Pancreatic Cancer Meets Human Microbiota: Close Encounters of the Third Kind.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal types of cancer with a dismal prognosis. The five-year survival rate has not changed significantly in over 40 years. Current first-line treatments only offer a modest increase in overall survival in unselected populations, and there is an urgent need to personalize treatment in this aggressive disease and develop new therapeutic strategies. Evolving evidence suggests that the human microbiome impacts cancerogenesis and cancer resistance to therapy. The mechanism of action and interaction of microbiome and PDAC is still under investigation. Direct and indirect effects have been proposed, and the use of several microbiome signatures as predictive and prognostic biomarkers for pancreatic cancer are opening new therapeutic horizons. In this review, we provide an overview for the clinicians of studies describing the influence and associations of oral, gastrointestinal and intratumoral microbiota on PDAC development, progression and resistance to therapy and the potential use of microbiota as a diagnostic, prognostic and predictive biomarker for PDAC.

Pancreatic Ductal Adenocarcinoma Arising in Young and Old Patients Displays Similar Molecular Features.

Pancreatic ducal adenocarcinoma is classically diagnosed in the 7th decade, but approximately 10% of patients are diagnosed under 55 years (y.o.). While the genomic and transcriptomic landscapes of late-onset tumors (LOT) have been described, little is known about early-onset tumors (EOT). Ageing is known to impact DNA methylation and proteome integrity through carbonylation-related oxidative damages. We therefore aimed to assess the global molecular features of EOT. We compared 176 EOT (≤55 y.o.) and 316 LOT (≥70 y.o.) from three distinct surgical cohorts at the clinical/genomic/epigenomic/transcriptomic level. Furthermore, we assessed oxidative stress responses and oxidative proteome damages using 2D gel electrophoresis followed by mass spectrometry protein identification. There was no consistent clinical difference between EOT and LOT across the three cohorts. The mutational landscape of key driver genes and the global methylation profile were similar in the two groups. LOT did display age-related features such as enriched DNA repair gene signatures and upregulation of oxidative stress defenses together with increased proteome carbonylation. However, these age-related differences were more preeminent in non-tumor tissues while tumor proteome and proteome damages were fairly comparable. In conclusion, this multi-omics comparison showed that EOT harbor a comparable molecular profile to that of LOT.

Tumour and stroma RNA signatures predict more accurately distant recurrence than clinicopathological factors in resected pancreatic adenocarcinoma.

BACKGROUND: Few patients with pancreatic adenocarcinoma (PAC) are eligible for surgery. Patients with early relapse have a poor prognosis and might be better candidates for a medical approach. Clinical and pathological parameters only partially predict recurrence and are only obtained after surgery. PAC subtypes based on gene expression were proposed, and we assessed if they could predict the risk and type of recurrence independently of clinicopathological parameters. METHODS: Patients with curative-intent surgery for PAC without pretreatment were selected and divided into two independent cohorts defined as discovery (n = 381) and validation (n = 149) cohorts. Transcriptomic analyses were performed on formalin-fixed paraffin-embedded surgical samples to characterise tumour and stroma compartments using previously defined signatures. We associated molecular and clinicopathological characteristics with general, distant, and local recurrences using Cox regression analyses. RESULTS: We found that tumour biology predicted distant recurrence contrary to local recurrence, which was directly related to resection margin status. Pure basal-like and stroma-activated subtypes were strongly associated with distant recurrence, independently of clinicopathological factors (hazard ratios [HRs] = 5.85, p < 0.001 and HR = 1.75, p = 0.007, respectively). By dissecting tumoural and stromal compartments, we demonstrated that the basal-like tumour component positively correlated with distant recurrence in both cohorts (HR = 1.45, p < 0.001 and HR = 1.90, p < 0.001), whereas the inactive structural stroma component was protective against distant recurrence (HR = 0.68, p < 0.001 and HR = 0.72, p < 0.001). CONCLUSIONS: In addition to suggesting a different mechanism for local and distant relapse (incomplete resection and high metastatic potential, respectively), our results show the potency of molecular phenotype to predict patient outcome regarding distant recurrences.

Undifferentiated Pancreatic Carcinoma With Osteoclast-Like Giant Cells: What Do We Know So Far?

Undifferentiated carcinoma of the pancreas is an aggressive but rare tumor for which several other terms have been used to describe its histological appearance. In addition, as osteoclast-like giant cells may accompany undifferentiated carcinoma of the pancreas, the WHO Classification distinguishes undifferentiated carcinoma with osteoclast-like giant cells (UC-OGC) from plain undifferentiated carcinoma since there are a few histopathological and clinical differences. UC-OGC was initially thought to be associated with worse prognosis compared to invasive ductal pancreatic adenocarcinoma, since it is often unresectable at diagnosis and tends to recur rapidly even if completely resected. When true UC-OGGs are carefully dissected out from other anaplastic carcinomas, it becomes, however, clear that UC-OGCs do have more indolent behavior, especially the pure UC-OGCs. This mini-review summarizes the current knowledge on UC-OGC.

hENT1 Testing in Pancreatic Ductal Adenocarcinoma: Are We Ready? A Multimodal Evaluation of hENT1 Status.

Gemcitabine is still one of the standard chemotherapy regimens for pancreatic ductal adenocarcinoma (PDAC). Gemcitabine uptake into tumor cells is mainly through the human equilibrative nucleoside transport 1 (hENT1). It was therefore proposed as a potential predictive biomarker of gemcitabine efficacy but reports are conflicting, with an important heterogeneity in methods to assess hENT1 expression. A multicenter cohort of 471 patients with a resected PDAC was used to assess simultaneously the predictive value of the 2 best described hENT1 antibodies (10D7G2 and SP120). Three additional antibodies and the predictive value of hENT1 mRNA were also tested on 251 and 302 patients, respectively. hENT1 expression was assessed in 54 patients with matched primary tumors and metastases samples. The 10D7G2 clone was the only hENT1 antibody whose high expression was associated with a prolonged progression free survival and overall survival in patients who received adjuvant gemcitabine. hENT1 mRNA level was also predictive of gemcitabine benefit. hENT1 status was concordant in 83% of the cases with the best concordance in synchronous metastases. The 10D7G2 clone has the best predictive value of gemcitabine benefit in PDAC patients. Since it is not commercially available, hENT1 mRNA level could represent an alternative to assess hENT1 status.

Stratification of Pancreatic Ductal Adenocarcinomas Based on Tumor and Microenvironment Features.

BACKGROUND & AIMS: Genomic studies have revealed subtypes of pancreatic ductal adenocarcinoma (PDA) based on their molecular features, but different studies have reported different classification systems. It is a challenge to obtain high-quality, freshly frozen tissue for clinical analysis and determination of PDA subtypes. We aimed to redefine subtypes of PDA using a large number of formalin-fixed and paraffin-embedded PDA samples, which are more amenable to routine clinical evaluation. METHODS: We collected PDA samples from 309 consecutive patients who underwent surgery from September 1996 through December 2010 at 4 academic hospitals in Europe; nontumor tissue samples were not included. Samples were formalin fixed and paraffin embedded. DNA and RNA were isolated; gene expression, targeted DNA sequencing, and immunohistochemical analyses were performed. We used independent component analysis to deconvolute normal, tumor, and microenvironment transcriptome patterns in samples. We devised classification systems from an unsupervised analysis using a consensus clustering approach of our data set after removing normal contamination components. We associated subtypes with overall survival and disease-free survival of patients using Cox proportional hazards regression with estimation of hazard ratios and 95% confidence interval. We used The Cancer Genome Consortium and International Cancer Genome Consortium PDA data sets as validation cohorts. RESULTS: We validated the previously reported basal-like and classical tumor-specific subtypes of PDAs. We identified features of the PDA, including microenvironment gene expression patterns, that allowed tumors to be categorized into 5 subtypes, called pure basal like, stroma activated, desmoplastic, pure classical, and immune classical. These PDA subtypes have features of cancer cells and immune cells that could be targeted by pharmacologic agents. Tumor subtypes were associated with patient outcomes, based on analysis of our data set and the International Cancer Genome Consortium and The Cancer Genome Consortium PDA data sets. We also observed an exocrine signal associated with acinar cell contamination (from pancreatic tissue). CONCLUSIONS: We identified a classification system based on gene expression analysis of formalin-fixed PDA samples. We identified 5 PDA subtypes, based on features of cancer cells and the tumor microenvironment. This system might be used to select therapies and predict patient outcomes. We found evidence that the previously reported exocrine-like (called ADEX) tumor subtype resulted from contamination with pancreatic acinar cells. ArrayExpress accession number: E-MTAB-6134.

Circulating tumor DNA in early response assessment and monitoring of advanced colorectal cancer treated with a multi-kinase inhibitor.

Predictive biomarkers are eagerly awaited in advanced colorectal cancer (aCRC). Targeted sequencing performed on tumor and baseline plasma samples in 20 patients with aCRC treated with regorafenib identified 89 tumor-specific mutations of which ≥50% are also present in baseline plasma. Droplet digital PCR (ddPCR) assays were optimized to monitor circulating tumor DNA (ctDNA) levels in plasmatic samples collected throughout the treatment course and showed the importance of using the absolute value for ctDNA rather than the mutant/wild type ratio in monitoring the therapy outcome. High baseline cell free DNA (cfDNA) levels are associated with shorter overall survival (OS) (HR 7.38, P=0.001). An early increase (D14) in mutated copies/mL is associated with a significantly worse PFS (HR 6.12, P=0.008) and OS (HR 8.02, P=0.004). These data suggest a high prognostic value for early ctDNA level changes and support the use of blood-born genomic markers as a tool for treatment.

New challenges in perioperative management of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in the industrialized world. Despite progress in the understanding of the molecular and genetic basis of this disease, the 5-year survival rate has remained low and usually does not exceed 5%. Only 20%-25% of patients present with potentially resectable disease and surgery represents the only chance for a cure. After decades of gemcitabine hegemony and limited therapeutic options, more active chemotherapies are emerging in advanced PDAC, like 5-Fluorouracil, folinic acid, irinotecan and oxaliplatin and nab-paclitaxel plus gemcitabine, that have profoundly impacted therapeutic possibilities. PDAC is considered a systemic disease because of the high rate of relapse after curative surgery in patients with resectable disease at diagnosis. Neoadjuvant strategies in resectable, borderline resectable, or locally advanced pancreatic cancer may improve outcomes. Incorporation of tissue biomarker testing and imaging techniques into preoperative strategies should allow clinicians to identify patients who may ultimately achieve curative benefit from surgery. This review summarizes current knowledge of adjuvant and neoadjuvant treatment for PDAC and discusses the rationale for moving from adjuvant to preoperative and perioperative therapeutic strategies in the current era of more active chemotherapies and personalized medicine. We also discuss the integration of good specimen collection, tissue biomarkers, and imaging tools into newly designed preoperative and perioperative strategies.

Sonic hedgehog and Gli1 expression predict outcome in resected pancreatic adenocarcinoma.

PURPOSE: Aberrant activation of the hedgehog (Hh) pathway is implicated in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis. We investigated the prognostic and predictive value of four Hh signaling proteins and of the tumor stromal density. EXPERIMENTAL DESIGN: Using tissue microarray and immunohistochemistry, the expression of Shh, Gli1, SMO, and PTCH1 was assessed in 567 patients from three independent cohorts who underwent surgical resection for PDAC. In 82 patients, the tumor stromal index (SI) was calculated, and its association with overall survival (OS) and disease-free survival (DFS) was investigated. RESULTS: Shh and Gli1 protein abundance were independent prognostic factors in resected PDACs; low expressors for those proteins experiencing a better OS and DFS. The combination of Shh and Gli1 levels was the most significant predictor for OS and defined 3 clinically relevant subgroups of patients with different prognosis (Gli1 and Shh low; HR set at 1 vs. 3.08 for Shh or Gli1 high vs. 5.69 for Shh and Gli1 high; P < 0.001). The two validating cohorts recapitulated the findings of the training cohort. After further stratification by lymph node status, the prognostic significance of combined Shh and Gli1 was maintained. The tumor SI was correlated with Shh levels and was significantly associated with OS (P = 0.023). CONCLUSIONS: Shh and Gli1 are prognostic biomarkers for patients with resected PDAC.

Assessing the learning curve for totally laparoscopic major-complex liver resections: a single hepatobiliary surgeon experience.

BACKGROUND: Encouraging results have been reported in terms of feasibility, safety, and oncologic, outcomes even for major (≥ 3 segments) or complex for location-specific (right posterior segments) laparoscopic liver resections. Despite this, technically challenging issues and advanced laparoscopic skills required to perform it have limited its use in few highly specialized centers. The aim of this study was to assess the learning curve for major-complex totally laparoscopic liver resections (TLLR) performed by a single HPB surgeon. MATERIALS AND METHODS: From October 2008 to February 2012, a total of 70 TLLR were performed; 24 (33.3%) were major-complex resections. This series was divided in 2 groups according to time of operation: group A (12 cases early series) and group B (12 cases late series); perioperative outcomes were retrospectively analyzed and compared. RESULTS: Comparing the 2 groups, a statistically significant improvement was found in terms of operative time (P=0.017), blood loss (P=0.004), number of cases requiring a Pringle maneuver (P=0.006), and blood transfusion (P=0.001) from case number ten onward. CONCLUSIONS: This study shows that a minimum of 10 cases are required to obtain a significant improvement in perioperative outcome for surgeons with specific training on hepatobiliary surgery and advanced laparoscopic surgical procedures. More studies are required to clarify the minimum standard of training to perform safely this kind of advanced laparoscopic liver surgery on a large scale.

Personalized medicine in pancreatic cancer: the revolution has begun.

Pancreatic ductal adenocarcinoma carries a dismal prognosis. Both chemotherapy and targeted therapies have been disappointing when administered to unselected populations. Recently, progress has been made in our understanding of the genomic landscape of this cancer which displays remarkable heterogeneity suggesting a reorientation of management and research strategies based on molecular characterization and adapted personalized therapy. Resectable disease offers new opportunities for translational research through functional imaging response evaluation and tumor tissue acquisition before and after neoadjuvant therapy. There is urgent need for clinical trials based on molecular profiling in pancreatic ductal adenocarcinoma. In this review we discuss opportunities and limitations of these new strategies, underlining the importance of tissue acquisition and integration of molecular biomarkers in future molecularly driven clinical trials.

Perioperative outcomes of laparoscopic and robot-assisted major hepatectomies: an Italian multi-institutional comparative study.

BACKGROUND: Laparoscopic major hepatectomy (LMH), although safely feasible in experienced hands and in selected patients, is a formidable challenge because of the technical demands of controlling hemorrhage, sealing bile ducts, avoiding gas embolism, and maintaining oncologic surgical principles. The enhanced surgical dexterity offered by robotic assistance could improve feasibility and/or safety of minimally invasive major hepatectomy. The aim of this study was to compare perioperative outcomes of LMH and robotic-assisted major hepatectomy (RMH). METHODS: Pooled data from four Italian hepatobiliary centers were analyzed retrospectively. Demographic data, operative, and postoperative outcomes were collected from prospectively maintained databases and compared. RESULTS: Between January 2009 and December 2012, 25 patients underwent LMH and 25 RMH. The two groups were comparable for all baseline characteristics including type of resection and underlying pathology. Conversion to open surgery was required in one patient in each group (4%). No difference was noted in operative time, estimated blood, and need for allogenic blood transfusions. Intermittent pedicle occlusion was required only in LMH (32% vs. 0; p = 0.004). Length of hospital stay, including time spent in intensive care unit, was similar between the two groups, but patients undergoing LMH showed quicker recovery of bowel activity, with shorter time to first flatus (1 vs. 3 days; p = 0.023) and earlier tolerance to oral liquid diet (1 vs. 2 days; p = 0.001). No difference was noted in complication rate, 90-day mortality, and readmission rate. CONCLUSIONS: This retrospective multi-institution study confirms that selected patients can safely undergo minimally invasive major hepatectomy, either LMH or RMH. The fact that intermittent pedicle occlusion could be avoided in RMH suggests improved surgical ability to deal with bleeding during liver transection, but further studies are needed before any final conclusion can be drawn.

Totally laparoscopic liver resections for primary and metastatic cancer in the elderly: safety, feasibility and short-term outcomes.

BACKGROUND: Standard oncologic liver resections performed on elderly patients (≥70 years old) have been shown to be safe and effective. The aim of this study was to analyze operative and oncologic short-term outcomes of totally laparoscopic liver resections (TLLR) performed on elderly patients for malignancies. METHODS: We performed a retrospective statistical analysis of prospectively recorded data of TLLR performed from October 2008 to February 2012 by a single hepato-pancreato-biliary (HPB) surgeon. Patients were divided into two groups according to age (<70 vs. ≥ 70 years old) and perioperative outcomes were compared. RESULT: A total of 60 TLLR for malignancies were identified of which 25 patients (42 %) were aged ≥ 70 years (Group A) and 35 (58 %) were aged <70 years (Group B). There was no difference in operative time (170 vs. 180 min, p = 0.267), median blood loss (200 vs. 250 ml, p = 0.183), number and time of Pringle maneuver (p = 0.563 and p = 0.180), blood transfusion rate (4 vs. 17 %, p = 0.222), conversion rate (4 vs. 9 %, p = 0.443), morbidity rate (12 vs. 20 %, p = 0.797), and perioperative mortality rate (0 vs. 3 %, p = 0.688). An R0 resection was achieved in 92 (Group A) versus 83 % (Group B) (p = 0.265). At a median follow-up of 18 months, 12 % of patients in Group A experienced a disease recurrence with a related mortality rate similar to that of Group B (8 vs. 12 %, p = 0.375). CONCLUSION: This retrospective comparative study shows that TLLR performed on elderly for liver neoplasm are feasible and safe and lead to short-term outcomes similar to those of younger patients.

Gut failure in the ICU.

The role of dysfunction of the gastrointestinal tract in the pathogenesis of multiple organ failure (MOF) complicating the course of critically ill patients has been suspected for more than 40 years. However, several hypotheses have been proposed and sometimes refuted to establish a link. This review summarizes the current knowledge on gastrointestinal physiology and recapitulates existing evidence on the link between gastrointestinal dysfunction and MOF. The gastrointestinal tract has various functions apart from digestion. It produces hormones with local and systemic effects, plays a major role in immunological function, and serves as a barrier against antigens within its lumen. Gastrointestinal dysfunction or gut failure is frequently encountered in critical care patients and is associated with bacterial translocation, which can lead to the development of sepsis, initiation of a cytokine-mediated systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), and death. The aim of this manuscript is to define gut failure, to review physiopathological mechanisms and clinical implications, and, finally, to suggest preventive measures.