Proposal for a New Pathologic Prognostic Index After Neoadjuvant Chemotherapy in Pancreatic Ductal Adenocarcinoma (PINC).

BACKGROUND: Limited information is available on the relevant prognostic variables after surgery for patients with pancreatic ductal adenocarcinoma (PDAC) subjected to neoadjuvant chemotherapy (NACT). NACT is known to induce a spectrum of histological changes in PDAC. Different grading regression systems are currently available; unfortunately, they lack precision and accuracy. We aimed to identify a new quantitative prognostic index based on tumor morphology. PATIENTS AND METHODS: The study population was composed of 69 patients with resectable or borderline resectable PDAC treated with preoperative NACT (neoadjuvant group) and 36 patients submitted to upfront surgery (upfront-surgery group). A comprehensive histological assessment on hematoxylin and eosin (H&E) stained sections evaluated 20 morphological parameters. The association between patient survival and morphological variables was evaluated to generate a prognostic index. RESULTS: The distribution of morphological parameters evaluated was significantly different between upfront-surgery and neoadjuvant groups, demonstrating the effect of NACT on tumor morphology. On multivariate analysis for patients that received NACT, the predictors of shorter overall survival (OS) and disease-free survival (DFS) were perineural invasion and lymph node ratio. Conversely, high stroma to neoplasia ratio predicted longer OS and DFS. These variables were combined to generate a semiquantitative prognostic index based on both OS and DFS, which significantly distinguished patients with poor outcomes from those with a good outcome. Bootstrap analysis confirmed the reproducibility of the model. CONCLUSIONS: The pathologic prognostic index proposed is mostly quantitative in nature, easy to use, and may represent a reliable tumor regression grading system to predict patient outcomes after NACT followed by surgery for PDAC.

68Ga-DOTATOC PET/MR imaging and radiomic parameters in predicting histopathological prognostic factors in patients with pancreatic neuroendocrine well-differentiated tumours.

PURPOSE: To explore the role of fully hybrid 68Ga-DOTATOC PET/MR imaging and radiomic parameters in predicting histopathological prognostic factors in patients with pancreatic neuroendocrine tumours (PanNETs) undergoing surgery. METHODS: One hundred eighty-seven consecutive 68Ga-DOTATOC PET/MRI scans (March 2018-June 2020) performed for gastroenteropancreatic neuroendocrine tumour were retrospectively evaluated; 16/187 patients met the eligibility criteria (68Ga-DOTATOC PET/MRI for preoperative staging of PanNET and availability of histological data). PET/MR scans were qualitatively and quantitatively interpreted, and the following imaging parameters were derived: PET-derived SUVmax, SUVmean, somatostatin receptor density (SRD), total lesion somatostatin receptor density (TLSRD), and MRI-derived apparent diffusion coefficient (ADC), arterial and late enhancement, necrosis, cystic degeneration, and maximum diameter. Additionally, first-, second-, and higher-order radiomic parameters were extracted from both PET and MRI scans. Correlations with several PanNETs' histopathological prognostic factors were evaluated using Spearman's coefficient, while the area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to evaluate parameters' predictive performance. RESULTS: Primary tumour was detected in all 16 patients (15/16 by 68Ga-DOTATOC PET and 16/16 by MRI). SUVmax and SUVmean resulted good predictors of lymphnodal (LN) involvement (AUC of 0.850 and 0.783, respectively). Second-order radiomic parameters GrayLevelVariance and HighGrayLevelZoneEmphasis extracted from T2 MRI demonstrated significant correlations with LN involvement (adjusted p = 0.009), also showing good predictive performance (AUC = 0.992). CONCLUSION: This study demonstrates the role of the fully hybrid PET/MRI tool for the synergic function of imaging parameters extracted by the two modalities and highlights the potentiality of imaging and radiomic parameters in assessing histopathological features of PanNET aggressiveness.

Predictors of disease recurrence after curative surgery for nonfunctioning pancreatic neuroendocrine neoplasms (NF-PanNENs): a systematic review and meta-analysis.

PURPOSE: Patients submitted to curative surgery for non-functioning pancreatic neuroendocrine neoplasms (NF-PanNENs) exhibit a variable risk of disease relapse. Aims of this meta-analysis were to estimate the rate of disease recurrence and to investigate the risk factors for disease relapse in patients submitted to curative surgery for NF-PanNENs. METHODS: Medline/Pubmed and Web of Science databases were searched for relevant studies. A meta-regression analysis was performed to investigate the source of recurrence rate heterogeneity. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CI) were used to assess the effect of each possible prognostic factor on disease-free survival. RESULTS: Fifteen studies, involving 2754 patients submitted to curative surgery for NF-PanNENs, were included. The pooled rate of disease recurrence was 21% (95% CI 15-26%). Study quality (Odds ratio, OR 0.94, P = 0.016) and G3-PanNENs rate (OR 2.18, P = 0.040) independently predicted the recurrence rate variability. Nodal metastases (HR 1.63, P < 0.001), tumor grade G2-G3 (G1 versus G2: HR 1.72, P < 0.001, G1 versus G3 HR 2.57, P < 0.001), microvascular (HR 1.25, P = 0.046) and perineural (HR 1.29, P = 0.019) invasion were identified as significant prognostic factors. T stage (T1-T2 versus T3-T4, P = 0.253) and status of resection margins (R0 versus R1, P = 0.173) did not show any significant relationship with NF-PanNENs recurrence. CONCLUSION: Disease relapse occurs in approximately one out of five patients submitted to curative surgery for NF-PanNENs. Nodal involvement, tumor grade, microvascular and perineural invasion are relevant prognostic factors, that should be taken into account for follow-up and for possible trials investigating adjuvant or neoadjuvant treatments.

Role of chromogranin A-derived fragments after resection of nonfunctioning pancreatic neuroendocrine tumors.

PURPOSE: No single reliable biomarker is available for nonfunctioning pancreatic neuroendocrine tumors (NF-PanNETs). Vasostatin-1 (VS-1), the N-terminal fragment of chromogranin A (CgA), seems to be a more accurate biomarker compared to its precursor. Primary aim was to investigate the ability of VS-1, compared to total-CgA, to assess the effectiveness of surgical resection performed for NF-PanNETs. Secondary aim was to evaluate two additional CgA-derived fragments, pancreastatin (PST) and vasostatin-2 (VS-2), as possible biomarkers for NF-PanNETs. METHODS: Consecutive patients who underwent surgery for NF-PanNETs at San Raffaele Scientific Institute were included (n = 35). Plasma levels of CgA and CgA-derived fragments were measured by Enzyme-Linked ImmunoSorbent Assay (ELISA), preoperatively and postoperatively. RESULTS: Preoperative VS-1 was significantly higher compared to VS-1 measured on postoperative day 5 (POD5) (pre: 0.338 nM versus POD5: 0.147 nM, P < 0.001), whereas total-CgA significantly increased after surgery (pre: 1.123 nM versus POD5: 1.949 nM, P = 0.006). Overall, 24 patients showed ≥ 1 feature of tumor aggressiveness (T3-T4, nodal/distant metastases, Ki67 > 5%, microvascular/perineural invasion, necrosis). The median percentage decrease in VS-1 plasma levels was 63% (IQR 28-88%) among patients with aggressive tumors, compared to 13% (IQR 0-57%) in the remaining population (P = 0.033). No significant differences in terms of PST (P = 0.870) and VS-2 (P = 0.909) were observed between preoperative and postoperative time. CONCLUSION: VS-1 provides an early assessment of surgical efficacy in patients who undergo resection for NF-PanNETs, especially in those with aggressive neoplasms. Total-CgA, PST and VS-2 have no clinical utility in this setting.

A multigenomic liquid biopsy biomarker for neuroendocrine tumor disease outperforms CgA and has surgical and clinical utility.

BACKGROUND: Biomarkers are key tools in cancer management. In neuroendocrine tumors (NETs), Chromogranin A (CgA) was considered acceptable as a biomarker. We compared the clinical efficacy of a multigenomic blood biomarker (NETest) to CgA over a 5-year period. PATIENTS AND METHODS: An observational, prospective, cross-sectional, multicenter, multinational, comparative cohort assessment. Cohort 1: NETest evaluation in NETs (n = 1684) and cancers, benign diseases, controls (n = 731). Cohort 2: (n = 1270): matched analysis of NETest/CgA in a sub-cohort of NETs (n = 922) versus other diseases and controls (n = 348). Disease status was assessed by response evaluation criteria in solid tumors (RECIST). NETest measurement: qPCR [upper limit of normal (ULN: 20)], CgA (EuroDiagnostica, ULN: 108 ng/ml). STATISTICS: Mann-Whitney U-test, AUROC, chi-square and McNemar' test. RESULTS: Cohort 1: NETest diagnostic accuracy was 91% (P < 0.0001) and identified pheochromocytomas (98%), small intestine (94%), pancreas (91%), lung (88%), gastric (80%) and appendix (79%). NETest reflected grading: G1: 40 ± 1, G2 (50 ± 1) and G3 (52 ± 1). Locoregional disease levels were lower (38 ± 1) than metastatic (52 ± 1, P < 0.0001). NETest accurately stratified RECIST-assessed disease extent: no disease (21 ± 1), stable (43 ± 2), progressive (62 ± 2) (P < 0.0001). NETest concordance with imaging (CT/MRI/68Ga-SSA-PET) 91%. Presurgery, all NETs (n = 153) were positive (100%). After palliative R1/R2 surgery (n = 51) all (100%) remained elevated. After curative R0-surgery (n = 102), NETest levels were normal in 81 (70%) with no recurrence at 2 years. In the 31 (30%) with elevated levels, 25 (81%) recurred within 2 years. Cohort #2: NETest diagnostic accuracy was 87% and CgA 54% (P < 0.0001). NETest was more accurate than CgA for grading (chi-square = 7.7, OR = 18.5) and metastatic identification (chi-square = 180, OR = 8.4). NETest identified progressive disease (95%) versus CgA (57%, P < 0.0001). Imaging concordance for NETest was 91% versus CgA (46%) (P < 0.0001). Recurrence prediction after surgery was NETest-positive in >94% versus CgA 11%. CONCLUSION: NETest accurately diagnoses NETs and is an effective surrogate marker for imaging, grade, metastases and disease status compared to CgA. A multigenomic liquid biopsy is an accurate biomarker of NET disease.

Actual malignancy risk of either operated or non-operated presumed mucinous cystic neoplasms of the pancreas under surveillance.

BACKGROUND: Despite the low malignant potential of pancreatic mucinous cystic neoplasms (MCNs), surgery is still performed. The aim of this pragmatic study was to assess the outcome of surgery and surveillance for patients presenting with a presumed MCN at the first evaluation. METHODS: Data for patients with a presumed MCN observed from 2000 to 2016 at the Verona Pancreas Institute and San Raffaele Hospital were extracted from prospective databases. The endpoints were risk of malignancy at pathology and rate of misdiagnosis for the surgical series, expressed as an odds ratio (OR) with 95 per cent confidence interval, and disease-specific survival (DSS) for the surveillance cohort investigated by the Kaplan-Meier method. RESULTS: A total of 424 patients were identified. In the surgical series (229 patients), the rate of misdiagnosis was 19.2 per cent. The rate of malignant MCNs was 10.9 per cent (25 patients). The overall rate of malignancy, including misdiagnoses, was 11.3 per cent (26 patients). Predictors of malignancy were mural nodules (OR 27.75, 95 per cent c.i. 4.44-173.61; P < 0.001), size at least 50 mm (OR 13.39, 2.01 to 89.47; P = 0.007), and carbohydrate antigen 19.9 level (OR 3.98, 1.19 to 13.30; P = 0.025). In the absence of mural nodules and enhancing walls, none of the resected presumed MCNs smaller than 50 mm were malignant. Only patients with high-risk stigmata undergoing surgery experienced a significantly reduced 5-year DSS compared with all other patients (88 versus 100 per cent; P = 0.031). CONCLUSION: Presumed MCNs with mural nodules, enhancing walls or cysts of 50 mm or larger should be considered for upfront surgical resection owing to the high risk of malignancy. In the absence of these features, the incidence of malignancy is negligible, favouring surveillance in selected patients given the low risk of malignancy and the high rate of misdiagnosis. LAY SUMMARY: Malignant degeneration of presumed pancreatic mucinous cystic neoplasms takes several years, if it occurs at all. Mural nodules, enhancing walls or cysts of 50 mm or larger call for surgical resection owing to an increased risk of malignancy; otherwise, surveillance seems a good option.

Malignant degeneration of presumed pancreatic mucinous cystic neoplasms takes several years, if it occurs at all. Mural nodules, enhancing walls or cysts of 50 mm or larger call for surgical resection owing to an increased risk of malignancy; otherwise, surveillance seems a good option.

Sporadic non-functioning pancreatic neuroendocrine tumours: multicentre analysis.

BACKGROUND: Outcomes after surgery for sporadic pancreatic neuroendocrine neoplasms (Pan-NENs) were evaluated. METHODS: This multicentre study included patients who underwent radical pancreatic resection for sporadic non-functioning Pan-NENs. In survival analysis, the risk of mortality in this cohort was analysed in relation to that of the matched healthy Italian population. Relative survival (RS) was calculated as the rate between observed and expected survival. Factors related to RS were investigated using multivariable modelling. RESULTS: Among 964 patients who had pancreatic resection for sporadic non-functioning Pan-NENs, the overall RS rate was 91.8 (95 per cent c.i. 81.5 to 96.5) per cent. 2019 WHO grade (hazard ratio (HR) 5.75 (s.e. 4.63); P = 0.030) and European Neuroendocrine Tumour Society (ENETS) TNM stage (6.73 (3.61); P < 0.001) were independent predictors of RS. The probability of a normal lifespan for patients with G1, G2, G3 Pan-NENS, and pancreatic neuroendocrine carcinomas (Pan-NECs) was 96.7, 54.8, 0, and 0 per cent respectively. The probability of a normal lifespan was 99.8, 99.3, 79.8, and 46.8 per cent for those with stage I, II, III, and IV disease respectively. The overall disease-free RS rate was 73.6 (65.2 to 79.5) per cent. 2019 WHO grade (HR 2.10 (0.19); P < 0.001) and ENETS TNM stage (HR 2.50 (0.24); P < 0.001) significantly influenced disease-free RS. The probability of disease-free survival was 93.2, 84.9, 45.2, and 6.8 per cent for patients with stage I, II, III, and IV disease, and 91.9, 45.2, 9.4, and 0.7 per cent for those with G1, G2, G3 Pan-NENS, and Pan-NECs, respectively. CONCLUSION: A surgical approach seems without benefit for Pan-NECs, and unnecessary for small G1 sporadic Pan-NENs. Surgery alone may be insufficient for stage III-IV and G3 Pan-NENs.

Radiomics in pancreatic neuroendocrine tumors: methodological issues and clinical significance.

PURPOSE: To present the state-of-art of radiomics in the context of pancreatic neuroendocrine tumors (PanNETs), with a focus on the methodological and technical approaches used, to support the search of guidelines for optimal applications. Furthermore, an up-to-date overview of the current clinical applications of radiomics in the field of PanNETs is provided. METHODS: Original articles were searched on PubMed and Science Direct with specific keywords. Evaluations of the selected studies have been focused mainly on (i) the general radiomic workflow and the assessment of radiomic features robustness/reproducibility, as well as on the major clinical applications and investigations accomplished so far with radiomics in the field of PanNETs: (ii) grade prediction, (iii) differential diagnosis from other neoplasms, (iv) assessment of tumor behavior and aggressiveness, and (v) treatment response prediction. RESULTS: Thirty-one articles involving PanNETs radiomic-related objectives were selected. In regard to the grade differentiation task, yielded AUCs are currently in the range of 0.7-0.9. For differential diagnosis, the majority of studies are still focused on the preliminary identification of discriminative radiomic features. Limited information is known on the prediction of tumors aggressiveness and of treatment response. CONCLUSIONS: Radiomics is recently expanding in the setting of PanNETs. From the analysis of the published data, it is emerging how, prior to clinical application, further validations are necessary and methodological implementations require optimization. Nevertheless, this new discipline might have the potential in assisting the current urgent need of improving the management strategies in PanNETs patients.

Urgent manifestations of immunoglobulin G4-related disease.

Objective: Immunoglobulin G4-related disease (IgG4-RD) is considered a chronic condition with insidious presentation, but clinical experience suggests that disease onset prompts admission to the emergency department (ED) in a sizeable proportion of patients. We assessed the prevalence of acute manifestations associated with IgG4-RD onset requiring referral to the ED. Method: We revised our database and identified patients admitted to the ED because of symptoms latterly attributed to IgG4-RD onset (Group 1) and those who were referred to our outpatient clinic without previous urgent manifestations (Group 2). Acute manifestations were clustered based on the anatomical region affected by IgG4-RD. Epidemiological, clinical, and serological features of Groups 1 and 2 were compared. Results: The study included 141 patients with IgG4-RD. Of these, 76 (54%) presented to the ED at disease onset. The most common clinical manifestations requiring admission to the ED were jaundice (53%), abdominal pain (41%), and fever (10%). Gastrointestinal involvement was the most frequent cause of referral to the ED (71% of cases), followed by involvement of the retroperitoneum (14.5%) and the nervous system (6.6%). Pancreatobiliary involvement was significantly more frequent in Group 1 than in Group 2. Head and neck, and salivary and lacrimal gland involvement was more frequent in Group 2 than in Group 1. The diagnostic delay was significantly shorter in Group 1 than in Group 2. Conclusion: Clinical manifestations associated with IgG4-RD onset require referral to the ED in most cases. This finding contrasts with the general view of IgG4-RD as a condition with non-acute presentation.

Laparoscopic versus open extended radical left pancreatectomy for pancreatic ductal adenocarcinoma: an international propensity-score matched study.

BACKGROUND: A radical left pancreatectomy in patients with pancreatic ductal adenocarcinoma (PDAC) may require extended, multivisceral resections. The role of a laparoscopic approach in extended radical left pancreatectomy (ERLP) is unclear since comparative studies are lacking. The aim of this study was to compare outcomes after laparoscopic vs open ERLP in patients with PDAC. METHODS: An international multicenter propensity-score matched study including patients who underwent either laparoscopic or open ERLP (L-ERLP; O-ERLP) for PDAC was performed (2007-2015). The ISGPS definition for extended resection was used. Primary outcomes were overall survival, margin negative rate (R0), and lymph node retrieval. RESULTS: Between 2007 and 2015, 320 patients underwent ERLP in 34 centers from 12 countries (65 L-ERLP vs. 255 O-ERLP). After propensity-score matching, 44 L-ERLP could be matched to 44 O-ERLP. In the matched cohort, the conversion rate in L-ERLP group was 35%. The L-ERLP R0 resection rate (matched cohort) was comparable to O-ERLP (67% vs 48%; P = 0.063) but the lymph node yield was lower for L-ERLP than O-ERLP (median 11 vs 19, P = 0.023). L-ERLP was associated with less delayed gastric emptying (0% vs 16%, P = 0.006) and shorter hospital stay (median 9 vs 13 days, P = 0.005), as compared to O-ERLP. Outcomes were comparable for additional organ resections, vascular resections (besides splenic vessels), Clavien-Dindo grade ≥ III complications, or 90-day mortality (2% vs 2%, P = 0.973). The median overall survival was comparable between both groups (19 vs 20 months, P = 0.571). Conversion did not worsen outcomes in L-ERLP. CONCLUSION: The laparoscopic approach may be used safely in selected patients requiring ERLP for PDAC, since morbidity, mortality, and overall survival seem comparable, as compared to O-ERLP. L-ERLP is associated with a high conversion rate and reduced lymph node yield but also with less delayed gastric emptying and a shorter hospital stay, as compared to O-ERLP.

Risk of preoperative understaging of duodenal neuroendocrine neoplasms: a plea for caution in the treatment strategy.

PURPOSE: Pretreatment staging is the milestone for planning either surgical or endoscopic treatment in duodenal neuroendocrine neoplasms (dNENs). Herein, a series of surgically treated dNEN patients was evaluated to assess the concordance between the pre- and postsurgical staging. METHODS: Retrospective analysis of patients with a histologically confirmed diagnosis of dNENs, who underwent surgical resection observed at eight Italian tertiary referral centers. The presurgical TNM stage, based on the radiological and functional imaging, was compared with the pathological TNM stage, after surgery. RESULTS: From 2000 to 2019, 109 patients were included. Sixty-six patients had G1, 26 a G2, 7 a G3 dNEN (Ki-67 not available in 10 patients). In 46/109 patients (42%) there was disagreement between the pre- and postsurgical staging, being it understaged in 42 patients (38%), overstaged in 4 (3%). As regards understaging, in 25 patients (22.9%), metastatic loco-regional nodes (N) resulted undetected at both radiological and functional imaging. Understaging due to the presence of distal micrometastases (M) was observed in 2 cases (1.8%). Underestimation of tumor extent (T) was observed in 12 patients (11%); in three cases the tumor was understaged both in T and N extent. CONCLUSIONS: Conventional imaging has a poor detection rate for loco-regional nodes and micrometastases in the presurgical setting of the dNENs. These results represent important advice when local conservative approaches, such as endoscopy or local surgical excision are considered and it represents a strong recommendation to include endoscopic ultrasound in the preoperative tools for a more accurate local staging.

Impact of the SARS-CoV2 pandemic dissemination on the management of neuroendocrine neoplasia in Italy: a report from the Italian Association for Neuroendocrine Tumors (Itanet).

INTRODUCTION: The organization of the healthcare system has significantly changed after the recent COVID-19 outbreak, with a negative impact on the management of oncological patients. The present survey reports data collected by the Italian Association for Neuroendocrine Tumors on the management of patients with neuroendocrine neoplasia (NEN) during the pandemic dissemination. METHODS: A survey with 57 questions was sent to NEN-dedicated Italian centers regarding the management of patients in the period March 9, 2020, to May 9, 2020 RESULTS: The main modification in the centers' activity consisted of decreases in newly diagnosed NEN patients (- 76.8%), decreases in performed surgical procedures (- 58%), delays to starting peptide receptor radionuclide therapy (45.5%), postponed/canceled follow-up examinations (26%), and canceled multidisciplinary teams' activity (20.8%). A low proportion of centers (< 10%) reported having to withdraw systemic anti-tumor medical treatment due to concerns about the pandemic situation, whereas PRRT was withdrawn from no patients. CONCLUSION: Although the COVID-19 outbreak induced the centers to reduce some important activities in the management of NEN patients, the Italian network was able to provide continuity in care without withdrawing anti-tumor treatment for the majority of patients.

Modelling centralization of pancreatic surgery in a nationwide analysis.

BACKGROUND: The benefits of centralization of pancreatic surgery have been documented, but policy differs between countries. This study aimed to model various centralization criteria for their effect on a nationwide cohort. METHODS: Data on all pancreatic resections performed between 2014 and 2016 were obtained from the Italian Ministry of Health. Mortality was assessed for different hospital volume categories and for each individual facility. Observed mortality and risk-standardized mortality rate (RSMR) were calculated. Various models of centralization were tested by applying volume criteria alone or in combination with mortality thresholds. RESULTS: A total of 395 hospitals performed 12 662 resections; 305 hospitals were in the very low-volume category (mean 2·6 resections per year). The nationwide mortality rate was 6·2 per cent, increasing progressively from 3·1 per cent in very high-volume to 10·6 per cent in very low-volume hospitals. For the purposes of centralization, applying a minimum volume threshold of at least ten resections per year would lead to selection of 92 facilities, with an overall mortality rate of 5·3 per cent. However, the mortality rate would exceed 5 per cent in 48 hospitals and be greater than 10 per cent in 17. If the minimum volume were 25 resections per year, the overall mortality rate would be 4·7 per cent in 38 facilities, but still over 5 per cent in 17 centres and more than 10 per cent in five. The combination of a volume requirement (at least 10 resections per year) with a mortality threshold (maximum RSMR 5 or 10 per cent) would allow exclusion of facilities with unacceptable results, yielding a lower overall mortality rate (2·7 per cent in 45 hospitals or 4·2 per cent in 76 respectively). CONCLUSION: The best performance model for centralization involved a threshold for volume combined with a mortality threshold.

ANTECEDENTES: Los beneficios de la centralización de la cirugía pancreática están bien documentados, pero la política de actuación difiere entre los países. Este estudio tuvo como objetivo desarrollar modelos de centralización basados en varios criterios y analizar su aplicación en una cohorte nacional. MÉTODOS: Los datos de todas las resecciones pancreáticas realizadas entre 2014 y 2016 se obtuvieron del Ministerio de Salud italiano. La mortalidad se evaluó para diferentes categorías del volumen hospitalario y para cada centro individualmente. Se calculó la mortalidad observada y la tasa estandarizada de riesgo de mortalidad (risk standardized mortality rate, RSMR). Se analizaron varios modelos de centralización aplicando criterios de volumen solos o en combinación con umbrales de mortalidad. RESULTADOS: Un total de 395 hospitales realizaron 12.662 resecciones; 305 de ellos pertenecían a la categoría de muy bajo volumen (media de 2,6 resecciones/año). La mortalidad nacional fue del 6,2%, aumentando progresivamente del 3,1% en los hospitales de muy alto volumen al 10,6% en los hospitales de muy bajo volumen. Para fines de centralización, al aplicar un umbral de volumen mínimo ≥ 10 resecciones/año, se seleccionarían 92 centros, con una mortalidad global del 5,3%. Sin embargo, la mortalidad sería > 5% en 48 hospitales y > 10% en 17 hospitales. Si el volumen mínimo fuera de 25 resecciones/año, la mortalidad global sería del 4,7% en 38 hospitales, pero aún > 5% en 17 centros y > 10% en seis centros. La combinación de un volumen necesario (≥ 10 resecciones/año) con un umbral de mortalidad (RSMR ≤ 5% o ≤ 10%) permitiría excluir hospitales con resultados inaceptables, determinando una mortalidad global más baja (2,7% en 45 hospitales o 4,2% en 76 hospitales, respectivamente). CONCLUSIÓN: El mejor modelo para la centralización de resecciones pancreáticas incluyó un umbral para el volumen hospitalario combinado con un umbral de mortalidad.

Comparison between adult and foetal adnexa derived equine post-natal mesenchymal stem cells.

BACKGROUND: Little is known about the differences among adult and foetal equine mesenchymal stem cells (MSCs), and no data exist about their comparative ultrastructural morphology. The aim of this study was to describe and compare characteristics, immune properties, and ultrastructural morphology of equine adult (bone marrow: BM, and adipose tissue: AT) and foetal adnexa derived (umbilical cord blood: UCB, and Wharton's jelly: WJ) MSCs. RESULTS: No differences were observed in proliferation during the first 3 passages. While migration ability was similar among cells, foetal MSCs showed a higher adhesion ability, forming smaller spheroids after hanging drop culture (P < 0.05). All MSCs differentiated toward adipogenic, chondrogenic and osteogenic lineages, only tenogenic differentiation was less evident for WJ-MSCs. Data obtained by PCR confirmed MHC1 expression and lack of MHC2 expression in all four cell types. Foetal adnexa MSCs were positive for genes specific for anti-inflammatory and angiogenic factors (IL6, IL8, ILß1) and WJ-MSCs were the only positive for OCT4 pluripotency gene. At immunofluorescence all cells expressed typical mesenchymal markers (α-SMA, N-cadherin), except for BM-MSCs, which did not express N-cadherin. By transmission electron microscopy, it was observed that WJ-MSCs had a higher (P < 0.05) number of microvesicles compared to adult MSCs, and UCB-MSCs showed more microvesicles than BM-MSCs (P < 0.05). AT-MSCs had a lower number of mitochondria than WJ-MSCs (P < 0.05), and mitochondrial area was higher for WJ-MSCs compared to UCB and AT-MSCs (P < 0.05). CONCLUSIONS: Results demonstrate that MSCs from adult and foetal tissues have different characteristics, and foetal MSCs, particularly WJ derived ones, seem to have some charactestics that warrant further investigation into potential advantages for clinical application.

Recurrence of Pancreatic Neuroendocrine Tumors and Survival Predicted by Ki67.

BACKGROUND: Despite evidence of different malignant potentials, postoperative follow-up assessment is similar for G1 and G2 pancreatic neuroendocrine tumors (panNETs) and adjuvant treatment currently is not indicated. This study investigated the role of Ki67 with regard to recurrence and survival after curative resection of panNET. METHODS: Patients with resected non-functioning panNET diagnosed between 1992 and 2016 from three institutions were retrospectively analyzed. Patients who had G1 or G2 tumor without distant metastases or hereditary syndromes were included in the study. The patients were re-categorized into Ki67 0-5 and Ki67 6-20%. Cox regression analysis with log-rank testing for recurrence and survival was performed. RESULTS: The study enrolled 241 patients (86%) with Ki67 0-5% and 39 patients (14%) with Ki67 6-20%. Recurrence was seen in 34 patients (14%) with Ki67 0-5% after a median period of 34 months and in 16 patients (41%) with Ki67 6-20% after a median period of 16 months (p < 0.001). The 5-year recurrence-free and 10-year disease-specific survival periods were respectively 90 and 91% for Ki67 0-5% and respectively 55 and 26% for Ki67 6-20% (p < 0.001). The overall survival period after recurrence was 44.9 months, which was comparable between the two groups (p = 0.283). In addition to a Ki67 rate higher than 5%, tumor larger than 4 cm and lymph node metastases were independently associated with recurrence. CONCLUSIONS: Patients at high risk for recurrence after curative resection of G1 or G2 panNET can be identified by a Ki67 rate higher than 5%. These patients should be more closely monitored postoperatively to detect recurrence early and might benefit from adjuvant treatment. A clear postoperative follow-up regimen is proposed.

Meta-analysis of mortality in patients with high-risk intraductal papillary mucinous neoplasms under observation.

BACKGROUND: Although consensus guidelines suggest that patients with high-risk intraductal papillary mucinous neoplasms (IPMNs) should have surgery, a non-operative strategy is often selected in patients who are poor surgical candidates. The aim was to determine the risk of disease-related death from IPMN in patients with worrisome features or high-risk stigmata who were kept under observation. METHODS: A PubMed literature search was undertaken of articles published from August 1992 to June 2016 (updated October 2017). The methodology was developed from PRISMA and MOOSE checklists. Incidence proportions and rates of overall and IPMN-related deaths were calculated, with subgroup analyses for main-duct/mixed-type and branch-duct IPMNs. Quality of the studies, publication bias and heterogeneity were explored. RESULTS: Six studies reported data on overall mortality and eight described disease-specific mortality for 556 patients during follow-up ranging from 24·9 to 60·0 months. Pooled rates of overall and IPMN-related mortality were 30·9 (95 per cent c.i. 19·6 to 45·1) and 11·6 (6·0 to 21·2) per cent respectively. The pooled incidence rate for overall mortality was substantially higher than that for IPMN-related mortality: 78 (95 per cent c.i. 44 to 111) and 23 (9 to 37) per 1000 patient-years respectively. The pooled incidence rate for disease-specific mortality was considerably lower for branch-duct than for main-duct or mixed-type IPMNs: 5 (0 to 10) and 32 (12 to 52) per 1000 patient-years respectively. CONCLUSION: In patients unfit for surgery, IPMN-related mortality among patients with worrisome features and high-risk stigmata is low, and the risk of death from other causes much higher.

Selecting patients for resection after primary chemotherapy for non-metastatic pancreatic adenocarcinoma.

BACKGROUND: Patients with borderline (BL) or locally advanced (LA) pancreatic adenocarcinoma are usually treated with primary chemotherapy (CT), followed by resection when feasible. Scanty data are available about the criteria to candidate patients to resection after CT. PATIENTS AND METHODS: Between 2002 and 2016 overall 223 patients diagnosed with BL or LA pancreatic adenocarcinoma were primarily treated with Gemcitabine combination (4-drugs or nab-paclitaxel-gemcitabine) for 3-6 months followed by surgery and/or chemoradiation. Resection was carried out when radical resection could be predicted by imaging studies and intraoperative findings. The prognostic value of both pre-treatment factors and treatment response was retrospectively evaluated, searching for criteria that could improve the selection of patients for surgery. RESULTS: Median survival (MS) for the whole population was 18.3 months. Surgical resection was carried out in 61 patients; MS in resected patients was significantly longer (30.0 months) as compared with 162 non-resected patients (16.5 months) (P < 0.00001). According to response criteria, 48% had a radiological partial response, 47% a stable disease and 5% a disease progression); CA19.9 response (reduction >50%) was obtained in 77.8% of patients. Among resected patients, neither pre-treatment factors, including BL/LA distinction, nor radiological response, were able to prognosticate survival differences. Survival of resected patients having no CA19.9 response was significantly lower as compared with responders (MS 15.0 versus 31.5 months, P = 0.04), and was similar to non-responders patients that did not undergo resection (MS 10.9 months, P= 0.25). Multivariate analysis carried out on the overall population, showed that Karnofsky performance status, T3-T4 status, resection and CA19.9 response were independent prognostic factors, while radiological response, BL/LA distinction and baseline CA19.9 had not significant influence on survival. CONCLUSIONS: CA19.9 response may allow a better selection of patients who will benefit from resection after primary CT for BL or LA pancreatic adenocarcinoma.

Systematic review of active surveillance versus surgical management of asymptomatic small non-functioning pancreatic neuroendocrine neoplasms.

BACKGROUND: The incidence of asymptomatic, sporadic, small non-functioning pancreatic neuroendocrine neoplasms (NF-PNENs) has increased in recent decades. Conservative treatment has been advocated for these tumours. The aim of this study was systematically to evaluate the literature on active surveillance and to compare this with surgical management for asymptomatic sporadic small NF-PNENs. METHODS: PubMed, Embase and the Cochrane Library were searched systematically for studies that compared the active surveillance of asymptomatic, sporadic, small NF-PNENs with surgical management. PRISMA guidelines for systematic reviews were followed. RESULTS: After screening 3915 records, five retrospective studies with a total of 540 patients were included. Of these, 327 patients (60·6 per cent) underwent active surveillance and 213 (39·4 per cent) had surgery. There was wide variation in the tumour diameter threshold considered as inclusion criterion (2 cm to any size). The median length of follow-up ranged from 28 to 45 months. Measurable tumour growth was observed in 0-51·0 per cent of patients. Overall, 46 patients (14·1 per cent) underwent pancreatic resection after initial conservative treatment. In most patients the reason was an increase in tumour size (19 of 46). There were no disease-related deaths in the active surveillance group in any of the studies. CONCLUSION: This systematic review suggests that active surveillance of patients affected by sporadic, small, asymptomatic NF-PNENs may be a good alternative to surgical treatment.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas).

OBJECTIVES: Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality. DESIGN: Retrospective multinational study including SCN diagnosed between 1990 and 2014. RESULTS: 2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1). CONCLUSIONS: After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN. TRIAL REGISTRATION NUMBER: IRB 00006477.

Structural insights into the multi-determinant aggregation of TDP-43 in motor neuron-like cells.

TDP-43 is aggregated in patients with ALS and FLTD through mechanisms still incompletely understood. Since aggregation in the cytosol is most probably responsible for the delocalization and loss of proper RNA-binding function of TDP-43 in the nucleus, interception of the formation of aggregates may represent a useful therapeutic option. In this study, we investigated the relative importance of the N-terminal and C-terminal moieties of TDP-43 in the aggregation process and the weight of each of the six cysteine residues in determining unfolding and aggregation of the different domains. We report that cytoplasmic inclusions formed by WT and mutant TDP-43 in motor neuron-like NSC34 cells are redox-sensitive only in part, and contain at least two components, i.e. oligomers and large aggregates, that are made of different molecular species. The two N-terminal cysteine residues contribute to the seeding for the first step in oligomerization, which is then accomplished by mechanisms depending on the four cysteines in the RNA-recognition motifs. Cysteine-independent large aggregates contain unfolded isoforms of the protein, held together by unspecific hydrophobic interactions. Interestingly, truncated isoforms are entrapped exclusively in oligomers. Ab initio modeling of TDP-43 structure, molecular dynamics and molecular docking analysis indicate a differential accessibility of cysteine residues that contributes to aggregation propensity. We propose a model of TDP-43 aggregation involving cysteine-dependent and cysteine-independent stages that may constitute a starting point to devise strategies counteracting the formation of inclusions in TDP-43 proteinopathies.