The falciform/round ligament "flooring," an effective method to reduce life-threatening post-pancreatectomy hemorrhage occurrence

PURPOSE

Late post-pancreatectomy hemorrhage (PPH) represents the most severe complication after pancreatic surgery. We have measured the efficacy of major vessels "flooring" with falciform/round ligament to prevent life-threatening grade C late PPH after pancreaticoduodenectomy (PD) and distal pancreatectomy (DP).

METHODS

All consecutive patients who underwent PD and DP between 2013 and 2021 were retrospectively reviewed on a prospectively maintained database. The cohort was divided in two groups: "flooring" vs. "no flooring" method group. The "no flooring" group had omental flap interposition. Patient characteristics and operative and postoperative data including clinically relevant postoperative pancreatic fistula (CR-POPF), late PPH (grade B and C), and 90-day mortality were compared between the two groups.

RESULTS

Two hundred and forty patients underwent pancreatic resections, including 143 PD and 97 DP. The "flooring" method was performed in 61 patients (39 PD and 22 DP). No difference was found between the two groups concerning severe morbidity, CR-POPF, delayed PPH, and mortality rate. The rate of patients requiring postoperative intensive care unit was lower in the "flooring" than in the "no flooring" method group (11.5% vs. 25.1%, p = 0.030). Among patients with grade B/C late PPH (n = 30), the rate of life-threatening grade C late PPH was lower in the "flooring" than in the "no flooring" method group (28.6% (n = 2/7) vs. 82.6% (n = 19/24), p = 0.014). Risk factor analysis showed that the "flooring" method was the only protective factor against grade C late PPH occurrence (p = 0.013).

CONCLUSION

The "flooring" method using the falciform/round ligament should be considered during pancreatectomies to reduce the occurrence of life-threatening grade C late PPH.

Relevance of biopsy-derived pancreatic organoids in the development of efficient transcriptomic signatures to predict adjuvant chemosensitivity in pancreatic cancer

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Most patient with pancreatic cancer are treated by chemotherapy.

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Treatments selection are not personalized on the tumor characteristics.

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Signatures predicting chemotherapy efficiency are essential for personalizing treatments.

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An RNA signature of gemcitabine-sensitivity is developed leveraged on the dissimilarities between 2D and 3D in vitro models.

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Combining different in vitro models can help in defining clinically efficient transcriptomic signatures.

Pancreatic ductal adenocarcinoma (PDAC) patients are frequently treated by chemotherapy. Even if personalized therapy based on molecular analysis can be performed for some tumors, PDAC regimens selection is still mainly based on patients' performance status and expected efficacy. Therefore, the establishment of molecular predictors of chemotherapeutic efficacy could potentially improve prognosis by tailoring treatments. We have recently developed an RNA-based signature that predicts the efficacy of adjuvant gemcitabine using 38 PDAC primary cell cultures. While demonstrated its efficiency, a significant association with the classical/basal-like PDAC spectrum was observed. We hypothesized that this flaw was due to the basal-like biased phenotype of cellular models used in our strategy. To overcome this limitation, we generated a prospective cohort of 27 consecutive biopsied derived pancreatic organoids (BDPO) and include them in the signature identification strategy. As BDPO's do not have the same biased phenotype as primary cell cultures we expect they can compensate one with each other and cover a broader range of molecular phenotypes. We then obtained an improved signature predicting gemcitabine sensibility that was validated in a cohort of 300 resected PDAC patients that have or have not received adjuvant gemcitabine. We demonstrated a significant association between the improved signature and the overall and disease-free survival in patients predicted as sensitive and treated with adjuvant gemcitabine. We propose then that including BDPO along primary cell cultures represent a powerful strategy that helps to overcome primary cell cultures limitations producing unbiased RNA-based signatures predictive of adjuvant treatments in PDAC.

Prognostic impact of splenic vessel involvement and tumor size in distal pancreatectomy for adenocarcinoma: a retrospective multicentric cohort study

PURPOSE

Splenic vessel involvement occurs frequently in pancreatic ductal adenocarcinoma (PDAC) of the body and the tail (B/T) but the impact on survival is unknown. We assessed the influence of radiological and pathologic involvement of splenic artery (p-SA +) and vein (p-SV +) on patient outcomes after distal pancreatectomy (DP) for PDAC.

METHODS

From 2013 to 2019, all DP for PDAC in five centers were included. Factors associated with overall (OS) and disease-free (DFS) survival were identified.

RESULTS

Among the 76 patients included, 5 (6.6%) had p-SA + only, 11 (14.5%) had p-SV + only, and 24 (31.6%) had both p-SA + and p-SV + . The preoperative CT-scan accuracy to predict p-SV + and p-SA + was high (sensitivity: 91.4% and 82.8%, respectively; negative predictive value: 89.7% and 88.3%, respectively). The 5-year OS and DFS rates were 3.9% and 8.3%, respectively. Multivariate analysis identified splenic vessel involvement (i.e., p-SA + or p-SV + , or both p-SA + and p-SV +) as the only independent factor influencing DFS (HR 4.04; 95% CI [1.22-13.44], p = 0.023). Tumor size ≥ 30 mm was the only independent factor influencing OS (HR 4.04; 95% CI [1.26-12.95], p = 0.019) and was associated with a high risk of p-SA + (p = 0.001) and p-SV + (p < 0.001).

CONCLUSION

Tumor size ≥ 30 mm and splenic vessel involvement occurred in more than half of the patients who underwent DP for PDAC and had negative impact on long-term survival. Preoperative CT-scan was reliable to identify splenic vessel involvement in B/T PDAC. Large tumor size and radiological splenic vessel involvement could be taken into account to propose a neoadjuvant treatment.

Surgery of small bowel melanoma metastases in the era of efficient medical therapies: a retrospective cohort study

Surgery of small bowel melanoma metastases has to be reconsidered in the era of targeted treatments and immunotherapy. To retrospectively assess context and outcomes of small bowel melanoma metastases resections. All consecutive melanoma patients who underwent resection of small bowel metastases between 2011 and 2017, in a single referral center, were retrospectively analyzed through melanoma-specific survival (MSS). A total of 20 patients were included with a 47.8 months median follow-up. Before small bowel surgery, eight patients (40%) were asymptomatic while seven had anemia and five patients had abdominal pain. All resections were decided on tumor boards except for three surgeries performed in the emergency setting. In the whole cohort, MSS was 89.5 months with 50% of patients alive at the study endpoint. We classified surgical indications in three groups: (1) surgery as a pivotal treatment for mono- or oligo-metastases limited to the small bowel (n = 6); (2) salvage surgery for symptomatic patients in order to preserve their chances to switch to an active line of medical treatment (n = 8); and (3) surgery of small bowel dissociated metastatic progression for patients otherwise controlled (n = 6), aiming at keeping patients with the same treatment or active follow-up. In these three situations, the objective of surgery was usually met, and most patients had a long median MSS after surgery: 70.3 months, 89.5 months and 72.4 months, respectively. Although medical treatments have dramatically improved survival in metastatic melanoma, surgical control of life-threatening localization like small bowel metastases is often a condition for long survival.

Postoperative day 1 combination of serum C-reactive protein and drain amylase values predicts risks of clinically relevant pancreatic fistula. The "90-1000" score

BACKGROUND

Several scoring systems predict risks of clinically relevant postoperative pancreatic fistula after pancreatectomy, but none have emerged as the gold standard. This study aimed to evaluate the accuracy of postoperative day 1 drain amylase and serum C-reactive protein levels in predicting clinically relevant postoperative pancreatic fistula compared with intraoperative pancreatic characteristics.

METHODS

Patients who underwent pancreatectomy between 2017 and 2019 were included prospectively. Cutoff values were determined using receiver operating characteristic curves, and a score combining postoperative day 1 drain amylase and serum C-reactive protein was tested in a multivariate logistic regression model to evaluate clinically relevant postoperative pancreatic fistula risk.

RESULTS

A total of 274 pancreatic resections (182 pancreaticoduodenectomies and 92 distal pancreatectomies) were included. The pancreatic gland texture was "soft" in 47.8% (n = 131), and 55.8% (n = 153) had a small size main pancreatic duct (≤3 mm). Clinically relevant postoperative pancreatic fistula occurred in 58 patients (21.2%). Drain amylase ≥1,000 UI/L and serum C-reactive protein ≥90 mg/L were identified as the optimal cutoffs to predict clinically relevant postoperative pancreatic fistula. On multivariate analysis these cutoffs were independent predictors of clinically relevant postoperative pancreatic fistula after both pancreaticoduodenectomies (drain amylase: P < .001, serum C-reactive protein: P = .006) and distal pancreatectomies (drain amylase: P = .009, serum C-reactive protein: P = .001). The postoperative day 1 "90-1000" model, a 2-value score relying on these cutoffs, significantly (P < .001) outperformed intraoperative pancreatic parenchymal characteristics in predicting clinically relevant postoperative pancreatic fistula after both pancreaticoduodenectomies and distal pancreatectomies. A postoperative day 1 "90-1000" score = 0 had a negative predictive value of 97% and 94%, respectively, after pancreaticoduodenectomy and distal pancreatectomies.

CONCLUSION

A combined score relying on postoperative day 1 values of drain amylase and serum C-reactive protein levels was accurate in predicting risks of clinically relevant postoperative pancreatic fistula after pancreatectomy.

Intra-pancreatic distal cholangiocarcinoma and pancreatic ductal adenocarcinoma: a common short and long-term prognosis?

The aim of the study was to compare histological features, postoperative outcomes, and long-term prognostic factors after pancreaticoduodenectomy for distal cholangiocarcinoma and pancreatic ductal adenocarcinoma. From 2005 to 2017, 188 pancreaticoduodenectomies (pancreatic ductal adenocarcinoma n = 151, distal cholangiocarcinoma n = 37) were included. Postoperative outcomes were compared after matching on pancreatic gland texture and main pancreatic duct size. Matching according to tumor size, lymph node invasion and resection margin was used to compare overall and disease-free survival. Distal cholangiocarcinoma patients had more often "soft" pancreatic gland (P = 0.002) and small size main pancreatic duct (P = 0.001). Pancreatic ductal adenocarcinoma patients had larger tumors (P = 0.009), and higher lymph node ratio (P = 0.017). Severe morbidity (P = 0.023) and clinically relevant pancreatic fistula (P = 0.018) were higher in distal cholangiocarcinoma patients. After matching on gland texture and main pancreatic duct diameter, clinically relevant postoperative pancreatic fistula was still more frequent in distal cholangiocarcinoma patients (P = 0.007). Tumor size > 20 mm was predictive of impaired overall survival (P = 0.024) and disease-free survival (P = 0.003), tumor differentiation (P = 0.027) was predictive of impaired overall survival. Survival outcomes for distal cholangiocarcinoma and pancreatic ductal cholangiocarcinoma were similar after matching patients according to tumor size, lymph node invasion and resection margin. Long-term outcomes after pancreaticoduodenectomy for distal cholangiocarcinoma and pancreatic ductal adenocarcinoma patients are similar. Postoperative course is more complicated after pancreaticoduodenectomy for distal cholangiocarcinoma than pancreatic ductal adenocarcinoma. After pancreaticoduodenectomy, patients with distal cholangiocarcinoma and pancreatic ductal adenocarcinoma have similar long-term oncological outcomes.

Establishment of a pancreatic adenocarcinoma molecular gradient (PAMG) that predicts the clinical outcome of pancreatic cancer

BACKGROUND

A significant gap in pancreatic ductal adenocarcinoma (PDAC) patient's care is the lack of molecular parameters characterizing tumours and allowing a personalized treatment.

METHODS

Patient-derived xenografts (PDX) were obtained from 76 consecutive PDAC and classified according to their histology into five groups. A PDAC molecular gradient (PAMG) was constructed from PDX transcriptomes recapitulating the five histological groups along a continuous gradient. The prognostic and predictive value for PMAG was evaluated in: i/ two independent series (n = 598) of resected tumours; ii/ 60 advanced tumours obtained by diagnostic EUS-guided biopsy needle flushing and iii/ on 28 biopsies from mFOLFIRINOX treated metastatic tumours.

FINDINGS

A unique transcriptomic signature (PAGM) was generated with significant and independent prognostic value. PAMG significantly improves the characterization of PDAC heterogeneity compared to non-overlapping classifications as validated in 4 independent series of tumours (e.g. 308 consecutive resected PDAC, uHR=0.321 95% CI [0.207-0.5] and 60 locally-advanced or metastatic PDAC, uHR=0.308 95% CI [0.113-0.836]). The PAMG signature is also associated with progression under mFOLFIRINOX treatment (Pearson correlation to tumour response: -0.67, p-value < 0.001).

INTERPRETATION

PAMG unify all PDAC pre-existing classifications inducing a shift in the actual paradigm of binary classifications towards a better characterization in a gradient.

FUNDING

Project funding was provided by INCa (Grants number 2018-078 and 2018-079, BACAP BCB INCa_6294), Canceropole PACA, DGOS (labellisation SIRIC), Amidex Foundation, Fondation de France, INSERM and Ligue Contre le Cancer.

Prospective study on predictability of complications by pancreatic surgeons

PURPOSE

We evaluated the intuition of expert pancreatic surgeons, in predicting the associated risk of pancreatic resection and compared this "intuition" to actual operative follow-up. The objective was to avoid major complications following pancreatic resection, which remains a challenge.

METHODS

From January 2015 to February 2018, all patients who were 18 years old or more undergoing a pancreatic resection (pancreaticoduodenectomy [PD], distal pancreatectomy [DP], or central pancreatectomy [CP]) for pancreatic lesions were included. Preoperatively and postoperatively, all surgeons completed a form assessing the expected potential occurrence of clinically relevant postoperative pancreatic fistula (CR-POPF: grade B or C), postoperative hemorrhage, and length of stay.

RESULTS

Preoperative intuition was assessed for 101 patients for 52 PD, 44 DP, and 5 CP cases. Overall mortality and morbidity rates were 6.9% (n = 7) and 67.3% (n = 68), respectively, and 38 patients (37.6%) developed a POPF, including 27 (26.7%) CR-POPF. Concordance between preoperative intuition of CR-POPF occurrence and reality was minimal, with a Cohen's kappa coefficient (κ) of 0.175 (P value = 0.009), and the same result was obtained between postoperative intuition and reality (κ = 0.351; P < 0.001). When the pancreatic parenchyma was hard, surgeons predicted the absence of CR-POPF with a negative predictive value of 91.3%. However, they were not able to predict the occurrence of CR-POPF when the pancreas was soft (positive predictive value 48%).

CONCLUSIONS

This study assessed for the first time the surgeon's intuition in pancreatic surgery, and demonstrated that pancreatic surgeons cannot accurately assess outcomes except when the pancreatic parenchyma is hard.

Prognostic impact of tumour-infiltrating lymphocytes and cancer-associated fibroblasts in patients with pancreatic adenocarcinoma of the body and tail undergoing resection

BACKGROUND

The prognosis of patients with pancreatic cancer remains poor and novel therapeutic targets are required urgently. Treatment resistance could be due to the tumour microenvironment, a desmoplastic stroma consisting of cancer-associated fibroblasts and tumour-infiltrating lymphocytes (TILs). The aim of the study was to evaluate the prognostic value of TILs and cancer-associated fibroblasts (CAFs) in pancreatic cancer of the body and tail.

METHODS

Using tissue microarray from resected left-sided pancreatic cancer specimens, the immunohistochemistry of TILs (cluster of differentiation (CD) 45, CD3, CD4, FoxP3 and CD8), CAFs (vimentin and α-smooth muscle actin (αSMA)) and functional markers (PD-L1 and Ki-67) was examined, and the association with disease-free (DFS) and overall (OS) survival investigated using a computer-assisted quantitative analysis. Patients were classified into two groups, with low or high levels or ratios, using the 75th percentile value as the cut-off.

RESULTS

Forty-three patients were included in the study. Their median DFS and OS were 9 and 27 months respectively. A high CD4/CD3 lymphocyte ratio was associated with poorer DFS (8 months versus 11 months for a low ratio) (hazard ratio (HR) 2·23, 95 per cent c.i. 1·04 to 4·61; P = 0·041) and OS (13 versus 27 months respectively) (HR 2·62, 1·11 to 5·88; P = 0·028). A low αSMA/vimentin ratio together with a high CD4/CD3 ratio was correlated with poorer outcomes. No significant association was found between Ki-67, PD-L1 and survival.

CONCLUSION

In patients with resected left-sided pancreatic cancer, a tumour microenvironment characterized by a high CD4/CD3 lymphocyte ratio along with a low αSMA/vimentin ratio is correlated with poorer survival.

HVEM has a broader expression than PD-L1 and constitutes a negative prognostic marker and potential treatment target for melanoma

HVEM (Herpes Virus Entry Mediator) engagement of BTLA (B and T Lymphocyte Attenuator) triggers inhibitory signals in T cells and could play a role in evading antitumor immunity. Here, HVEM expression levels in melanoma metastases were analyzed by immunohistochemistry, correlated with overall survival (OS) in 116 patients, and validated by TCGA transcriptomic data. Coincident expression of HVEM and its ligand BTLA was studied in tumor cells and tumor-infiltrating lymphocytes (TILs) by flow cytometry (n = 21) and immunofluorescence (n = 5). Candidate genes controlling HVEM expression in melanoma were defined by bioinformatics studies and validated by siRNA gene silencing. We found that in patients with AJCC stage III and IV melanoma, OS was poorer in those with high HVEM expression on melanoma cells, than in those with a low expression, by immunohistochemistry (p = .0160) or TCGA transcriptomics (p = .0282). We showed a coincident expression of HVEM at the surface of melanoma cells and of BTLA on TILs. HVEM was more widely expressed than PD-L1 in melanoma cells. From a mechanistic perspective, in contrast to PDL1, HVEM expression did not correlate with an IFNγ signature but with an aggressive gene signature. Interestingly, this signature contained MITF, a key player in melanoma biology, whose expression correlated strongly with HVEM. Finally, siRNA gene silencing validated MITF control of HVEM expression. In conclusion, HVEM expression seems to be a prognosis marker and targeting this axis by checkpoint-inhibitors may be of interest in metastatic melanoma.

Prognostic value of PDL1 expression in pancreatic cancer

Pancreatic cancer is one of the most aggressive human cancers. PD1/PDL1-inhibitors recently showed promising results in different cancers with correlation between PDL1 tumor expression and responses. Expression of programmed cell death receptor ligand 1 (PDL1) has been scarcely studied in pancreatic cancer. In this retrospective study, we analyzed PDL1 mRNA expression in 453 clinical pancreatic cancer samples profiled using DNA microarrays and RNASeq. Compared to normal pancreatic samples, PDL1 expression was upregulated in 19% of cancer samples. Upregulation was not associated with clinicopathological features such as patients' age and sex, pathological type, tumor size, lymph node status, and grade, but was associated with shorter disease-free survival and overall survival in multivariate analyses. Analysis of correlations with biological parameters showed that PDL1 upregulation was associated with some degree of lymphocyte infiltration and signs of anti-tumor T-cell response, but to a lesser extent than what has been reported in breast cancer and GIST. PDL1-up pancreatic cancers displayed profiles of lymphocyte exhaustion, were more enriched in inhibitory molecules and pro-tumor populations (Tregs with upregulation of FOXP3 and IL10, myeloid-derived suppressor cells with upregulation of CD33 and S100A8/A9), and demonstrated a down-modulation of most MHC class I members (HLA-A/B/C, HLA-E/F/G) suggestive of a defect in antigen processing and presentation. In conclusion, our results suggest that PDL1 expression might refine the prediction of metastatic relapse in operated pancreatic cancer, and that PD1/PDL1 inhibitors might reactivate inhibited T-cells to increase the anti-tumor immune response in PDL1-upregulated tumors.

Risk factors of exocrine and endocrine pancreatic insufficiency after pancreatic resection: A multi-center prospective study

Management of functional consequences after pancreatic resection has become a new therapeutic challenge. The goal of our study is to evaluate the risk factors for exocrine (ExoPI) and endocrine (EndoPI) pancreatic insufficiency after pancreatic surgery and to establish a predictive model for their onset.

PATIENTS AND METHODS

Between January 1, 2014 and June 19, 2015, 91 consecutive patients undergoing pancreatoduodenectomy (PD) or left pancreatectomy (LP) (72% and 28%, respectively) were followed prospectively. ExoPI was defined as fecal elastase content<200μg per gram of feces while EndoPI was defined as fasting glucose>126mg/dL or aggravation of preexisting diabetes. The volume of residual pancreas was measured according to the same principles as liver volumetry.

RESULTS

The ExoPI and EndoPI rates at 6 months were 75.9% and 30.8%, respectively. The rate of ExoPI after PD was statistically significantly higher than after LP (98% vs. 21%; P<0.001), while the rate of EndoPI was lower after PD vs. LP, but this difference did not reach statistical significance (28% vs. 38.5%; P=0.412). There was no statistically significant difference in ExoPI found between pancreatico-gastrostomy (PG) and pancreatico-jejunostomy (PJ) (100% vs. 98%; P=1.000). Remnant pancreatic volume less than 39.5% was predictive of ExoPI.

CONCLUSION

ExoPI occurs quasi-systematically after PD irrespective of the reconstruction scheme. The rate of EndoPI did not differ between PD and LP.

Preoperative Prediction of Small Bowel Length Using CT Scan and Tridimensional Reconstructions: a New Tool in Bariatric Surgery?

PURPOSE

During Roux-en-Y-gastric Bypass, the limb lengths are preoperatively determined regardless of individual small bowel length (SBL), which presents a great variability. Few studies highlighted anthropometric factors associated with SBL, and none attempted to predict SBL preoperatively.

OBJECTIVE

The aim of this study is to evaluate factors correlated to SBL (anthropometric and radiologic) and to establish a preoperative SBL prediction.

MATERIAL AND METHODS

In this single-center prospective study, 30 adult patients who underwent laparotomy with a preoperative CT scan were included. Intraoperative SBL measurement was performed with an umbilical tape. Anthropometric parameters were age, gender, height, and BMI. 2D radiological measurements consisted of subcutaneous thickness, abdominal diameters, waist circumference, and mesenteric root length. 3D radiological volumetric reconstructions consisted of whole small bowel and mesentery (WSBM), lean small bowel and mesentery (LSBM), and fat small bowel and mesentery (FSBM).

RESULTS

Mean intraoperative measurement of SBL was 531 ± 105 cm. Among the clinical and radiological measurements, the FSBM volume presented the greatest dispersion. Height (p < 0.02) and LSBM volume (p < 0.01) were significantly correlated to the SBL in univariate analysis. LSBM volume was the only measurement significantly associated with SBL in multivariate analysis (p < 0.006). From the multivariate model, a formula was created to predict SBL. The mean percentage difference between predicted and intraoperative SBL measurements for all patients was 13.7%, and 8.4% for obese patients.

CONCLUSION

LSBM volume is significantly correlated to the SBL. A preoperative SBL prediction with low percentage error could be performed with LSBM volume.

A pancreatic ductal adenocarcinoma subpopulation is sensitive to FK866, an inhibitor of NAMPT

Treating pancreatic cancer is extremely challenging due to multiple factors, including chemoresistance and poor disease prognosis. Chemoresistance can be explained by: the presence of a dense stromal barrier leading to a lower vascularized condition, therefore limiting drug delivery; the huge intra-tumoral heterogeneity; and the status of epithelial-to-mesenchymal transition. These factors are highly variable between patients making it difficult to predict responses to chemotherapy. Nicotinamide phosphoribosyl transferase (NAMPT) is the main enzyme responsible for recycling cytosolic NAD⁺ in hypoxic conditions. FK866 is a noncompetitive specific inhibitor of NAMPT, which has proven anti-tumoral effects, although a clinical advantage has still not been demonstrated. Here, we tested the effect of FK866 on pancreatic cancer-derived primary cell cultures (PCCs), both alone and in combination with three different drugs typically used against this cancer: gemcitabine, 5-Fluorouracil (5FU) and oxaliplatin. The aims of this study were to evaluate the benefit of drug combinations, define groups of sensitivity, and identify a potential biomarker for predicting treatment sensitivity. We performed cell viability tests in the presence of either FK866 alone or in combination with the drugs above-mentioned. We confirmed both inter- and intra-tumoral heterogeneity. Interestingly, only the in vitro effect of gemcitabine was influenced by the addition of FK866. We also found that NAMPT mRNA expression levels can predict the sensitivity of cells to FK866. Overall, our results suggest that patients with tumors sensitive to FK866 can be identified using NAMPT mRNA levels as a biomarker and could therefore benefit from a co-treatment of gemcitabine plus FK866.

Pancreatic Adenocarcinoma Therapeutic Targets Revealed by Tumor-Stroma Cross-Talk Analyses in Patient-Derived Xenografts

Preclinical models based on patient-derived xenografts have remarkable specificity in distinguishing transformed human tumor cells from non-transformed murine stromal cells computationally. We obtained 29 pancreatic ductal adenocarcinoma (PDAC) xenografts from either resectable or non-resectable patients (surgery and endoscopic ultrasound-guided fine-needle aspirate, respectively). Extensive multiomic profiling revealed two subtypes with distinct clinical outcomes. These subtypes uncovered specific alterations in DNA methylation and transcription as well as in signaling pathways involved in tumor-stromal cross-talk. The analysis of these pathways indicates therapeutic opportunities for targeting both compartments and their interactions. In particular, we show that inhibiting NPC1L1 with Ezetimibe, a clinically available drug, might be an efficient approach for treating pancreatic cancers. These findings uncover the complex and diverse interplay between PDAC tumors and the stroma and demonstrate the pivotal role of xenografts for drug discovery and relevance to PDAC.

Gene expression profiling of patient-derived pancreatic cancer xenografts predicts sensitivity to the BET bromodomain inhibitor JQ1: implications for individualized medicine efforts

c-MYC controls more than 15% of genes responsible for proliferation, differentiation, and cellular metabolism in pancreatic as well as other cancers making this transcription factor a prime target for treating patients. The transcriptome of 55 patient-derived xenografts show that 30% of them share an exacerbated expression profile of MYC transcriptional targets (MYC-high). This cohort is characterized by a high level of Ki67 staining, a lower differentiation state, and a shorter survival time compared to the MYC-low subgroup. To define classifier expression signature, we selected a group of 10 MYC target transcripts which expression is increased in the MYC-high group and six transcripts increased in the MYC-low group. We validated the ability of these markers panel to identify MYC-high patient-derived xenografts from both: discovery and validation cohorts as well as primary cell cultures from the same patients. We then showed that cells from MYC-high patients are more sensitive to JQ1 treatment compared to MYC-low cells, in monolayer, 3D cultured spheroids and in vivo xenografted tumors, due to cell cycle arrest followed by apoptosis. Therefore, these results provide new markers and potentially novel therapeutic modalities for distinct subgroups of pancreatic tumors and may find application to the future management of these patients within the setting of individualized medicine clinics.

A 25-gene classifier predicts overall survival in resectable pancreatic cancer

BACKGROUND

Pancreatic carcinoma is one of the most lethal human cancers. In patients with resectable tumors, surgery followed by adjuvant chemotherapy is the only curative treatment. However, the 5-year survival is 20%. Because of a strong metastatic propensity, neoadjuvant chemotherapy is being tested in randomized clinical trials. In this context, improving the selection of patients for immediate surgery or neoadjuvant chemotherapy is crucial, and high-throughput molecular analyses may help; the present study aims to address this.

METHODS

Clinicopathological and gene expression data of 695 pancreatic carcinoma samples were collected from nine datasets and supervised analysis was applied to search for a gene expression signature predictive for overall survival (OS) in the 601 informative operated patients. The signature was identified in a learning set of patients and tested for its robustness in a large independent validation set.

RESULTS

Supervised analysis identified 1400 genes differentially expressed between two selected patient groups in the learning set, namely 17 long-term survivors (LTS; ≥ 36 months after surgery) and 22 short-term survivors (STS; dead of disease between 2 and 6 months after surgery). From these, a 25-gene prognostic classifier was developed, which identified two classes ("STS-like" and "LTS-like") in the independent validation set (n = 562), with a 25% (95% CI 18-33) and 48% (95% CI 42-54) 2-year OS (P = 4.33 × 10-9), respectively. Importantly, the prognostic value of this classifier was independent from both clinicopathological prognostic features and molecular subtypes in multivariate analysis, and existed in each of the nine datasets separately. The generation of 100,000 random gene signatures by a resampling scheme showed the non-random nature of our prognostic classifier.

CONCLUSION

This study, the largest prognostic study of gene expression profiles in pancreatic carcinoma, reports a 25-gene signature associated with post-operative OS independently of classical factors and molecular subtypes. This classifier may help select patients with resectable disease for either immediate surgery (the LTS-like class) or neoadjuvant chemotherapy (the STS-like class). Its assessment in the current prospective trials of adjuvant and neoadjuvant chemotherapy trials is warranted, as well as the functional analysis of the classifier genes, which may provide new therapeutic targets.

Venous Resection in Pancreatic Ductal Adenocarcinoma: Impact of Surgical Experience on Early Postoperative Courses

BACKGROUND/AIM

The aim of this study was to determine the effects of surgical experience on early postoperative courses after pancreaticoduodenectomy (PD) with venous resection.

PATIENTS AND METHODS

From 2005 to 2014, 134 patients were analyzed, 62 and 72 patients were resected in periods 1 (2005-2009) and 2 (2010-2014) respectively; 115 and 19 patients underwent PD with venous resection in high- and low-volume center groups respectively.

RESULTS

Of the entire cohort, mortality rate was 4%. There were no significant differences between the two periods. In the low-volume center group, the mortality rate was increased (21% vs. 2%, p<0.01) and the mean length of hospital stay was longer (25 (±27) days vs. 17 (±8) days, p=0.04). The high-volume center group was the only independent protective factor regarding death (OR=0.04, 95%CI (0.01-0.38), p<0.01) and length of hospital stay (OR<0.01, 95%CI (0.00-0.43), p=0.03).

CONCLUSION

Patients who present isolated venous invasion must be referred to high-volume centers for surgery.

Comparison of different feeding regimes after pancreatoduodenectomy - a retrospective cohort analysis

BACKGROUND

Delayed gastric emptying (DGE) is the most frequent pancreatic specific complication (PSC) after pancreaticoduodenectomy (PD). Several gastric decompression systems exist to manage DGE. Patients with a pancreatic tumor require prolonged nutrition; however, controversies exist concerning nutrition protocol after PD. The aim of the study was to assess the safety and efficacy of nasogastric (NG), gastrostomy (GT), and gastrojejunostomy (GJ) tubes with different feeding systems on postoperative courses.

METHODS

Between January 2013 and March 2016, 86 patients underwent PD with pancreaticogastrostomy. Patients were divided into three groups: GJ group with enteral nutrition (EN, n = 12, 14%), NG (n = 31, 36%) and GT groups (n = 43, 50%), both with total parenteral nutrition (TPN).

RESULTS

Patients in the GJ (n = 9, 75%) and GT (n = 18, 42%) groups had an American Society of Anesthesiologists (ASA) score of 3 more often than those in the NG group (n = 5, 16%, p ≤ 0.01). Multivariate analysis identified the GT tube with TPN as an independent risk factor of severe morbidity (p = 0.02) and DGE (p < 0.01). An ASA score of 3, jaundice, common pancreatic duct size ≤3 mm and soft pancreatic gland texture (p < 0.05) were found as independent risk factors of PSCs. Use of a GJ tube with EN, GT tube with TPN, jaundice, and PSCs were identified as independent risk factors for greater postoperative length of hospital stay (p < 0.01). Mean global hospitalization cost did not differ between groups.

CONCLUSION

GT tube insertion with TPN was associated with increased severe postoperative morbidity and DGE and should not be recommended. EN through a GJ tube after PD is feasible but does not have clear advantages on postoperative courses compared to an NG tube.

Abstract 4396: Multiomics assessment of the cancer and stromal compartments of patient-derived pancreatic xenografts reveals clinically-relevant subtypes and novel targeted therapies

Patient-derived xenografts (PDX) are appearing as a prime approach for preclinical studies despite being insufficiently characterized as a model of the human disease and its diversity. In this work, 29 PDX were obtained from either surgery or endoscopic ultrasound-guided fine needle aspirate of pancreatic adenocarcinoma. The extensive genomic profiling of these pancreatic PDX, revealed two clinically-relevant subtypes having broad similarities with human primary tumors. These subtypes are defined by highly specific DNA methylation and transcriptomic profiles (mRNA, miRNA or lncRNA) but are not distinguishable by exonic mutations or copy number aberrations. Moreover, by specifically analyzing the stroma transcriptome, as defined by the expression of murine transcripts, we found that it is able to stratify the patients with the same efficiency than the analysis of grafted human tumor cells. This finding suggest that transformed pancreatic cells drive the composition of their own stroma. Finally, the multiomics analysis pinpoints novel therapeutic targets, one of which we demonstrate to be an efficient method for treating pancreatic cancer. Overall, we show that PDX are trustworthy pre-clinical models of pancreatic adenocarcinoma including of unresectable tumors. Their multiomics profiling allow the independent analysis of the uncontaminated cancer or stromal compartments and discloses several original therapeutics targets.

Citation Format: Remy Nicolle, Yuna Blum, Laetitia Marisa, Celine Loncle, Odile Gayet, Vincent Moutardier, Olivier Turrini, Marc Giovannini, Benjamin Bian, Martin Bigonnet, Marion Rubis, Nabila Elarouci, Lucile Armenoult, Mira Ayadi, Pauline Duconseil, Mohamed Gasmi, Mehdi Ouaissi, Aurélie Maignan, Gwen Lomberk, Jean-Marie Boher, Jacques Ewald, Erwan Bories, Jonathan Garnier, Anthony Goncalves, Flora Poizat, Jean-Luc Raoul, Veronique Secq, Stephane Garcia, Philippe Grandval, Marine Barraud-Blanc, Emmanuelle Norguet, Marine Gilabert, Jean-Robert Delpero, Julie Roques, Ezequiel Calvo, Fabienne Guillaumond, Sophie Vasseur, Raul Urrutia, Aurélien de Reyniès, Nelson Dusetti, Juan Iovanna. Multiomics assessment of the cancer and stromal compartments of patient-derived pancreatic xenografts reveals clinically-relevant subtypes and novel targeted therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4396. doi:10.1158/1538-7445.AM2017-4396

HVEM: A novel cosignaling molecule of major interest in melanoma

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Background: Herpes Virus Entry Mediator (HVEM) is a member of the TNF superfamily, its ligation of the immunoglobulin family member B-lymphocyte and T-lymphocyte attenuator (BTLA) activates inhibitory signaling in T-cells and could play a role in evading host anti-tumor immunity. Ectopic overexpression of HVEM is associated with poor survival in some solid tumors. Our objectives were: -to evaluate HVEM expression in melanoma (MM) -to explore potential link of its overexpression with clinical outcomes -to understand the mechanisms by which HVEM was ectopically expressed in MM, and how HVEM-BTLA may play a role in MM. Methods: HVEM expression was analyzed by IHC in formalin-fixed samples of mm metastases and was correlated with OS in 130 patients. To better understand how HVEM could interfere with prognosis, relation of HVEM with its ligand BTLA was studied in the tumor and tumor microenvironment on 15 fresh metastases by flow cytometry after tumor dissociation. Bioinformatic studies based on TCGA and CCLE data combined to targeting of candidate genes by siRNA were used to investigate HVEM regulation on MM. Results: Patients with high HVEM expression on mm cells in their metastases have a significantly (p = 0.0142) poorer overall survival than those with a low expression. TCGA transcriptomic data support these results. From the mechanistic point of view, we could show that 1-HVEM expressed at the tumor cell surface interacts with BTLA expressed by tumor-infiltrated lymphocytes. 2-HVEM expression is neither linked to the mm mutational status nor inducible by IFN 3-Genes co-regulated with HVEM are associated with an aggressive gene signature 4- HVEM strongly correlate with MITF expression, MITF binds HVEM promoter, and its downregulation by siRNA results in a decrease in HVEM expression. Conclusions: A high expression of HVEM by mm metastases seems to be a pejorative prognostic marker. HVEM-BTLA interaction is a co-signaling system similar to the PD1-PDL1 one, but seem to be constitutive rather than inducible. HVEM and its co-regulated genes may constitute a signature of aggressiveness associated to MITF. High HVEM expression on mm cells may dampen anti-tumor immune responses, making HVEM and BTLA potential new targets for “checkpoint blockade” therapy.

Anti-proliferative and anti-secretory effects of everolimus on human pancreatic neuroendocrine tumors primary cultures: is there any benefit from combination with somatostatin analogs?

Therapeutic management of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) is challenging. The mammalian target of rapamycin (mTOR) inhibitor everolimus recently obtained approval from the Food and Drug Administration for the treatment of patients with advanced pancreatic neuroendocrine tumors (pNETs). Despite its promising antitumor efficacy observed in cell lines, clinical benefit for patients is unsatisfactory. The limited therapeutic potential of everolimus in cancer cells has been attributed to Akt activation due to feedback loops relief following mTOR inhibition. Combined inhibition of Akt might then improve everolimus antitumoral effect. In this regard, the somatostatin analog (SSA) octreotide has been shown to repress the PI3K/Akt pathway in some tumor cell lines. Moreover, SSAs are well tolerated and routinely used to reduce symptoms caused by peptide release in patients carrying functional GEP-NETs. We have recently established and characterized primary cultures of human pNETs and demonstrated the anti-proliferative effects of both octreotide and pasireotide. In this study, we aim at determining the antitumor efficacy of everolimus alone or in combination with the SSAs octreotide and pasireotide in primary cultures of pNETs. Everolimus reduced both Chromogranin A secretion and cell viability and upregulated Akt activity in single treatment. Its anti-proliferative and anti-secretory efficacy was not improved combined with the SSAs. Both SSAs did not overcome everolimus-induced Akt upregulation. Furthermore, caspase-dependent apoptosis induced by SSAs was lost in combined treatments. These molecular events provide the first evidence supporting the lack of marked benefit in patients co-treated with everolimus and SSA.

Abstract A48: Multi-omics characterization of PDAC subtypes using PDX reveals that epigenetic but not genetic analysis permit a clinically relevant classification

Genome-wide molecular profiles have been proven to be beneficial for the identification of clinically relevant tumor subtypes in many neoplastic diseases. While pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death, very few genomic and transcriptomic studies have been conducted. This is mainly due to the difficulty to obtain a suitable cohort of PDAC tumor samples. The major obstacle is the usually high proportion of non-transformed stromal cells, which can greatly hinder the analysis of carcinogenic-specific processes. Moreover, tumor cohorts requiring resection samples can be biased by the exclusion of inoperable patients, representing 85% of all patients presenting PDAC.

In this study, we generated Patient Derived Xenografts (PDX) with samples collected from 29 patients using either Endoscopic Ultrasound-Guided Fine-Needle Aspirates or, for operable patients, resections. The transcriptomic profiles, of both mRNA and miRNA, and the epigenetic landscape of early PDX passages consistently identified two tumor-specific molecular subtypes: a well differentiated group often referred to as classical, and an undifferentiated group previously recognized as Basal, Quasi-Mesenchymal or Squamous. Of all the genetic alterations determined by Copy Number analysis and exome sequencing, none were specific to any of the two subtypes, which therefore could not be discriminated solely on genetic basis.

These two PDAC subtypes are characterized by distinct epigenetic and transcriptomic profiles of which the analysis revealed the deregulation of several pathways previously imputed in PDAC development and carcinogenesis in general. In particular, we showed that the Wnt pathway as well as several metabolic pathways, including cytochrome P450 genes recently implicated in drug resistance, are both epigenetically and transcriptionally deregulated. Altogether, our results provide new insights on pancreatic carcinogenesis and suggest that PDAC phenotypical heterogeneity is mainly driven by epigenetic rather than genetic events.

Citation Format: Remy Nicolle, Yuna Blum, Laetitia Marisa, Jonathan Garnier, Benjamin Bian, Celine Loncle, Martin Bigonnet, Odile Gayet, Vincent Moutardier, Pauline Duconseil, Mohamed Gasmi, Mehdi Ouaissi, Olivier Turrini, Marc Giovannini, Aurélie Maignan, Jean-Marie Boher, Jacques Ewald, Erwan Bories, Marc Barthet, Anthony Goncalves, Flora Poizat, Jean-Luc Raoul, Veronique Secq, Stephane Garcia, Philippe Grandval, Marine Barraud-Blanc, Emmanuelle Norguet, Marine Gilabert, Jean-Robert Delpero, Ezequiel Calvo, Aurélien de Reyniès, Nelson Dusetti, Juan Iovanna.{Authors}. Multi-omics characterization of PDAC subtypes using PDX reveals that epigenetic but not genetic analysis permit a clinically relevant classification. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A48.

Abstract B72: Pancreatic cancer cell drives stroma composition

The extensive desmoplasia in pancreatic ductal adenocarcinoma (PDAC) has raised major interrogations on its role and function in the carcinogenic process. Patient-derived xenograft (PDX) offers an ideal setting to distinguish and to study the interactions between the cancerous epithelial cells and its stroma. Indeed, sequencing profiles of a mix of cancerous/Human and stroma/Mouse cells can be analyzed separately in silico by unambiguously assigning each sequence to the human or mouse genome. Using RNA sequencing, we profiled 30 pancreatic tumor PDXs and extracted the transcriptome profiles of epithelial cancerous cells as well as their corresponding stroma. On average, 70% of RNA sequencing reads were specifically attributed to a human origin, and therefore an epithelial origin, while 22% of RNA sequencing reads were mouse-specific. Using the rate of mouse sequences as a surrogate of the proportion of non-transformed cells, we observe a high variability in the infiltration level from 7% to 60%. The estimation was also consistent in whole exome sequencing (using the same sequencing process) and with the histological quantification of fibrotic tissue.

By specifically analyzing the gene expression in mouse-stromal cells, we show that their transcriptomic profile is consistent with the recent description of human PDAC in situ tumors with high levels of genes of the reported activated-stroma and normal-stroma signatures. We also show that stromal cells over-express genes involved in the SLIT/ROBO axon guidance signalling pathway, in angiogenesis as well as a large number of collagens, cytokines and ligands associated with growth and developmental pathways.

Recent studies identified two major subtypes of PDAC from transcriptomic analysis: a well differentiated, often referred as classical, and an undifferentiated, previously recognized as Basal, Quasi-Mesenchymal or Squamous. The stroma characterized in this work broadly reflects this heterogeneity with stromal gene expression signatures predictive of each subtype. For instance, collagens are significantly over-expressed in the stroma of squamous tumors. The concomitant analysis of transcriptomic profiles of both subtypes shows potential cross-talks between cancerous and stromal cells. Particularly in Squamous tumors, genes implicated in the axon-guidance and Wnt pathways are significantly upregulated in both, stroma and transformed cells. On the other hand, the stroma and transformed cells of Classical tumors shows an upregulation of complementary genes associated with several metabolic pathways.

Taken together, our transcriptomic analysis reveals that human transformed pancreatic cells determine the composition, quantitatively and qualitatively, of stroma mouse cells in a PDX model. This model also reveals a broad variability of PDAC stromas and highlights potential cross-talks between them through known and novel pathways.

Citation Format: Rémy Nicolle, Yuna Blum, Laetitia Marisa, Jonathan Garnier, Benjamin Bian, Celine Loncle, Martin Bigonnet, Odile Gayet, Vincent Moutardier, Pauline Duconseil, Mohamed Gasmi, Mehdi Ouaissi, Olivier Turrini, Marc Giovannini, Aurélie Maignan, Jean-Marie Boher, Jacques Ewald, Erwan Bories, Marc Barthet, Anthony Goncalves, Flora Poizat, Jean-Luc Raoul, Veronique Secq, Stephane Garcia, Philippe Grandval, Marine Barraud-Blanc, Emmanuelle Norguet, Marine Gilabert, Jean-Robert Delpero, Ezequiel Calvo, Aurélien de Reyniès, Juan Iovanna, Nelson Dusetti.{Authors}. Pancreatic cancer cell drives stroma composition. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B72.

Hydrolytic Fate of 3/15-Acetyldeoxynivalenol in Humans: Specific Deacetylation by the Small Intestine and Liver Revealed Using in Vitro and ex Vivo Approaches

In addition to deoxynivalenol (DON), acetylated derivatives, i.e., 3-acetyl and 15-acetyldexynivalenol (or 3/15ADON), are present in cereals leading to exposure to these mycotoxins. Animal and human studies suggest that 3/15ADON are converted into DON after their ingestion through hydrolysis of the acetyl moiety, the site(s) of such deacetylation being still uncharacterized. We used in vitro and ex vivo approaches to study the deacetylation of 3/15ADON by enzymes and cells/tissues present on their way from the food matrix to the blood in humans. We found that luminal deacetylation by digestive enzymes and bacteria is limited. Using human cells, tissues and S9 fractions, we were able to demonstrate that small intestine and liver possess strong deacetylation capacity compared to colon and kidneys. Interestingly, in most cases, deacetylation was more efficient for 3ADON than 15ADON. Although we initially thought that carboxylesterases (CES) could be responsible for the deacetylation of 3/15ADON, the use of pure human CES1/2 and of CES inhibitor demonstrated that CES are not involved. Taken together, our original model system allowed us to identify the small intestine and the liver as the main site of deacetylation of ingested 3/15ADON in humans.

Expression of Genes with Copy Number Alterations and Survival of Patients with Pancreatic Adenocarcinoma

BACKGROUND/AIM

Individual molecular information might improve management of pancreatic adenocarcinoma. To identify actionable genes, at the transcriptional level, we investigated candidate genes that we had previously identified using array-comparative genomic hybridization (aCGH).

MATERIALS AND METHODS

We collected 10 public gene-expression datasets, gathering a total of 524 pancreatic samples (105 normal and 419 malignant tissues). Based on our previous aCGH analysis, we searched for genes differentially expressed between normal and malignant samples and genes associated with survival.

RESULTS

Among genes amplified/gained by aCGH, 48% were overexpressed in malignant tissues. The majority of these genes were related to apoptosis, cell-cycle regulation and differentiation. Among genes located in areas of loss, 41% were underexpressed in malignant tissues; most of them were involved in ion transport, homeostasis maintenance and fatty acid metabolism. Survival analysis identified genes significantly related to shorter (n=17) or longer (n=29) survival.

CONCLUSION

Some of these genes can be further investigated as potential prognostic markers.

Long-term survivors after pancreatectomy for cancer: the TNM classification is outdated

BACKGROUND

According to knowledge, patients with resectable pancreatic adenocarcinoma (PA) should receive adjuvant gemcitabine-based chemotherapy. Thus, the tumour node metastasis (TNM) classification is not used to determine post-operative treatment but rather only to establish patient prognosis. However, the TNM classification does not include strong factors influencing survival, such as perineural invasion or margin status. This study compared the survival of patients with very similar tumours.

METHODS

From 1997 to 2007, 118 patients underwent pancreatectomy for PA. Twenty-six patients (22%) had long-term survival (>5 years; LTS group). According to the major prognostic factors of PA, we matched (1:1) patients in the LTS group with patients who did not have long-term survival (<5 years; control group).

RESULTS

Surprisingly, we did not have any difficulty identifying patients to include in the control group. Consequently, no differences were noted between patients of the LTS group when compared with patients of the control group according to major prognostic factors and the TNM classification. Three patients (12%) in the LTS group had positive margin status, and two patients (8%) had positive lymph node status. Unsurprisingly, the median survival for the control group versus the LTS group was 16 months versus not reached (P < 0.01).

CONCLUSION

The lack of difficulty in matching the two groups confirmed that patients of the LTS group did not have an exclusive tumour pattern. TNM classification is outdated because it did not influence adjuvant therapies and did not include two crucial factors: tumour biology and tumour response to chemo/radio therapies.

Predictors of Survival in Ampullary, Bile Duct and Duodenal Cancers Following Pancreaticoduodenectomy: a 10-Year Multicentre Analysis

INTRODUCTION

Predictors of survival following pancreaticoduodenectomy (PD) are well described for pancreatic cancers but are less detailed in ampullary (AC), bile duct (BDC) and duodenal cancers (DC). We therefore sought to evaluate the long-term results of PD for AC, BDC and DC, and to determine for each tumour the predictive factors of survival.

METHODS

Medical charts of patients operated on between 2001 and 2011 were retrospectively reviewed. Univariate and multivariate analyses were performed to determine predictors of survival.

RESULTS

One hundred thirty-five patients were identified. Mean follow-up was 47 ± 33 months. Median survival was not reached for DC and was 66 and 24 months for AC and BDC, respectively. Two-year and five-year survival rates were 80 and 51% for DC and 69 and 51% for AC, respectively. BDC had a significantly poorer prognosis, with two-year and five-year survival rates of 51 and 34%, respectively. Predictors of survival were weight loss, N stage and International Union Against Cancer (UICC) stage for AC, T stage and resection margin status for BDC and N stage for DC.

CONCLUSION

AC, BDC and DC display distinctive predictors of survival related to the biological aggressiveness. Preoperative malnutrition worsens the prognosis. The effect of adapted nutritional management on the survival improvement has to be studied.

Targeting CD44 as a novel therapeutic approach for treating pancreatic cancer recurrence

Pancreatic ductal adenocarcinoma (PDAC) is an extraordinarily lethal disease, which, despite a more or less efficient chemotherapeutic treatment, systematically displays a rapid and uncontrolled progression towards a fatal recurrence. Determining which cells give rise to such tumor recurrence is thus crucial before an improved therapeutics outcome can be envisaged for patients with PDAC. In this regard, we recently reported that following a standard chemotherapy for PDAC, a heterogeneous subpopulation of CD44+ cells proliferates and is responsible for tumor recurrence, as shown by almost all recurrent tumor cells becoming CD44+. We designed a strategy to eliminate these cells based on a weekly administration of an anti-CD44 monoclonal antibody to human PDAC-derived xenografts in mice. We demonstrate that xenografts, which were unresponsive to gemcitabine treatment, are however sensitive to this strategy. In conclusion, CD44 represents an efficient therapeutic target in patients with recurrent PDAC.

'Peripheric' pancreatic cysts: performance of CT scan, MRI and endoscopy according to final pathological examination

OBJECTIVE

To assess the accuracy of pre-operative staging in patients with peripheral pancreatic cystic neoplasms (pPCNs).

METHODS

From 2005 to 2011, 148 patients underwent a pancreatectomy for pPCNs. The pre-operative examination methods of computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) were compared for their ability to predict the suggested diagnosis accurately, and the definitive diagnosis was affirmed by pathological examination.

RESULTS

A mural nodule was detected in 34 patients (23%): only 1 patient (3%) had an invasive pPCN at the final histological examination. A biopsy was performed in 79 patients (53%) during EUS: in 55 patients (70%), the biopsy could not conclude a diagnosis; the biopsy provided the correct and wrong diagnosis in 19 patients (24%) and 5 patients (6%), respectively. A correct diagnosis was affirmed by CT, EUS and pancreatic MRI in 60 (41%), 103 (74%) and 80 (86%) patients (when comparing EUS and MRI; P = 0.03), respectively. The positive predictive values (PPVs) of CT, EUS and MRI were 70%, 75% and 87%, respectively.

CONCLUSIONS

Pancreatic MRI appears to be the most appropriate examination to diagnose pPCNs accurately. EUS alone had a poor PPV. Mural nodules in a PCN should not be considered an indisputable sign of pPCN invasiveness.

Deciphering the cellular source of tumor relapse identifies CD44 as a major therapeutic target in pancreatic adenocarcinoma

It has been commonly found that in patients presenting Pancreatic Ductal Adenocarcinoma (PDAC), after a period of satisfactory response to standard treatments, the tumor becomes non-responsive and patient death quickly follows. This phenomenon is mainly due to the rapid and uncontrolled development of the residual tumor. The origin and biological characteristics of residual tumor cells in PDAC still remain unclear. In this work, using PDACs from patients, preserved as xenografts in nude mice, we demonstrated that a residual PDAC tumor originated from a small number of CD44+ cells present in the tumor. During PDAC relapse, proliferating CD44+ cells decrease expression of ZEB1, while overexpressing the MUC1 protein, and gain morphological and biological characteristics of differentiation. Also, we report that CD44+ cells, in primary and residual PDAC tumors, are part of a heterogeneous population, which includes variable numbers of CD133+ and EpCAM+ cells. We confirmed the propagation of CD44+ cells in samples from cases of human relapse, following standard PDAC treatment. Finally, using systemic administration of anti-CD44 antibodies in vivo, we demonstrated that CD44 is an efficient therapeutic target for treating tumor relapse, but not primary PDAC tumors. We conclude that CD44+ cells generate the relapsing tumor and, as such, are themselves promising therapeutic targets for treating patients with recurrent PDAC.

Transcriptomic analysis predicts survival and sensitivity to anticancer drugs of patients with a pancreatic adenocarcinoma

A major impediment to the effective treatment of patients with pancreatic ductal adenocarcinoma (PDAC) is the molecular heterogeneity of this disease, which is reflected in an equally diverse pattern of clinical outcome and in responses to therapies. We developed an efficient strategy in which PDAC samples from 17 consecutive patients were collected by endoscopic ultrasound-guided fine-needle aspiration or surgery and were preserved as breathing tumors by xenografting and as a primary culture of epithelial cells. Transcriptomic analysis was performed from breathing tumors by an Affymetrix approach. We observed significant heterogeneity in the RNA expression profile of tumors. However, the bioinformatic analysis of these data was able to discriminate between patients with long- and short-term survival corresponding to patients with moderately or poorly differentiated PDAC tumors, respectively. Primary culture of cells allowed us to analyze their relative sensitivity to anticancer drugs in vitro using a chemogram, similar to the antibiogram for microorganisms, establishing an individual profile of drug sensitivity. As expected, the response was patient dependent. We also found that transcriptomic analysis predicts the sensitivity of cells to the five anticancer drugs most frequently used to treat patients with PDAC. In conclusion, using this approach, we found that transcriptomic analysis could predict the sensitivity to anticancer drugs and the clinical outcome of patients with PDAC.

A subgroup of pancreatic adenocarcinoma is sensitive to the 5-aza-dC DNA methyltransferase inhibitor

Pancreatic Ductal Adenocarcinoma (PDAC) is a disease with a great heterogeneity in the response to treatments. To improve the responsiveness to treatments there are two different approaches, the first one consist to develop new and more efficient drugs that intent to cure all patients and the second one is to use already-approved drugs, alone or in combination, but selecting beforehand the most sensitive patients. In this work we explored the efficiency of the second possibility. We developed a collection of 17 PDAC samples collected by Endoscopic Ultrasound-Guided Fine-Needle Aspiration (EUS-FNA) or surgery and preserved as xenografts and as primary cultures. This collection was characterized at molecular level by a transcriptomic analysis using an Affymetrix approach. In this paper we present data demonstrating that a subgroup of PDAC responds to low doses of 5-aza-dC. These tumors show a specific RNA expression profile that could serve as a marker, but there is no correlation with Dnmt1, Dnmt3A or Dnmt3B expression. Responder tumors corresponded to well-differentiated samples and longer survival patients. In conclusion, we present data obtained with the well-known drug 5-aza-dC as a proof of concept that a drug that seems to be inefficient in solid tumors in general could be applicable to a particular subgroup of patients with PDAC.

Stromal SLIT2 impacts on pancreatic cancer-associated neural remodeling

Pancreatic ductal adenocarcinoma (PDA) is a critical health issue in the field of cancer, with few therapeutic options. Evidence supports an implication of the intratumoral microenvironment (stroma) on PDA progression. However, its contribution to the role of neuroplastic changes within the pathophysiology and clinical course of PDA, through tumor recurrence and neuropathic pain, remains unknown, neglecting a putative, therapeutic window. Here, we report that the intratumoral microenvironment is a mediator of PDA-associated neural remodeling (PANR), and we highlight factors such as 'SLIT2' (an axon guidance molecule), which is expressed by cancer-associated fibroblasts (CAFs), that impact on neuroplastic changes in human PDA. We showed that 'CAF-secreted SLIT2' increases neurite outgrowth from dorsal root ganglia neurons as well as from Schwann cell migration/proliferation by modulating N-cadherin/β-catenin signaling. Importantly, SLIT2/ROBO signaling inhibition disrupts this stromal/neural connection. Finally, we revealed that SLIT2 expression and CAFs are correlated with neural remodeling within human and mouse PDA. All together, our data demonstrate the implication of CAFs, through the secretion of axon guidance molecule, in PANR. Furthermore, it provides rationale to investigate the disruption of the stromal/neural compartment connection with SLIT2/ROBO inhibitors for the treatment of pancreatic cancer recurrence and pain.

Pasireotide and octreotide antiproliferative effects and sst2 trafficking in human pancreatic neuroendocrine tumor cultures

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) raise difficult therapeutic problems despite the emergence of targeted therapies. Somatostatin analogs (SSA) remain pivotal therapeutic drugs. However, the tachyphylaxis and the limited antitumoral effects observed with the classical somatostatin 2 (sst2) agonists (octreotide and lanreotide) led to the development of new SSA, such as the pan sst receptor agonist pasireotide. Our aim was to compare the effects of pasireotide and octreotide on cell survival, chromogranin A (CgA) secretion, and sst2 phosphorylation/trafficking in pancreatic NET (pNET) primary cells from 15 tumors. We established and characterized the primary cultures of human pancreatic tumors (pNETs) as powerful preclinical models for understanding the biological effects of SSA. At clinically relevant concentrations (1-10 nM), pasireotide was at least as efficient as octreotide in inhibiting CgA secretion and cell viability through caspase-dependent apoptosis during short treatments, irrespective of the expression levels of the different sst receptors or the WHO grade of the parental tumor. Interestingly, unlike octreotide, which induces a rapid and persistent partial internalization of sst2 associated with its phosphorylation on Ser341/343, pasireotide did not phosphorylate sst2 and induced a rapid and transient internalization of the receptor followed by a persistent recycling at the cell surface. These results provide the first evidence, to our knowledge, of striking differences in the dynamics of sst2 trafficking in pNET cells treated with the two SSAs, but with similar efficiency in the control of CgA secretion and cell viability.

Pancreatic cancer-induced cachexia is Jak2-dependent in mice

Cancer cachexia syndrome is observed in 80% of patients with advanced-stage cancer, and it is one of the most frequent causes of death. Severe wasting accounts for more than 80% in patients with advanced pancreatic cancer. Here we wanted to define, by using an microarray approach and the Pdx1-cre;LSL-Kras(G12D) ;INK4a/arf(fl/fl) mice model, the pathways involved in muscle, liver, and white adipose tissue wasting. These mice, which develop systematically pancreatic cancer, successfully reproduced many human symptoms afflicted with this disease, and particularly cachexia. Using the profiling analysis of pancreatic cancer-dependent cachectic tissues we found that Jak2/Stat3 pathways, p53 and NFkB results activated. Thus, our interest was focused on the Jak2 pathways because it is pharmacologically targetable with low toxicity and FDA approved drugs are available. Therefore, Pdx1-cre;LSL-Kras(G12D) ;INK4a/arf(fl/fl) mice were treated with the Jak2 inhibitor AG490 compound daily starting at 7 weeks old and for a period of 3 weeks and animals were sacrificed at 10 weeks old. Body weight for control mice was 27.84 ± 2.14 g, for untreated Pdx1-cre;LSL-Kras(G12D) ;INK4a/arf(fl/fl) was 14.97 ± 1.99 g, whereas in animals treated with the AG490 compound the weight loss was significantly less to 24.53 ± 2.04 g. Treatment with AG490 compound was efficient since phosphorylation of Jak2 and circulating interleukin-6 (IL6) levels were significantly reduced in cachectic tissues and in mice respectively. In conclusion, we found that Jak2/Stat3-dependent intracellular pathway plays an essential role since its pharmacological inhibition strongly attenuates cachexia progression in a lethal transgenic pancreatic cancer model.

Surgical management of advanced pancreatic neuroendocrine tumors: short-term and long-term results from an international multi-institutional study

BACKGROUND

The role of extended resections in the management of advanced pancreatic neuroendocrine tumors (PNETs) is not well defined.

METHODS

Between 1995 and 2012, 134 patients with PNET underwent isolated (isoPNET group: 91 patients) or extended pancreatic resection (synchronous liver metastases and/or adjacent organs) (advPNET group: 43 patients).

RESULTS

The associated resections included 27 hepatectomies, 9 vascular resections, 12 colectomies, 10 gastrectomies, 4 nephrectomies, 4 adrenalectomies, and 3 duodenojejunal resections. R0 was achieved in 41 patients (95%) in the advPNET. The rates of T3-T4 (73 vs 16%; p < .0001) and N+ (35 vs 13%; p = .007) were higher in the advPNET group. Mortality (5 vs 2%) and major morbidity (21 vs 19%) rates were similar between the 2 groups. The 5-year overall survival (OS) of the series was 87% in the isoPNET group and 66% in the advPNET group (p = .006). Only patients with both locally advanced disease and liver metastases showed worse survival (p = .0003). The advPNET group developed recurrence earlier [disease-free survival (DFS) at 5 years: 26 vs 81%; p < .001]. In univariate analysis, negative prognostic factors of survival were: poor degree of differentiation (p < .001), liver metastasis (p = .011), NE carcinoma (p < .001), and resection of adjacent organs (p = .013). The multivariate analysis did not highlight any factor that influenced OS. In multivariate analysis independent DFS factors were a poor degree of differentiation (p = .03) and the European Neuroendocrine Tumor Society stage (p = .01).

CONCLUSIONS

An aggressive surgical approach for locally advanced or metastatic tumors is safe and offers long-term survival.

Conservative surgery vs. duodeneopancreatectomy in primary duodenal gastrointestinal stromal tumors (GIST): a retrospective review of 114 patients from the French sarcoma group (FSG)

BACKGROUND

Duodenal GISTs represent 3-5% of all GISTs with limited understanding of patient outcomes. We conducted a retrospective analysis of primary localized duodenal GISTs.

METHODS

Patients were identified via a survey from 16 FSG centers (n = 105), and a group of 9 patients enrolled in the BFR14 trial. Data were collected from the original database and patient files, in agreement with French legislation.

RESULTS

114 patients were included, with a median age of 57. Tumors originated mainly in D2 (33%), or D3 (24%), with a median size of 5 cm. 109 patients had resection of the primary tumor; with a Local Resection (LR, n = 82), a pancreaticoduodenectomy (PD, n = 23), and data were missing for 4 patients. Resections were R0 (n = 87, 79%), R1 (n = 8, 7%), R2 (n = 6). Tumor characteristics were: KIT+ (n = 104), CD34+ (n = 58). Miettinen risk was low (n = 43), and high (n = 52). Imatinib was administered preoperatively (n = 11) and post-operatively (n = 20). With a median follow-up of 36 months (2-250), 98 patients are alive, and 33 relapsed. The 5-year OS and EFS rates are 86.5% and 54.5%. EFS was similar for patients in the LR and the PD groups (P > 0.05). In multivariate analysis, ECOG PS, and CD34 expression are independent prognostic factors on OS. Miettinen risk and spindle cell type are independent predictive factors for relapse.

CONCLUSIONS

Patients with resected duodenal GIST have a reasonably favorable prognosis. This study favors a preservation of pancreas when there are no anatomical constraints. LR exhibit similar survival and smaller morbidity then PD.

Isolated pancreatic metastasis from malignant melanoma: is pancreatectomy worthwile?

Isolated pancreatic metastasis from malignant melanoma (IPMMM) is rare because most melanoma patients already have a widespread disease at diagnosis. No adjuvant systemic treatment is known to be efficient in this setting. Experience with pancreatic resection for IPMMM is limited and controversial. We report here the case of an IPMMM patient successfully treated by pancreaticoduodenectomy with a prolonged survival of 6 years.

Novel role of VMP1 as modifier of the pancreatic tumor cell response to chemotherapeutic drugs

We hypothesized that inhibiting molecules that mediate the adaptation response to cellular stress can antagonize the resistance of pancreatic cancer cells to chemotherapeutic drugs. Toward this end, here, we investigated how VMP1, a stress-induced autophagy-associated protein, modulate stress responses triggered by chemotherapeutic agents in PDAC. We find that VMP1 is particularly over-expressed in poorly differentiated human pancreatic cancer. Pharmacological studies show that drugs that work, in part, via the endoplasmic reticulum stress response, induce VMP1 expression. Similarly, VMP1 is induced by known endoplasmic reticulum stress activators. Genetic inactivation of VMP1 using RNAi-based antagonize the pancreatic cancer stress response to antitumoral agents. Functionally, we find that VMP1 regulates both autophagy and chemotherapeutic resistance even in the presence of chloroquin, ATG5 or Beclin 1 siRNAs, or a Beclin 1-binding VMP1 mutant. In addition, VMP1 modulates endoplasmic reticulum stress independently of its coupling to the molecular and cellular autophagy machinery. Preclinical studies demonstrate that xenografts expressing an inducible and tractable form of VMP1 show increased resistance to the gemcitabine treatment. These results underscore a novel role for VMP1 as a potential therapeutic target for combinatorial therapies aimed at sensitizing pancreatic cancer cells to chemotherapeutic agents as well as provide novel molecular mechanisms to better understand this phenomenon.

Cardiac rhabdomyosarcoma mimicking a mediastinal tumor and the role of endoscopic ultrasonography

We report a case of cardiac rhabdomyosarcoma, with initial clinical features of "atrial rhythmic dysfunction", which was concluded as a mediastinal tumor by computed tomography (CT) scan. Endoscopic ultrasonography (EUS) and EUS-FNA (fine needle aspiration) were initially conducted to diagnose the isolated mediastinal mass. In this case, EUS re-assessed the previous diagnosis as a cardiac tumor, and the patient eventually achieved a 17-month survival rate after chemotherapy. In this paper, EUS findings obtained in our case are described and a review of literatures is briefly discussed. We also describe the advantages and limitations of this technique compared with other image diagnosis alternatives.