Luca Albarello

TNM Staging of Neoplasms of the Endocrine Pancreas: Results From a Large International Cohort Study

BACKGROUND Both the European Neuroendocrine Tumor Society (ENETS) and the International Union for Cancer Control/American Joint Cancer Committee/World Health Organization (UICC/AJCC/WHO) have proposed TNM staging systems for pancreatic neuroendocrine neoplasms. This study aims to identify the most accurate and useful TNM system for pancreatic neuroendocrine neoplasms. METHODS The study included 1072 patients who had undergone previous surgery for their cancer and for which at least 2 years of follow-up from 1990 to 2007 was available. Data on 28 variables were collected, and the performance of the two TNM staging systems was compared by Cox regression analysis and multivariable analyses. All statistical tests were two-sided. RESULTS Differences in distribution of sex and age were observed for the ENETS TNM staging system. At Cox regression analysis, only the ENETS TNM staging system perfectly allocated patients into four statistically significantly different and equally populated risk groups (with stage I as the reference; stage II hazard ratio [HR] of death = 16.23, 95% confidence interval [CI] = 2.14 to 123, P = .007; stage III HR of death = 51.81, 95% CI = 7.11 to 377, P < .001; and stage IV HR of death = 160, 95% CI = 22.30 to 1143, P < .001). However, the UICC/AJCC/WHO 2010 TNM staging system compressed the disease into three differently populated classes, with most patients in stage I, and with the patients being equally distributed into stages II-III (statistically similar) and IV (with stage I as the reference; stage II HR of death = 9.57, 95% CI = 4.62 to 19.88, P < .001; stage III HR of death = 9.32, 95% CI = 3.69 to 23.53, P = .94; and stage IV HR of death = 30.84, 95% CI = 15.62 to 60.87, P < .001). Multivariable modeling indicated curative surgery, TNM staging, and grading were effective predictors of death, and grading was the second most effective independent predictor of survival in the absence of staging information. Though both TNM staging systems were independent predictors of survival, the UICC/AJCC/WHO 2010 TNM stages showed very large 95% confidence intervals for each stage, indicating an inaccurate predictive ability. CONCLUSION Our data suggest the ENETS TNM staging system is superior to the UICC/AJCC/WHO 2010 TNM staging system and supports its use in clinical practice.

Improved histologic and clinicopathologic criteria for prognostic evaluation of pancreatic endocrine tumors

Currently used histopathologic criteria for the diagnosis of pancreatic endocrine tumors are still under discussion as far as to their capacity to identify prognostically different tumor subsets, which are potentially helpful for patient management. A recently developed TNM staging system and a variety of proposed histologic and clinicopathologic parameters still need to be fully validated. One hundred fifty-five pancreatic endocrine tumors encompassing all the main histologic types and stages, operated with intention to cure and then followed up for a median 126 months, were carefully investigated histologically to identify prognostically informative parameters at univariable, bivariable, and multivariable analysis. Ki67 index, mitotic rate, neuroinvasion with or without vascular, peritumoral or stromal infiltrative patterns, as well as tumor size, and association with endocrine syndromes other than insulinoma proved effective in predicting recurrence and disease-specific death among well-differentiated tumors. Poorly differentiated histologic features, more than 10 mitoses/10 high power fields, and necrosis were helpful in the identification of high-grade cancers with an invariably poor prognosis. The TNM system proved to be highly predictive of patient outcome and easy to combine with histologic and clinicopathologic parameters to classify pancreatic endocrine tumors into groups of increasing malignant potential.

HER2 testing in gastric cancer.

Molecular therapies targeting HER2 are part of the established drug armamentarium in breast carcinoma. Now the ToGA trial, an international multicenter phase III clinical study, involving 24 countries globally, has shown that the anti-HER2 humanized monoclonal antibody Trastuzumab is effective in prolonging survival in HER2-positive carcinoma of the stomach and the gastroesophageal junction (GEJ). Similarly to breast carcinoma, >20% of gastric cancers show HER2 overexpression and/or amplification, and this percentage increases to 33% in GEJ tumors. Thus, as in breast carcinoma, pathologists are now asked to evaluate HER2 status in gastric carcinoma samples. As validated in the ToGA trial, the HER2 testing criteria that must be used in evaluating both gastric carcinoma biopsies and surgical specimens significantly differ from those routinely applied in breast carcinoma. The main variations with regard to the pattern of reactivity in HER2-expressing cells are as follows: the completeness of membrane staining is not a “conditio sine qua non” and the number of stained cells necessary to consider a case as positive is different. We must also take note of the much more frequent heterogeneity of HER2 positivity in gastric cancer compared with breast carcinoma and the less stringent correlation between HER2 amplification and protein overexpression that is observed in gastric carcinoma, where more than 20% of cases may carry HER2 amplification, although of low level, without HER2 expression. In these patients, in the ToGA trial, there was no apparent benefit from adding Trastuzumab to chemotherapy: for this reason the European Medicines Agency, while approving usage of Trastuzumab for metastatic adenocarcinoma treatment, indicated HER2 testing by immunohistochemistry as first evaluation assay, followed by fluorescence in situ hybridization in 2+ equivocal cases. HER2 testing in gastric carcinoma is a new field, opening several opportunities: for patients with gastric cancer, this is a new promising therapeutic option; for pathologists, strengthening our role in therapy selection and emphasizing our duty of providing accurate and reproducible HER2 testing results; for all interested in understanding the biology of gastric and GEJ cancer and in discovering new possible molecular therapy targets.

The Chemokine Receptor CX3CR1 Is Involved in the Neural Tropism and Malignant Behavior of Pancreatic Ductal Adenocarcinoma

Tumor perineural dissemination is a hallmark of human pancreatic ductal adenocarcinoma (PDAC) and represents a major source of local tumor recurrence after surgery. In this study, we provide in vitro and in vivo evidence that the chemokine receptor CX3CR1 may be involved in the neurotropism of PDAC cells to local peripheral nerves. Neoplastic cells from PDAC cell lines and surgical specimens express the chemokine receptor CX3CR1, absent in normal pancreatic ducts. Its unique ligand, the transmembrane chemokine CX3CL1, is expressed by neurons and nerve fibers. CX3CR1 + PDAC cell lines migrated in response to human recombinant CX3CL1 and specifically adhered to CX3CL1-expressing cells of neural origin via mechanisms involving activation of G proteins, beta1 integrins, and focal adhesion kinase. In vivo experiments with transplanted PDAC showed that only CX3CR1-transfected tumor cells infiltrated the local peripheral nerves. Immunohistochemistry of CX3CR1 in PDAC specimens revealed that 90% of the samples were positive with a heterogeneous pattern of expression. High receptor score was significantly associated with more prominent tumor perineural infiltration evaluated histologically (P = 0.026). Regression analyses (univariate and multivariate) showed that high CX3CR1 expression and perineural invasion were strongly associated with local and earlier tumor recurrence (P = 0.007). Collectively, this study shows that the CX3CR1 receptor may be involved in PDAC tumor neurotropism and is a relevant and independent risk factor to predict an early local tumor relapse in resected patients. Thus, the CX3CR1-CX3CL1 axis could represent a valuable therapeutic target to prevent tumor perineural dissemination in pancreatic cancer.

Clinicopathologic Study of 62 Acinar Cell Carcinomas of the Pancreas: Insights Into the Morphology and Immunophenotype and Search for Prognostic Markers.

Acinar cell carcinoma (ACC) of the pancreas is a very rare tumor that has various morphologic features, which may give rise to diagnostic difficulties. Because of its rarity, many clinicopathologic characteristics remain to be further elucidated, and prognostic factors are yet to be well established. With the aim of better characterizing this carcinoma and searching for prognostic indicators, we collected 62 ACCs and investigated the following parameters: site, size, local infiltration, node and distant metastases, architectural pattern, nuclear atypia, presence of necrosis, lymphovascular and perineural invasion, proliferation, BCL10, trypsin, carboxyl ester lipase, amylase, lipase, PDX1, cytokeratin 19 (CK19), CK7, p53, and &bgr;-catenin expression. Twelve cases showing >30% of endocrine cells were reclassified as mixed acinar-neuroendocrine carcinomas, whereas 1 tumor was reclassified as a mixed ductal-acinar carcinoma and was excluded from the statistical prognostic evaluations. BCL10 and trypsin were the most reliable immunohistochemical markers, whereas amylase and lipase were not. Surgery was statistically correlated with a better prognosis (P=0.0008). Among resected tumors there was no difference in survival between ACCs and mixed acinar-neuroendocrine carcinomas, and factors that significantly correlated with poor prognosis were size >6.5 cm (P=0.004), lymph node (P=0.0039) and distant (P=0.008) metastases, and UICC stage (P=0.009). Stage was the only independent prognostic factor at multivariable analysis, and the best prognostic discrimination was observed on grouping together stages I and II and grouping together stages III and IV, suggesting a simplification of the UICC staging for such cancers. In addition, vascular and perineural invasion and CK19 and p53 expression showed a trend for poor prognosis, not reaching statistical significance.

MEN1 in pancreatic endocrine tumors: analysis of gene and protein status in 169 sporadic neoplasms reveals alterations in the vast majority of cases

Pancreatic endocrine tumors (PETs) may be part of hereditary multiple endocrine neoplasia type 1 (MEN1) syndrome. While MEN1 gene mutation is the only ascertained genetic anomaly described in PETs, no data exist on the cellular localization of MEN1-encoded protein, menin, in normal pancreas and PETs. A total of 169 PETs were used to assess the i) MEN1 gene mutational status in 100 clinically sporadic PETs by direct DNA sequencing, ii) immunohistochemical expression of menin in normal pancreas and 140 PETs, including 71 cases screened for gene mutations, and iii) correlation of these findings with clinical-pathological parameters. Twenty-seven PETs showed mutations that were somatic in 25 patients and revealed to be germline in 2 patients. Menin immunostaining showed strong nuclear and very faint cytoplasmic signal in normal islet cells, whereas it displayed abnormal location and expression levels in 80% of tumors. PETs harboring MEN1 truncating mutations lacked nuclear protein, and most PETs with MEN1 missense mutations showed a strong cytoplasmic positivity for menin. Menin was also misplaced in a significant number of cases lacking MEN1 mutations. In conclusion, the vast majority of PETs showed qualitative and/or quantitative alterations in menin localization. In 30% of cases, this was associated with MEN1 mutations affecting sequences involved in nuclear localization or protein-protein interaction. In cases lacking MEN1 mutations, the alteration of one of the menin interactors may have prevented its proper localization, as suggested by recent data showing that menin protein shuttles between the nucleus and cytoplasm and also affects the subcellular localization of its interactors.

Endoscopic ultrasound-guided application of a new hybrid cryotherm probe in porcine pancreas: A preliminary study

BACKGROUND AND STUDY AIMS Open, laparoscopic, or percutaneous radiofrequency (RF) ablation of the pancreas is still dangerous, whereas endoscopic ultrasound (EUS)-guided ablation might reduce risk because it is less invasive and provides real-time monitoring. We aimed to demonstrate the feasibility of transluminal RF ablation and to evaluate the efficacy and safety of a new flexible bipolar ablation probe combining RF and cryotechnology. METHODS 14 ablations were performed in 14 pigs. Energy input (16 W) and simultaneous cryogenic cooling with carbon dioxide (650 psi) were standardized. Application time range was 120 - 900 seconds. Ablation area was measured by EUS immediately after ablation (area T0), and before euthanasia (area T1). Macroscopic findings (area T2) and histological findings after necropsy served as gold standard. The interval from application to euthanasia was either 1 or 2 weeks. RESULTS The correlation between EUS findings (area T1) and macroscopic appearance (area T2) was good ( R = 0.89). The correlation between the T2 ablation area and the application time showed a fitted ratio of 2.3 ( P < 0.0001) with a 1-week interval and 0.2 ( P = 0.01) with a 2-week interval. No pig died because of the procedure. Two pigs showed histochemical pancreatitis, which was clinically overt in one. Necropsy additionally revealed one burn to the gastric wall and four gut adhesions. CONCLUSIONS Selective transluminal RF ablation of the pancreas under EUS control in a living pig model is feasible. The new flexible bipolar probe creates an ablation area with extent related to the duration of application, and with fewer complications than conventional RF ablation techniques.

Cytological Ki-67 in pancreatic endocrine tumours: An opportunity for pre-operative grading

The cytological Ki-67 expression measured on cytological samples collected by endoscopic ultrasonography-guided fine needle aspiration cytology (EUS-FNAC) may provide pre-operative indications for pancreatic endocrine tumours (PETs) management. The aim of our study was to assess reliability of Ki-67 expression measured on cytological samples obtained by EUS-FNAC in patients with PETs. Eighteen patients with PETs underwent EUS-FNAC before surgery. Ki-67 expression was measured on FNACs and on histological sections. Using a cut-off of 2%, percent agreement of Ki-67 expression on cytological and histological samples was 89% (k-statistic: 0.78, 95% confidence intervals (95% CI): 0.5, 1.0). Using cut-off values of 2 and 10%, percent agreement was 78% (k-statistic: 0.65, 95% CI: 0.3, 0.9). Ki-67 expression measured on cytological samples obtained by EUS-FNAC before surgery showed good agreement with that measured on histological samples.

Carcinoembryonic Antigen-Specific but Not Antiviral CD4+ T Cell Immunity Is Impaired in Pancreatic Carcinoma Patients

Pancreatic carcinoma is a very aggressive disease with dismal prognosis. Although evidences for tumor-specific T cell immunity exist, factors related to tumor microenvironment and the presence of immunosuppressive cytokines in patients’ sera have been related to its aggressive behavior. Carcinoembryonic Ag (CEA) is overexpressed in 80–90% of pancreatic carcinomas and contains epitopes recognized by CD4+ T cells. The aim of this study was to evaluate the extent of cancer-immune surveillance and immune suppression in pancreatic carcinoma patients by comparing the anti-CEA and antiviral CD4+ T cell immunity. CD4+ T cells from 23 normal donors and 44 patients undergoing surgical resection were tested for recognition of peptides corresponding to CEA and viral naturally processed promiscuous epitopes by proliferation and cytokine release assays. Anti-CEA CD4+ T cell immunity was present in a significantly higher number of normal donors than pancreatic cancer patients. Importantly, whereas CD4+ T cells from normal donors produced mainly GM-CSF and IFN-γ, CD4+ T cells from the patients produced mainly IL-5, demonstrating a skew toward a Th2 type. On the contrary, the extent of antiviral CD4+ T cell immunity was comparable between the two groups and showed a Th1 type. The immunohistochemical analysis of tumor-infiltrating lymphocytes showed a significantly higher number of GATA-3+ compared with T-bet+ lymphoid cells, supporting a Th2 skew also at the tumor site. Collectively, these results demonstrate that Th2-immune deviation in pancreatic cancer is not generalized but tumor related and suggests that the skew might be possibly due to factor(s) present at the tumor site.

Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms.

This report contains clinically oriented guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms in patients fit for treatment. The statements were elaborated by working groups of experts by searching and analysing the literature, and then underwent a consensus process using a modified Delphi procedure. The statements report recommendations regarding the most appropriate use and timing of various imaging techniques and of endoscopic ultrasound, the role of circulating and intracystic markers and the pathologic evaluation for the diagnosis and follow-up of cystic pancreatic neoplasms.