The Impact of Molecular Subtyping on Pathological Staging of Pancreatic Cancer

BACKGROUND

The long-term outcomes following surgical resection for pancreatic ductal adenocarcinoma (PDAC) remains poor, with only 20% of patients surviving 5 years after pancreatectomy. Patient selection for surgery remains suboptimal largely due to the absence of consideration of aggressive tumor biology.

OBJECTIVE

The aim of this study was to evaluate traditional staging criteria for PDAC in the setting of molecular subtypes.

METHODS

Clinicopathological data were obtained for 5 independent cohorts of consecutive unselected patients, totaling n = 1298, including n = 442 that underwent molecular subtyping. The main outcome measure was disease-specific survival following surgical resection for PDAC stratified according to the American Joint Commission for Cancer (TNM) staging criteria, margin status, and molecular subtype.

RESULTS

TNM staging criteria and margin status confers prognostic value only in tumors with classical pancreatic subtype. Patients with tumors that are of squamous subtype, have a poor outcome irrespective of favorable traditional pathological staging [hazard ratio (HR) 1.54, 95% confidence interval (CI) 1.04-2.28, P = 0.032]. Margin status has no impact on survival in the squamous subtype (16.0 vs 12.1 months, P = 0.374). There were no differences in molecular subtype or gene expression of tumors with positive resection margin status.

CONCLUSIONS

Aggressive tumor biology as measured by molecular subtype predicts poor outcome following pancreatectomy for PDAC and should be utilized to inform patient selection for surgery.

Can trainees safely perform pancreatoenteric anastomosis? A systematic review, meta-analysis, and risk-adjusted analysis of postoperative pancreatic fistula

BACKGROUND

The complexity of pancreaticoduodenectomy and fear of morbidity, particularly postoperative pancreatic fistula, can be a barrier to surgical trainees gaining operative experience. This meta-analysis sought to compare the postoperative pancreatic fistula rate after pancreatoenteric anastomosis by trainees or established surgeons.

METHODS

A systematic review of the literature was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, with differences in postoperative pancreatic fistula rates after pancreatoenteric anastomosis between trainee-led versus consultant/attending surgeons pooled using meta-analysis. Variation in rates of postoperative pancreatic fistula was further explored using risk-adjusted outcomes using published risk scores and cumulative sum control chart analysis in a retrospective cohort.

RESULTS

Across 14 cohorts included in the meta-analysis, trainees tended toward a lower but nonsignificant rate of all postoperative pancreatic fistula (odds ratio: 0.77, P = .45) and clinically relevant postoperative pancreatic fistula (odds ratio: 0.69, P = .37). However, there was evidence of case selection, with trainees being less likely to operate on patients with a pancreatic duct width <3 mm (odds ratio: 0.45, P = .05). Similarly, analysis of a retrospective cohort (N = 756 cases) found patients operated by trainees to have significantly lower predicted all postoperative pancreatic fistula (median: 20 vs 26%, P < .001) and clinically relevant postoperative pancreatic fistula (7 vs 9%, P = .020) rates than consultant/attending surgeons, based on preoperative risk scores. After adjusting for this on multivariable analysis, the risks of all postoperative pancreatic fistula (odds ratio: 1.18, P = .604) and clinically relevant postoperative pancreatic fistula (odds ratio: 0.85, P = .693) remained similar after pancreatoenteric anastomosis by trainees or consultant/attending surgeons.

CONCLUSION

Pancreatoenteric anastomosis, when performed by trainees, is associated with acceptable outcomes. There is evidence of case selection among patients undergoing surgery by trainees; hence, risk adjustment provides a critical tool for the objective evaluation of performance.

External validation of postoperative pancreatic fistula prediction scores in pancreatoduodenectomy: a systematic review and meta-analysis

BACKGROUND

Multiple risk scores claim to predict the probability of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy. It is unclear which scores have undergone external validation and are the most accurate. The aim of this study was to identify risk scores for POPF, and assess the clinical validity of these scores.

METHODS

Areas under receiving operator characteristic curve (AUROCs) were extracted from studies that performed external validation of POPF risk scores. These were pooled for each risk score, using intercept-only random-effects meta-regression models.

RESULTS

Systematic review identified 34 risk scores, of which six had been subjected to external validation, and so included in the meta-analysis, (Tokyo (N=2 validation studies), Birmingham (N=5), FRS (N=19), a-FRS (N=12), m-FRS (N=3) and ua-FRS (N=3) scores). Overall predictive accuracies were similar for all six scores, with pooled AUROCs of 0.61, 0.70, 0.71, 0.70, 0.70 and 0.72, respectively. Considerably heterogeneity was observed, with I2 statistics ranging from 52.1-88.6%.

CONCLUSION

Most risk scores lack external validation; where this was performed, risk scores were found to have limited predictive accuracy. . Consensus is needed for which score to use in clinical practice. Due to the limited predictive accuracy, future studies to derive a more accurate risk score are warranted.

The Fistula Risk Score Catalog: Toward Precision Medicine for Pancreatic Fistula After Pancreatoduodenectomy

OBJECTIVE

This study aims to present a full spectrum of individual patient presentations of pancreatic fistula risk, and to define the utility of mitigation strategies amongst some of the most prevalent, and vulnerable scenarios surgeons encounter.

BACKGROUND

The FRS has been utilized to identify technical strategies associated with reduced CR-POPF incidence across various risk strata. However, risk-stratification using the FRS has never been investigated with greater granularity. By deriving all possible combinations of FRS elements, individualized risk assessment could be utilized for precision medicine purposes.

METHODS

FRS profiles and outcomes of 5533 PDs were accrued from 17 international institutions (2003-2019). The FRS was used to derive 80 unique combinations of patient "scenarios." Risk-matched analyses were conducted using a Bonferroni adjustment to identify scenarios with increased vulnerability for CR-POPF occurrence. Subsequently, these scenarios were analyzed using multivariable regression to explore optimal mitigation approaches.

RESULTS

The overall CR-POPF rate was 13.6%. All 80 possible scenarios were encountered, with the most frequent being scenario #1 (8.1%) - the only negligible-risk scenario (CR-POPF rate = 0.7%). The moderate-risk zone had the most scenarios (50), patients (N = 3246), CR-POPFs (65.2%), and greatest non-zero discrepancy in CR-POPF rates between scenarios (18-fold). In the risk-matched analysis, 2 scenarios (#59 and 60) displayed increased vulnerability for CR-POPF relative to the moderate-risk zone (both P < 0.001). Multivariable analysis revealed factors associated with CR-POPF in these scenarios: pancreaticogastrostomy reconstruction [odds ratio (OR) 4.67], omission of drain placement (OR 5.51), and prophylactic octreotide (OR 3.09). When comparing the utilization of best practice strategies to patients who did not have these conjointly utilized, there was a significant decrease in CR-POPF (10.7% vs 35.5%, P < 0.001; OR 0.20, 95% confidence interval 0.12-0.33).

CONCLUSION

Through this data, a comprehensive fistula risk catalog has been created and the most clinically-impactful scenarios have been discerned. Focusing on individual scenarios provides a practical way to approach precision medicine, allowing for more directed and efficient management of CR-POPF.

Surgeon experience contributes to improved outcomes in pancreatoduodenectomies at high risk for fistula development

BACKGROUND

Pancreatoduodenectomies at high risk for clinically relevant pancreatic fistula are uncommon, yet intimidating, situations. In such scenarios, the impact of individual surgeon experience on outcomes is poorly understood.

METHODS

The fistula risk score was applied to identify high-risk patients (fistula risk score 7-10) from 7,706 pancreatoduodenectomies performed at 18 international institutions (2003-2020). For each case, surgeon pancreatoduodenectomy career volume and years of practice were linked to intraoperative fistula mitigation strategy adoption and outcomes. Consequently, best operative approaches for clinically relevant pancreatic fistula prevention and best performer profiles were identified through multivariable analysis models.

RESULTS

Eight hundred and thirty high-risk pancreatoduodenectomies, performed by 64 surgeons, displayed an overall clinically relevant pancreatic fistula rate of 33.7%. Clinically relevant pancreatic fistula rates decreased with escalating surgeon career pancreatoduodenectomy (-49.7%) and career length (-41.2%; both P < .001), as did transfusion and reoperation rates, postoperative morbidity index, and duration of stay. Great experience (≥400 pancreatoduodenectomies performed or ≥21-year-long career) was a significant predictor of clinically relevant pancreatic fistula prevention (odds ratio 0.52, 95% confidence interval 0.35-0.76) and was more often associated with pancreatojejunostomy reconstruction and prophylactic octreotide omission, which were both independently associated with clinically relevant pancreatic fistula reduction. A risk-adjusted performance analysis also correlated with experience. Moreover, minimizing blood loss (≤400 mL) significantly contributed to clinically relevant pancreatic fistula prevention (odds ratio 0.40, 95% confidence interval 0.22-0.74).

CONCLUSION

Surgeon experience is a key contributor to achieve better outcomes after high-risk pancreatoduodenectomy. Surgeons can improve their performance in these challenging situations by employing pancreatojejunostomy reconstruction, omitting prophylactic octreotide, and minimizing blood loss.

Feasibility and clinical utility of endoscopic ultrasound guided biopsy of pancreatic cancer for next-generation molecular profiling

Next-generation sequencing is enabling molecularly guided therapy for many cancer types, yet failure rates remain relatively high in pancreatic cancer (PC). The aim of this study is to investigate the feasibility of genomic profiling using endoscopic ultrasound (EUS) biopsy samples to facilitate personalised therapy for PC. Ninty-five patients underwent additional research biopsies at the time of diagnostic EUS. Diagnostic formalin-fixed (FFPE) and fresh frozen EUS samples underwent DNA extraction, quantification and targeted gene sequencing. Whole genome (WGS) and RNA sequencing was performed as proof of concept. Only 2 patients (2%) with a diagnosis of PC had insufficient material for targeted sequencing in both FFPE and frozen specimens. Targeted panel sequencing (n=54) revealed mutations in PC genes (KRAS, GNAS, TP53, CDKN2A, SMAD4) in patients with histological evidence of PC, including potentially actionable mutations (BRCA1, BRCA2, ATM, BRAF). WGS (n=5) of EUS samples revealed mutational signatures that are potential biomarkers of therapeutic responsiveness. RNA sequencing (n=35) segregated patients into clinically relevant molecular subtypes based on transcriptome. Integrated multi-omic analysis of PC using standard EUS guided biopsies offers clinical utility to guide personalized therapy and study the molecular pathology in all patients with PC.

Hypermutation In Pancreatic Cancer

Pancreatic cancer is molecularly diverse, with few effective therapies. Increased mutation burden and defective DNA repair are associated with response to immune checkpoint inhibitors in several other cancer types. We interrogated 385 pancreatic cancer genomes to define hypermutation and its causes. Mutational signatures inferring defects in DNA repair were enriched in those with the highest mutation burdens. Mismatch repair deficiency was identified in 1% of tumors harboring different mechanisms of somatic inactivation of MLH1 and MSH2. Defining mutation load in individual pancreatic cancers and the optimal assay for patient selection may inform clinical trial design for immunotherapy in pancreatic cancer.

A Glasgow Tipple-transjugular intrahepatic portosystemic shunt insertion prior to Whipple resection

Abdominal surgery performed in patients with significant liver disease and portal hypertension is associated with high mortality rates, with even poorer outcomes associated with complex pancreaticobiliary operations. We report on a patient requiring portal decompression via transjugular intrahepatic portosystemic shunt (TIPS) prior to a pancreaticoduodenectomy. The 49-year-old patient presented with pain, jaundice and weight loss. At ERCP an edematous ampulla was biopsied, revealing high-grade dysplasia within a distal bile duct adenoma. Liver biopsy was performed to investigate portal hypertension, confirming congenital hepatic fibrosis (CHF). A TIPS was performed to enable a pancreaticoduodenectomy. Prophylactic TIPS can be performed for preoperative portal decompression for patients requiring pancreatic resection. A potentially curative resection was performed when abdominal surgery was initially thought impossible. Notably, CHF has been associated with the development of cholangiocarcinoma in only four previous instances, with this case being only the second reported distal bile duct cholangiocarcinoma.

Serum amylase and C-reactive protein in risk stratification of pancreas-specific complications after pancreaticoduodenectomy

Background

Pancreas-specific complications (PSCs), comprising postoperative pancreatic fistula, haemorrhage and intra-abdominal collections, are drivers of morbidity and mortality after pancreaticoduodenectomy (PD). A serum amylase concentration of 130 units/l or more on postoperative day (POD) 0 has been shown to be an objective surrogate of pancreatic texture, a determinant of PSCs. This study evaluated serial measurements of C-reactive protein (CRP) to refine PSC risk stratification.

Methods

Consecutive patients undergoing PD between 2008 and 2014, with vascular resection if required and without preoperative chemoradiotherapy, had serum investigations from the day before operation until discharge. Receiver operating characteristic (ROC) curve analysis was used to identify a threshold value of serum CRP with clinically relevant PSCs for up to 30 days after discharge as outcome measure.

Results

Of 230 patients, 95 (41·3 per cent) experienced a clinically relevant PSC. A serum CRP level of 180 mg/l or higher on POD 2 was associated with PSCs, prolonged critical care stay and relaparotomy (all P &lt; 0·050). Patients with a serum amylase concentration of 130 units/l or more on POD 0 who developed a serum CRP level of at least 180 mg/l on POD 2 had a higher incidence of morbidity. Patients were stratified into high-, intermediate- and low-risk groups using these markers. The low-risk category was associated with a negative predictive value of 86·5 per cent for development of clinically relevant PSCs. There were no deaths among 52 patients in the low-risk group, but seven deaths among 79 (9 per cent) in the high-risk group.

Conclusion

A serum amylase level below 130 units/l on POD 0 combined with a serum CRP level under 180 mg/l on POD 2 constitutes a low-risk profile following PD, and may help identify patients suitable for early discharge.

Prospective cohort study comparing transient EUS guided elastography to EUS-FNA for the diagnosis of solid pancreatic mass lesions

BACKGROUND

Semiquantitative EUS-elastography has been introduced to distinguish between malignant and benign pancreatic lesions. This study investigated whether semiquantitative EUS-guided transient real time elastography increases the diagnostic accuracy for solid pancreatic lesions compared to EUS-FNA.

PATIENTS AND METHODS

This single centre prospective cohort study included all patients with solitary pancreatic lesions on EUS during one year. Patients underwent EUS-FNA and semiquantitative EUS-elastography during the same session. EUS and elastography results were compared with final diagnosis which was made on the basis of tissue samples and long-term outcome.

RESULTS

91 patients were recruited of which 68 had pancreatic malignancy, 17 showed benign disease and 6 had cystic lesions and were excluded from further analysis. Strain ratios from malignant lesions were significantly higher (24.00; 8.01-43.94 95% CI vs 44.00; 32.42-55.00 95% CI) and ROC analysis indicated optimal cut-off of 24.82 with resulting sensitivity, specificity and accuracy of 77%, 65% and 73% respectively. B-mode EUS and EUS-FNA had an accuracy for the correct diagnosis of malignant lesions of 87% and 85%. When lowering the cut-off strain ratio for elastography to 10 the sensitivity rose to 96% with specificity of 43% and accuracy of 84%, resulting in the least accurate EUS-based method. This was confirmed by pairwise comparison.

CONCLUSION

Semiquantitative EUS-elastography does not add substantial value to the EUS-based assessment of solid pancreatic lesions when compared to B-mode imaging.

SIRT3 & SIRT7: Potential Novel Biomarkers for Determining Outcome in Pancreatic Cancer Patients

PURPOSE

The sirtuin gene family has been linked with tumourigenesis, in both a tumour promoter and suppressor capacity. Information regarding the function of sirtuins in pancreatic cancer is sparse and equivocal. We undertook a novel study investigating SIRT1-7 protein expression in a cohort of pancreatic tumours. The aim of this study was to establish a protein expression profile for SIRT1-7 in pancreatic ductal adenocarcinomas (PDAC) and to determine if there were associations between SIRT1-7 expression, clinico-pathological parameters and patient outcome.

MATERIAL AND METHODS

Immunohistochemical analysis of SIRT1-7 protein levels was undertaken in a tissue micro-array comprising 77 resected PDACs. Statistical analyses determined if SIRT1-7 protein expression was associated with clinical parameters or outcome.

RESULTS

Two sirtuin family members demonstrated significant associations with clinico-pathological parameters and patient outcome. Low level SIRT3 expression in the tumour cytoplasm correlated with more aggressive tumours, and a shorter time to relapse and death, in the absence of chemotherapeutic intervention. Low levels of nuclear SIRT7 expression were also associated with an aggressive tumour phenotype and poorer outcome, as measured by disease-free and disease-specific survival time, 12 months post-diagnosis.

CONCLUSIONS

Our data suggests that SIRT3 and SIRT7 possess tumour suppressor properties in the context of pancreatic cancer. SIRT3 may also represent a novel predictive biomarker to determine which patients may or may not respond to chemotherapy. This study opens up an interesting avenue of investigation to potentially identify predictive biomarkers and novel therapeutic targets for pancreatic cancer, a disease that has seen no significant improvement in survival over the past 40 years.

The epidemiology of and outcome from pancreatoduodenal trauma in the UK, 1989-2013

INTRODUCTION

Pancreatoduodenal (PD) injury is an uncommon but serious complication of blunt and penetrating trauma, associated with high mortality. The aim of this study was to assess the incidence, mechanisms of injury, initial operation rates and outcome of patients who sustained PD trauma in the UK from a large trauma registry, over the period 1989-2013.

METHODS

The Trauma Audit and Research Network database was searched for details of any patient with blunt or penetrating trauma to the pancreas, duodenum or both.

RESULTS

Of 356,534 trauma cases, 1,155 (0.32%) sustained PD trauma. The median patient age was 27 years for blunt trauma and 27.5 years for penetrating trauma. The male-to-female ratio was 2.5:1. Blunt trauma was the most common type of injury seen, with a ratio of blunt-to-penetrating PD injury ratio of 3.6:1. Road traffic collision was the most common mechanism of injury, accounting for 673 cases (58.3%). The median injury severity score (ISS) was 25 (IQR: 14-35) for blunt trauma and 14 (IQR: 9-18) for penetrating trauma. The mortality rate for blunt PD trauma was 17.6%; it was 12.2% for penetrating PD trauma. Variables predicting mortality after pancreatic trauma were increasing age, ISS, haemodynamic compromise and not having undergone an operation.

CONCLUSIONS

Isolated pancreatic injuries are uncommon; most coexist with other injuries. In the UK, a high proportion of cases are due to blunt trauma, which differs from US and South African series. Mortality is high in the UK but comparison with other surgical series is difficult because of selection bias in their datasets.

Serum amylase on the night of surgery predicts clinically significant pancreatic fistula after pancreaticoduodenectomy

OBJECTIVES

Drainage after pancreaticoduodenectomy (PD) remains controversial because the risk for uncontrolled postoperative pancreatic fistula (POPF) must be balanced against the potential morbidity associated with prolonged and possibly unnecessary drainage. This study investigated the utility of the level of serum amylase on the night of surgery [postoperative day (PoD) 0 serum amylase] to predict POPF.

METHODS

A total of 185 patients who underwent PD were studied. Occurrences of POPF were graded using the International Study Group on Pancreatic Fistula (ISGPF) classification. Receiver operating characteristic (ROC) analysis identified a threshold value of PoD 0 serum amylase associated with clinically significant POPF (ISGPF Grades B and C) in a test cohort (n = 45). The accuracy of this threshold value was then tested in a validation cohort (n = 140).

RESULTS

Overall, 43 (23.2%) patients developed clinically significant POPF. The threshold value of PoD 0 serum amylase for the identification of clinically significant POPF was ≥ 130 IU/l (P = 0.003). Serum amylase of <130 IU/l had a negative predictive value of 88.8% for clinically significant POPF (P < 0.001). Serum amylase of ≥ 130 IU/l on PoD 0 and a soft pancreatic parenchyma were independent risk factors for clinically significant POPF.

CONCLUSIONS

Postoperative day 0 serum amylase of <130 IU/l allows for the early and accurate categorization of patients at least risk for clinically significant POPF and may identify patients suitable for early drain removal.

'Step-port' laparoscopic cystgastrostomy for the management of organized solid predominant post-acute fluid collections after severe acute pancreatitis

BACKGROUND

Post-acute pancreatic collections (PAPCs) may require intervention when persistent, large or symptomatic. An open cystgastrostomy is an effective treatment option particularly for larger, solid predominant collections. A laparoscopic cystgastrostomy (LCG) as initially described, could be technically challenging. This report describes the evolution of the operative technique and the results from LCG in a tertiary referral centre.

METHODS

Retrospective analysis of the unit's prospectively populated database was conducted. All patients who underwent a surgical cystgastrostomy (SCG) were identified. Patient demographics, outcome and complications were collected and analysed.

RESULTS

Forty-four patients underwent SCG: 8 open and 36 laparoscopic. Of the 36 LCG, 6 required open conversion, although with evolution of the technique all of the last 17 cases were completed laparoscopically. The median interquartile range (IQR) length of stay in patients completed laparoscopically was 6 (2-10) compared with 15.5 days (8-19) in those patients who were converted (P = 0.0351). The only peri-operative complication after a LCG was a self-limiting upper gastrointestinal bleed. With a median (IQR) follow-up of 891 days (527-1495) one patient required re-intervention for a residual collection with no recurrent collections identified.

CONCLUSION

LCG is a safe and effective procedure in patients with large, solid predominant PAPCs. With increased experience and technical expertise conversion rates can be lowered and outcome optimized.

Pre-operative cardiopulmonary exercise testing predicts adverse post-operative events and non-progression to adjuvant therapy after major pancreatic surgery

BACKGROUND

Surgery followed by chemotherapy is the primary modality of cure for patients with resectable pancreatic cancer but is associated with significant morbidity. The aim of the present study was to evaluate the role of cardiopulmonary exercise testing (CPET) in predicting post-operative adverse events and fitness for chemotherapy after major pancreatic surgery.

METHODS

Patients who underwent a pancreaticoduodenectomy or total pancreatectomy for pancreatic head lesions and had undergone pre-operative CPET were included in this retrospective study. Data on patient demographics, comorbidity and results of pre-operative evaluation were collected. Post-operative adverse events, hospital stay and receipt of adjuvant therapy were outcome measures.

RESULTS

One hundred patients were included. Patients with an anaerobic threshold less than 10 ml/kg/min had a significantly greater incidence of a post-operative pancreatic fistula [International Study Group for Pancreatic Surgery (ISGPS) Grades A-C, 35.4% versus 16%, P = 0.028] and major intra-abdominal abscesses [Clavien-Dindo (CD) Grades III-V, 22.4% versus 7.8%, P = 0.042] and were less likely to receive adjuvant therapy [hazard ratio (HR) 6.30, 95% confidence interval (CI) 1.25-31.75, P = 0.026]. A low anaerobic threshold was also associated with a prolonged hospital stay (median 20 versus 14 days, P = 0.005) but not with other adverse events.

DISCUSSION

CPET predicts a post-operative pancreatic fistula, major intra-abdominal abscesses as well as length of hospital stay after major pancreatic surgery. Patients with a low anaerobic threshold are less likely to receive adjuvant therapy.

The prognostic influence of resection margin clearance following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma

INTRODUCTION

The poor overall survival associated with pancreatic ductal adenocarcinoma (PDAC) despite complete resection suggests that occult metastatic disease is present in most at the time of surgery. Resection margin involvement (R1) following resection is an established poor prognostic factor. However, the definition of an R1 resection varies and the impact of margin clearance on outcome has not been examined in detail.

METHODS

In a cohort of 217 consecutive patients who underwent pancreaticoduodenectomy for PDAC with curative intent at a single institution between 1996 and 2011, the prognostic significance of the proximity of margin clearance was investigated. Microscopic margin clearance was stratified by 0.5 mm increments from tumor present at the margin to >2.0 mm. Groups were dichotomized into clear and involved groups according to the different R1 definitions. Multivariate survival analysis was used to establish independent prognostic factors.

RESULTS

For the 38 patients (17.5 %) where the tumor was >1.5 mm from the closest involved margin, there was a significantly prolonged overall median survival (63.1 months; 95 % confidence interval, 32.5-93.8) compared to R1 resections (16.9 months; 95 % confidence interval, 14.5-19.4; P < 0.0001, log-rank test). This cutoff represented the optimum distance for predicting long-term survival. As margin clearance increased, R1 status became a more powerful independent predictor of outcome; however, margin clearance did not relate to site of tumor recurrence.

CONCLUSION

These data demonstrate that margin clearance by at least 1.5 mm identifies a subgroup of patients which may potentially achieve long-term survival. This study further confirms the need to achieve standardization across pancreatic specimen reporting. Stratification of patients into future clinical trials based upon the degree of margin clearance may identify those patients likely to benefit from adjuvant therapy.

Histomolecular phenotypes and outcome in adenocarcinoma of the ampulla of vater

PURPOSE

Individuals with adenocarcinoma of the ampulla of Vater demonstrate a broad range of outcomes, presumably because these cancers may arise from any one of the three epithelia that converge at that location. This variability poses challenges for clinical decision making and the development of novel therapeutic strategies.

PATIENTS AND METHODS

We assessed the potential clinical utility of histomolecular phenotypes defined using a combination of histopathology and protein expression (CDX2 and MUC1) in 208 patients from three independent cohorts who underwent surgical resection for adenocarcinoma of the ampulla of Vater.

RESULTS

Histologic subtype and CDX2 and MUC1 expression were significant prognostic variables. Patients with a histomolecular pancreaticobiliary phenotype (CDX2 negative, MUC1 positive) segregated into a poor prognostic group in the training (hazard ratio [HR], 3.34; 95% CI, 1.69 to 6.62; P < .001) and both validation cohorts (HR, 5.65; 95% CI, 2.77 to 11.5; P < .001 and HR, 2.78; 95% CI, 1.25 to 7.17; P = .0119) compared with histomolecular nonpancreaticobiliary carcinomas. Further stratification by lymph node (LN) status defined three clinically relevant subgroups: one, patients with histomolecular nonpancreaticobiliary (intestinal) carcinoma without LN metastases who had an excellent prognosis; two, those with histomolecular pancreaticobiliary carcinoma with LN metastases who had a poor outcome; and three, the remainder of patients (nonpancreaticobiliary, LN positive or pancreaticobiliary, LN negative) who had an intermediate outcome.

CONCLUSION

Histopathologic and molecular criteria combine to define clinically relevant histomolecular phenotypes of adenocarcinoma of the ampulla of Vater and potentially represent distinct diseases with significant implications for current therapeutic strategies, the ability to interpret past clinical trials, and future trial design.

Utility of admission physiology in the surgical triage of isolated ballistic battlefield torso trauma

BACKGROUND

An assessment of hemodynamic stability is central to surgical decision-making in the management of battlefield ballistic torso trauma (BBTT).

AIMS

To analyse the utility of admission physiological parameters in characterising hemodynamic stability.

SETTINGS AND DESIGN

A retrospective analysis of consecutive admissions, with BBTT, to forward surgical facility in Afghanistan.

MATERIALS AND METHODS

The cohorts' admission physiology, need for operative intervention, and mortality data were collected retrospectively. The cohort was divided into patients requiring surgery for Life-Threatening Torso Hemorrhage (LTTH) and those not requiring immediate surgery (non-LTTH).

STATISTICAL ANALYSIS

Parameters were compared using two sample t tests, Mann-Whitney, Fisher's exact, and Chi-square tests. Receiver operator characteristic curves were used to identify significant parameters and determine optimum cut-off values.

RESULTS

A total of 103 patients with isolated BBTT were identified: 44 in the LTTH group and 59 in the non-LTTH group. The mean New Injury Severity Score ± Standard Deviation (NISS±SD) was 28±14 and 13±12, respectively. The heart rate, systolic blood pressure (SBP), pulse pressure, shock index (SI=heart rate/SBP) and base excess were analysed. SI correlated best with the need for surgical torso hemorrhage control, P<0.05. An optimal cut-off of 0.9 was identified, producing a positive and negative predictive value of 81% and 82%, respectively.

CONCLUSIONS

Shock index (SI) is a useful parameter for helping military surgeons triage BBTT, identifying patients requiring operative torso hemorrhage control. SI performance requires a normal physiological response to hypovolemia, and thus should always be considered in clinical context.

MicroRNA molecular profiles associated with diagnosis, clinicopathologic criteria, and overall survival in patients with resectable pancreatic ductal adenocarcinoma

PURPOSE

MicroRNAs (miRNA) have potential as diagnostic and prognostic biomarkers and as therapeutic targets in cancer. We sought to establish the relationship between miRNA expression and clinicopathologic parameters, including prognosis, in pancreatic ductal adenocarcinoma (PDAC).

EXPERIMENTAL DESIGN

Global miRNA microarray expression profiling of prospectively collected fresh-frozen PDAC tissue was done on an initial test cohort of 48 patients, who had undergone pancreaticoduodenectomy between 2003 and 2008 at a single institution. We evaluated association with tumor stage, lymph node status, and site of recurrence, in addition to overall survival, using Cox regression multivariate analysis. Validation of selected potentially prognostic miRNAs was done in a separate cohort of 24 patients.

RESULTS

miRNA profiling identified expression signatures associated with PDAC, lymph node involvement, high tumor grade, and 20 miRNAs were associated with overall survival. In the initial cohort of 48 PDAC patients, high expression of miR-21 (HR = 3.22, 95% CI: 1.21-8.58) and reduced expression of miR-34a (HR = 0.15, 95% CI: 0.06-0.37) and miR-30d (HR = 0.30, 95% CI: 0.12-0.79) were associated with poor overall survival following resection independent of clinical covariates. In a further validation set of 24 patients, miR-21 and miR-34a expression again significantly correlated with overall survival (P = 0.031 and P = 0.001).

CONCLUSION

Expression patterns of miRNAs are significantly altered in PDAC. Aberrant expression of a number of miRNAs was independently associated with reduced survival, including overexpression of miR-21 and underexpression of miR-34a.

SUMMARY

miRNA expression profiles for resected PDAC were examined to identify potentially prognostic miRNAs. miRNA microarray analysis identified statistically unique profiles, which could discriminate PDAC from paired nonmalignant pancreatic tissues as well as molecular signatures that differ according to pathologic features. miRNA expression profiles correlated with overall survival of PDAC following resection, indicating that miRNAs provide prognostic utility.

Peripancreatic fat invasion is an independent predictor of poor outcome following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma

BACKGROUND

Following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma (PDAC), identification of peripancreatic fat tumor invasion promotes a tumor to stage T3. We sought to understand better the impact of histological peripancreatic fat invasion on prognosis and site of recurrence in a cohort of patients with PDAC.

METHODS

We analyzed the patient demographics, outcome, and recurrence data that had been prospectively collected in 189 consecutive PDAC undergoing potentially curative pancreaticoduodenectomy between 1996 and 2009. Pathological features were reassessed for all patients. Survival outcome was compared using Kaplan-Meier/Cox proportional hazards analysis. The primary site of recurrence was defined as either locoregional or distant metastases.

RESULTS

The median survival of this PDAC cohort was 18.9 months (95% confidence interval (CI) 15.7-22.2). Histological peripancreatic fat invasion was evident in 51 (27%) patients and was associated with lymph node metastases (p = 0.004) and larger tumor size (p = 0.015). The presence of peripancreatic fat invasion was associated with reduced overall survival following resection (12.4 months [95% CI 9.9-15.0]) when compared to those patients with no evidence of fat invasion (22.6 months [95% CI 18.5-26.7]; p < 0.0001). By multivariate survival analysis, independent predictors of overall survival included tumor grade (p = 0.002), lymph node involvement (p = 0.025), resection margin status (p = 0.003), venous invasion (p = 0.045), and peripancreatic fat invasion (p = 0.007). Invasion into the pancreatic fat was significantly associated with the primary site of recurrence being locoregional failure (p = 0.002).

CONCLUSIONS

Peripancreatic fat invasion was identified as being an independent predictor of poor outcome following pancreaticoduodenectomy for PDAC. Additionally, the presence of peripancreatic fat invasion was associated with locoregional disease as the primary site of recurrence. This may have implications for the staging of PDAC and potentially require incorporation into future staging systems to improve outcome stratification.

A prospective comparison of the prognostic value of tumor- and patient-related factors in patients undergoing potentially curative surgery for pancreatic ductal adenocarcinoma

BACKGROUND

Outcome prediction after resection with curative intent for pancreatic ductal adenocarcinoma remains a challenge. There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor outcome in patients undergoing resection for a variety of common solid tumors. Our aim was to prospectively evaluate the prognostic value of tumor- and patient-related factors including the systemic inflammatory response in patients undergoing potentially curative surgery for pancreatic ductal adenocarcinoma of the head of pancreas.

METHODS

The prognostic impact of tumor factors such as stage and host factors, including the systemic inflammatory response (modified Glasgow Prognostic Score [mGPS]), were evaluated in a prospective study of 135 patients who underwent elective pancreaticoduodenectomy for pancreatic ductal adenocarcinoma from January 2002 to April 2009.

RESULTS

In addition to the established tumor-related pathological factors (in particular margin involvement; hazard ratio [HR] 2.82, 95% confidence interval [CI] 1.65-4.84, P < 0.001), an elevated mGPS (HR 2.26, 95% CI 1.43-3.57, P < 0.001) was independently associated with lower overall survival after pancreaticoduodenectomy. Additionally, in an adjuvant therapy subgroup of 74 patients, both margin involvement and an elevated mGPS remained independently associated with reduced overall survival.

CONCLUSIONS

We have prospectively validated the influence of tumor-related and patient-related factors. Margin involvement and the preoperative mGPS were the most important determinants of overall survival in patients undergoing potentially curative pancreaticoduodenectomy. Furthermore, both had independent prognostic value in those patients receiving adjuvant chemotherapy. In the future, this may be considered a stratification factor for entry onto therapeutic trials.

Positive mobilization margins alone do not influence survival following pancreatico-duodenectomy for pancreatic ductal adenocarcinoma

OBJECTIVE

To determine the prognostic influence of residual tumor at or within 1 mm of the mobilization margins (R1Mobilization) compared with transection margins (R1Transection) following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

The prognostic strength of R1 status increases with frequency of margin positivity and is enhanced by protocol driven pathology reporting. Currently, margins are treated uniformly with tumor at or close to any margin considered of equal prognostic significance. The resection involves a mobilization phase freeing the posterior margin and anterior surface then a transection phase requiring lympho-vascular division forming the medial resection and pancreatic transection margin. The comparative assessment of the relative importance of tumor involvement of these different margins has not previously been investigated.

METHODS

Retrospective analysis of 148 consecutive resections for PDAC from 1996-2007 was performed. The individual (pancreatic transection, medial, posterior, and anterior surface) margins were separately identified and analyzed by a senior pathologist. An R1 resection was defined as microscopic evidence of tumor < or = 1 mm from a resection margin. R1Mobilization tumor extension included both R1Anterior and R1Posterior cases; while R1Transection included pancreatic neck/body transection, R1Medial and adjacent transection margins.

RESULTS

R1 status was confirmed in 109 patients (74%). The medial (46%) and posterior (44%) margins were most commonly involved. R1 status was found to an independent predictor of poor outcome (P < 0.001). R1Mobilization involvement only (n = 48) was associated with a significantly longer median survival of 18.9 months (95% CI, 13.7-24.8) versus 11.1 months (95% CI, 7.1-15.0) for those with R1Transection tumor involvement (n = 61) (P < 0.001). There was no significant difference in the survival of the R1Mobilization compared with R0 group (P = 0.52).

CONCLUSIONS

Following pancreaticoduodenectomy for PDAC, involvement of the transection margins in contrast to mobilization margins defines a group whose outcome is significantly worse. This may impact upon the allocation of adjuvant therapy within the setting of randomized controlled trials.

Protocol-driven trauma resuscitation: survey of UK practice

OBJECTIVE

To evaluate the use of protocol-driven trauma resuscitation strategies in UK emergency departments.

METHODS

Postal/internet questionnaire survey of emergency departments to evaluate the existence of guidelines or protocols to direct resuscitation, blood component treatment, second line imaging of patients who had major trauma and the existence of a trauma team/trauma call system.

RESULTS

243 departments were identified and contacted, 183 responded. Five replies were excluded. Of the remaining 178 departments, 139 (78.1%) had a trauma team or trauma call system, but only 49 (27.5%) had a guideline or protocol for resuscitation. 92 (51.7%) had guidelines or protocols for blood component treatment in trauma, and 88 (49.4%) had guidelines or protocols for the use of second line imaging in trauma. The use of protocols and guidelines did not correlate with emergency department size, as measured by volume of activity.

CONCLUSIONS

The utilisation of trauma resuscitation protocols and guidelines in British emergency departments is limited. Given the clear benefits of these strategies, consideration should be given to greater integration of such algorithms into practice.

Recent advances in enteric neurobiology: mechanosensitive interneurons

Until recently, it was generally assumed that the only intrinsic sensory neuron, or primary afferent neuron, in the gut was the after-hyperpolarizing AH/Type II neuron. AH neurons excited by local chemical and mechanical stimulation of the mucosa appear to be necessary for activating the peristaltic reflex (oral excitation and anal inhibition of the muscle layers) and anally propagating ring like contractions (peristaltic waves) that depend upon smooth muscle tone. However, our recent findings in the guinea-pig distal colon suggest that different neurochemical classes of interneuron in the colon are also mechanosensitive in that they respond directly to changes in muscle length, rather than muscle tone or tension. These interneurons have electrophysiological properties consistent with myenteric S-neurons. Ascending and descending interneurons respond directly to circumferential stretch by generating an ongoing polarized peristaltic reflex activity (oral excitatory and anal inhibitory junction potentials) in the muscle for as long as the stimulus is maintained. Some descending (nitric oxide synthase +ve) interneurons, on the other hand, appear to respond directly to longitudinal stretch and are involved in accommodation and slow transit of faecal pellets down the colon. This review will present recent evidence that suggests some myenteric S interneurons, in addition to AH neurons, behave as intrinsic sensory neurons.

Genetics of Response to Proton Pump Inhibitor Therapy

Proton pump inhibitors (PPIs) are highly effective agents for the treatment of gastric acid-related disorders. They are metabolized by the cytochrome P450 (CYP) system, mainly via the enzyme CYP2C19. A genetically determined defect in this pathway results in impaired metabolism of PPIs, giving rise to three distinct phenotypes: rapid extensive (fast), extensive (medium), and poor (slow) metabolizers. These genetic mutations are more common in certain races, and there is, therefore, considerable inter-individual and -ethnic variation in the capacity to metabolize PPIs. The incidence of mutant alleles in a population treated for acid-related disorders may influence the efficacy of the treatment, with clinical implications for the prescribers of PPIs. Therapeutic failure, such as lack of symptom relief, or ineffective Helicobacter pylori eradication, can occur in rapid metabolizers who will have less available drug at a given dose. Conversely, poor metabolizers may be at risk of over-treatment, with increased incidence of adverse effects and unnecessary financial burden. Approaches to this problem include phenotyping or, preferably, genotyping patients prior to treatment with PPIs. This will allow tailoring dose regimens to the individual's metabolic capacity. An alternative strategy is the development of drugs that are either metabolized by genotype-independent pathways or are less susceptible to inter-individual genetic variation. Non-racemic PPIs fall into the latter category, and the first such agent, esomeprazole, is now commercially available.