Clinical usefulness of routinely performed drain fluid cultures after pancreaticoduodenectomy. A new ally to predict patients' outcomes?

BACKGROUND

Previous studies showed that bacterial contamination of surgical drains was associated with higher morbidity and mortality following pancreaticoduodenectomy (PD). However, there is still no agreement on the routine use of fluid drainage cultures in the management of patients underwent PD. Therefore, we aimed to clarify the role of surgical drain bacterial contamination in predicting patients' postoperative course.

METHOD

Single-centre study including patients underwent PD at Humanitas Research Hospital (2010-2021). Preoperative, intraoperative and postoperative data were collected. Routinely performed fluid drain cultures on postoperative day (POD) 5 were analyzed and compared among patients throughout the cohort.

RESULTS

A total of 825 patients were analyzed. Bacterial contamination of surgical drains was observed in 420 (50.9 %) patients and it was found to be associated with a higher rate of B/C grade pancreatic fistula (POPF) (P < 0.001), Clavien-Dindo≥3 (P < 0.001), 30-day mortality (P = 0.011), wound infection (P < 0.001), relaparotomies (P = 0.003) and greater length of hospital stay (LOS) (P < 0.001). Also, E. coli surgical drain contamination was demonstrated to double the risk of B/C grade POPF development (OR = 1.628, 95 % IC = 1.009-2.625, P = 0.046). Finally, preoperative biliary drainage (OR = 2.474, 95 % IC = 1.855-3.298, P < 0.001), age ≥75 years old (OR = 1.492, 95 % IC = 1.077-2.067, P = 0.016) and isolated Roux-en-Y pancreaticojejunostomy (OR = 1.639, 95 % IC = 1.229-2.188, P < 0.001) were identified as risk factors for surgical drains bacterial contamination.

CONCLUSION

Bacterial contamination of surgical drains predicts the development of B/C grade POPF and other major complications after PD. Therefore, we suggest the routine use of fluid drain cultures following PD.

Exploring a novel composite method using non-contrast EUS enhanced microvascular imaging and cyst fluid analysis to differentiate pancreatic cystic lesions

BACKGROUND AND AIMS

Differentiating pancreatic cystic lesions (PCLs) remains a diagnostic challenge. The use of high-definition imaging modalities which detect tumor microvasculature have been described in solid lesions. We aim to evaluate the usefulness of cystic microvasculature when used in combination with cyst fluid biochemistry to differentiate PCLs.

METHODS

We retrospectively analyzed 110 consecutive patients with PCLs from 2 Italian Hospitals who underwent EUS with H-Flow and EUS fine needle aspiration to obtain cystic fluid. The accuracy of fluid biomarkers was evaluated against morphological features on radiology and EUS. Gold standard for diagnosis was surgical resection. A clinical and radiological follow up was applied in those patients who were not resected because not surgical indication and no signs of malignancy were shown.

RESULTS

Of 110 patients, 65 were diagnosed with a mucinous cyst, 41 with a non-mucinous cyst, and 4 with an undetermined cyst. Fluid analysis alone yielded 76.7% sensitivity, 56.7% specificity, 77.8 positive predictive value (PPV), 55.3 negative predictive value (NPV) and 56% accuracy in diagnosing pancreatic cysts alone. Our composite method yielded 97.3% sensitivity, 77.1% specificity, 90.1% PPV, 93.1% NPV, 73.2% accuracy.

CONCLUSIONS

This new composite could be applied to the holistic approach of combining cyst morphology, vascularity, and fluid analysis alongside endoscopist expertise.

Early Recurrence after Upfront Surgery for Pancreatic Ductal Adenocarcinoma

Background. Survival after surgery for pancreatic ductal adenocarcinoma (PDAC) remains poor, due to early recurrence (ER) of the disease. A global definition of ER is lacking and different cut-off values (6, 8, and 12 months) have been adopted. The aims of this study were to define the optimal cut-off for the definition of ER and predictive factors for ER. Methods. Recurrence was recorded for all consecutive patients undergoing upfront surgery for PDAC at our institute between 2010 and 2017. Receiver operating characteristic (ROC) curves were utilized, to estimate the optimal cut-off for the definition of ER as a predictive factor for poor post-progression survival (PPS). To identify predictive factors of ER, univariable and multivariable logistic regression models were used. Results. Three hundred and fifty one cases were retrospectively evaluated. The recurrence rate was 76.9%. ER rates were 29.0%, 37.6%, and 47.6%, when adopting 6, 8, and 12 months as cut-offs, respectively. A significant difference in median PPS was only shown between ER and late recurrence using 12 months as cut-off (p = 0.005). In the multivariate analysis, a pre-operative value of CA 19-9 > 70.5 UI/L (OR 3.10 (1.41–6.81); p = 0.005) and the omission of adjuvant treatment (OR 0.18 (0.08–0.41); p < 0.001) were significant predictive factors of ER. Conclusions. A twelve-months cut-off should be adopted for the definition of ER. Almost 50% of upfront-resected patients presented ER, and it significantly affected the prognosis. A high preoperative value of CA 19-9 and the omission of adjuvant treatment were the only predictive factors for ER.

Invasive IPMN relapse later and more often in lungs in comparison to pancreatic ductal adenocarcinoma

BACKGROUND

The different oncological outcomes of invasive intraductal papillary mucinous neoplasm (I-IPMN) and pancreatic ductal adenocarcinoma (PDAC) are debated. This study aimed to compare disease recurrence patterns and histopathological characteristics in patients with resected I-IPMN and PDAC.

METHODS

Consecutive patients undergoing surgical resection for stage I-III I-IPMN or PDAC between 2010 and 2016 were retrospectively analyzed. Patients treated with neoadjuvant therapy or resected for Tis neoplasia were excluded. All surgical specimens were re-staged according to AJCC-8th-edition.

RESULTS

A total of 330 patients were included, of whom 43 had I-IPMN and 287 had PDAC. Median follow-up time was 26.7 (1.3-92.3) months and estimated median disease-free survival (DFS) was 60.3 months (47.2-73.4) for I-IPMN and 23.8 (19.3-28.2) months for PDAC (p < 0.001). During follow-up, 32.6% of I-IPMN and 67.9% of PDAC patients experienced recurrence (p < 0.001). The sites of first recurrence were the lungs (38.5% vs 13.1%, p = 0.027), liver (28.6% vs 45.0%, p = 0.180) and local (15.4% vs 36.6%, p = 0.101) for I-IPMN and PDAC, respectively. At multivariate analysis, I-IPMN histology remained an independent predictive factor for longer DFS (OR 0.528, CI 95% 0.278-1.000, p = 0.050), regardless of stage or adjuvant chemotherapy. I-IPMN and PDAC differed in rates of neuroinvasion (51.2% vs 97.2%) and positive lymph node status (N+) (46.5% vs 82.7%), especially in patients with lower T status.

CONCLUSION

I-IPMN showed a different recurrence pattern compared to PDAC, with a higher lung tropism, and longer DFS. This different biological behavior is associated with lower rates of neuroinvasion and nodal involvement, especially in early-stage disease.

Pancreatic ductal adenocarcinoma and invasive intraductal papillary mucinous tumor: Different prognostic factors for different overall survival

BACKGROUND

It is unclear whether invasive intraductal papillary mucinous neoplasm (IPMN) has different clinical and prognostic characteristics, beyond histological factors, when compared to pancreatic ductal adenocarcinoma (PDAC).

AIMS

compare prognostic features of resected PDAC and invasive IPMN METHODS: A retrospective study of patients resected for PDAC or invasive IPMN realized at Humanitas Cancer Center's Pancreatic Surgery Unit, Milan, Italy, between 2010 and 2016. Data recorded included patient demographics, onset symptoms, preoperative health status, tumor features, histology and surgical characteristics. Overall survival was estimated using Kaplan-Meier and prognostic factors for survival were assessed by multivariate Cox regression.

RESULTS

A total of 332 patients were included (PDAC, n = 289; invasive IPMN, n = 43). Patients with invasive IPMN had better overall survival than PDAC patients (median: 76.6 versus 25.6 months; 5-year OS rate: 65.4% vs. 14.2%; p < 0.001). PDAC histology was associated with a significantly higher risk of death than IPMN (hazard ratio 1.815, 95% CI: 1.02, 3.24; p = 0.044). Survival was also worse with PDAC in early-stage disease (IA-IB-IIA, N0). In multivariate analysis, independent predictors of worse survival included perineural invasion, preoperative ASA physical status ≥3 and pain at diagnosis.

CONCLUSIONS

Patients with IPMN had a better prognosis than PDAC patients, regardless of disease stage.

Trans-duodenal ampullectomy for ampullary neoplasms: early and long-term outcomes in 36 consecutive patients

BACKGROUND

Trans-duodenal ampullectomy (TDA) is a surgical option for the treatment of selected ampullary neoplasms. The aim of this study was to evaluate our experience with TDA for the treatment of ampullary neoplasms, focusing on indications, technical aspects, and short- and long-term outcomes.

METHODS

All TDAs for ampullary neoplasms performed between January 2010 and December 2018 at our institution were retrospectively evaluated. Patients had ampullary neoplasms with low-grade dysplasia or in situ carcinoma (Tis) not suitable for an endoscopic approach, ampullary carcinoma unfit for pancreaticoduodenectomy (PD), or ampullary neuroendocrine G1-tumours.

RESULTS

Thirty-six patients were included in the study: 9 (25.0%) with neoplasms with low-grade dysplasia, 4 (11.1%) with G1 neuroendocrine tumours and 23 (63.9%) with Tis or invasive carcinoma. Mean operative time was 252.5 min. Overall and severe (Clavien-Dindo > IIIa) morbidity rate was 44.4% and 13.9%, respectively. No 90-day mortality was observed. At follow-up, no deaths were observed and local recurrence rate was 11.1% for patients with ampullary adenomas with low-grade dysplasia. Among four patients with neuroendocrine neoplasms, only one developed recurrence (pulmonary). Tis, T1 and T2 lesions were found in 16 (69.6%), 2 (8.7%) and 5 (21.7%) patients, respectively: recurrence occurred in 3 patients with Tis lesions (one malignant), no patients with T1 neoplasms and 2 patients with T2 lesions (3 patients had a survival of > 3 years).

CONCLUSIONS

TDA is a feasible and effective surgical procedure for the treatment of ampullary adenomas with low-grade dysplasia when endoscopic approach is contraindicated or has failed. For lesions with evidence of malignancy, TDA seems to be an oncological safe procedure for Tis ampullary cancer and a good palliative procedure for patients unfit for PD. Moreover, TDA may be appropriate for the treatment of G1 ampullary neuroendocrine neoplasms. A large multicentre study of TDA for early ampullary cancers is needed.

P1358Atrial electromechanical interval in patients with arrhythmias: is everyone the same?

Background

Atrial electromechanical delay, assessed calculating the PA-TDI interval using tissue Doppler imaging, is a known and promising determinant for atrial fibrillation recurrence prediction after pulmonary vein isolation and electrical cardioversion.

Purpose

To determine the relationship between atrial electromechanical delay and the presence of atrial fibrillation.

Methods

We prospectively enrolled patients presenting at our Unit in sinus rhythm scheduled for an arrhythmogenic substrate ablation (atrial fibrillation -AF-, supraventricular tachycardia -SVT- and premature ventricular contractions -PVC-). Demographic and echocardiographic characteristics were evaluated upon admission. Atrial electromechanical delay was inferred via the PA-TDI interval, obtained by calculating the time difference between the P wave onset and the A" wave peak on TDI recordings.

Results

From October 2018 to August 2019, 200 patients (60% male, mean age 58,21 ± 14,26, mean BSA 1,9 ± 0,21 m2, mean BMI 26,42 ± 6,28 kg/m2, mean EF 60,91% ± 5,43%) were admitted to our unit to undergo AF (group 1: n = 145; 72,50%), SVT or PVC ablation (group 2: n = 55; 27,5%). Compared with the control group (group 2), patients admitted for AF ablation had a larger LA size (group 1 vs group 2: mean LA area 23,21 ± 5,07 vs 16,87 ± 4,01 cm2, p &lt; 0,001; mean indexed LA volume 46,71 ± 20,41 ml vs 32,04 ± 14,7 ml, p &lt; 0,001; mean LAD 41,77 ± 5,66 vs 33,84 ± 6,06, p &lt; 0,001) and a longer PA-TDI interval (lateral 148,55 ± 28,5 vs 128,57 ± 20,9, p &lt; 0,001; medial 125,34 ± 21,02 vs 109,11 ± 21,49, p &lt; 0,001; average 141,43 ± 27,58 vs 119,08 ± 18,63, p &lt; 0,001).

Conclusion

The PA-TDI interval is a non-invasive and easily achievable echocardiographic parameter, which is demonstrated to be prolonged in patients with a history of AF in contrast with patients with other arrhythmias, as expression of atrial conduction heterogeneity.

Abstract Figure. PA-TDI measurement

Metabolome of Pancreatic Juice Delineates Distinct Clinical Profiles of Pancreatic Cancer and Reveals a Link between Glucose Metabolism and PD-1+ Cells

Better understanding of pancreatic diseases, including pancreatic ductal adenocarcinoma (PDAC), is an urgent medical need, with little advances in preoperative differential diagnosis, preventing rational selection of therapeutic strategies. The clinical management of pancreatic cancer patients would benefit from the identification of variables distinctively associated with the multiplicity of pancreatic disorders. We investigated, by ¹H nuclear magnetic resonance, the metabolomic fingerprint of pancreatic juice (the biofluid that collects pancreatic products) in 40 patients with different pancreatic diseases. Metabolic variables discriminated PDAC from other less aggressive pancreatic diseases and identified metabolic clusters of patients with distinct clinical behaviors. PDAC specimens were overtly glycolytic, with significant accumulation of lactate, which was probed as a disease-specific variable in pancreatic juice from a larger cohort of 106 patients. In human PDAC sections, high expression of the glucose transporter GLUT-1 correlated with tumor grade and a higher density of PD-1⁺ T cells, suggesting their accumulation in glycolytic tumors. In a preclinical model, PD-1⁺ CD8 tumor-infiltrating lymphocytes differentially infiltrated PDAC tumors obtained from cell lines with different metabolic consumption, and tumors metabolically rewired by knocking down the phosphofructokinase (Pfkm) gene displayed a decrease in PD-1⁺ cell infiltration. Collectively, we introduced pancreatic juice as a valuable source of metabolic variables that could contribute to differential diagnosis. The correlation of metabolic markers with immune infiltration suggests that upfront evaluation of the metabolic profile of PDAC patients could foster the introduction of immunotherapeutic approaches for pancreatic cancer.

Pancreatic Neuroendocrine Tumours: The Role of Endoscopic Ultrasound Biopsy in Diagnosis and Grading Based on the WHO 2017 Classification

BACKGROUND

One of the controversial issues in the diagnosis of pancreatic neuroendocrine tumours (pNETs) is the accurate prediction of their clinical behaviour.

OBJECTIVES

The aim of the study was to evaluate the role of endoscopic ultrasound (EUS) biopsy in the diagnosis and grading of pNETs in a certified ENETS Center.

METHODS

A prospectively maintained database of EUS biopsy procedures was retrospectively reviewed to identify all consecutive patients referred to a certified ENETS Center with a suspicion of pNET between June 2014 and April 2017. The cytological and/or histological specimens were stained and the Ki-67 labeling index was evaluated. In patients undergoing surgery, the grade obtained with EUS-guided biopsy was compared with the final histological grade. The grade was evaluated according to the 2017 WHO classifications and grading.

RESULTS

The study population included 59 patients. EUS biopsy material reached an adequacy of 98.3% and was adequate for Ki-67 evaluation in 84.7% of cases. Twenty-nine patients (49.2%) underwent surgery. Of these, 25 patients had Ki-67 evaluated on EUS biopsy: the agreement between EUS biopsy grading and surgical specimen grading was 84%.

CONCLUSION

EUS biopsy is an accurate method for the diagnosis and grading of pNETs based on the WHO 2017 Ki-67 labelling scheme.

Abstract P3-11-05: Everolimus-exemestane (EE) vs palbociclib-fulvestrant (PF) or abemaciclib-fulvestrant (AF) or everolimus-fulvestrant (EF) in the treatment of metastatic HR+, HER2- metastatic breast cancer and prior aromatase inhibitors treatment. An indirect comparison with network meta-analysis

Background. Treatment options for patients with hormone receptor positive metastatic breast cancer (MBC) and prior treatment with aromatase inhibitors (AIs) include EE or PF. To date no direct comparison has been presented between EE and Fulvestrant plus Cyclin-dependent Kinase 4/6 (CDK4/6) inhibitors in this setting. The objective of this study was to compare the efficacy of EE to PF or AF or EF in the treatment of metastatic HR+, HER2- breast cancer pre-treated with AIs.

Methods. An indirect comparison with a network meta-analysis comparing EE with PF or AF or EF in the treatment of metastatic HR+, HER2- breast cancer pre-treated with AIs was performed. The Progression-Free-Survival (PFS) was the primary end point of all our indirect comparisons. Efficacy data were expressed as Hazard Ratio (HR) and 95% Confidence Interval (95CI), assuming an α-error of 5% as index of statistical significance.

Results. All the data of the BOLERO-2 trial, the Bachelot et al network meta-analysis (Breast Cancer Treat Rep 2014), the Paloma-3, the Monarch-2, and the prECOG trials were analyzed and indirectly compared in a network meta-analysis. 6 orders of comparison were performed: AF vs PL, PF vs EE, AF vs EE, EF vs AF, EF vs PF and EF vs EE. The pooled HR and 95%CI are reported in table1.

Table 1: difference in PFS between comparatorsComparisonsHR (95% CI)AF vs PF1.202 (0.87-1.661) p = 0.265PF vs EE1.674 (0.995-2.818) p = 0.89AF vs EE2.012 (1.09-3.714) p = 0.025EF vs AF1.085 (0.681-1.728) p = 0.731EF vs PF1.304 (0.804-2.117) p = 0.283EF vs EE2.183 (1.072-4.444) p = 0.031Everolimus-exemestane (EE), palbociclib-fulvestrant (PF), abemaciclib-fulvestrant (AF), everolimus-fulvestrant (EF).

Conclusions. Till today EE and PF represent active and approved treatments for patients with metastatic HR+, HER2- breast cancer treated with AIs. The results of Monarch-2 study with AF vs Fulvestrant and prECOG study with FE vs Fulvestrant were recently presented and were included in this metaanalysis, while the results of Ribociclib and Fulvestrant vs Fulvestrant (Monaleesa-3 study) are not currently available.

These studies generally show that combination of hormone therapies with Everolimus or CDK4/6 inhibitors are better than hormone-therapy alone, however no direct comparisons between these treatment combinations exist in literature. The results of our indirect treatment comparisons suggests that EE is similar and, in some cases, it may be even better than other treatment options. The optimal treatment strategy and sequence for patient with MBC and prior treatment with AIs should be evaluated in clinical trials. Meanwhile these data could be considered together with safety and the economic profile to help physicians in daily clinical practice.

Citation Format: Gianni L, Arcangeli V, Gianni C, Stocchi L, Menghini L, Samorani D, Ridolfi C, Emiliano T, Tassinari D. Everolimus-exemestane (EE) vs palbociclib-fulvestrant (PF) or abemaciclib-fulvestrant (AF) or everolimus-fulvestrant (EF) in the treatment of metastatic HR+, HER2- metastatic breast cancer and prior aromatase inhibitors treatment. An indirect comparison with network meta-analysis [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-11-05.

Dual prognostic significance of tumour-associated macrophages in human pancreatic adenocarcinoma treated or untreated with chemotherapy

OBJECTIVE

Tumour-associated macrophages (TAMs) play key roles in tumour progression. Recent evidence suggests that TAMs critically modulate the efficacy of anticancer therapies, raising the prospect of their targeting in human cancer.

DESIGN

In a large retrospective cohort study involving 110 patients with pancreatic ductal adenocarcinoma (PDAC), we assessed the density of CD68-TAM immune reactive area (%IRA) at the tumour-stroma interface and addressed their prognostic relevance in relation to postsurgical adjuvant chemotherapy (CTX). In vitro, we dissected the synergism of CTX and TAMs.

RESULTS

In human PDAC, TAMs predominantly exhibited an immunoregulatory profile, characterised by expression of scavenger receptors (CD206, CD163) and production of interleukin 10 (IL-10). Surprisingly, while the density of TAMs associated to worse prognosis and distant metastasis, CTX restrained their protumour prognostic significance. High density of TAMs at the tumour-stroma interface positively dictated prognostic responsiveness to CTX independently of T-cell density. Accordingly, in vitro, gemcitabine-treated macrophages became tumoricidal, activating a cytotoxic gene expression programme, inhibiting their protumoural effect and switching to an antitumour phenotype. In patients with human PDAC, neoadjuvant CTX was associated to a decreased density of CD206(+) and IL-10(+) TAMs at the tumour-stroma interface.

CONCLUSIONS

Overall, our data highlight TAMs as critical determinants of prognostic responsiveness to CTX and provide clinical and in vitro evidence that CTX overall directly re-educates TAMs to restrain tumour progression. These results suggest that the quantification of TAMs could be exploited to select patients more likely to respond to CTX and provide the basis for novel strategies aimed at re-educating macrophages in the context of CTX.

Role of C-Reactive Protein Assessment as Early Predictor of Surgical Site Infections Development after Pancreaticoduodenectomy

BACKGROUND

Surgical site infections (SSIs) are extremely common in pancreatic surgery and explain its considerable morbidity and mortality, even in tertiary centers. Early detection of these complications, with the help of laboratory assays, improve clinical outcome. The aim of the present study is to evaluate C-reactive protein (CRP) diagnostic accuracy as early predictor of SSIs after pancreaticoduodenectomy (PD).

METHODOLOGY

We considered 251 consecutive PD. We prospectively recorded preoperative clinical and anthropometric data, intraoperative details and the postoperative outcome. In the first pool of consecutive patients (n = 150), we analyzed CRP levels from postoperative day 1 to 7 and investigated the prediction of SSIs. We then validated the diagnostic accuracy on the following 101 consecutive cases.

RESULTS

At multivariate analysis, high BMI and preoperative biliary stenting appeared to be independently associated with SSIs and organ-space SSI development. The CRP cutoff of 17.27 mg/dl on postoperative day 3 (78% sensitivity, 79% specificity) and of 14.72 mg/dl on postoperative day 4 (87% sensitivity, 82% specificity) was in a position to predict the course of 78.2 and 80.2% of patients, respectively.

CONCLUSIONS

CRP on postoperative days 3 and 4 seems able to predict postoperative course, selecting patients deserving intensification of diagnostic assessment; patients not satisfying these conditions could be reasonably directed toward early discharge.

Role of preoperative biliary stents, bile contamination and antibiotic prophylaxis in surgical site infections after pancreaticoduodenectomy

BACKGROUND

The routine use of preoperative biliary drainage before pancreaticoduodenectomy (PD) remains controversial. This observational retrospective study compared stented and non-stented patients undergoing PD to assess any differences in post-operative morbidity and mortality.

METHODS

A total of 180 consecutive patients who underwent PD and had intra-operative bile cultures performed between January 2010 and February 2013 were retrospectively identified. All patients received peri-operative intravenous antibiotic prophylaxis, primarily cefazolin.

RESULTS

Overall incidence of post-operative surgical complications was 52.3 %, with no difference between stented and non-stented patients (53.4 % vs. 51.1 %; p = 0.875). However, stented patients had a significantly higher incidence of deep incisional surgical site infections (SSIs) (p = 0.038). In multivariate analysis, biliary stenting was confirmed as a risk factor for deep incisional SSIs (p = 0.044). Significant associations were also observed for cardiac disease (p = 0.010) and BMI ≥25 kg/m(2) (p = 0.045). Enterococcus spp. were the most frequent bacterial isolates in bile (74.5 %) and in drain fluid (69.1 %). In antimicrobial susceptibilty testing, all Enterococci isolates were cefazolin-resistant.

CONCLUSION

Given the increased risk of deep incisional SSIs, preoperative biliary stenting in patients underging PD should be used only in selected patients. In stented patients, an antibiotic with anti-enterococcal activity should be chosen for PD prophylaxis.

Spatial distribution of B cells predicts prognosis in human pancreatic adenocarcinoma

B-cell responses are emerging as critical regulators of cancer progression. In this study, we investigated the role of B lymphocytes in the microenvironment of human pancreatic ductal adenocarcinoma (PDAC), in a retrospective consecutive series of 104 PDAC patients and in PDAC preclinical models. Immunohistochemical analysis revealed that B cells occupy two histologically distinct compartments in human PDAC, either scatteringly infiltrating (CD20-TILs), or organized in tertiary lymphoid tissue (CD20-TLT). Only when retained within TLT, high density of B cells predicted longer survival (median survival 16.9 mo CD20-TLT^hi vs. 10.7 mo CD20-TLT^lo; p = 0.0085). Presence of B cells within TLT associated to a germinal center (GC) immune signature, correlated with CD8-TIL infiltration, and empowered their favorable prognostic value. Immunotherapeutic vaccination of spontaneously developing PDAC (Kras^G12D-Pdx1-Cre) mice with α-enolase (ENO1) induced formation of TLT with active GCs and correlated with increased recruitment of T lymphocytes, suggesting induction of TLT as a strategy to favor mobilization of immune cells in PDAC. In contrast, in an implanted tumor model devoid of TLT, depletion of B cells with an anti-CD20 antibody reinstated an antitumor immune response. Our results highlight B cells as an essential element of the microenvironment of PDAC and identify their spatial organization as a key regulator of their antitumor function. A mindfully evaluation of B cells in human PDAC could represent a powerful prognostic tool to identify patients with distinct clinical behaviors and responses to immunotherapeutic strategies.

[Echo-color Doppler and echo-Doppler in the diagnosis of carotid body tumors]

Echo-Doppler and Color Flow Doppler examinations, are able to combine the advantages offered by echography with those had with the Doppler exam. In the presence of tumours of the carotid body, these exams can furnish morphological data with regard to tumor size, its precise location and its rapport with contiguous organ as well as data regarding blood flow in the mass itself. The color Flow Doppler exam, in particular, can reveal the echographic aspect and the flow toward and away from the sonde all on the same image. This enables a precise diagnosis of a tumor of the carotid body to be reached even without angiography. The personal experience here reported involves ten cases observed during the last seven years.