocrine Neoplasms: Prognostication Based on Lowest Lesion Uptake and Total Tumor Volume

Patients with neuroendocrine neoplasms (NENs) have heterogeneous somatostatin receptor expression, with highly differentiated lesions having higher expression. Receptor expression of the total tumor burden may be visualized by somatostatin receptor imaging, such as with ⁶⁴Cu-DOTATATE PET/CT. Assessment of maximal lesion uptake is associated with progression-free survival (PFS) but not overall survival (OS). We hypothesized that the lesion with the lowest, rather than the highest, ⁶⁴Cu-DOTATATE uptake would be more prognostic, and we developed a semiautomatic method for evaluating this hypothesis. Methods: Patients with NENs underwent ⁶⁴Cu-DOTATATE PET/CT. A standardized semiautomatic tumor delineation method was developed and used to identify the lesion with the lowest uptake, that is, with the lowest SUV_mean Additionally, we assessed total tumor volume derived from the semiautomatic tumor delineation. Kaplan-Meier and Cox regression analyses were used to determine whether there was any association with OS and PFS. Results: In 116 patients with NENs, median PFS (95% CI) was 23 mo (range, 20-31 mo) and median OS was 85 mo (range, 68-113 mo). Minimum SUV_mean and total tumor volume were significantly associated with PFS and OS in univariate Cox regression analyses, whereas SUV_max was significant only for PFS. In multivariate Cox analyses, both minimum SUV_mean and total tumor volume remained statistically significant. Minimum SUV_mean and total tumor volume were then dichotomized by their median, and patients were categorized into 4 groups: high or low total tumor volume and high or low minimum SUV_mean Patients with a low total tumor volume and high minimum SUV_mean had a hazard ratio of 0.32 (95% CI, 0.20-0.51) for PFS and 0.24 (95% CI, 0.13-0.43) for OS, both with P values of less than 0.001 (reference: high total tumor volume and low minimum SUV_mean). Conclusion: We propose a standardized semiautomatic tumor delineation method to identify the lesion with the lowest ⁶⁴Cu-DOTATATE uptake and total tumor volume. Assessment of the lowest, rather than the highest, lesion uptake greatly increases prognostication by ⁶⁴Cu-DOTATATE PET/CT. Combining lesion uptake and total tumor volume, we derived a novel prognostic classification system for patients with NENs.

Ki-67 Labeling Index Variability Between Surgically Resected Primary and Metastatic Hepatic Lesions of Gastroenteropancreatic Neuroendocrine Neoplasms

Background. A higher Ki-67 labeling index is associated with a poorer prognosis in gastroenteropancreatic neuroendocrine neoplasms. It has also been proposed that the Ki-67 labeling index may increase during disease progression from the primary site to metastatic sites. Although biopsy specimens are used to measure the Ki-67 labeling index, heterogeneity in lesions is thought to affect the assessment of the Ki-67 labeling index. To overcome tumor heterogeneity, we evaluated the variability in the Ki-67 labeling index between primary lesions and hepatic metastases by analyzing only surgically resected specimens. Methods. We conducted a single-center retrospective study to analyze the variability in the Ki-67 labeling index and the change in tumor grade between the primary site and metastatic hepatic sites in 19 patients diagnosed with gastroenteropancreatic neuroendocrine neoplasms at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 1998 to 2018. Both the primary site and metastatic hepatic sites were surgically resected. Results. Among the 19 patients with gastroenteropancreatic neuroendocrine neoplasms, 12 patients (63%) showed higher levels of the Ki-67 labeling index at metastatic hepatic sites than at the primary site. The median Ki-67 labeling index levels for the primary lesion and metastatic hepatic lesions were 5% and 10%, respectively. The Ki-67 labeling index levels were significantly elevated in the metastatic hepatic lesions compared to the primary lesion (P = .002). Conclusions. This study addressed the heterogeneity of the Ki-67 labeling index by analyzing only surgically resected specimens. We observed a statistically significant increase in the Ki-67 labeling index in hepatic metastases compared to the primary lesion.

Clinicopathological heterogeneity between primary and metastatic sites of gastroenteropancreatic neuroendocrine neoplasm

Background

Chromogranin A (CgA), synaptophysin (Syn) and the Ki-67 index play significant roles in diagnosis or the evaluation of the proliferative activity of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). However, little is known about whether these biological markers change during tumor metastasis and whether such changes have effect on prognosis.

Methods

We analyzed 35 specimens of both primary and metastatic tumor from 779 patients who had been diagnosed as GEP-NENs at Wuhan Union Hospital from August 2011 to October 2019. The heterogeneity of CgA, Syn and Ki-67 index was evaluated by immunohistochemical analysis.

Results

Among these 779 patients, the three most common sites of NENs in the digestive tract were the pancreas, rectum and stomach. Metastases were found in 311 (39.9%) patients. Among the 35 patients with both primary and metastatic pathological specimens, differences in the Ki-67 level were detected in 54.3% of the patients, while 37.1% showed a difference in CgA and only 11.4% showed a difference in Syn. Importantly, due to the difference in the Ki-67 index between primary and metastatic lesions, the WHO grade was changed in 8.6% of the patients. In addition, a Kaplan–Meier survival analysis showed that patients with Ki-67 index variation had a shorter overall survival (p = 0.0346), while neither Syn variation nor CgA variation was related to patient survival (p = 0.7194, p = 0.4829).

Conclusions

Our data indicate that primary and metastatic sites of GEP-NENs may exhibit pathological heterogeneity. Ki-67 index variation is closely related to the poor prognosis of patients with tumor metastasis, but neither Syn variation nor CgA variation is related to patient prognosis. Therefore, clinicopathologic evaluation of the primary tumor and metastatic sites could be helpful for predicting the prognosis.

[Indications for the Surgical Management of Pancreatic Neuroendocrine Neoplasms]

Neuroendocrine neoplasms of the pancreas (pNEN) have an increasing incidence and prevalence. Thus, this entity is of increasing clinical significance. Patients with pNEN become clinically apparent due to different and unspecific symptoms. Some tumours secrete hormones and peptides and become clinically symptomatic. In general, these tumours can metastasise early and even small tumours lead to distant metastases. Nonetheless, primary tumour size and grading are important prognostic factors. On the basis of a systematic literature research and the formulation of key issues according to the PICO system, therapeutic concepts were established. These concepts were evaluated with a Delphi process among the members of the pancreas research group and the indications for surgery group of the German Society of General and Visceral Surgery. Thus this article gives an overview of the surgical treatment modalities and indications for the treatment of pNEN. Surgery is still the gold standard in treatment and the only potential chance of cure. Surgery is indicated for sporadic as well as hereditary pNEN > 2 cm independent of the functional activity. A so called "wait and see" strategy might be indicated in smaller pNEN; however, there is little evidence for this approach. In this respect, pNEN of 1 - 2 cm represent a surgical indication. The treatment of hereditary pNEN is challenging and should be interdisciplinary. Even in the case of distant metastases, a curative approach might be feasible and multimodal treatment is indicated.

Automated quantitative analysis of Ki-67 staining and HE images recognition and registration based on whole tissue sections in breast carcinoma

Background

The scoring of Ki-67 is highly relevant for the diagnosis, classification, prognosis, and treatment in breast invasive ductal carcinoma (IDC). Traditional scoring method of Ki-67 staining followed by manual counting, is time-consumption and inter−/intra observer variability, which may limit its clinical value. Although more and more algorithms and individual platforms have been developed for the assessment of Ki-67 stained images to improve its accuracy level, most of them lack of accurate registration of immunohistochemical (IHC) images and their matched hematoxylin-eosin (HE) images, or did not accurately labelled each positive and negative cell with Ki-67 staining based on whole tissue sections (WTS). In view of this, we introduce an accurate image registration method and an automatic identification and counting software of Ki-67 based on WTS by deep learning.

Methods

We marked 1017 breast IDC whole slide imaging (WSI), established a research workflow based on the (i) identification of IDC area, (ii) registration of HE and IHC slides from the same anatomical region, and (iii) counting of positive Ki-67 staining.

Results

The accuracy, sensitivity, and specificity levels of identifying breast IDC regions were 89.44, 85.05, and 95.23%, respectively, and the contiguous HE and Ki-67 stained slides perfectly registered. We counted and labelled each cell of 10 Ki-67 slides as standard for testing on WTS, the accuracy by automatic calculation of Ki-67 positive rate in attained IDC was 90.2%. In the human-machine competition of Ki-67 scoring, the average time of 1 slide was 2.3 min with 1 GPU by using this software, and the accuracy was 99.4%, which was over 90% of the results provided by participating doctors.

Conclusions

Our study demonstrates the enormous potential of automated quantitative analysis of Ki-67 staining and HE images recognition and registration based on WTS, and the automated scoring of Ki67 can thus successfully address issues of consistency, reproducibility and accuracy. We will provide those labelled images as an open-free platform for researchers to assess the performance of computer algorithms for automated Ki-67 scoring on IHC stained slides.

The Correlation Between [68Ga]DOTATATE PET/CT and Cell Proliferation in Patients With GEP-NENs

PURPOSE

Objectives of the study are to analyze the correlation between [⁶⁸Ga]DOTATATE positron emission tomography (PET)/X-ray computed tomography (CT) measurements and various biological characteristics of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), and to determine optimal cutoff value of SUVmax (standard uptake value) to differentiate neuroendocrine tumors (NETs) and neuroendocrine cancers (NECs).

PROCEDURES

Of the GEP-NEN cases (73 males, 53 females; age 18-77 years) with pathologically proven primary and/or metastatic lesions, 126 were studied. All of the short axes of lesions were larger than 0.5 cm in order to avoid the partial volume effect. Patients fasted for 6 h before the PET/CT scans. The dose of [⁶⁸Ga]DOTATATE was 100-200 MBq and the acquisition began at 1 h after injection. The lesion with the highest SUVmax in each patient was analyzed.

RESULTS

In the total sample, the sensitivity of [68Ga]DOTATATE was 69.05 %. The sensitivities were significantly different among G1, G2, and G3 groups (72.22 %, 91.53 %, and 40.82 %, respectively; p < 0.01). The SUVmax of the G3 group was lowest. We also found that the sensitivity and SUVmax were significantly higher (p < 0.05) in patients with pancreatic NENs (Pan-NENs) than in patients with gastrointestinal NENs (Gi-NENs) and unknown primary NENs (Up-NENs). A significant negative correlation between SUVmax and Ki-67 was found (r = - 0.429, p < 0.01). Using SUVmax to differentiate neuroendocrine tumors (NETs) and neuroendocrine cancers (NECs), the area under the ROC curve (AUC) was 0.771 and the cutoff value of SUVmax was 11.25 (sensitivity 79.2 %, specificity 65.3 %). However, Pan-NENs did not show any statistical significance results in correlation and ROC analysis.

CONCLUSION

[⁶⁸Ga]DOTATATE PET/CT results showed a negative correlation with GEP-NEN cell proliferation and were complementary to Ki-67. Pan-NENs were different from Gi-NENs and Up-NENs when compared to somatostatin receptor expression.

Neuroendocrine Neoplasms of the Small Bowel and Pancreas

The traditionally promulgated perspectives of neuroendocrine neoplasms (NEN) as rare, indolent tumours are blunt and have been outdated for the last 2 decades. Clear increments in their incidence over the past decades render them increasingly clinically relevant, and at initial diagnosis many present with nodal and/or distant metastases (notably hepatic). The molecular pathogenesis of these tumours is increasingly yet incompletely understood. Those arising from the small bowel (SB) or pancreas typically occur sporadically; the latter may occur within the context of hereditary tumour predisposition syndromes. NENs can also be associated with endocrinopathy of hormonal hypersecretion. Tangible advances in the development of novel biomarkers, functional imaging modalities and therapy are especially applicable to this sub-set of tumours. The management of SB and pancreatic neuroendocrine tumours (NET) may be challenging, and often comprises a multidisciplinary approach wherein surgical, medical, interventional radiological and radiotherapeutic modalities are implemented. This review provides a comprehensive overview of the epidemiology, pathophysiology, diagnosis and treatment of SB and pancreatic NETs. Moreover, we provide an outlook of the future in these tumour types which will include the development of precision oncology frameworks for individualised therapy, multi-analyte predictive biomarkers, artificial intelligence-derived clinical decision support tools and elucidation of the role of the microbiome in NEN development and clinical behaviour.

Histopathologist-level quantification of Ki-67 immunoexpression in gastroenteropancreatic neuroendocrine tumors using semiautomated method

The role of Ki-67 index in determining the prognosis and management of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has become more important yet presents a challenging assessment dilemma. Although the precise method of Ki-67 index evaluation has not been standardized, several methods have been proposed, and each has its pros and cons. Our study proposes an imaging semiautomated informatics framework [semiautomated counting (SAC)] using the popular biomedical imaging tool "ImageJ" to quantify Ki-67 index of the GEP-NETs using camera-captured images of tumor hotspots. It aims to assist pathologists in achieving an accurate and rapid interpretation of Ki-67 index and better reproducibility of the results with minimal human interaction and calibration. Twenty cases of resected GEP-NETs with Ki-67 staining that had been done for diagnostic purposes have been randomly selected from the pathology archive. All of these cases were reviewed in a multidisciplinary cancer center between 2012 and 2019. For each case, the Ki-67 immunostained slide was evaluated and five camera-captured images at 40 × magnification were taken. Prints of images were used by three pathologists to manually count the tumor cells. The digital versions of the images were used for the semiautomated cell counting using ImageJ. Statistical analysis of the Ki-67 index correlation between the proposed method and the MC revealed strong agreement on all the cases evaluates ( n = 20 ), with an intraclass correlation coefficient of 0.993, "95% CI: 0.984 to 0.997." The results obtained from the SAC are promising and demonstrate the capability of this methodology for the development of reproducible and accurate semiautomated quantitative pathological assessments. ImageJ features are investigated carefully and accurately fine-tuned to obtain the optimal sequence of steps that will accurately calculate Ki-67 index. SAC is able to accurately grade all the cases evaluated perfectly mating histopathologists' manual grading, providing reliable and efficient solution for Ki-67 index assessment.

Lesion-by-lesion correlation between uptake at FDG PET and the Ki67 proliferation index in resected pancreatic neuroendocrine tumors

BACKGROUND

Ki67 proliferation index and tumor uptake on 18fluorodeoxyglucose positron-emitting tomography (FDG-PET) could be correlated in pancreatic neuroendocrine tumors (PanNET), but the evaluation of the former is subject to tumor heterogeneity.

AIMS

Explore the correlation between Ki67 and FDG-PET uptake at the lesion scale in PanNET.

METHODS

We identified target lesions ≥10 mm in patients operated on for a PanNET and/or associated metastases with preoperative FDG-PET and without neoadjuvant treatment. We assessed the lesion-by-lesion correlation between Ki67 and the tumor-to-liver SUVmax ratio (SUVmax T/L), and between pathological grade (G) and metabolic grade (mG) (mG1, SUVmax T/L ≤ 1, mG2, SUVmax T/L 1-2.3 and mG3, SUVmax T/L > 2.3).

RESULTS

Twenty-one patients underwent pancreatic (n = 12), liver (n = 2) or combined surgery (n = 7). Overall, 36 target lesions (21 primary PanNET, 13 liver metastases and 2 lymph-node metastases) were identified, of median Ki67 4%. Ki67 correlated with SUVmax T/L (r = 0.55, p < 0.001). Median SUVmax T/L was 0.76, 1.41 and 2.67 for lesions G1, G2 and G3, respectively (p = 0.005). Median Ki67 was 1, 4 and 25 for lesions mG1, mG2 and mG3, respectively (p = 0.005).

CONCLUSIONS

Uptake on FDG-PET could predict the pathological grade of PanNET lesions. Hence, FDG-PET could supplement pathological evaluation of tumor biological aggressiveness and could guide the choice of the most relevant lesions to biopsy.

Transcriptomic analysis and identification of prognostic biomarkers in cholangiocarcinoma

Cholangiocarcinoma (CCA) is acknowledged as the second most commonly diagnosed primary liver tumor and is associated with a poor patient prognosis. The present study aimed to explore the biological functions, signaling pathways and potential prognostic biomarkers involved in CCA through transcriptomic analysis. Based on the transcriptomic dataset of CCA from The Cancer Genome Atlas (TCGA), differentially expressed protein-coding genes (DEGs) were identified. Biological function enrichment analysis, including Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, was applied. Through protein-protein interaction (PPI) network analysis, hub genes were identified and further verified using open-access datasets and qRT-PCR. Finally, a survival analysis was conducted. A total of 1,463 DEGs were distinguished, including 267 upregulated genes and 1,196 downregulated genes. For the GO analysis, the upregulated DEGs were enriched in ‘cadherin binding in cell-cell adhesion’, ‘extracellular matrix (ECM) organization’ and ‘cell-cell adherens junctions’. Correspondingly, the downregulated DEGs were enriched in the ‘oxidation-reduction process’, ‘extracellular exosomes’ and ‘blood microparticles’. In regards to the KEGG pathway analysis, the upregulated DEGs were enriched in ‘ECM-receptor interactions’, ‘focal adhesions’ and ‘small cell lung cancer’. The downregulated DEGs were enriched in ‘metabolic pathways’, ‘complement and coagulation cascades’ and ‘biosynthesis of antibiotics’. The PPI network suggested that CDK1 and another 20 genes were hub genes. Furthermore, survival analysis suggested that CDK1, MKI67, TOP2A and PRC1 were significantly associated with patient prognosis. These results enhance the current understanding of CCA development and provide new insight into distinguishing candidate biomarkers for predicting the prognosis of CCA.

UCHL1 loss alters the cell-cycle in metastatic pancreatic neuroendocrine tumors

Loss of ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) expression by CpG promoter hypermethylation is associated with metastasis in gastroenteropancreatic neuroendocrine tumors; however, the mechanism of how UCHL1 loss contributes to metastatic potential remains unclear. In this study, we first confirmed that loss of UCHL1 expression on immunohistochemistry was significantly associated with metastatic tumors in a translational pancreatic neuroendocrine tumor (PNET) cohort, with a sensitivity and specificity of 78% and 89%, respectively. To study the mechanism driving this aggressive phenotype, BON and QGP-1 metastatic PNET cell lines, which do not produce UCHL1, were stably transfected to re-express UCHL1. In vitro assays, RNA-sequencing, and reverse-phase protein array (RPPA) analyses were performed comparing empty-vector negative controls and UCHL1-expressing cell lines. UCHL1 re-expression is associated with lower anchorage-independent colony growth in BON cells, lower colony formation in QGP cells, and a higher percentage of cells in the G0/G1 cell-cycle phase in BON and QGP cells. On RPPA proteomic analysis, there was an upregulation of cell-cycle regulatory proteins CHK2 (1.2 fold change, p=0.004) and P21 (1.2 fold change, p=0.023) in BON cells expressing UCHL1; western blot confirmed upregulation of phosphorylated CHK2 and P21. There were no transcriptomic differences detected on RNA-Sequencing between empty-vector negative controls and UCHL1-expressing cell lines. In conclusion, UCHL1 loss correlates with metastatic potential in PNETs and its re-expression induces a less aggressive phenotype in vitro, in part by inducing cell-cycle arrest through post-translational regulation of phosphorylated CHK2. UCHL1 re-expression should be considered as a functional biomarker in detecting PNETs capable of metastasis.

Accuracy of grading pancreatic neuroendocrine neoplasms with Ki-67 index in fine-needle aspiration cellblock material

OBJECTIVE

The aim of this study was to assess the preoperative tumour grade of pancreatic neuroendocrine neoplasms (panNENs) by determining the Ki-67 index in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) material and to correlate the preoperative tumour grade with the postoperative tumour grade in surgical specimens.

METHODS

We performed a retrospective review of the institutional pathology database over a 10-year period (2007-2017) to identify all cases of panNENs with corresponding preoperative EUS-FNA cytological material and surgical specimens. Fifteen cases with adequate EUS-FNA material (more than 400 tumour cells on cellblock) were identified. The cytological and histological samples were graded based on the mitotic rate and the Ki-67 index in accordance with the 2017 World Health Organisation grading system for panNENs. The tumour grades determined on EUS-FNA cellblock material were compared with the histological tumour grades.

RESULTS

Mean age at diagnosis was 64.8 ± 12.7 years (range, 38-85 years). The grading scores assigned to the cytological and histological samples were concordant in all 15 (100%) cases. Of those, two (13%) cases were scored as grade 1, nine (60%) cases as grade 2 and four (27%) cases as grade 3 tumours.

CONCLUSION

Our study shows that tumour grade in patients with PanNENs can be reliably determined by assessing the Ki-67 index in EUS-FNA specimens based on the 2017 World Health Organisation classification and grading system.

Variability of the Ki-67 proliferation index in gastroenteropancreatic neuroendocrine neoplasms - a single-center retrospective study

BACKGROUND

The Ki-67 index in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) may change throughout the disease course. However, the definitive effect of Ki-67 variability on GEP-NENs remains unknown. The aims of this study were to evaluate changes in Ki-67 levels throughout the disease course and investigate the role of Ki-67 index variability in GEP-NENs.

METHODS

Specimens with multiple pathologies were evaluated from 30 patients who were selected from 514 patients with GEP-NENs, being treated at Wuhan Union Hospital from July 2009 to February 2018. The Ki-67 index was evaluated among multiple specimens over the disease course. Univariable and multivariable Cox proportional hazards regression analyses were performed to assess the prognostic significance of various clinical and histopathologic features.

RESULTS

Among the 514 patients with GEP-NENs, metastases were seen in 182 (35.41%). Among the 30 patients from whom specimens with multiple pathologies were obtained, 24 were both primary and metastatic specimens and six were specimens collected over the course of the disease. Changes in Ki-67 levels were detected in 53.3% of the patients, of whom 40% had up-regulated Ki-67 levels, and 13.3% had down-regulated Ki-67 levels. Kaplan-Meier survival analysis showed that the group with Ki-67 variability had a shorter overall survival (p = 0.0297). The Cox regression analysis indicated that Ki-67 variability (p = 0.038) was the only independent prognostic factor for overall survival.

CONCLUSIONS

Our data suggest that patients with GEP-NENs and Ki-67 variability had a poorer prognosis. The re-assessment of Ki-67 at sites of metastasis or during the disease course might play a role in predicting the prognosis of patients with GEP-NENs. This finding could have implications for how GEP-NENs are monitored and treated.

Liver transplantation and multivisceral transplantation in the management of patients with advanced neuroendocrine tumours

Orthotopic liver transplantation (OLT) represents a generally accepted albeit somewhat controversially discussed therapeutic strategy in highly selected patients with non-resectable hepatic metastases from neuroendocrine tumours (NET). Whilst there are some exclusion criteria, these are not universally followed, and the optimal set of inclusion parameters for deeming patients eligible has not yet been elucidated. This is due to heterogeneity in the study populations, as well differing approaches employed and also divergences in selection criteria between centres. Recent data have suggested that OLT may represent the most efficacious approach in terms of overall and disease-free survival to the management of NET metastatic to the liver when conducted in accordance with the modified Milan criteria. Therefore, a consensus set of selection criteria requires definition to facilitate stringent and fair allocation of deceased-donor organs, as well as consideration for living-donor organs. In the context of classically non-resectable metastatic tumour bulk, multivisceral transplantation with or without the liver may also be indicated, yet experience is very limited. In this review, we discuss the diagnostic work-up of patients in whom the aforementioned transplantation approaches are being considered, critically analyse the published experience and also anticipate future developments in this field, including a discussion of immediate and longer-term research priorities.

Assessment of the American Joint Commission on Cancer 8th Edition Staging System for Patients with Pancreatic Neuroendocrine Tumors: A Surveillance, Epidemiology, and End Results analysis

Although several staging systems have been proposed for pancreatic neuroendocrine tumors (pNETs), the optimal staging system remains unclear. Here, we aimed to assess the application of the newly revised 8th edition American Joint Committee on Cancer (AJCC) staging system for exocrine pancreatic carcinoma (EPC) to pNETs, in comparison with that of other staging systems. We identified pNETs patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004–2014). Overall survival was analyzed using Kaplan–Meier curves with the log‐rank test. The predictive accuracy of each staging system was assessed by the concordance index (c‐index). Cox proportional hazards regression was conducted to calculate the impact of different stages. In total, 2424 patients with pNETs, including 2350 who underwent resection, were identified using SEER data. Patients with different stages were evenly stratified based on the 8th edition AJCC staging system for EPC. Kaplan–Meier curves were well separated in all patients and patients with resection using the 8th edition AJCC staging system for EPC. Moreover, the hazard ratio increased with worsening disease stage. The c‐index of the 8th edition AJCC staging system for EPC was similar to that of the other systems. For pNETs patients, the 8th edition AJCC staging system for EPC exhibits good prognostic discrimination among different stages in both all patients and those with resection.

Comparative evaluation of three proliferation markers, Ki-67, TOP2A, and RacGAP1, in bronchopulmonary neuroendocrine neoplasms: Issues and prospects

The classification of bronchopulmonary neuroendocrine neoplasms (BP-NEN) into four tumor entities (typical carcinoids (TC), atypical carcinoids (AC), small cell lung cancers (SCLC), large cell neuroendocrine lung carcinomas (LCNEC)) is difficult to perform accurately, but important for prognostic statements and therapeutic management decisions. In this regard, we compared the expression of three proliferation markers, Ki-67, Topoisomerase II alpha (TOP2A), and RacGAP1, in a series of tumor samples from 104 BP-NEN patients (24 TC, 21 AC, 52 SCLC, 7 LCNEC) using different evaluation methods (immunohistochemistry (IHC): Average evaluation, Hotspot evaluation, digital image analysis; RT-qPCR).

The results indicated that all three markers had increased protein and mRNA expression with poorer differentiation and correlated well with each other, as well as with grading, staging, and poor survival. Compared with Ki-67 and TOP2A, RacGAP1 allowed for a clearer prognostic statement. The cut-off limits obtained for Ki-67-Average (IHC) were TC-AC 1.5, AC-SCLC 19, and AC-LCNEC 23.5. The Hotspot evaluation generated equal to higher, the digital image analysis generally lower between-entity cut-off limits.

All three markers enabled a clear-cut differentiation between the BP-NEN entities, and all methods evaluated were suitable for marker assessment. However, to define optimal cut-off limits, the Ki-67 evaluation methods should be standardized. RacGAP1 appeared to be a new marker with great potential.

Orthopedia homeobox is preferentially expressed in typical carcinoids of the lung

BACKGROUND

Twenty-seven percent of neuroendocrine tumors (NETs) are associated with distant metastases, and in some patients, the primary site is unknown. Orthopedia homeobox protein (OTP) has been described as a useful marker for lung carcinoids (LCs) and for separating low-grade typical carcinoids (TCs) from intermediate-grade atypical carcinoids (ACs) in resection specimens. This study evaluated OTP, thyroid transcription factor 1 (TTF-1), and Ki-67 expression in fine-needle aspiration (FNA) samples of various NETs.

METHODS

A search for NETs diagnosed via FNA with subsequent resection was performed. Cell block sections were stained for OTP, TTF-1, and mindbomb E3 ubiquitin protein ligase 1 (Mib-1). Nuclear expression for OTP and TTF-1 was considered positive. Nuclear Ki-67 staining was reported as a percentage. Results were correlated with the grade and primary site for resection specimens.

RESULTS

Sixty-three FNA samples of NETs were identified: 14 liver samples, 14 pancreatic samples, 13 lymph node samples, 12 lung samples, 3 retroperitoneum samples, 2 small intestine samples, and 5 other samples. OTP was positive in 12 of 63 NETs (19%) from the following sites: lung (n = 8), liver (lung primary; n = 2), skin (n = 1), and lymph node (lung primary; n = 1). In well-differentiated NETs, only LCs were OTP-positive, whereas TTF-1 was positive in LCs and nonlung NETs (67% vs 7%). Within the LC category, OTP was positive in 100% of the TCs versus 17% of the ACs.

CONCLUSIONS

OTP is specific for LCs because well-differentiated nonlung NETs are negative for OTP. OTP preferentially stains TCs over ACs. In well-differentiated NETs, OTP staining is highly specific for LCs, and in combination with a low Ki-67 index, it suggests a pulmonary TC. Cancer Cytopathol 2018;126:236-42. © 2018 American Cancer Society.

The diagnostic value of FNA biopsy in grading pancreatic neuroendocrine tumors

BACKGROUND

There has been much controversy regarding the accuracy of grading pancreatic neuroendocrine tumors (PNETs) on fine-needle aspiration (FNA) biopsy. The objectives of this study were to evaluate whether grading according to the fraction of Ki-67-positive tumor cells (the Ki-67 proliferation index) on material from endoscopic ultrasound-guided FNA biopsies correlated with grading on surgical resection specimens and to evaluate the minimum amount of FNA material needed.

METHODS

A case series of 27 PNETs with FNA biopsies and corresponding surgical resection specimens at the authors' institution were evaluated. Tumors were graded on FNA and surgical specimens with an evaluation of Ki-67 index according to 2010 World Health Organization criteria. Chart reviews were conducted to evaluate recurrence or clinical progression in patients who were being managed conservatively with observation.

RESULTS

The evaluation of grading between FNA and tumor resection specimens revealed that 22 of 26 FNA specimens (84.6%) had Ki-67 results comparable to those in the corresponding surgical resection specimens, thus allowing for accurate grading. Correct FNA diagnosis with the ability to distinguish between grade 1 and 2 tumors had a positive predictive value of 88.9%, with 72.7% sensitivity, 93.3% specificity, and a P value of .00081. In addition, 24 of 26 cases contained less than 2000 cells, of which 20 were correctly graded on FNA material. Seven of 26 FNA samples had less than 1000 cells, of which 6 were correctly graded, including 2 that had only 50 cells.

CONCLUSIONS

The current results exhibit good correlation between FNA grade and final grade on surgical resection specimens using Ki-67 index, even in samples with less than the recommended total cell count. Therefore, grading of PNETs on FNA with the Ki-67 proliferation index should be assessed and is a practical parameter to report to clinicians. Cancer Cytopathol 2018;126:170-8. © 2017 American Cancer Society.

Decreased UCHL1 expression as a cytologic biomarker for aggressive behavior in pancreatic neuroendocrine tumors

BACKGROUND

There are currently no reliable markers associated with aggressive behavior in well-differentiated and moderately differentiated pancreatic neuroendocrine tumors. We aimed to determine whether expression of ubiquitin carboxyl-terminal hydrolase L1 in conjunction with Ki67 can identify metastatic potential of well-differentiated and moderately differentiated pancreatic neuroendocrine tumors from fine-needle aspiration samples obtained by endoscopic ultrasound.

METHODS

Retrospective review of 48 patients with well-differentiated and moderately differentiated pancreatic neuroendocrine tumors diagnosed by endoscopic ultrasound fine-needle aspiration at a single center identified 35 biopsy samples with adequate material for analysis. Ubiquitin carboxyl-terminal esterase L1 immunocytochemistry of primary pancreatic neuroendocrine tumors was performed along with Ki67 staining and scored semiquantitatively. The combination of ubiquitin carboxyl-terminal esterase L1 score ≤4 (weak) and Ki67 ≥3% (high) was considered a positive test for predicting tumors associated with metastases.

RESULTS

Weak ubiquitin carboxyl-terminal hydrolase L1 staining had 80% sensitivity, 65% specificity, 63% positive predictive value, and 81% negative predictive value to identify primary tumors associated with metastatic disease. The combination of weak ubiquitin carboxyl-terminal hydrolase L1 staining and high Ki67 staining increased the test specificity to 95%. On multivariable analysis, combined positive test of weak ubiquitin carboxyl-terminal esterase L1 staining and high Ki67 staining was an independent predictor of metastatic disease (P = .047).

CONCLUSION

Ubiquitin carboxyl-terminal hydrolase L1 is a novel biomarker for identifying malignant potential of primary well-differentiated and moderately differentiated pancreatic neuroendocrine tumors and in combination with Ki67 is an independent predictor of development of metastatic disease.

Redefining the Ki-67 Index Stratification for Low-Grade Pancreatic Neuroendocrine Tumors: Improving Its Prognostic Value for Recurrence of Disease

BACKGROUND

The Ki-67 index is an established prognostic marker for recurrence after resection of pancreatic neuroendocrine tumors (PanNETs) that groups tumors into three categories: low grade (< 3%), intermediate grade (3-20%), and high grade (> 20%). Given that the majority of resected PanNETs have a Ki-67 less than 3%, this study aimed to stratify this group further to predict disease recurrence more accurately.

METHODS

The Ki-67 index was pathologically re-reviewed and scored by a pathologist blinded to all other clinicopathologic variables using tissue microarray blocks made in triplicate. All patients who underwent curative-intent resection of non-metastatic PanNETs at a single institution from 2000 to 2013 were included in the study. The primary outcome was recurrence-free survival (RFS).

RESULTS

Of 113 patients with well-differentiated PanNETs resected, 83 had tissue available for pathologic re-review. The Ki-67 index was lower than 3% for 72 tumors (87%) and between 3 and 20% for 11 tumors (13%). Considering only Ki-67 less than 3%, the tumors were further stratified by Ki-67 into three groups: group A (< 1%, n = 43), group B (1-1.99%, n = 23), and group C (2-2.99%, n = 6). Compared with group A, groups B and C more frequently had advanced T stage (T3: 44% and 67% vs 12%; p = 0.003) and lymphovascular invasion (50% and 83% vs 23%; p = 0.007). Groups B and C had similar 1- and 3-year RFS, both less than group A. After combining groups B and C, a Ki-67 of 1-2.99% was associated with decreased RFS compared with group A (< 1%). This persisted in the multivariable analysis (hazard ratio [HR] 8.6; 95% confidence interval [CI] 1.0-70.7; p = 0.045), with control used for tumor size, margin-positivity, lymph node involvement, and advanced T stage.

CONCLUSIONS

PanNETs with a Ki-67 of 1-2.99% exhibit distinct biologic behavior and earlier disease recurrence than those with a Ki-67 lower than 1%. This new stratification scheme, if externally validated, should be incorporated into future grading systems to guide both surveillance protocols and treatment strategies.

Neoadjuvant peptide receptor radionuclide therapy and modified multivisceral transplantation for an advanced small intestinal neuroendocrine neoplasm: an updated case report

Small intestinal neuroendocrine neoplasms (SI-NEN) frequently metastasise to regional lymph nodes, and surgery is the mainstay of therapy for such patients. However, despite the possible use of advanced surgical techniques, the resection of both primary and locoregional diseases is not always attainable. Intestinal and multivisceral transplantation has been performed in a small number of patients with conventionally nonresectable, slow-growing tumours threatening the mesenteric root but has remained controversial. The use of donor skin in “sentinel flaps” in transplantation theoretically offers advantages in tailoring immunosuppression and monitoring for rejection. We represent (with extended follow-up) the first case of a patient with inoperable extensive mesenteric metastases from SI-NEN, who underwent neoadjuvant peptide receptor radionuclide therapy before a modified multivisceral transplant with a concomitant vascularised sentinel forearm flap. At 48 months after transplantation, our patient remained at full physical activity with no evidence of disease recurrence on either tumour biochemistry or radiological imaging.

Impact of Ki67 re-assessment at time of disease progression in patients with pancreatic neuroendocrine neoplasms

Background

Although re-assessment of proliferative activity by K67 evaluation during the course of neuroendocrine neoplasms (NENs) is recommended in selected patients, its impact on patients’ management is not clear due to the lack of data supporting this practice.

Aim

To investigate Ki67 change at time of progressive disease (PD) in entero-pancreatic NENs (EP-NENs).

Patients and methods

Retrospective analysis of sporadic EP-NENs which received histological re-assessment after PD once radiologically documented.

Results

Forty-three patients were evaluated, including 24 pancreatic NENs (PNENs), and 19 small intestine NENs (SI-NENs). At time of initial histological evaluation, 19 patients had grade 1 (G1) NETs (44.2%), and 24 grade 2 (G2) NETs (55.8%), overall median Ki67 being 3% (range 1%-20%). At time of PD, 13 patients had G1 NETs (30.2%), 26 G2 NETs (60.5%), and 4 had grade 3 (G3) NECs (9.3%), thus resulting in a significant median Ki67 increase (8%, range 1%-70%; p = 0.0006), and a G upgrading in 12 patients (27.9%). A statistically significant Ki67 increase and G grading change at time of PD was observed in PNENs (p = 0.0005 and p = 0.028, respectively). Conversely, no statistically significant change occurred in non-PNENs.

Conclusions

In PNENs with documented PD, Ki67 increase occurs in a significant proportion of patients, providing useful information necessary to choose appropriate therapeutic options.

Factors influencing Ki67 calculation in neuroendocrine neoplasia

Aim: We compared different methodologies to evaluate Ki67 in neuroendocrine neoplasia (NEN). Patients & methods: ki67 was evaluated using three methods in 70 NEN cases: manual-count, eyeballed estimate made by three pathologists and ImmunoRatio-software. Manual-count was the standard method and agreement with it was evaluated through intraclass correlation (ICC). Results: Agreement between manual-count and eyeballed estimate had ICC: 0.887–0.929. Eyeballed estimate by three pathologists produced upgradation in 5.7–32.9% and downgradation in 5.7% of NEN cases. Agreement for ImmunoRatio-count had ICC: 0.989. Immunoratio produced upgradation in 17.1% and downgradation in 8.5% cases. Agreement between all methods was higher at low-Ki67. Cellularity, immune-cell infiltration, staining and sample quality did not affect agreement. Conclusion: Eyeballed estimate and ImmunoRatio showed good accuracy, especially at low-Ki67.

Clinicopathological Features and Prognostic Factors of Colorectal Neuroendocrine Neoplasms

Background. Limited research is available regarding colorectal NENs and the prognostic factors remain controversial. Materials and Methods. A total of 68 patients with colorectal NENs were studied retrospectively. Clinical characteristics and prognosis between colonic and rectal NENs were compared. The Cox regression models were used to evaluate the predictive capacity. Results. Of the 68 colorectal NENs patients, 43 (63.2%) had rectal NENs, and 25 (36.8%) had colonic NENs. Compared with rectal NENs, colonic NENs more frequently exhibited larger tumor size (P < 0.0001) and distant metastasis (P < 0.0001). Colonic NENs had a worse prognosis (P = 0.027), with 5-year overall survival rates of 66.7% versus 88.1%. NET, NEC, and MANEC were noted in 61.8%, 23.5%, and 14.7% of patients, respectively. Multivariate analyses revealed that tumor location was not an independent prognostic factor (P = 0.081), but tumor size (P = 0.037) and pathological classification (P = 0.012) were independent prognostic factors. Conclusion. Significant differences exist between colonic and rectal NENs. Multivariate analysis indicated that tumor size and pathological classification were associated with prognosis. Tumor location was not an independent factor. The worse outcome of colonic NENs observed in clinical practice might be due not only to the biological differences, but also to larger tumor size in colonic NENs caused by the delayed diagnosis.

Reliability of Ki-67 Determination in FNA Samples for Grading Pancreatic Neuroendocrine Tumors

Neuroendocrine pancreatic tumors (PanNETs) are graded on the basis of their proliferative activity. Cytological samples are commonly the only samples available, but the determination of Ki-67 in cytology and its reliability as a measure of tumor mitotic activity is not well settled. We have retrospectively reviewed all the cases of FNA under EUS control of PanNETs in a 10-year period (2006-2016) in the Hospital Clínico San Carlos (Madrid). We identified 10 PanNET cases with histological correlation. Median age was 49.4 years and the patients were mainly women. PanNETs were located more frequently in the tail of the pancreas, with a median size of 33.8 mm. None of our cases was a grade 3 tumor. The seven grade 1 tumors confirmed in histology had consistent Ki-67 in cytology. In three cases (30 %), there were discrepancies between the Ki-67 index measured in cytology and histology, and the differences ranged from 2 to 15 %; all these cases were grade 2 tumors in histology and were graded as grade 1 tumors in FNA material. Our results are consistent with previous studies which showed understaging when tumor grade was assessed in cytological samples, mainly in G2 tumors. Previous literature has shown that Ki-67 assessment in EUS-FNA samples is a useful tool to rule out G3 tumors, but can be problematic for distinguishing G1 and G2 tumors.

MicroRNAs associated with small bowel neuroendocrine tumours and their metastases

Novel molecular analytes are needed in small bowel neuroendocrine tumours (SBNETs) to better determine disease aggressiveness and predict treatment response. In this study, we aimed to profile the global miRNome of SBNETs, and identify microRNAs (miRNAs) involved in tumour progression for use as potential biomarkers. Two independent miRNA profiling experiments were performed (n=90), including primary SBNETs (n=28), adjacent normal small bowel (NSB; n=14), matched lymph node (LN) metastases (n=24), normal LNs (n=7), normal liver (n=2) and liver metastases (n=15). We then evaluated potentially targeted genes by performing integrated computational analyses. We discovered 39 miRNAs significantly deregulated in SBNETs compared with adjacent NSB. The most upregulated (miR-204-5p, miR-7-5p and miR-375) were confirmed by qRT-PCR. Two miRNAs (miR-1 and miR-143-3p) were significantly downregulated in LN and liver metastases compared with primary tumours. Furthermore, we identified upregulated gene targets for miR-1 and miR-143-3p in an existing SBNET dataset, which could contribute to disease progression, and show that these miRNAs directly regulate FOSB and NUAK2 oncogenes. Our study represents the largest global miRNA profiling of SBNETs using matched primary tumour and metastatic samples. We revealed novel miRNAs deregulated during SBNET disease progression, and important miRNA-mRNA interactions. These miRNAs have the potential to act as biomarkers for patient stratification and may also be able to guide treatment decisions. Further experiments to define molecular mechanisms and validate these miRNAs in larger tissue cohorts and in biofluids are now warranted.

Can PPH3 be helpful to assess the discordant grade in primary and metastatic enteropancreatic neuroendocrine tumors?

Therapeutic strategy in neuroendocrine tumors (NETs) is based on histological characteristics of the primary tumor (PT), even in case of metastatic disease. Our aim was to compare the tumor grade between PT and their liver metastases (LM) in patients with enteropancreatic NETs. Forty-one patients treated for sporadic NETs (10 pancreatic, 31 intestinal) were included. All presented synchronous (35) or metachronous (6) LM. Tumor grade was evaluated for PT and LM according to the WHO classification, using Ki-67 labeling and mitotic count (MC) evaluated with or without phospho-histone H3 (PPH3). Tumor grade differed between primary and metastatic tumor in 16/41 patients (39 %), with an increase of grade in 13 of them (32 %). The median Ki-67, MC, and PPH3 in metastases were statistically higher than in PT (p = 0.0002, 0.02, and 0.01). In 17 of 65 cases tested with PPH3 (26 %), this antibody was more efficient in assessing the grade compared to the usual MC, and in 2/65 cases compared to the Ki-67. A better correlation was observed between Ki-67 and PPH3 (p = 0.0001) than between Ki-67 and MC without immunohistochemistry. There is a significant difference in tumor grade between primary and metastatic NETs, underlining the necessity of a systematic biopsy on LM for patient management. Moreover, PPH3 appears to be a powerful antibody to assess the MC and the tumor grade much more accurately when associated with Ki-67.

The ENETS/WHO grading system for neuroendocrine neoplasms of the gastroenteropancreatic system: a review of the current state, limitations and proposals for modifications

The understanding of neuroendocrine neoplasms has evolved significantly since their initial descriptions in the 1800s to early 1900s. In the gastroenteropancreatic system, this group of malignant tumors is subdivided into well and poorly differentiated neuroendocrine neoplasms based on morphologic, proliferative and biologic differences. However, it has become increasingly apparent that well-differentiated neuroendocrine tumors are not a homogeneous group. Attempting to better predict outcome of these tumors has been the motivation behind numerous proposed classification systems, the evolution of which culminated with the currently used system, the ENETS/WHO classification. Herein, we review the genesis of this classification system and some of its shortcomings. In addition, we discuss some of the most recent proposals that suggest modifications to the current system.

Evaluation of the concordance between the stage of the disease and Ki-67 proliferation index in gastroenteropancreatic neuroendocrine tumors

AIM

This study aimed to determine the degree of concordance between TNM staging used in the determination of the prognosis of gastroenteropancreatic neuroendocrine tumor (GEP-NET) patients and the Ki-67 proliferation index value used in the grading of these tumors and investigate the most reliable prognostic parameter among them.

MATERIALS AND METHODS

The medical files of the patients with GEP-NET who were diagnosed or followed up in Erciyes University Faculty of Medicine were retrospectively examined and demographic characteristics, survival times, grade of these tumors, histopathologically detected Ki-67 values, and histopathological characteristics were recorded and evaluated statistically.

RESULTS

The mean age (53.09±14.6 years; range, 16-85 years) of all (n=141) the patients was estimated. The patient population included 72 (51.1%) female and 69 (48.9%) male patients, with a male/female ratio of 0.95. The most frequently encountered primary sites were the stomach (33.3%), and then in decreasing oder of frequency the pancreas (27%), colon-rectum (15.6%), the small intestine (12.8%), and the appendix (11.3%). The GEP-NET of the patients was in grade 1 (G1) (n: 103; 73%), grade 2 (G2) (n: 24; 17%), and grade 3 (G3) (n: 14; 10%). The GEP-NET of the patients was stage I (n: 66; 46.8%), stage II (n: 14; 9.9%), stage III (n: 12; 8.5%), and stage IV (n: 49; 34.8%). In the statistical analysis, Ki-67 increased in parallel with the stage of the disease (P<0.001). As Ki-67 increased at a rate of 1%, survival rates of the patients decreased 1.027 times (P=0.01). Five-year survival rates of the patients were 88% in G1, 44% in G2, and 24% in G3. Patients in G2 and G3 had a 6.67 and 12.38 times lower chance of survival compared with G1 patients, respectively. Survival rates of stage IV patients were 5.6 times lower relative to stages I and II patients, respectively (P<0.001). The median 5-year survival rates of the patients were 90% in stage I, 100% in stage II, 47% in stage III, and 46% in stage IV. In univariate analysis, age of the patients, grade, stage of the tumor, and lymph node metastases were found to be parameters that affected overall survival, whereas no significant correlation was found between the sex of the patient and the primary organ from which the tumor originated and survival rates. However, in the multivariate analysis, survival rates decreased inversely with age, whereas no significant correlation was found between grade and stage of the tumor and survival rates.

CONCLUSION

In conclusion, a decrease in the average survival rate in parallel with an increase in the grade of the tumor was more prominent compared with a decrease in survival rates in accordance with an increase in the stage of the tumor. This indicates that in the prediction of prognosis in patients with GEP-NET, the Ki-67 value can be a more important evaluation factor relative to staging.

Gastro-entero-pancreatic neuroendocrine tumors: Is now time for a new approach?

Gastro-entero-pancreatic tumors (GEP-NETs) are rare neoplasms often characterized by an overexpression of somatostatin receptors. Thus, radiolabeled somatostatin analogues have showed an increasing relevance both in diagnosis and treatment, especially in low- and intermediate-differentiated GEP-NETs. These evidences have led to a growing development of new functional imaging techniques as 68Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) proved useful in the management of these neoplasms. However these tumors have a heterogeneous behavior also modifying their aggressiveness through time. Therefore sometimes 18F-fluorodeoxyglucose PET/CT appears to be more appropriate to obtain a better assessment of the disease. According to these considerations, the combination of different functional imaging techniques should be considered in the management of GEP-NETs patients allowing clinicians to choose the tailored therapeutic approach among available options.

Ki-67 expression in luminal type breast cancer and its association with the clinicopathology of the cancer

The aim of the present study was to examine Ki-67 expression in tissue of luminal type breast cancer and to investigate the association between the Ki-67 expression level and clinicopathology of breast cancer. A total of 62 patients with breast cancer were included in the study group, whereas 30 patients undergoing a health check-up who were diagnosed with breast hyperplasia were included in the control group. Levels of Ki-67 expression in patients of the two groups were assessed using fluorescent quantitative polymerase chain reaction. The association between Ki-67 and the clinicopathology of the cancer was investigated by analyzing cancer cell proliferation and migration by reducing Ki-67 expression in the human MCF-7 cancer cell line. Compared with the controls, Ki-67 expression was significantly increased in the serum and cancer tissue of breast cancer patients (P<0.05). Ki-67 mRNA expression was significantly higher in cancer tissue than that in the corresponding paracancerous tissue of breast cancer (P<0.05). In addition, a high expression of Ki-67 was positively correlated with the clinical staging of tumor, tumor size and lymphatic metastasis of breast cancer, with statistical significance (P<0.05). In MCF-7 cells with a reduced Ki-67 expression, the proliferation activity and migration of breast cancer cells were significantly reduced (P<0.05). In conclusion, Ki-67 may be involved in promoting the genesis and development of breast cancer by affecting the proliferation and migration of cancer cells.

Role of Staging in Patients with Small Intestinal Neuroendocrine Tumours

Small bowel neuroendocrine tumours are the commonest malignancy arising in the small intestine and have substantially increased in incidence in recent decades. Patients with small bowel neuroendocrine tumours commonly develop lymph node and/or distant metastases. Here, we examine the role of staging in 84 surgically treated patients with small bowel neuroendocrine tumours, comparing diagnostic information yielded from morphological, functional and endoscopic modalities. Furthermore, we correlate pre-operative staging with intra-operative findings in a sub-cohort of 20 patients. The vast majority of patients had been histologically confirmed to have low-grade (Ki-67 <2%) disease; however, lymph node and distant metastases were observed in 74 (88.1%) and 51 (60.7%) of patients at presentation, respectively. Liver metastases were evident in 48 (57.1%) patients, with solely peritoneal and bone metastases observed in 2 (2.4%) and 1 (1.2%) patients, respectively. Forty patients (47.6%) received multimodal treatment. In our sub-cohort analysis, pre-operative imaging understaged disease in 14/20 (70%) when compared with intra-operative findings. In patients with multifocal primary tumours and miliary liver metastases, no imaging modality was able to detect entire disease spread. Overall, presently available imaging modalities heavily underestimate disease stage, with meticulous intra-operative abdominal examination being superior to any imaging technology. Multimodal treatment has an important role in prolonging survival.

Grade Increases in Gastroenteropancreatic Neuroendocrine Tumor Metastases Compared to the Primary Tumor

BACKGROUND/AIM

The neuroendocrine tumor (NET) proliferation-based grading system (ENETS/WHO) for gastroenteropancreatic (GEP) tumors has proved reliable for prognostic stratification. To date, concerns exist regarding Ki-67 heterogeneity within the tumor and little is known on whether grade varies between primary and secondary sites. As tumor heterogeneity may have a significant impact on clinical management, our aim was to retrospectively evaluate Ki-67 on a series of GEP NETs in order to establish whether there is variability in different samples of the same lesion or between primary and metastatic disease (local/distant, synchronous/metachronous).

METHODS

Sixty patients with multiple samples of tumor were accrued from a total of 338 GEP NETs; 44 of them also had tissue from local/distant metastases and a further 5 had multiple metastatic foci from unknown primary tumors. Immunohistochemistry for Ki-67 was performed on all paraffin blocks from both primary and metastatic tumors.

RESULTS

Intratumor Ki-67 heterogeneity sufficient to change grade at first diagnosis was seen in 3/60 cases (5%). Out of 49 patients with primary NETs and/or multiple metastases, discrepancy in grade between sites was identified in 19 (39%) cases and in particular in 11/47 (23%) and in 10/12 (83%) patients with synchronous and metachronous metastases, respectively (p = 0.0002). Change in grade was more frequent in distant compared to locoregional metastases (p = 0.024) and in particular in distant sites other than the liver (p = 0.006).

CONCLUSIONS

NETs show frequent differences in grade between primary sites and their synchronous/metachronous metastases; assessment of Ki-67 at all sites may prove to be significant for patient management.

Prediction of survival and tumor recurrence in patients undergoing surgery for pancreatic neuroendocrine neoplasms

BACKGROUND

This study strives to define prognostic models for outcome after surgery for malignant pancreatic neuroendocrine tumors.

METHODS

Forty-one patients were included. Prognostic models for mortality and disease recurrence were developed with multivariate binary logistic regression.

RESULTS

The proposed prognostic model for tumor recurrence risk after surgery in percentage (AUROC = 0.774, 95%CI = 0.611-0.937) is: Risk in % = Exp(Y)/(1 + Exp(Y)), with Y = -4.360 + (0.015 × tumor diameter in cm) + (0.010 × preoperative platelet count in thousand/μl) + (1.077 × distant metastases, if yes = 1; if no = 0) + (-0.026 × Ki-67-positive cells in %) + (-1.086 × upper abdominal pain, if yes = 1; if no = 0). The proposed prognostic model for observed 3-year survival probability after surgery in % (AUROC = 0.932, 95%CI = 0.857-0.999) is: Survival probability in % = Exp(Y)/(1 + Exp(Y)), with Y = -12.492 + (0.054 × preoperative platelet count in thousand/μl) + (0.112 × minimal distance of the resection margin from the tumor in mm) + (-1.574 × number of positive lymph nodes) + (2.292 × histological tumor infiltration, if yes = 1; if no = 0) CONCLUSIONS: The platelet count was identified as a relevant risk factor. Proposed prognostic models with good model-fit display properties that indicate potential clinical usefulness.