Management and outcomes of hemorrhage after distal pancreatectomy: a multicenter study at high volume centers

BACKGROUND

Data on clinically relevant post-pancreatectomy hemorrhage (CR-PPH) are derived from series mostly focused on pancreatoduodenectomy, and data after distal pancreatectomy (DP) are scarce.

METHODS

All non-extended DP performed from 2014 to 2018 were included. CR-PPH encompassed grade B and C PPH. Risk factors, management, and outcomes of CR-PPH were evaluated.

RESULTS

Overall, 1188 patients were included, of which 561 (47.2 %) were operated on minimally invasively. Spleen-preserving DP was performed in 574 patients (48.4 %). Ninety-day mortality, severe morbidity and CR-POPF rates were 1.1 % (n = 13), 17.4 % (n = 196) and 15.5 % (n = 115), respectively. After a median interval of 8 days (range, 0-37), 65 patients (5.5 %) developed CR-PPH, including 28 grade B and 37 grade C. Reintervention was required in 57 patients (87.7 %). CR-PPH was associated with a significant increase of 90-day mortality, morbidity and hospital stay (p < 0.001). Upon multivariable analysis, prolonged operative time and co-existing POPF were independently associated with CR-PPH (p < 0.005) while a chronic use of antithrombotic agent trended towards an increase of CR-PPH (p = 0.081). As compared to CR-POPF, the failure-to-rescue rate in patients who developed CR-PPH was significantly higher (13.8 % vs. 1.3 %, p < 0.001).

CONCLUSION

CR-PPH after DP remains rare but significantly associated with an increased risk of 90-day mortality and failure-to-rescue.

Defining Benchmark Outcomes for Distal Pancreatectomy: Results of a French Multicentric Study

OBJECTIVE

Defining robust and standardized outcome references for distal pancreatectomy (DP) by using Benchmark analysis.

BACKGROUND

Outcomes after DP are recorded in medium or small-sized studies without standardized analysis. Therefore, the best results remain uncertain.

METHODS

This multicenter study included all patients undergoing DP for resectable benign or malignant tumors in 21 French expert centers in pancreas surgery from 2014 to 2018. A low-risk cohort defined by no significant comorbidities was analyzed to establish 18 outcome benchmarks for DP. These values were tested in high risk, minimally invasive and benign tumor cohorts.

RESULTS

A total of 1188 patients were identified and 749 low-risk patients were screened to establish Benchmark cut-offs. Therefore, Benchmark rate for mini-invasive approach was ≥36.8%. Benchmark cut-offs for postoperative mortality, major morbidity grade ≥3a and clinically significant pancreatic fistula rates were 0%, ≤27%, and ≤28%, respectively. The benchmark rate for readmission was ≤16%. For patients with pancreatic adenocarcinoma, cut-offs were ≥75%, ≥69.5%, and ≥66% for free resection margins (R0), 1-year disease-free survival and 3-year overall survival, respectively. The rate of mini-invasive approach in high-risk cohort was lower than the Benchmark cut-off (34.1% vs ≥36.8%). All Benchmark cut-offs were respected for benign tumor group. The proportion of benchmark cases was correlated to outcomes of DP. Centers with a majority of low-risk patients had worse results than those operating complex cases.

CONCLUSION

This large-scale study is the first benchmark analysis of DP outcomes and provides robust and standardized data. This may allow for comparisons between surgeons, centers, studies, and surgical techniques.

Transcriptomic Analysis of Laser Capture Microdissected Tumors Reveals Cancer- and Stromal-Specific Molecular Subtypes of Pancreatic Ductal Adenocarcinoma

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) lethality is multifactorial; although studies have identified transcriptional and genetic subsets of tumors with different prognostic significance, there is limited understanding of features associated with the minority of patients who have durable remission after surgical resection. In this study, we performed laser capture microdissection (LCM) of PDAC samples to define their cancer- and stroma-specific molecular subtypes and identify a prognostic gene expression signature for short-term and long-term survival.

EXPERIMENTAL DESIGN

LCM and RNA sequencing (RNA-seq) analysis of cancer and adjacent stroma of 19 treatment-naïve PDAC tumors was performed. Gene expression signatures were tested for their robustness in a large independent validation set. An RNA-ISH assay with pooled probes for genes associated with disease-free survival (DFS) was developed to probe 111 PDAC tumor samples.

RESULTS

Gene expression profiling identified four subtypes of cancer cells (C1-C4) and three subtypes of cancer-adjacent stroma (S1-S3). These stroma-specific subtypes were associated with DFS (P = 5.55E-07), with S1 associated with better prognoses when paired with C1 and C2. Thirteen genes were found to be predominantly expressed in cancer cells and corresponded with DFS in a validation using existing RNA-seq datasets. A second validation on an independent cohort of patients using RNA-ISH probes to six of these prognostic genes demonstrated significant association with overall survival (median 17 vs. 25 months; P < 0.02).

CONCLUSIONS

Our results identified specific signatures from the epithelial and the stroma components of PDAC, which add clarity to the nature of PDAC molecular subtypes and may help predict survival.

Neoplastic-Stromal Cell Cross-talk Regulates Matrisome Expression in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly desmoplastic reaction, warranting intense cancer-stroma communication. In this study, we interrogated the contribution of the BET family of chromatin adaptors to the cross-talk between PDAC cells and the tumor stroma. Short-term treatment of orthotopic xenograft tumors with CPI203, a small-molecule inhibitor of BET proteins, resulted in broad changes in the expression of genes encoding components of the extracellular matrix (matrisome) in both cancer and stromal cells. Remarkably, more than half of matrisome genes were expressed by cancer cells. In vitro cocultures of PDAC cells and cancer-associated fibroblasts (CAF) demonstrated that matrisome expression was regulated by BET-dependent cancer-CAF cross-talk. Disrupting this cross-talk in vivo resulted in diminished growth of orthotopic patient-derived xenograft tumors, reduced proliferation of cancer cells, and changes in collagen structure consistent with that of patients who experienced better survival. Examination of matrisome gene expression in publicly available data sets of 573 PDAC tumors identified a 65-gene signature that was able to distinguish long- and short-term PDAC survivors. Importantly, the expression of genes predictive of short-term survival was diminished in the cancer cells of orthotopic xenograft tumors of mice treated with CPI203. Taken together, these results demonstrate that inhibiting the activity BET proteins results in transcriptional and structural differences in the matrisome are associated with better patient survival. IMPLICATIONS: These studies highlight the biological relevance of the matrisome program in PDAC and suggest targeting of epigenetically driven tumor-stroma cross-talk as a potential therapeutic avenue.

FOLFIRINOX Versus Gemcitabine-based Therapy for Pancreatic Ductal Adenocarcinoma: Lessons from Patient-derived Cell Lines

BACKGROUND/AIM

FOLFIRINOX [fluorouracil (5-FU), irinotecan, oxaliplatin] and gemcitabine plus nab-paclitaxel are standard treatments for patients with pancreatic ductal adenocarcinoma (PDAC). Despite efficacy rates of less than 32%, evidence is lacking to guide the use of one drug over the other. Herein, we compared the sensitivity of patient-derived PDAC cell lines to each of these regimens.

MATERIALS AND METHODS

Changes in the growth of 19 low-passage patient-derived PDAC cell lines were evaluated in response to treatment with FOLFIRINOX and gemcitabine plus paclitaxel (Gem-Pac).

RESULTS

Six cell lines exhibited optimal sensitivity (high EMax and low GI50) to FOLFIRINOX and three cell lines exhibited optimal sensitivity to Gem-Pac. Several cell lines that were optimally sensitive to one drug regimen exhibited very poor response to the other.

CONCLUSION

Further characterization of cancer cells exhibiting preferential sensitivity to each of these regimens may allow the identification of biomarkers to guide the selection of appropriate chemotherapy for a given patient.

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.

Molecular classification as prognostic factor and guide for treatment decision of pancreatic cancer

Clinico-pathological factors fail to consistently predict the outcome after pancreatic resection for pancreatic ductal adenocarcinoma (PDAC). PDACs show a high level of inter- and intra- tumor genetic heterogeneity. A molecular classification should help sort patients into less heterogeneous and more appropriate groups regarding the metastatic risk and the therapeutic response, with the consequences of better predicting evolution and better orienting the treatment. PDAC can be classified based on mutational subtypes and 18gene alterations. Whole-genome sequencing identified mutational signatures, mutational burden and hyper-mutated tumors with specific DNA repair defects. Their overlap/similarities allow the definition of molecular subtypes. DNA and RNA classifications can be used in prognosis assessment. They are useful in therapeutic choice for they allow the design of approaches that can predict the respective drug sensitivity of each molecular subtype. This review provides a comprehensive analysis of available molecular classifications in PDAC and how this can help guide clinical decisions.

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.

Validation and comparison of the molecular classifications of pancreatic carcinomas

Four molecular classifications of pancreatic ductal adenocarcinoma (PDAC), biologically and clinically relevant and based on gene expression profiles, were established in the recent years, including the Collisson's, Moffitt's ("tumor" and "stroma" classifications), and Bailey's classifications. The aim of this study was to validate the prognostic value of the Moffitt's classifications and to compare the Collisson's, Moffitt's, and Bailey's classifications in a large series of samples. We collected clinical and gene expression data of PDAC samples from 15 public data sets, resulting in a total of 846 primary cancer samples, including 601 with survival annotation. All samples were classified according to each of the four multigene classifiers. We confirmed the independent prognostic value of the Moffitt "tumor", Moffitt "stroma", and Bailey's classifications, but not that of the Collisson's classification. Despite a relatively low gene overlap, all classifications were associated with pathological grade, an important prognostic feature and reflect of intrinsic molecular characteristics of tumors. The concordance rate in term of "good-prognosis" vs. "poor-prognosis" prediction by classifiers was relatively high (from 73 to 86%) between the three "tumor" classifications based on tumor gene lists (Collisson, Moffitt "tumor", Bailey), but low (from 50 to 60%) with the Moffitt's stroma classification based on stroma genes. Multivariate analysis incorporating the four classifiers together retained as significant variables the Moffitt "stroma" and Bailey classifications, highlighting the complementarity of classifiers based on tumor epithelium (Bailey) and tumor stroma (Moffitt stroma). Our results reinforce the clinical validity of subtyping in PDAC, which should be regarded as a collection of separate diseases. Beside their clinical utility that remains to be demonstrated, the clinical interest of the subtypes, notably those from Bailey's and Moffitt's "stroma" classifiers that show independent prognostic value, will be reinforced by the identification of new biomarkers and/or therapeutic targets in each subtype for designing and testing novel specific targeted therapies.

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.

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.

Locally advanced gallbladder cancer: which patients benefit from resection?

OBJECTIVES

Patients with T3-4 gallbladder cancers (GBCs) often require extended surgical procedures, and up to 30% of patients have N2 metastases. This study investigated which patients with T3-4 GBC benefit from resection.

METHODS

Consecutive patients (n = 78) with T3-4 GBC who underwent resection between 1990 and 2011 were analysed (38 before 2003, 40 in 2003-2011). Forty patients required common bile duct (CBD) resection, 10 pancreatoduodenectomy, 4 right colectomy and 2 gastric resection. Fifty-two (67%) patients had LN metastases, including 22 with N2 metastases.

RESULTS

The in-hospital mortality rate was 8%, 11% before 2003 vs. 5% in 2003-2011. The morbidity rate (47%) remained stable during the study. Undergoing liver and pancreatic resection did not increase severe morbidity (0%) or mortality (10%). Sixty-seven (86%) patients had R0 resection. The 5-year survival rate was 17% (median follow-up, 65 months). Survival improved after 2002 (26% vs. 9%, p = 0.04). R1 patients had poor 3-year survival (0% vs. 32%, p = 0.001). N+ patients also had low survival (5-year survival, 10% vs. 32% in N0, p = 0.019), but N1 and N2 patients had similar outcomes. CBD resection and major hepatectomy did not worsen prognosis. Patients requiring pancreatoduodenectomy, gastric or colonic resection had 0% 3-year survival (p = 0.036 in multivariate analysis).

CONCLUSIONS

Resection of T3-4 GBC is worthwhile only if R0 surgery is achievable. Outcomes improved in most recent years. N2 metastases should not preclude surgery. Good results are possible even with CBD resection or major hepatectomy, while benefits from surgery are doubtful if pancreatoduodenectomy or other organ resection is needed.

Genome profiling of pancreatic adenocarcinoma

Pancreatic adenocarcinoma is one of the most aggressive human cancers. It displays many different chromosomal abnormalities and mutations. By using 244 K high-resolution array-comparative genomic hybridization (aCGH) we studied the genome alterations of 39 fine-needle aspirations from pancreatic adenocarcinoma and eight human adenocarcinoma pancreatic cell lines. Using both visual inspection and GISTIC analysis, recurrent losses were observed on 1p, 3p, 4p, 6, 8p, 9, 10, 11q, 15q, 17, 18, 19p, 20p, 21, and 22 and comprised several known or suspected tumor suppressor genes such as ARHGEF10, ARID1A, CDKN2A/B, FHIT, PTEN, RB1, RUNX1-3, SMAD4, STK11/LKB1, TP53, and TUSC3. Heterozygous deletion of the 1p35-p36 chromosomal region was identified in one-third of the tumors and three of the cell lines. This region, commonly deleted in human cancers, contains several tumor suppressor genes including ARID1A and RUNX3. We identified frequent genetic gains on chromosome arms 1q, 3q, 5p, 6p, 7q, 8q, 12q, 15q, 18q, 19q, and 20q. Amplifications were observed in 16 tumors. AKT2, CCND3, CDK4, FOXA2, GATA6, MDM2, MYC, and SMURF1 genes were gained or amplified. The most obvious amplification was located at 18q11.2 and targeted the GATA6 gene, which plays a predominant role in the initial specification of the pancreas and in pancreatic cell type differentiation. In conclusion, we have identified novel biomarkers and potential therapeutic targets in pancreatic adenocarcinoma.

Very low stapling of the anal canal in laparoscopic ileal pouch-anal anastomosis

Performing a double-stapled ileal pouch-anal anastomosis requires very low stapling of the anal canal. However, this laparoscopic procedure is often difficult to perform. We describe here a transanal method of everting the rectum, which allows easier transection under visual control and a sufficiently low anastomosis. Once the entire colon and rectum have been dissected out at laparoscopy, a plastic tube is introduced per anum and advanced into the mid sigmoid. The rectum is then divided at the level of the rectosigmoid junction by an endostapler, which also attaches the plastic tube to the rectum. The colon specimen is removed by a small incision at the chosen stoma site. Gentle traction on the plastic tube at the perineum everts the rectal tube. The anal canal is then transected at the desired level relative to the dentate line.